Display device, optical device, and imaging device

Abstract

To provide a display device capable of acquiring a high-quality image.SOLUTION: A display apparatus (200) including an optical system (201) including a transflective device (100) and a display device (9), the transflective device including a substrate (2) having a curved surface (2a), a plurality of convex portions (3) arranged along a first direction on the curved surface, and a conductor (4) provided on each of the plurality of convex portions, each of the plurality of convex portions extends in the second direction and protrudes in the third direction, and each of the plurality of convex portions has an end surface (side 3a) in the third direction, and a first side surface (side 3b) and a second side surface (side 3c) disposed on both sides of the end surface in the first direction, in a cross section including the first direction and the third direction, the conductor covers at least a part of an end surface of each of the plurality of projections and at least a part of the first side surface, and an angle α 1 (°) formed by the second direction and a direction in which the eyes of the user are aligned satisfies a predetermined conditional expression.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a display device, an optical device, and an imaging device. [Background technology]

[0002] There is a demand for miniaturization of optical devices equipped with observation optical systems such as head-mounted displays (HMDs) and electronic viewfinders (EVFs). Patent Document 1 discloses an observation optical system (VR optical system) that uses two semi-transmitting surfaces. Patent Document 1 also discloses that a film-like wire-grid polarizer is used as a polarization-selective transmission / reflection element on one of the two semi-transmitting surfaces. Patent Document 2 discloses a method for producing a film-like wire-grid polarizer by forming a lattice-like uneven structure while winding a rolled substrate film, and depositing a metal by oblique vapor deposition while changing the vapor deposition angle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-81530 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-39183 Summary of the Invention [Problem to be solved by the invention]

[0004] When the film-like wire grid polarizers disclosed in Patent Documents 1 and 2 are applied to an optical element with a curved surface, color unevenness occurs in the image, and it may not be possible to obtain a high-quality image.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a display device that is capable of acquiring high-quality images. [Means for solving the problem]

[0006] A display device according to one aspect of the present invention is a display device having an optical system with a transflective element and a display element, wherein the transflective element includes a base having a curved surface, a plurality of convex portions arranged on the curved surface along a first direction, and a conductor provided on each of the plurality of convex portions, each of the plurality of convex portions extending in a second direction perpendicular to the first direction and protruding in a third direction perpendicular to both the first direction and the second direction, each of the plurality of convex portions having an end face in the third direction and a first side face and a second side face disposed on both sides of the end face in the first direction, and in a cross section including the first direction and the third direction, the conductor covers at least a part of the end face and at least a part of the first side face of each of the plurality of convex portions, and when an angle formed between the second direction and a direction in which a user's eyes are aligned is α1 (°), |α1|≦45 The following condition is satisfied.

[0007] Other objects and features of the present invention are illustrated in the following examples. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a display device that can acquire high-quality images. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a front view of a transflective element in each example. [Figure 2] 3 is an enlarged cross-sectional view of a portion of a transflective element in each example. FIG. [Figure 3] FIG. 3 is an explanatory diagram of the shape of a conductor in each example. [Figure 4] 1 is a cross-sectional view of a display device according to a first embodiment. [Figure 5] 1 is an external view of a display device according to a first embodiment. [Figure 6] FIG. 2 is a side view of the transflective element in the first embodiment. [Figure 7] FIG. 3 is a diagram showing transmittance and reflectance in Example 1. [Figure 8] 4 is a diagram showing color unevenness of transmitted light of the transflective element in Example 1. FIG. [Figure 9] FIG. 2 is a cross-sectional view of the observation optical system in Example 1. [Figure 10] 10 is a diagram showing color unevenness of transmitted light of the transflective element of Comparative Example 1. FIG. [Figure 11] FIG. 10 is a cross-sectional view of an imaging device according to a second embodiment. [Figure 12] FIG. 10 is a side view of the transflective element in the second embodiment. [Figure 13] FIG. 10 is a diagram showing transmittance and reflectance in Example 2. [Figure 14] 10 is a diagram showing color unevenness of transmitted light of the transflective element in Example 2. FIG. [Figure 15] FIG. 10 is a cross-sectional view of an imaging device according to a third embodiment. [Figure 16] FIG. 10 is a side view of a transflective element according to a third embodiment. [Figure 17] FIG. 10 is a diagram showing transmittance and reflectance in Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0011] First, with reference to FIGS. 1 and 2, a transflective element (polarization-selective transflective element, optical element) 100 in each embodiment will be described. FIG. 1 is a front view of the transflective element 100. In FIG. 1, the horizontal direction is the first direction (the arrangement direction of the multiple convex portions 3), and the vertical direction is the second direction (the extension direction of the convex portions 3). FIG. 2 is an enlarged cross-sectional view of a portion of the transflective element 100, and shows a schematic enlargement of a portion of the cross-sectional shape of the transflective element 100 in FIG. 1 cut along line A-A'. In FIG. 2, the direction along the curved surface 2a of the substrate 2 (the arrangement direction of the multiple convex portions 3) is the first direction, and the direction into the paper is the second direction (the extension direction of the convex portions 3). The direction perpendicular to each of the first and second directions is the third direction (surface normal direction 5), which corresponds to the direction in which the convex portions 3 protrude from the substrate 2. The third direction of a specific one of the plurality of protrusions 3 (for example, the protrusion 3 located at the center of the transflective element 100) is the direction along the optical axis 6.

[0012] As shown in Figure 2, the concave-convex structure consisting of multiple convex portions 3 and concave portions formed between two adjacent convex portions 3 periodically extends in one direction (second direction) (extends along one direction). Extending in one direction does not mean that the convex-convex structure needs to extend strictly parallel, but only needs to extend approximately parallel. Note that Figures 1 and 2 are not to the actual scale and are deformed drawings.

[0013] As shown in FIG. 1, a plurality of thin conductor wires 1 extending in the vertical direction are formed on one surface of the transflective element 100. As shown in FIG. 2, the transflective element 100 includes a base (substrate) 2, convex portions 3 formed on the base 2 using the same material as the base 2, and conductors 4 formed on the top (upper surface) and left side surface of the convex portions 3. Note that the embodiments are not limited to this; the conductors 4 may be formed on the upper surface and both side surfaces (both the left and right sides) of the convex portions 3. In other words, it is sufficient that the conductors are formed on the upper surface and at least one side surface of the both side surfaces of the convex portions 3. In each embodiment, a plurality of convex portions 3 are arranged on the surface of the base 2 at a predetermined pitch (arrangement pitch, pitch P) along a first direction (a direction along the curved surface 2a of the base 2). The conductors 4 in FIG. 2 correspond to the thin conductor wires 1 in FIG. 1.

[0014] 2, each of the multiple protrusions 3 protrudes in the third direction and has an upper surface 3a, a first side surface 3b, and a second side surface 3c opposite the first side surface 3b. That is, each of the multiple protrusions 3 has an end surface (upper surface 3a) in the third direction, and a first side surface 3b and a second side surface 3c arranged on both sides of the end surface in the first direction.

[0015] The conductor 4 covers at least a portion of the upper surface 3a and at least a portion of the first side surface 3b of each of the multiple protrusions 3. The conductor 4 may also cover at least a portion of the second side surface 3c. Dx (nm) is the thickness of the conductor 4 in the first direction (the direction along the curved surface 2a of the substrate 2) at the position of the top (upper surface 3a) of the protrusion 3. In other words, Dx corresponds to the thickness of the conductor 4 provided on the first side surface 3b of the protrusion 3 in the second direction perpendicular to both the first direction and the surface normal direction 5 of the substrate 2 at the position of the top of the protrusion 3.

[0016] The substrate 2 and the multiple convex portions 3 are integrally formed, for example, by injection molding a thermoplastic resin using a lens mold having a concave-convex structure on its surface. Alternatively, a grating may be formed on the lens surface by applying an ultraviolet curable resin to the lens surface and pressing a mold against it.

[0017] The surface shape of the substrate 2 has a curved surface 2a. The convex portions 3 are formed to extend (protrude) along the surface normal direction 5 of the curved surface 2a of the substrate 2. For example, a lens mold in which the convex portions face the surface normal direction 5 can be produced by patterning a concave-convex structure on the mirror-finish surface of an injection mold and then forming the concave-convex structure by etching. By integrally forming the substrate 2 and the convex portions 3, the process of bonding a transmissive-reflective element to the optical element is unnecessary, which reduces disadvantages such as increased manufacturing costs and, in particular, element defects that occur when the surface is curved.

[0018] The material of the substrate 2 may be any material that is transparent in the target wavelength region, such as polymethyl methacrylate (PMMA), polycarbonate resin (PC), cycloolefin resin (COP), cycloolefin copolymer (COC), polystyrene resin (PS), etc. To avoid a decrease in the polarization separation function, it is preferable to reduce the phase change in the light beam at the wavelength used, and it is preferable to use a material with low birefringence properties.

[0019] The thickness of the substrate 2 of the transmissive reflecting element 100 is preferably set to 100 μm or more so that the element can be easily held when incorporated into an optical system having a plurality of lenses, for example.

[0020] The cross-sectional shape of the protrusions 3 is composed of repeated concave and convex shapes in the cross section shown in Fig. 2 (surface viewed from the second direction). This shape may be any shape, such as a rectangle, parabola, trapezoid, or triangle, as long as the conductor 4 can be formed on at least one of the top surface and both side surfaces of each of the multiple protrusions 3. These cross-sectional shapes do not have to be strict shapes defined mathematically, and the protrusions 3 may have blunted corners at the top or tapered bottoms.

[0021] In each example, the conductor 4 is obliquely vapor-deposited onto the protrusions 3 at a fixed angle to obtain the thin conductor wires 1. For this reason, it is difficult to independently control the height of the conductor 4 deposited above the upper surface of the protrusions 3, and the height of the conductor 4 is highly dependent on the height of the protrusions 3. Since a wire-grid polarizer exhibits good polarization separation performance when the conductor 4 has a certain height or more, it is preferable that the height h (nm) of the protrusions 3 in the third direction is similarly high. For this reason, it is preferable that the height h of the protrusions 3 in the third direction satisfy the following conditional expression (1):

[0022] 50≦h≦300 (1) A high height h of the protrusions 3 increases the area where the conductor 4 adheres to the side surfaces of the protrusions 3, improving adhesion. On the other hand, making the height h extremely large is not preferable because it is difficult to manufacture. Here, the height h of the protrusions refers to the height in the surface normal direction 5 of the substrate 2 (the distance in the surface normal direction 5 from the curved surface 2a of the substrate 2 to the maximum height of the protrusions 3).

[0023] More preferably, the numerical range of conditional expression (1) is set as in the following conditional expression (1a).

[0024] 55≦h≦300 (1a) More preferably, the numerical range of conditional expression (1) is set as in the following conditional expression (1b).

[0025] 60≦h≦300 (1b) When the conductor 4 is obtained by the above-described method, the thickness Ax in the first direction of the conductor 4 in the region above the upper surface of the convex portion 3 depends on the width of the convex portion 3. As will be described in detail later, to obtain good polarization separation performance, it is necessary to control the thickness Ax in the first direction of the conductor 4 in the region above the upper surface of the convex portion 3. For this reason, when the width in the first direction of the convex portion 3 at half the height h of the convex portion 3 is w (nm), it is preferable that the width w is small. Here, the thickness Ax in the first direction of the conductor 4 may be, for example, the average value of the thickness in the first direction at the height of the apexes of multiple convex portions 3 in the transflective element 100. The width w of the convex portion 3 is the thickness in the first direction at half the height h of the convex portion 3.

[0026] As mentioned above, the height h of the protrusions 3 is preferably 50 nm or more, and by appropriately setting the ratio h / w of the width w to the height h of the protrusions 3, it is possible to achieve both moldability and good polarization separation performance. Fine protrusions with a width w of 10 nm or less are more likely to suffer from defects such as deformation or "seizure" during mold release in the injection molding process. Therefore, it is preferable that the ratio h / w of the width w to the height h of the protrusions 3 satisfy the following conditional expression (2):

[0027] 1.5≦h / w≦8.0 (2) More preferably, the numerical range of conditional expression (2) is set as in the following conditional expression (2a).

[0028] 2.0≦h / w≦7.8 (2a) More preferably, the numerical range of conditional expression (2) is set as in the following conditional expression (2b).

[0029] 3.5≦h / w≦7.5 (2b) In each embodiment, it is preferable that the pitch P (nm) of the plurality of convex portions 3 satisfies the following conditional expression (3).

[0030] 70≦P≦170 (3) Generally, the smaller the pitch P of the conductors 4 of a wire grid polarizer, the better its polarization separation performance over a wide wavelength range. However, if the pitch P is too large for the target wavelength, unwanted light is generated due to diffraction, degrading the polarization separation performance. Therefore, to achieve high polarization separation performance in the visible range, the pitch P is preferably 170 nm or less.

[0031] Furthermore, to form a fine uneven structure, the pitch P is preferably 70 nm or more. Setting the pitch P to 70 nm or less is undesirable because it requires the width w of the convex portions 3 in the first direction to be less than 10 nm in order to achieve a preferable range for the relationship between the pitch P and the thickness Ax in the first direction of the conductor in the region above the upper surface of the convex portions 3 (described later). The pitch P does not need to be such that the convex portions 3 are arranged at strictly equal intervals; it is acceptable for there to be a variation of about 10% within the plane due to manufacturing errors and shrinkage during transfer of the convex portions 3. The pitch P is the spacing between the centers of the convex portions 3 in the surface-normal direction 5 at their bases (the distance between the first intersection of the center line of the first convex portion in the surface-normal direction with the curved surface 2a of the substrate 2 and the second intersection of the center line of the second convex portion adjacent to the first convex portion in the surface-normal direction 5 with the curved surface 2a).

[0032] More preferably, the numerical range of conditional expression (3) is set as in the following conditional expression (3a).

[0033] 75≦P≦165 (3a) More preferably, the numerical range of conditional expression (3) is set as in the following conditional expression (3b).

[0034] 80≦P≦160 (3b) The conductor 4 is preferably made of a material having high reflectivity in the visible light region, such as aluminum, silver, gold, chromium, zirconium, titanium, copper, tungsten, magnesium, tantalum, platinum, or an alloy containing any of these as its main component.

[0035] At least a portion of the upper surface and at least a portion of one side surface (and at least a portion of the recesses) of the convex and concave portions 3 of the concave-convex structure are covered with a conductor 4 to form thin conductor wires 1. The method for covering the convex portions 3 with the conductor 4 is not limited to vacuum deposition or sputtering, as long as it is a method that can deposit the conductor 4 on the convex portions 3. For example, using oblique deposition in the vacuum deposition method is more preferable because it allows the deposition angle θ to be appropriately set depending on the shape or pitch P of the convex portions 3, making it easier to control the shape of the conductor 4. Here, the deposition angle θ is the angle between the direction along the optical axis 6 and the deposition direction from the deposition source.

[0036] Oblique deposition from a fixed angle is preferred for achieving good polarization separation function while keeping production costs low. When oblique deposition is performed on a convex portion 3, the adjacent convex portion 3 casts a shadow, resulting in some areas where the deposition material does not adhere, and a conductor 4 is formed on one side surface of the convex portion 3. Depending on the incident angle of the deposition material with respect to the convex portion 3, the conductor may also adhere to the concave portion, and an area where the deposition material does not adhere may also be formed on one side surface.

[0037] When the substrate is flat, the conductor formed by oblique deposition from a fixed angle is generally uniform within the surface of the optical element, although there may be some variation due to manufacturing errors. However, in an optical element (curved element) where the substrate is curved, if the conductor 4 is deposited by oblique deposition from a fixed angle toward the convex portion 3 extending in the surface normal direction 5, the film thickness and shape of the conductor 4 will not be uniform in the cross section shown in Figure 2. As a result, roughly divided into four patterns of conductor shapes can be obtained.

[0038] FIG. 3 is an explanatory diagram of the conductor shapes of four patterns (a) to (d). The conductor shape in pattern (a), in which the conductor extends upward from the bottom of the recesses to cover the top surfaces of the protrusions, is the conductor shape with the highest polarization separation performance. Here, the thickness in the first direction of the conductor that coats the side surfaces of the protrusions at the top of the protrusions is defined as Dx (nm). The conductor on the side surfaces of the protrusions is coated with a substantially uniform thickness from the recesses to the top of the protrusions. The incident angle of the deposition material to the protrusions having such a conductor shape is defined as θ1. Here, the incident angle of the deposition material to the protrusions is the angle between the surface normal direction 5 at the center of the width of the protrusions and the deposition direction from the deposition source. In pattern (a), the surface normal direction 5 coincides with the optical axis direction, so the deposition angle θ and the incident angle θ1 coincide.

[0039] When the substrate is a flat plate, oblique deposition of the deposition material onto the convex portions at an incident angle θ1 to form such a conductor shape results in the formation of a conductor shape as shown in pattern (a) in Figure 3 over the entire surface of the optical element.

[0040] On the other hand, when the substrate is curved, the incident angle of the vapor deposition material relative to the convex portions is smaller than θ1 (incident angle θ2) in regions closer to the deposition source than the position where pattern (a), which represents the conductor shape with the highest polarization (optical) characteristics, is formed. In this case, a conductor shape such as pattern (b) in Figure 3 is obtained. The conductor shape of pattern (b) is a shape in which the conductor is deposited in the concave portions to a thickness greater than Dx. Note that the curvature of the substrate in Figure 3 is positive. However, if the curvature is negative, the conductor shape shown in Figure 3(b) will be formed if the incident angle of the vapor deposition material is greater than θ1. In Figure 3, since the curvature of the substrate is positive, if the central region of the optical element is obliquely vapor-deposited at an incident angle θ1 of the vapor deposition material to form the ideal conductor shape shown in Figure 3(a), the region to the left of the center of the optical element will form the conductor shape shown in Figure 3(b). The incident angle of the vapor deposition material relative to the convex portions is θ2 (θ2<θ1). The conductor shape of pattern (b) has a conductor shape such that when the value obtained by subtracting thickness Dx from the maximum thickness of the conductor deposited on the side surface of protrusion 3 in the first direction is Bx (nm), the value Bx is greater than 0. Also, the film thickness in the surface normal direction 5 of the conductor deposited in recessed portions that is thicker than thickness Dx is Bz.

[0041] As the value Bx increases, the incidence angle θ2 of the deposition material deviates from the incidence angle θ1 and also deviates from the ideal conductor shape, resulting in a deterioration in polarization characteristics.

[0042] On the other hand, in regions farther from the deposition source than the optical element position forming the ideal conductor shape, pattern (a), the incident angle of the deposition material to the convex portions becomes larger than θ1, resulting in conductor shapes such as patterns (c) and (d). Here, the curvature of the substrate in Figure 3 is positive. However, if the curvature is negative, the incident angle of the deposition material to the convex portions becomes smaller than θ1, resulting in the formation of conductor shapes such as patterns (c) and (d). The incident angles of the deposition material to the convex portions at this time are θ3 and θ4. This region is located to the right of the center of the optical element in Figure 3. The conductor shape of pattern (c) has a height Sz (nm) in the third direction of a region lacking the conductor deposited on the side of the convex portions near the substrate. The conductor shape of pattern (d) is formed in a region where the incident angle of the deposition material is even larger than the incident angle θ3, and has a region of height Sz and a region of height Nz (completely uncoated region). The completely undeposited region is a region having a height Nz (nm) in the third direction of a region where no film is deposited on the side surface of the convex portion.

[0043] As the region of height Sz becomes smaller and the completely uncoated region of height Nz becomes larger, the angles of incidence θ3 and θ4 become more distant from the angle of incidence θ1 and the shape of the conductor becomes less ideal, resulting in a deterioration in polarization separation performance.

[0044] In the conductor shape of pattern (a) in Figure 3, Bx, Sz, and Nz are all 0. In summary, when oblique deposition is performed from a fixed angle on convex portions extending in the surface normal direction of a curved substrate, four patterns of conductor shapes are formed where Bx = 0 and Sz = 0, or Bx > 0, or Sz > 0 and Nz = 0, or Sz > 0 and Nz > 0. Note that Figure 3 is a schematic diagram that shows only the four patterns of conductors and the convex portions adjacent to the conductors in the deposition direction, omitting other configurations. In reality, the convex portions are arranged at equal intervals according to the pitch of the convex portions, and the conductor is deposited on them.

[0045] In Figure 3, only four patterns of conductor shapes within the plane of the optical element and the convex portions adjacent to the conductors in the deposition direction are shown. However, in reality, multiple convex portions and conductors exist between the four patterns of conductors. Furthermore, because the substrate is curved, the conductor shapes between the four patterns change continuously or stepwise within the plane of the optical element. Dx, Bx, Sz, and Nz also change continuously or stepwise from one end to the other end of the optical element in the first direction. That is, the thickness of the conductor in the first direction at each end face of the multiple convex portions changes from one end to the other end of the transflective element in the first direction. As a result, the conductor shapes become non-uniform within the plane of the optical element, causing changes in the polarization characteristics (optical characteristics).

[0046] This change in polarization characteristics results in a change in brightness and color, and occurs in a direction perpendicular to the direction in which the thin conductor wires extend. Therefore, the optical element detects the color difference (ΔE * When the maximum value of (a) and (b) is compared with the maximum value of the color difference of the transmitted light in the orthogonal direction, the maximum value of the color difference of the transmitted light in the orthogonal direction is larger. In other words, the maximum value of the first color difference of the transmitted light in the direction perpendicular to the second direction (the extension direction of the plurality of protrusions 3) of the transflective element 100 (above or below the center) is larger than the maximum value of the second color difference of the transmitted light in the second direction (to the right or left of the center).

[0047] To explain the viewing angle of the human eye, the horizontal viewing angle is 60° inward and 100° outward, for a total of approximately 200° left and right, and the vertical viewing angle is 60° upward and 70° downward. Within this range, the stable visual field, which is the area where effective information demand occurs, is 60-90° horizontally and 45-70° vertically. This means that the human field of vision is wider horizontally than vertically, and brightness and color unevenness are more noticeable in the horizontal direction (left and right) than in the vertical direction (up and down). Therefore, it is preferable to suppress brightness and color unevenness in the horizontal direction.

[0048] Therefore, when the transmissive reflective element 100 is used in a display device (observation device), it is preferable that conditional expression (4) be satisfied when the angle between the second direction (extension direction) in which each of the multiple convex portions 3 extends and the direction in which the user's eyes are aligned in a plane perpendicular to the optical axis 6 is α1 (°).

[0049] |α1|≦45 (4) More preferably, |α1|≦40, 35, 30, 20, 15, 10, or 5 is satisfied.

[0050] More preferably, the second direction is substantially parallel to the direction in which the user's eyes are aligned (α1≈0) so that unevenness in brightness and color occurs in the vertical direction.

[0051] Also, consider a case where an observation optical system (optical device) used in a display device has a first optical system and a second optical system arranged in parallel to the first optical system, and the first optical system and the second optical system each have a transmissive reflecting element 100. In this case, when the angle between the second direction (extension direction) and the direction in which the first optical system and the second optical system are arranged in parallel is α2 (°), it is preferable to satisfy the following conditional expression (5):

[0052] |α2|≦45 (5) More preferably, |α2|≦40, 35, 30, 20, 15, 10, or 5 is satisfied.

[0053] More preferably, the second direction is approximately parallel to the direction in which the first optical system and the second optical system are arranged in parallel (α2≈0) so that unevenness in brightness and color occurs in the vertical direction.

[0054] When the transflective element 100 is arranged as described above in a display device or an observation optical system, a high-quality image can be viewed by the observer.

[0055] Furthermore, when the transflective element 100 is used in an imaging device, color unevenness is greatest in the diagonal direction of the imaging element. For this reason, it is preferable to suppress color unevenness from occurring in the diagonal direction and to cause it to occur in the short side direction of the imaging element. Therefore, in each embodiment, when the length of the imaging element in the long side direction is a, the length of the imaging element in the short side direction is b, and the angle between the second direction in which each of the multiple protrusions 3 extends and the long side direction of the imaging element is α3 (°), it is preferable to satisfy the following conditional expression (6):

[0056] |α3|<90-tan -1 (b / a) (6) More preferably, |α3|<40, 35, 30, 20, 15, 10, or 5 is satisfied.

[0057] More preferably, the second direction is approximately parallel to the long side direction of the imaging element (α3≈0).

[0058] When arranged in this manner, brightness and color unevenness of the transmissive reflective element 100 occurs in a direction perpendicular to the extension direction of the thin conductive wire, so occurrence in the long side direction of the imaging element is suppressed, and an image with less brightness and color unevenness can be obtained in the captured image.

[0059] Color difference ΔE * ab When the color difference ΔE is 1.2, most people can easily recognize the color difference when they compare the colors side by side. * abWhen the maximum value of σ is 1.2 or greater, it is preferable to arrange the extension direction of the thin conductor wires so that they are aligned along the direction of the mesh or the long side of the image sensor, so that brightness and color unevenness occur in the vertical direction, where they are less noticeable. This enhances the effects of each embodiment. Here, color difference refers to color difference in the CIELAB color space. Furthermore, it is preferable that the maximum color difference in the horizontal direction relative to the extension direction of the thin conductor wires 1 of the optical element is 0.4 or less. In design, the conductor is uniformly deposited in the extension direction of the concave-convex structure, resulting in a horizontal color difference of 0. However, in reality, during film deposition, installation errors in the deposition machine can cause variations in the conductor film thickness in the extension direction of the concave-convex structure, resulting in horizontal color unevenness. Therefore, by setting the maximum horizontal color difference to 0.4 or less, a conductor can be obtained that suppresses film thickness variations within the surface of the optical element.

[0060] In each embodiment, it is preferable that the thickness Ax in the first direction and the pitch P of the conductors 4 in the region above the top surface of the largest convexity 3 within the plane of the transflective element 100 satisfy the following conditional expression (7).

[0061] 0.25≦Ax / P≦0.55 (7) By satisfying conditional expression (7), even better polarization separation performance can be obtained. When the value of Ax / P, which is the ratio of the conductor to the pitch P defined by conditional expression (7), is close to the lower limit, the transmittance is high, making it possible to provide a high-transmittance transflector. However, as the transmittance increases, the transmittance of unwanted light also increases. This reduces the polarization separation performance, making it difficult to obtain a high-contrast transflector. On the other hand, when this value is large, the transmittance decreases, but the transmittance of S-polarized light is suppressed, resulting in excellent polarization separation function and a high-contrast transflector. In this way, the characteristics of the transflector can be controlled by the shape of the conductor depending on the intended use. In other words, the thickness Ax is the thickness in the first direction of the conductor 4 on the outer side in the third direction from the top surface (end surface) of each of the multiple convex portions 3.

[0062] Preferably, the numerical range of conditional expression (7) is set as in the following conditional expression (7a).

[0063] 0.27≦Ax / P≦0.54 (7a) More preferably, the numerical range of conditional expression (7) is set as in the following conditional expression (7b).

[0064] 0.29≦Ax / P≦0.53 (7b) Each example will be described in detail below. [Example]

[0065] First, a head mounted display (display device, optical device) 200 according to a first embodiment of the present invention will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a cross-sectional view of the head mounted display 200. Fig. 5 is an external view of the head mounted display 200.

[0066] The head-mounted display 200 has, as observation optical systems, an optical system (first optical system) 201 and an optical system (second optical system) 202. The optical systems 201 and 202 each have a lens, a display device, a polarizing plate, a curved polarization-selective transmission / reflection element, a half mirror, and a quarter-wave plate, and the lens configurations of the optical systems 201 and 202 are the same. In Fig. 4, 7 indicates a human right eye, and 8 indicates a human left eye. The optical systems 201 and 202 are housed in a goggle-type case 11 and are positioned relative to the right eye 7 and the left eye 8, respectively.

[0067] The head-mounted display 200 is worn on the observer's head when in use. The observer sees an enlarged image on display devices (display elements) 9 and 10 via optical systems 201 and 202. Separate images with parallax are projected onto the display devices 9 and 10, allowing the observer to see a stereoscopic image.

[0068] The curved polarization-selective transmission / reflection element has a curved surface with a maximum open angle of 18 degrees and a flat back surface, and the curved surface side of the substrate is spherical and equipped with thin conductive wires.

[0069] 6 is a side view of the transflective element 100 of this example. The material forming the substrate 2 and the convex portions 3 is a cycloolefin copolymer, and the convex portions have a periodic structure with a pitch P of 130 nm, a height h of 170 nm, and a width w of 25 nm in the third direction at the top of the convex portions.

[0070] The material forming the conductor 4 is aluminum, and the shape of the conductor was obtained by simulating oblique deposition from a deposition angle of 28 degrees on only one side of the convex portion. Figure 6(a) shows the conductor shape at the center, Figure 6(b) shows the conductor shape at one end, and Figure 6(c) shows the conductor shape at the other end. The thin conductor wires between both ends and the center are omitted, but the conductor shape changes continuously or in stages depending on the incident angle of the deposition material on each convex portion.

[0071] The conductor shape in FIG. 6(a) is such that Sz=0 and Bx=0, Dx is 23 nm, and Dz is 41 nm. The conductor shape in FIG. 6(b) is such that Sz>0 and Nz>0, Dx is 32 nm, Dz is 38 nm, Sz=65 nm, and Nz=29 nm. The conductor shape at the other end is such that Bx>0, with Dx 23 nm, Dz 37 nm, Bx=24 nm, and Bz=29 nm. The conductor shape between both ends and the center has film thicknesses and Bx, Sz, and Nz that decrease or increase stepwise or continuously. The average thickness Ax in the first direction of the conductor above the top surface of the convex portion within the optical element plane is 51 nm.

[0072] Figures 7(a) to 7(c) show the transmittance and reflectance in this example, and show the results of a rigorous coupled-wave analysis of the conductor shape. Figure 7(a) shows the results for the conductor shape of Figure 6(a) at one end, Figure 7(b) shows the results for the conductor shape of Figure 6(b) at the center, and Figure 7(c) shows the results for the conductor shape of Figure 6(b) at the other end. In Figures 7(a) to 7(c), the horizontal axis represents wavelength (nm), and the vertical axis represents transmittance (%) or reflectance (%). Tp (%) is the transmittance of P-polarized light, Ts (%) is the transmittance of S-polarized light, Rp (%) is the reflectance of P-polarized light, and Rs (%) is the reflectance of S-polarized light.

[0073] Color difference ΔE of transmitted light in the direction perpendicular to the direction of extension of the thin conductive wires of the transflective element * ab The maximum value of ΔE is 7.3, and the color difference of the transmitted light in the horizontal direction is * ab The design value of is 0. Here, transmitted light is the product of Rs and Tp. In reality, the final observation light is the product of Rs and Tp of the transflective element and the spectral characteristics of various components of the optical system, but because the transmittance of various components is the same, the color difference is calculated from the product of Rs and Tp. Furthermore, the color of the display device is electrically corrected so that the center of the image is white, so the center of the optical element, as shown in Figure 7(a), is used as the reference. Therefore, the color difference is the difference in color between the center of the optical element and other areas.

[0074] Because the substrate on the conductor wire side is spherical, the areas where the shape changes most compared to the conductor shape in the center are the ends. Therefore, the results of the rigorous coupled wave analysis only show the center and both ends, and the maximum color difference in each direction is also the value at the ends. There are no restrictions on the light source used to evaluate transmitted light, but since color difference is compared, it is sufficient to use the same light source.

[0075] Figure 8 shows the color unevenness of the transmitted light of the transflective element 100 of this embodiment, with the center as the reference point. Compared to Figure 7(a), Figure 7(b) shows a bluish color due to a decrease in P-polarized light transmittance for wavelengths of 550 nm or more. On the other hand, compared to Figure 7(a), Figure 7(c) shows a yellowish color unevenness due to a decrease in P-polarized light transmittance for wavelengths of 550 nm or less.

[0076] Because the surface is curved with a maximum opening angle of 18 degrees, forming a conductor by oblique evaporation from a fixed angle on only one side of the convex portion results in significant changes in the shape of the conductor within the transflective element surface, which in turn results in significant changes in the polarization characteristics and, as a result, larger color differences in the transmitted light.

[0077] 9 is a cross-sectional view of the observation optical system (optical systems 201 and 202). The optical systems 201 and 202 have a first lens G1, a second lens G2, a second quarter-wave plate 14, a polarizing plate 15, and a display device 9. The second lens G2 is a cemented element including a transmissive reflector 100, a first quarter-wave plate 12, and a half mirror 13 on its surface. The display device 9 is a display element such as a liquid crystal display element or an organic EL element.

[0078] The light emitted from the display device 9 is converted into linearly polarized light by the polarizing plate 15, converted into circularly polarized light by the second quarter-wave plate 14, and then incident on the half mirror 13. A portion of the light incident on the half mirror 13 is reflected, becomes reverse circularly polarized light, and returns to the second quarter-wave plate 14. The reverse circularly polarized light that has returned to the second quarter-wave plate 14 is converted by the second quarter-wave plate 14 into linearly polarized light having a polarization direction perpendicular to the polarization direction when the light passed through the first polarizing plate 15, returns to the polarizing plate 15, and is absorbed by the polarizing plate 15.

[0079] On the other hand, the remainder of the light incident on the half mirror 13 passes through it and is converted by the first quarter-wave plate 12 into linearly polarized light in the same polarization direction as when it passed through the polarizing plate 15, and then incidents on the transmissive-reflecting element 100. This linearly polarized light is reflected by the polarization selectivity of the transmissive-reflecting element 100. The light reflected by the transmissive-reflecting element 100 is converted by the first quarter-wave plate 12 into circularly polarized light in the opposite direction to when it was first converted into circularly polarized light by the second quarter-wave plate 14, and then incidents on the half mirror 13, where it is reflected.

[0080] The light reflected by the half mirror 13 becomes circularly polarized light that is reversely polarized to the light before reflection and enters the first quarter-wave plate 12. It is then converted into linearly polarized light having a polarization direction perpendicular to the polarization direction when it first passed through the polarizing plate 15 and enters the transmissive reflector 100. This linearly polarized light passes through the transmissive reflector 100 due to its polarization selectivity and is guided to the eye 16. The image displayed on the display device 9 is magnified and observed by refractive optical elements with power that are arranged in the optical paths of the optical systems 201 and 202.

[0081] The head-mounted display 200 is worn on the observer's head when in use. The observer sees enlarged images on the display devices 9 and 10 through the optical systems 201 and 202. Different images with parallax are projected onto the display devices 9 and 10, allowing the observer to see a stereoscopic image.

[0082] Here, the concave-convex structure of each of the curved polarization-selective semi-transmissive reflective elements of the optical systems 201 and 202 of the head-mounted display 200 extends in the horizontal direction, which is the direction in which the eyes are aligned. Therefore, the aforementioned color unevenness occurs in the vertical direction (up and down direction), which is less noticeable to the human visual system, allowing the viewer to view a high-quality image.

[0083] In this embodiment, the color unevenness of the transmittance that occurs differs in hue and color difference at both ends. For example, the optical system may be configured so that blue color unevenness, which has low human visibility, appears on the lower side where the vertical viewing angle is wide, and yellow color unevenness, which has higher visibility compared to blue, appears on the upper side where the vertical viewing angle is narrow, thereby further reducing the visibility of the color unevenness. Alternatively, the optical system may be configured so that color unevenness with a larger color difference appears on the upper side where the vertical viewing angle is narrow, thereby minimizing the impact of color unevenness.

[0084] (Comparative Example 1) Comparative Example 1 is a head-mounted display with the same configuration as Example 1, but the uneven structure of each of the curved polarization-selective semi-transmissive reflective elements of the two optical systems extends in the vertical direction, which is perpendicular to the horizontal direction in which the eyes are aligned. Figure 10 shows the color unevenness of the transmitted light through the curved polarization-selective semi-transmissive reflective element of Comparative Example 1, based on the center. Because the uneven structure of the curved polarization-selective semi-transmissive reflective element extends in the vertical direction, color unevenness occurs in the horizontal direction (left and right), which is more noticeable to human vision, which is undesirable. [Example]

[0085] Next, an imaging device 300 according to a second embodiment of the present invention will be described. Fig. 11 is a cross-sectional view of the imaging device 300 according to this embodiment. The imaging device 300 is configured to include an imaging optical system and an image sensor 18. The imaging optical system includes a first lens G1, a second lens G2, a third lens G3, and a sensor protection glass 17, arranged in this order from the object side to the image plane side.

[0086] The first lens G1 is a transflective element 100, and has a thin conductor wire 1 and a first quarter-wave plate 12 on the image side. The third lens G3 has a half mirror 13 on the object side, and a second quarter-wave plate 14 and a polarizing plate 15 on the image side.

[0087] Light incident on the imaging optical system from the object side becomes linearly polarized light at the transflective element 100, becomes circularly polarized light at the first quarter-wave plate 12, and then enters the half mirror 13. A part of the light that reaches the half mirror 13 is reflected and becomes reverse circularly polarized light, and returns to the first quarter-wave plate 12.

[0088] The counter-circularly polarized light that has returned to the first quarter-wave plate 12 returns to the transmissive-reflecting element 100 as linearly polarized light polarized in a direction perpendicular to the direction of the light that initially passed through the transmissive-reflecting element 100. The light is then reflected by the transmissive-reflecting element 100. Due to the polarization selectivity of the transmissive-reflecting element 100, linearly polarized light polarized in a direction perpendicular to the direction of the light that initially passed through the transmissive-reflecting element 100 is reflected.

[0089] On the other hand, a portion of the light that reaches the half mirror 13 is transmitted and becomes linearly polarized light polarized in the same direction as when it passed through the transmissive-reflective element 100 by the second quarter-wave plate 14, and is incident on the polarizing plate (linear polarizing plate) 15 and absorbed by the polarizing plate 15.

[0090] The light reflected by the transflective element 100 is converted into circularly polarized light by the first quarter-wave plate 12 and enters the half mirror 13. A portion of the light that reaches the half mirror 13 is transmitted through and enters the second quarter-wave plate 14. The second quarter-wave plate 14 converts the incident light into linearly polarized light that is oriented parallel to the linearly polarized light reflected by the transflective element 100. The light that passes through the second quarter-wave plate 14 enters the polarizing plate 15. Here, the polarization of the light and the transmission axis of the polarizing plate coincide, so most of the light is transmitted through and directed to the imaging surface of the image sensor 18.

[0091] By the above action, only the light that has passed through the transmissive reflecting element 100 , reflected by the half mirror 13 , reflected by the transmissive reflecting element 100 , and passed through the half mirror 13 is guided to the imaging surface of the imaging element 18 .

[0092] Here, the transflective element 100 has a curved surface with a maximum open angle of 6 degrees and a flat back surface, and the curved surface side of the substrate is spherical and is provided with thin conductor wires 1. Fig. 12 is a side view of the transflective element 100 in this example. Fig. 12 is a deformed side view that is different from the actual scale.

[0093] The material forming the substrate 2 and the convex portions 3 is a cycloolefin copolymer. The convex portions have a periodic structure with a pitch P of 80 nm, a height h of 60 nm, and a width w in the third direction at the top of the convex portion of 15 nm. The material forming the conductor 4 is aluminum, and the convex portions have a shape in which a conductor is coated on both sides of the convex portions. This conductor shape was obtained by applying the conductor to the top and one side of the convex portions and at least a portion of the concave portions using oblique deposition simulation at a deposition angle θ, the angle between the optical axis and the deposition direction, of 50.3 degrees. The optical element was then rotated 180 degrees, and the conductor was applied to the other side of the convex portions using oblique deposition simulation from the same angle, resulting in the conductor shape shown in (a), (b), and (b') in Figure 12, in which a conductor is coated on both sides of the convex portions. (b) and (b') in Figure 12 are approximately symmetrical to each other.

[0094] When the conductor (a) in the central portion is divided into left and right halves from the center of the width of the convex portion, the conductor shapes are approximately symmetrical to each other, and a conductor shape is obtained in which Sz > 0 and Nz > 0. When the conductor is divided into left and right halves from the center of the width of the convex portion, the conductors on the right and left sides have Dx of 13.5 nm, Nz of 6.1 nm, Sz of 17.2 nm, and Dz of 22.4 nm.

[0095] When the conductor (b) at the outermost end is divided into left and right sides from the center of the width of the convex portion, or when the conductor (b') at the other outermost end is divided into left and right sides from the center of the width of the convex portion, the left conductor has a conductor shape where Bx = 0 and Sz = 0, and Dx is 12.9 nm. Furthermore, when the conductor (b) at the outermost end is divided into left and right sides from the center of the width of the convex portion, which is the other side of the conductor, or when the conductor (b') at the other outermost end is divided into left and right sides from the center of the width of the convex portion, the conductor shape on the right side is Sz > 0 and Nz > 0. The conductor shape had Sz of 22 nm, Nz of 11.6 nm, and Dx of 14 nm. Dz at the outermost end was 22.5 nm.

[0096] The thickness of the conductor between the central portion and the outermost portion increases or decreases stepwise or continuously. The average thickness Ax in the first direction of the conductor above the top surface of the convex portion within the plane of the transflective element is 42.0 nm.

[0097] Using the above structure obtained by the oblique deposition simulation, the results of rigorous coupled wave analysis of the center part are shown in Figure 13(a) and the edge part in Figure 13(b). Here, since the conductor shapes at the edge parts (b) and (b') are symmetrical to each other, only (b) is shown.

[0098] Color difference ΔE of light transmitted in a direction perpendicular to the direction in which the thin conductive wires of the transflective element 100 extend * ab The maximum value of ΔE is 1.3, and the color difference of the transmitted light in the horizontal direction is * abThe design value of is 0. Because the substrate on the conductor wire side is spherical, the areas where the shape changes most compared to the conductor shape in the center are the ends. Therefore, the results of the rigorous coupled wave analysis only show the center and both ends, and the maximum color difference in each direction is also the value at the ends. The conductor shape of the transflective element 100 of this embodiment is symmetrical on both sides from the center of the element, so the color unevenness that occurs is the same at both ends.

[0099] 14 is a diagram showing color unevenness of transmitted light of the transmissive reflective element 100 of this embodiment, with the center as the reference point. Here, it is preferable that the extending direction of the concave-convex structure of the transmissive reflective element 100 of the optical system of the imaging device 300 is arranged so that it coincides with the long side direction of the imaging element 18. With such an arrangement, brightness and color unevenness of the transmissive reflective element 100 occurs in a direction perpendicular to the extending direction of the concave-convex structure, and therefore occurs in the short side direction of the imaging element 18, and a good image with little brightness and color unevenness can be obtained in the acquired image. [Example]

[0100] Next, an imaging device 400 according to a third embodiment of the present invention will be described. Fig. 15 is a cross-sectional view of the imaging device 400 according to this embodiment. The imaging device 400 is configured to include an imaging optical system and an image sensor 18. The imaging optical system includes a first lens G1, a second lens G2, a third lens G3, a fourth lens G4, a fifth lens G5, and a sensor protection glass 17, arranged in this order from the object side to the image plane side.

[0101] The third lens G3 is a transflective element 100, and has a thin conductor wire 1 and a first quarter-wave plate 12 on the image side. The fifth lens G5 has a half mirror 13 on the object side, and a second quarter-wave plate 14 and a polarizing plate 15 on the image side.

[0102] Here, the surface of the transmission-reflection element 100 on which the thin conductor wires 1 are provided has a spherical shape with a maximum open angle of -20 degrees. Fig. 16 is a side view of the transmission-reflection element 100 of this example. Fig. 16 is a deformed side view, different from the actual scale.

[0103] The substrate 2 and the convex portions 3 are made of a cycloolefin copolymer. The convex portions have a periodic pitch P of 150 nm, a height h of 250 nm, and a width w in the third direction at the top of the convex portion of 35 nm. The conductor 4 is made of aluminum, and the convex portions have a shape in which the conductor is coated on both sides of the convex portions. This conductor shape is obtained by applying the conductor to the top and one side of the convex portions and at least a portion of the concave portions using oblique deposition simulation at a deposition angle θ, which is the angle between the optical axis and the deposition direction, of 32 degrees. The optical element is then rotated 180 degrees, and the conductor is applied to the other side of the convex portions using oblique deposition simulation from the same angle. This results in the conductor shape in which the conductor is coated on both sides of the convex portions as shown in (a), (b), and (b') in Figure 16. (b) and (b') in Figure 16 are approximately symmetrical to each other.

[0104] When the conductor (a) in the central portion is divided into left and right halves from the center of the width of the convex portion, the conductor shapes are approximately symmetrical to each other, and a conductor shape is obtained in which Sz > 0 and Nz > 0. When the conductor is divided into left and right halves from the center of the width of the convex portion, the conductors on the right and left sides have Dx of 5.3 nm, Nz of 66 nm, Sz of 74.5 nm, and Dz of 16.9 nm.

[0105] When the conductor (b) at the outermost end is divided into left and right sides from the center of the width of the convex portion, or when the conductor (b') at the other outermost end is divided into left and right sides from the center of the width of the convex portion, the conductor shape is such that Sz>0 and Nz>0. Sz is 129.7 nm, Nz is 122.3 nm, and Dx is 6.7 nm. Furthermore, when the conductor (b) at the outermost end is divided into left and right sides from the center of the width of the convex portion, which is another side of the conductor, or when the conductor (b') at the other outermost end is divided into left and right sides from the center of the width of the convex portion, the conductor shape is such that Bx=0 and Sz=0. Dx is 3.7 nm. Dz at the outermost end is 16.7 nm. The conductor shape between the center and the outermost end has a film thickness that increases or decreases stepwise or continuously. The average thickness Ax in the first direction of the conductor above the top surfaces of the convex portions within the plane of the transflective element is 45.5 nm.

[0106] Using the above structure obtained by the oblique deposition simulation, the results of rigorous coupled wave analysis of the center part are shown in Figure 17(a) and the edge part in Figure 17(b). Here, since the conductor shapes at the edge parts (b) and (b') are symmetrical to each other, only (b) is shown.

[0107] Color difference ΔE of light transmitted in a direction perpendicular to the direction in which the thin conductive wires of the transflective element 100 extend * ab The maximum value of ΔE is 5.0, and the color difference of the transmitted light in the horizontal direction is * ab The design value of is 0. Because the substrate on the conductor wire side is spherical, the areas where the shape changes the most compared to the conductor shape at the center are the ends. Therefore, the results of the rigorous coupled wave analysis only show the center and both ends, and the maximum color difference in each direction is also the value at the ends. The conductor shape of the transflective element 100 of this embodiment is symmetrical on both sides from the center of the element, so the color unevenness that occurs is the same at both ends.

[0108] Here, it is preferable that the extending direction of the concave-convex structure of the transmissive reflective element 100 of the optical system of the imaging device 400 is arranged so as to coincide with the long side direction of the imaging element 18. With such an arrangement, the brightness and color unevenness of the transmissive reflective element 100 occurs in a direction perpendicular to the extending direction of the concave-convex structure, and therefore occurs in the short side direction of the imaging element 18, and a good image with little brightness and color unevenness can be obtained in the acquired image.

[0109] Table 1 shows the numerical values ​​of the conditional expressions in Examples 1 to 3 and Comparative Example 1.

[0110] [Table 1]

[0111] According to each embodiment, it is possible to provide a display device, an optical device, and an imaging device that are capable of acquiring high-quality images.

[0112] The disclosure of each embodiment includes the following configuration. (Configuration 1) A display device having an optical system including a transmissive reflecting element and a display element, The transflective element is A substrate having a curved surface; a plurality of convex portions arranged on the curved surface along a first direction; a conductor provided on each of the plurality of protrusions, each of the plurality of protrusions extends in a second direction perpendicular to the first direction and protrudes in a third direction perpendicular to both the first direction and the second direction; each of the plurality of protrusions has an end face in the third direction and a first side face and a second side face disposed on both sides of the end face in the first direction; In a cross section including the first direction and the third direction, the conductor covers at least a part of the end face of each of the plurality of protrusions and at least a part of the first side face, When the angle between the second direction and the direction in which the user's eyes are aligned is α1 (°), |α1|≦45 A display device characterized by satisfying the following conditional expressions: (Configuration 2) 2. The display device according to configuration 1, wherein the second direction is parallel to the direction in which the user's eyes are aligned. (Configuration 3) The display device described in configuration 1 or 2, characterized in that the thickness of the conductor in the first direction at the end face of each of the multiple convex portions changes in the direction from one end side to the other end side of the transmissive reflecting element in the first direction. (Configuration 4) 4. The display device according to any one of configurations 1 to 3, wherein the base material and the plurality of protrusions are integrally formed with each other. (Configuration 5) A display device described in any one of configurations 1 to 4, characterized in that the maximum value of the first color difference of the transmitted light in a direction perpendicular to the second direction of the transmissive reflecting element is greater than the maximum value of the second color difference of the transmitted light in the second direction. (Configuration 6) 6. The display device according to configuration 5, wherein the maximum value of the first color difference is 1.2 or more, and the maximum value of the second color difference is 0.4 or less. (Configuration 7) When the height of the convex portion in the third direction in the cross section is h (nm), 50≦h≦300 7. The display device according to any one of configurations 1 to 6, wherein the following conditional expression is satisfied: (Configuration 8) When the arrangement pitch of the plurality of convex portions in the cross section is P (nm), 70≦P≦170 8. The display device according to any one of configurations 1 to 7, wherein the following conditional expression is satisfied: (Configuration 9) When the arrangement pitch of the plurality of protrusions is P (nm), and the thickness of each of the plurality of protrusions in the first direction of the conductor on the outer side of the end face in the third direction is Ax (nm), 0.25≦Ax / P≦0.55 9. The display device according to any one of configurations 1 to 8, wherein the following conditional expression is satisfied: (Configuration 10) a first optical system and a second optical system arranged in parallel; the first optical system and the second optical system each include a transmissive-reflective element; The transflective element is A substrate having a curved surface; a plurality of convex portions arranged on the curved surface along a first direction; a conductor provided on each of the plurality of protrusions, each of the plurality of protrusions extends in a second direction perpendicular to the first direction and protrudes in a third direction perpendicular to both the first direction and the second direction; each of the plurality of protrusions has an end face in the third direction and a first side face and a second side face disposed on both sides of the end face in the first direction; In a cross section including the first direction and the third direction, the conductor covers at least a part of the end face of each of the plurality of protrusions and at least a part of the first side face, When the angle between the second direction and the arrangement direction of the first optical system and the second optical system is α2 (°), |α2|≦45 An optical device characterized by satisfying the following conditional expression: (Configuration 11) 11. The optical device of configuration 10, wherein the second direction is parallel to the arrangement direction. (Configuration 12) An imaging device having an optical system including a transmissive / reflective element and an imaging element, The transflective element is A substrate having a curved surface; a plurality of convex portions arranged on the curved surface along a first direction; a conductor provided on each of the plurality of protrusions, each of the plurality of protrusions extends in a second direction perpendicular to the first direction and protrudes in a third direction perpendicular to both the first direction and the second direction; each of the plurality of protrusions has an end face in the third direction and a first side face and a second side face disposed on both sides of the end face in the first direction; In a cross section including the first direction and the third direction, the conductor covers at least a part of the end face of each of the plurality of protrusions and at least a part of the first side face, When the length of the imaging element in the long side direction is a, the length of the imaging element in the short side direction is b, and the angle between the second direction and the long side direction is α3 (°), |α3|<90-tan -1 (b / a) An imaging apparatus characterized in that the following conditional expression is satisfied: (Configuration 13) 13. The imaging device according to configuration 12, wherein the second direction is parallel to the long side direction. (Configuration 14) An imaging device described in configuration 12 or 13, characterized in that the thickness of the conductor in the first direction at the end face of each of the multiple convex portions changes in the direction from one end side to the other end side in the first direction of the transmissive reflecting element. (Configuration 15) 15. The imaging device according to any one of configurations 12 to 14, wherein the base material and the plurality of protrusions are integrally configured with each other. (Configuration 16) An imaging device described in any one of configurations 12 to 15, characterized in that the maximum value of the first color difference of the transmitted light in a direction perpendicular to the second direction of the transmissive reflecting element is greater than the maximum value of the second color difference of the transmitted light in the second direction. (Configuration 17) 17. The imaging device according to configuration 16, wherein the maximum value of the first color difference is 1.2 or more, and the maximum value of the second color difference is 0.4 or less. (Configuration 18) When the height of the convex portion in the third direction in the cross section is h (nm), 50≦h≦300 18. The imaging device according to any one of configurations 12 to 17, wherein the following condition is satisfied: (Configuration 19) When the arrangement pitch of the plurality of convex portions in the cross section is P (nm), 70≦P≦170 19. The imaging device according to any one of configurations 12 to 18, wherein the following condition is satisfied: (Configuration 20) When the arrangement pitch of the plurality of protrusions is P (nm), and the thickness of each of the plurality of protrusions in the first direction of the conductor on the outer side of the end face in the third direction is Ax (nm), 0.25≦Ax / P≦0.55 20. The imaging device according to any one of configurations 12 to 19, wherein the following condition is satisfied:

[0113] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0114] 2 Base material 2a curved surface 3 Convex part 3a Top surface (end surface) 3b 1st side 3c 2nd side 4 Conductors 9, 10 Display device (display element) 100 Transmissive / reflective element 201, 202 Optical system (observation optical system) 200 Head-mounted display (display device)

Claims

1. A display device having an optical system including a transmissive reflecting element and a display element, The transflective element is A substrate having a curved surface; a plurality of convex portions arranged on the curved surface along a first direction; a conductor provided on each of the plurality of protrusions, each of the plurality of protrusions extends in a second direction perpendicular to the first direction and protrudes in a third direction perpendicular to both the first direction and the second direction; each of the plurality of protrusions has an end surface in the third direction and a first side surface and a second side surface disposed on both sides of the end surface in the first direction; In a cross section including the first direction and the third direction, the conductor covers at least a portion of the end face of each of the plurality of protrusions and at least a portion of the first side face, When the angle between the second direction and the direction in which the user's eyes are aligned is α1 (°), ｜α１｜≦４５ A display device characterized by satisfying the following conditional expressions:

2. The display device according to claim 1 , wherein the second direction is parallel to the direction in which the user's eyes are aligned.

3. The display device according to claim 1, characterized in that the thickness of the conductor in the first direction at the end face of each of the plurality of convex portions varies in the direction from one end side to the other end side of the transmissive reflecting element in the first direction.

4. 2. The display device according to claim 1, wherein the base material and the plurality of protrusions are integrally formed with each other.

5. 5. A display device according to claim 1, wherein the maximum value of the first color difference of the transmitted light in a direction perpendicular to the second direction of the transmissive reflecting element is greater than the maximum value of the second color difference of the transmitted light in the second direction.

6. 6. The display device according to claim 5, wherein the maximum value of the first color difference is 1.2 or more, and the maximum value of the second color difference is 0.4 or less.

7. When the height of the convex portion in the third direction in the cross section is h (nm), 50≦h≦300 5. The display device according to claim 1, wherein the following condition is satisfied:

8. When the arrangement pitch of the plurality of convex portions in the cross section is P (nm), 70≦P≦170 5. The display device according to claim 1, wherein the following condition is satisfied:

9. When the arrangement pitch of the plurality of protrusions is P (nm), and the thickness of each of the plurality of protrusions in the first direction of the conductor on the outer side of the end face in the third direction is Ax (nm), 0.25≦Ax / P≦0.55 5. The display device according to claim 1, wherein the following condition is satisfied:

10. a first optical system and a second optical system arranged in parallel; the first optical system and the second optical system each include a transmissive-reflective element; The transflective element is A substrate having a curved surface; a plurality of convex portions arranged on the curved surface along a first direction; a conductor provided on each of the plurality of protrusions, each of the plurality of protrusions extends in a second direction perpendicular to the first direction and protrudes in a third direction perpendicular to both the first direction and the second direction; each of the plurality of protrusions has an end surface in the third direction and a first side surface and a second side surface disposed on both sides of the end surface in the first direction; In a cross section including the first direction and the third direction, the conductor covers at least a portion of the end face of each of the plurality of protrusions and at least a portion of the first side face, When the angle between the second direction and the arrangement direction of the first optical system and the second optical system is α2 (°), ｜α２｜≦４５ An optical device characterized by satisfying the following conditional expression:

11. The optical device according to claim 10 , wherein the second direction is parallel to the arrangement direction.

12. An imaging device having an optical system including a transmissive / reflective element and an imaging element, The transflective element is A substrate having a curved surface; a plurality of convex portions arranged on the curved surface along a first direction; a conductor provided on each of the plurality of protrusions, each of the plurality of protrusions extends in a second direction perpendicular to the first direction and protrudes in a third direction perpendicular to both the first direction and the second direction; each of the plurality of protrusions has an end surface in the third direction and a first side surface and a second side surface disposed on both sides of the end surface in the first direction; In a cross section including the first direction and the third direction, the conductor covers at least a portion of the end face of each of the plurality of protrusions and at least a portion of the first side face, When the length of the imaging element in the long side direction is a, the length of the imaging element in the short side direction is b, and the angle between the second direction and the long side direction is α3 (°), |α3|<90-tan －１ ((b / a) An imaging apparatus characterized in that the following conditional expression is satisfied:

13. The imaging device according to claim 12 , wherein the second direction is parallel to the long side direction.

14. The imaging device described in claim 12, characterized in that the thickness of the conductor in the first direction at the end face of each of the multiple convex portions changes in the direction from one end side to the other end side of the transmissive reflecting element in the first direction.

15. 13. The imaging device according to claim 12, wherein the base material and the plurality of protrusions are integrally formed with each other.

16. 16. The imaging device of claim 12, wherein the maximum value of the first color difference of the transmitted light in a direction perpendicular to the second direction of the transmissive reflecting element is greater than the maximum value of the second color difference of the transmitted light in the second direction.

17. 17. The imaging device according to claim 16, wherein the maximum value of the first color difference is 1.2 or more, and the maximum value of the second color difference is 0.4 or less.

18. When the height of the convex portion in the third direction in the cross section is h (nm), 50≦h≦300 16. The imaging device according to claim 12, wherein the following condition is satisfied:

19. When the arrangement pitch of the plurality of convex portions in the cross section is P (nm), 70≦P≦170 16. The imaging device according to claim 12, wherein the following condition is satisfied:

20. When the arrangement pitch of the plurality of protrusions is P (nm), and the thickness of each of the plurality of protrusions in the first direction of the conductor on the outer side of the end face in the third direction is Ax (nm), 0.25≦Ax / P≦0.55 16. The imaging device according to claim 12, wherein the following condition is satisfied:

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