Virtual image display device and optical unit

Abstract

The present invention relates to a virtual image display device and an optical unit, the virtual image display device comprising: a display that emits circularly polarized image light; and an optical member that forms a virtual image by reflecting the image light twice, the optical member having: a lens member; the transmission type reflective optical element is arranged opposite to a first optical surface, close to the display, of the lens component; a reflective polarizing optical element which is provided so as to face a second optical surface of the lens member, said second optical surface being away from the display, and which reflects image light that is linearly polarized light in the first polarization direction; and a wavelength plate element that is provided between the reflective optical element and the polarizing optical element, converts the image light that has passed through the reflective optical element into linearly polarized light in a first polarization direction, and converts the image light that has been reflected back and forth by the reflective optical element into linearly polarized light in a second polarization direction. The gradient normal angle of the wavelength plate element with respect to the optical surface on which the wavelength plate element is provided has an orientation of d + / -5 DEG or less.

Description

Technical Field

[0001] This invention relates to a virtual image display device and an optical unit capable of observing virtual images. Background Technology

[0002] As a pancake lens, there is a known type of lens in which the front optical element and the rear optical element constituting the optical components are integrally bonded together in order to suppress ghosting when viewing images (Patent Document 1). In the pancake lens of Patent Document 1, a composite film that functions as a polarizer and a quarter-wave plate is bonded to the cylindrical surface in the vertical direction between the front optical element and the rear optical element.

[0003] Patent Document 1: US Patent No. 2018 / 120579

[0004] In the pancake lens of Patent Document 1, the incident angle of light rays incident on the composite film varies depending on the cross-section in different directions, specifically a cylindrical curved surface and a cylindrical plane. Therefore, the displayed image may be degraded due to the influence of the composite film's field of view characteristics. Summary of the Invention

[0005] A virtual image display device according to one aspect of the present invention includes: a display that emits circularly polarized image light; and an optical component that forms a virtual image by reflecting the image light twice. The optical component includes: a lens component having one or more lenses; a transmissive reflective optical element disposed facing a first optical surface of the lens component near the display; a reflective polarizing optical element disposed facing a second optical surface of the lens component away from the display and reflecting image light that is linearly polarized in a first polarization direction; and a wavelength plate element disposed between the reflective optical element and the polarizing optical element, formed of a photocrosslinkable polymer liquid crystal material, which converts the image light passing through the reflective optical element into linearly polarized light in the first polarization direction and converts the image light reflected back and forth by the reflective optical element into linearly polarized light in a second polarization direction. The wavelength plate element has an orientation of d ± 5° or less relative to the gradient normal angle d of the optical surface on which the wavelength plate element is disposed.

[0006] An optical unit according to one aspect of the present invention comprises: a display that emits circularly polarized image light; and an optical component that forms a virtual image by reflecting the image light twice. The optical component comprises: a lens component having one or more lenses; a transmissive reflective optical element disposed facing a first optical surface of the lens component near the display; a reflective polarizing optical element disposed facing a second optical surface of the lens component away from the display and reflecting image light that is linearly polarized in a first polarization direction; and a wavelength plate element disposed between the reflective optical element and the polarizing optical element, formed of a photocrosslinkable polymer liquid crystal material, which converts the image light passing through the reflective optical element into linearly polarized light in the first polarization direction and converts the image light reflected back and forth by the reflective optical element into linearly polarized light in a second polarization direction. The wavelength plate element has an orientation of d ± 5° or less relative to the gradient normal angle d of the optical surface on which the wavelength plate element is disposed. Attached Figure Description

[0007] Figure 1 This is a perspective view illustrating the wearing state of the virtual image display device according to the first embodiment.

[0008] Figure 2 It is a side cross-sectional view illustrating the optical structure of the display optical system.

[0009] Figure 3 It is a diagram illustrating the exposure apparatus.

[0010] Figure 4 This is a diagram illustrating spherical wave exposure.

[0011] Figure 5 This is a schematic diagram illustrating the optical operation of a virtual image display device.

[0012] Figure 6 This diagram illustrates the setting conditions for the virtual image display device.

[0013] Figure 7 This is a diagram illustrating plane wave exposure.

[0014] Figure 8 This is a graph illustrating the angle of incident light in a wavelength plate element exposed to plane waves.

[0015] Figure 9 It is a graph illustrating the general field of view characteristics of a wavelength plate element.

[0016] Figure 10 This is a graph illustrating the angle of incidence of light in a wavelength plate element exposed to spherical waves.

[0017] Figure 11 It is a graph showing the relationship between the F-number and the radius of curvature.

[0018] Figure 12 This is a graph showing the light incident angle of the wavelength plate element in the embodiments and comparative examples.

[0019] Figure 13 It is a graph showing the brightness unevenness, color unevenness, and ghosting of the wavelength plate element in the embodiments and comparative examples.

[0020] Figure 14 This diagram illustrates the verification of the field of view characteristics of the wavelength plate element.

[0021] Figure 15 This is a side cross-sectional view illustrating the optical structure of the display optical system according to the second embodiment.

[0022] Figure 16 This is a side cross-sectional view illustrating the optical structure of the display optical system in a modified example.

[0023] Figure 17 This diagram illustrates the fabrication of the wavelength plate element in the modified example.

[0024] Explanation of reference numerals in the attached figures

[0025] 10: Display; 11: Image display panel; 14: Linear polarizer; 15: 1 / 4 wavelength plate; 16: Circular polarizer; 20: Optical component; 21: Lens component; 21a, 21b, 21f, 21g: Optical surfaces; 22: Reflective optical element; 24: Wavelength plate element; 25: Polarizing optical element; 50: Exposure device; 60: Observation device; 80: Circuit component; 90: User terminal; 100: Optical unit; 100A, 100B: Virtual image display device; 102: Driving device; 102a, 102b: Display driving unit; 103a, 103b: Display optical system; 200: Head-worn display device; AX: Optical axis; CS: Photocrosslinked polymer liquid crystal material; EY: Eye; ML: Image light; PC1, PC2: Polarization control component; PP: Pupil position; US: Wearer. Detailed Implementation

[0026] [First Implementation]

[0027] The following is for reference Figure 1 The virtual image display device and the like according to the first embodiment of the present invention will be described.

[0028] Figure 1 This is a perspective view illustrating the wearing state of a head-mounted display, or head-worn display device 200. The head-worn display device (hereinafter also referred to as HMD) 200 allows the observer or wearer US to perceive an image as a virtual image. Figure 1In this system, X, Y, and Z form an orthogonal coordinate system. The +X direction corresponds laterally to the EY alignment of the eyes of the observer or wearer US wearing the HMD200. The +Y direction is equivalent to the top, orthogonal to the EY alignment of the wearer US's eyes. The +Z direction corresponds to the front or facing direction of the wearer US. The ±Y directions are parallel to the vertical axis or the vertical direction.

[0029] The HMD200 includes a first virtual image display device 100A for the right eye, a second virtual image display device 100B for the left eye, a pair of temples 100C supporting the virtual image display devices 100A and 100B, and a user terminal 90 serving as an information terminal. The first virtual image display device 100A consists of a first display driving unit 102a located at the top and a first display optical system 103a covering the eye. The second virtual image display device 100B consists of a second display driving unit 102b located at the top and a second display optical system 103b covering the eye. The HMD200, which combines the first virtual image display device 100A and the second virtual image display device 100B, is also a virtual image display device in a broader sense. The pair of temples 100C support the upper ends of the pair of display optical systems 103a and 103b via the externally integrated display driving units 102a and 102b. The device combining the pair of display driving units 102a and 102b is referred to as the driving unit 102.

[0030] Figure 2 This is a schematic side view illustrating the structure of the first display optical system 103a. The first display optical system 103a includes a display 10 that emits circularly polarized image light ML, an optical component 20 that forms a virtual image by reflecting the image light ML twice, and a circuit component 80 that controls the operation of the display 10, etc.

[0031] It should be noted that in the first virtual image display device 100A, the optical device after removing the circuit component 80 (specifically the display 10 and the optical component 20) is referred to as the optical unit 100.

[0032] Although detailed descriptions are omitted, the second virtual image display device 100B or the second display optical system 103b is optically identical to the first virtual image display device 100A or the first display optical system 103a, or is obtained by reversing the first virtual image display device 100A or the first display optical system 103a horizontally. Hereinafter, the first virtual image display device 100A or the first display optical system 103a will be described, while the description of the second virtual image display device 100B or the second display optical system 103b will be omitted.

[0033] In the case of the first display optical system 103a shown in the figure, the FOV is about 100°, specifically 120°, and the thickness of the rear emission surface 21c from the outer edge of the display 10 to the optical component 20 is about 10mm to 15mm.

[0034] In the first display optical system 103a, the display 10 includes an image display panel 11 which is a self-emissive image light generating device, and a first polarization control component PC1 which makes the image light ML emitted from the image display panel 11 circularly polarized light.

[0035] The image display panel 11 is, for example, an OLED (Organic Light Emitting Diode) display, which forms monochrome or color still or moving images on a two-dimensional display surface 11d. The image light ML emitted from the image display panel 11 includes randomly polarized light. The image display panel 11 is driven by circuit components 80 to perform display operations. The image display panel 11 is not limited to an OLED display and can be replaced with display devices using micro-OLEDs, organic EL (Organic Electro-Luminescence), inorganic EL, LEDs, micro-LEDs, LED arrays, laser arrays, quantum dot light-emitting elements, etc.

[0036] The image display panel 11 is not limited to a self-emissive image light generating device; it can also be a device composed of an LCD and other light modulation elements, which forms an image by illuminating the light modulation elements using a light source such as a background. As the image display panel 11, LCOS (Liquid crystal on silicon: LCoS is a registered trademark), digital micromirror devices (specifically, DLP: a registered trademark), laser beam scanning, etc., can also be used instead of the LCD.

[0037] The first polarization control component PC1 has a linear polarizer 14 and a quarter-wavelength plate 15 sequentially from the image display panel 11 side. When the image display panel 11 is an OLED, the first polarization control component PC1 may also be a circular polarizer 16 formed by bonding the linear polarizer 14 and the quarter-wavelength plate 15 together.

[0038] The linear polarizer 14 is, for example, an absorption-type polarizer. In this embodiment, only the second linearly polarized light (vertically polarized light) in the Y direction, which is the vertical direction, is selectively allowed to pass through. That is, only the linearly polarized light in the Y direction of the image light ML emitted from the image display panel 11 passes through the linear polarizer 14 and is incident on the quarter-wave plate 15. The linear polarizer 14 is sheet-shaped and is manufactured by stretching a film impregnated with dichroic pigments such as iodine in a polyol (PVA) along a certain direction.

[0039] The main axis or fast axis of the quarter-wave plate 15 is set between the vertical and horizontal directions, that is, between the Y and X directions, to convert the second linearly polarized light (vertically polarized light) passing through the linear polarizer 14 into, for example, right-hand circularly polarized light C1. The quarter-wave plate 15 is formed of a liquid crystal material such as a photocrosslinked polymer liquid crystal material, but it can also be made by processing a birefringent crystal material such as crystal into a thin plate. As a specific manufacturing method, a linear polarizer 14 is provided on the cover glass 11c of the image display panel 11, and a quarter-wave plate 15 formed of a UV-curable photocrosslinked polymer liquid crystal material is provided on it. By coating the photocrosslinked polymer liquid crystal material on the cover glass 11c by spin coating, inkjet printing or the like while controlling the film thickness, and then irradiating it with polarized ultraviolet light or ultraviolet light, and then baking it, it functions as the quarter-wave plate 15.

[0040] Optical component 20, starting from the image display panel 11 side, includes a reflective optical element 22, a lens component 21, and a second polarization control component PC2 in sequence. Within optical component 20, the second polarization control component PC2, starting from the image display panel 11 side, includes a wavelength plate element 24 and a reflective polarizing optical element 25 in sequence. Specifically, the wavelength plate element 24 is disposed between the second optical surface 21b of the lens component 21 and the polarizing optical element 25.

[0041] In this embodiment, the lens component 21 constituting the imaging optical component 20 has only one lens element, resulting in a very simple optical configuration. Furthermore, since it can be constructed from a single lens, the number of components is simply small, eliminating the need for lens bonding processes and thus reducing costs. Consequently, the overall weight of the optical system can be made very lightweight.

[0042] The lens component 21 is a convex or concave lens or a meniscus lens with positive optical power, having a first optical surface 21a on the incident side and a second optical surface 21b on the exit side. The first optical surface 21a and the second optical surface 21b are curved surfaces, specifically spherical or aspherical surfaces.

[0043] The first optical surface 21a is convex, and the second optical surface 21b is concave. When the first optical surface 21a is convex, the reflective optical element 22 can have positive optical power, and by reducing the distance between the display 10 and the optical component 20, the first virtual image display device 100A can be easily miniaturized. When the second optical surface 21b is concave, the angle of the image light ML emitted from the image display panel 11 can be tilted inwards, that is, the optical axis AX can be tilted, which reduces the overall refraction of the principal ray on the second optical surface 21b of the lens component 21, and easily reduces the aberrations of the optical component 20.

[0044] The lens component 21 has an annular first end face 21d extending from the edge of the second optical surface 21b in a radial direction perpendicular to the optical axis AX and parallel or substantially parallel to the Y direction at the outer edge of the optical component 20. Additionally, the lens component 21 has a cylindrical second end face 21e extending from the edge of the first optical surface 21a parallel or substantially parallel to the Z direction at the outer edge of the optical component 20. The first end face 21d and the second end face 21e are orthogonal to each other. The first and second end faces 21d and 21e function, for example, as positioning portions PS or positioning surfaces for positioning relative to a housing (not shown). The second polarization control component PC2, that is, the wavelength plate element 24 and the polarizing optical element 25, are not provided on the first end face 21d, and their surfaces are exposed. The reflective optical element 22 is not provided on the first end face 21e, and its surface is exposed. Therefore, for example, it is possible to prevent the reflection of unwanted image light ML.

[0045] The lens component 21 may be formed of resin, but it can also be made of glass. From the perspective of miniaturization, it is advantageous to make the lens component 21 of glass.

[0046] The reflective optical element 22 is disposed opposite to the first optical surface 21a. That is, the first optical surface 21a and the reflective optical element 22 have the same shape, but the first optical surface 21a functions as a convex refractive surface, while the reflective optical element 22 functions as a concave reflective surface. On the other hand, the polarizing optical element 25 is disposed opposite to the second optical surface 21b, and more specifically, it is formed on the second optical surface 21b through a thin-film wavelength plate element 24. That is, the second optical surface 21b and the polarizing optical element 25 have the same shape, but the second optical surface 21b functions as a concave refractive surface, while the polarizing optical element 25 functions as a convex reflective surface.

[0047] The reflective optical element 22 is a transmissive semi-reflective mirror HM that partially transmits and partially reflects the image light ML. The reflective optical element 22 covers the pupil position PP where the eye EY or pupil is located, and has a concave shape facing the pupil position PP and a convex shape facing outwards. From the perspective of ensuring the brightness of the image light ML, the reflectivity of the reflective optical element 22 for the image light ML is, for example, about 50%, but it is not limited to this. The reflective optical element 22 is a single-layer or multi-layer film of a metal such as Al or Ag with adjusted film thickness. The reflective optical element 22 can be formed, for example, by using vapor deposition to stack layers, but it can also be formed by attaching a sheet-like reflective film.

[0048] The main axis or fast axis of the wavelength plate element 24 is set between the vertical and horizontal directions, that is, between the Y and X directions, equivalent to a 1 / 4 wavelength plate. The wavelength plate element 24 has a 1 / 4 wavelength phase state across its entire surface. In other words, the wavelength plate element 24 converts circularly polarized light, such as right-handed circularly polarized light C1, passing through the lens member 21 into first linearly polarized light (horizontally polarized light) L1, corresponding to the first polarization direction of the X direction (horizontal direction). Furthermore, the wavelength plate element 24 converts the first linearly polarized light L1 reflected by the polarizing optical element 25 into left-handed circularly polarized light C2. Additionally, the wavelength plate element 24 converts the left-handed circularly polarized light C2, which passes twice through the wavelength plate element 24 and is reflected again by the reflecting optical element 22 via the lens member 21, into second linearly polarized light (vertically polarized light) L2, corresponding to the second polarization direction of the Y direction (vertical direction). The wavelength plate element 24 is formed, for example, of a liquid crystal material such as a photocrosslinkable polymer liquid crystal material. The wavelength plate element 24 is a thin-film wavelength plate formed on the second optical surface 21b, specifically formed of a UV-curable photocrosslinkable polymer liquid crystal material.

[0049] The fabrication of the wavelength plate element 24 is explained. Figure 3 This is a diagram illustrating the exposure device 50. Figure 4 This is a diagram illustrating spherical wave exposure. For example... Figure 3As shown, the photocrosslinked polymeric liquid crystal material CS forming the wavelength plate element 24 is exposed using an exposure apparatus 50. The orientation of the wavelength plate element 24 is formed by the exposure light 9c of the exposure apparatus 50. The photocrosslinked polymeric liquid crystal material CS is coated on the second optical surface 21b of the lens component 21 to form a photocrosslinked polymeric liquid crystal material layer, i.e., a thin film. The thin film of the photocrosslinked polymeric liquid crystal material CS is irradiated with polarized UV 9b, which is a linearly polarized ultraviolet light with controlled polarization direction. In this embodiment, the lens component 21 coated with the photocrosslinked polymeric liquid crystal material CS is subjected to spherical wave exposure. As a result, the orientation state of the rod-shaped molecular species (i.e., molecules with a refractive index difference in their major and minor axes) exhibiting liquid crystal properties can be controlled while the thin film of the photocrosslinked polymeric liquid crystal material CS is cured. At this time, among the molecular species that exhibit liquid crystal properties due to ultraviolet light, the molecular species extending in the direction consistent with the polarization direction of the ultraviolet light are crosslinked, and the orientation state is fixed in the same direction as the polarization direction.

[0050] like Figure 3 As shown, the exposure apparatus 50 includes a UV laser source 51, a diffusion lens 52, a collimating lens 53, a linear polarizer 54, and a spherical wave forming lens 55. The spherical wave forming lens 55, which adjusts the exposure light 9c into a desired spherical wave, is disposed on the emission side of the linear polarizer 54. The lens component 21 is disposed with its second optical surface 21b coated with a photocrosslinkable polymer liquid crystal material CS located on the exposure side. The diffusion lens 52 diffuses the ultraviolet light 9a emitted from the UV laser source 51. The collimating lens 53 collimates the ultraviolet light 9a diffused by the diffusion lens 52. The linear polarizer 54 converts the ultraviolet light 9a collimated by the collimating lens 53 into polarized UV9b, which is the desired linearly polarized light. The spherical wave forming lens 55 adjusts the polarized UV9b emitted from the linear polarizer 54 into a spherical wave shape as the exposure light 9c. Exposure light 9c emitted from the spherical waveforming lens 55 irradiates the photocrosslinked polymer liquid crystal material CS coated on the second optical surface 21b.

[0051] In the above-described spherical wave exposure, a roughly spherical wave of d ± 5° or less is exposed to the gradient normal angle d of the second optical surface 21b of the lens component 21 on which the wavelength plate element 24 is provided. Thus, the wavelength plate element 24 has an orientation of d ± 5° or less relative to the gradient normal angle d of the second optical surface 21b. Furthermore, the incident angle of light to the wavelength plate element 24 is at most 10° or less, and the angle difference when light is incident on the wavelength plate element 24 three times, as described later, can also be set to ± 5% or less. In this case, the incident angle of light to the wavelength plate element 24 is considered in terms of the incident angle relative to the optical axis AX. Additionally, the gradient normal angle d is the angle between the axis parallel to the optical axis AX and the normal of the second optical surface 21b. When considering the intersection point with the second optical surface 21b based on the optical axis AX, the aforementioned approximate spherical wave angle difference of ±5° can be calculated from (i) the difference in the normal direction (gradient normal angle d) at the intersection point of the optical axis AX and the second optical surface 21b, and (ii) the difference in the direction vector at the intersection point of the optical axis AX and the second optical surface 21b. It should be noted that, considering only the angle difference, the angle difference can also be calculated from the spherical wave vector at the intersection point of the ray and the second optical surface 21b, and the normal vector of the second optical surface 21b. The gradient normal angle d of the peripheral portion of the lens component 21 relative to the surface is larger than the gradient normal angle d of the center of the lens component 21 relative to the surface. Figure 4 As shown, when the incident angle of the light incident on the wavelength plate element 24 follows the surface gradient of the first radius of curvature R1 of the second optical surface 21b, and is exposed to a spherical wave with the same radius of curvature as the first radius of curvature R1, the liquid crystal molecules are arranged in a manner that follows the gradient direction of the second optical surface 21b.

[0052] After exposure to light 9c, the thin film of the photocrosslinkable polymeric liquid crystal material CS is annealed. This liquid crystallizes the liquid crystallizing molecules whose orientation does not change due to ultraviolet light, aligning their orientation with that of the polymer portion already in the target orientation state, and then fixing the orientation state through subsequent cooling. In other words, a wavelength plate, or wavelength plate element 24, formed from the thin film is obtained, which aligns almost all orientation directions of the liquid crystallizing molecules constituting the photocrosslinkable polymeric liquid crystal material CS.

[0053] The polarizing optical element 25 is a wire-grid polarizer that selectively reflects first linearly polarized light L1 with a first polarization direction corresponding to the horizontal X direction, while selectively transmitting second vertically polarized light L2 with a second polarization direction corresponding to the vertical or vertical Y direction. By making the polarizing optical element 25 a wire-grid polarizer, it is possible to attach the polarizing optical element 25 to the second optical surface 21b via the wavelength plate element 24, and it is relatively easy to form the polarizing optical element 25 on the second optical surface 21b even if the second optical surface 21b is curved. The polarizing optical element 25 is a reflective polarizer with the following structure: for example, multiple metal wires made of materials such as aluminum or nickel are arranged in parallel on a flexible transparent resin substrate, and a wire-grid layer composed of the multiple metal wires is covered with a transparent protective layer. The polarizing optical element 25 reflects linearly polarized light that has an electric field component (corresponding to the polarization direction) that is parallel to the direction in which the multiple metal wires extend and perpendicular to the periodic direction corresponding to the arrangement direction. The main body of the polarizing optical element 25 is manufactured by transferring an uneven shape onto the surface of a resin film formed of UV resin or thermoplastic resin using a mold with an uneven structure, and then depositing aluminum onto the top and sides of the protrusions of the uneven shape from an oblique direction using a vacuum evaporation method. Alternatively, the main body of the polarizing optical element 25 can be manufactured by applying a polymer solution onto a mold with an uneven structure using a spin coating method and then curing the polymer solution formed on the surface of the mold (see, for example, Japanese Patent Application Publication No. 2011-221334). For example, the polarizing optical element 25 thus obtained can be adhered to the wavelength plate element 24 using an adhesive, thereby fixing it relative to the lens component 21.

[0054] The polarizing optical element 25 may not be a wire grid polarizer. For example, it may be a polarizer of the type that is formed by rolling multiple anisotropic film layers, a multilayer film, or a dielectric multilayer film formed by vacuum evaporation.

[0055] Figure 5 This is a schematic diagram illustrating the optical operation of the first virtual image display device 100A. For example... Figure 5As shown, the image light ML emitted from the display 10 becomes right-circularly polarized light C1 after passing through the first polarization control component PC1. Part of the right-circularly polarized light ML incident on the optical component 20 from the display 10 is transmitted through the reflection optical element 22, but its intensity is attenuated to about half during transmission. The image light ML that is transmitted through the reflection optical element 22 passes through the lens component 21 and then through the wavelength plate element 24. At this time, the image light ML is refracted by the lens component 21 and subjected to the relative convergence effect of positive optical power. Furthermore, the image light ML is converted from right-circularly polarized light C1 to first linearly polarized light L1 with a first polarization direction by passing through the wavelength plate element 24 in the forward direction, and then incident on the polarizing optical element 25. The image light ML incident on the polarizing optical element 25 is efficiently reflected by the polarizing optical element 25 in the state of first linearly polarized light L1, and then passes through the wavelength plate element 24 in the reverse direction when passing through the lens component 21. The image light ML that passes through the wavelength plate element 24 in the reverse direction is converted into left-circularly polarized light C2. The image light ML emitted from the lens component 21 via the wavelength plate element 24 is reflected by the reflecting optical element 22 and subjected to relative convergence of positive optical power, but its intensity is attenuated to about half during reflection. The image light ML, which is left circularly polarized light C2 reflected by the reflecting optical element 22, passes through the wavelength plate element 24 in the forward direction via the lens component 21, is converted into second linearly polarized light L2 with a second polarization direction, and is incident on the polarizing optical element 25. In the above, the image light ML passes back and forth in the lens component 21 by reflection from the reflecting optical element 22, passing through the lens component 21 twice, resulting in passing through the lens component 21 three times. The image light ML incident on the polarizing optical element 25 via the lens component 21 is efficiently transmitted to the polarizing optical element 25 in the state of second linearly polarized light L2 with a second polarization direction. The image light ML emitted outside the optical component 20 is collimated by the converging effect of the optical component 20 and incident on the pupil position PP (refer to) of the wearer's eye EY. Figure 2 In other words, the wearer US wearing the first virtual image display device 100A can observe a virtual image based on image light ML.

[0056] Figure 6 This diagram illustrates the setting conditions of the first virtual image display device 100A. (See diagram for example.) Figure 6 As shown, as Figure 1The HMD200 shown has an exit pupil distance D1 of 8mm or more to suit the shape of the wearer's face (US), and an F-number of 1.0 to 2.0 for the optical component 20. The exit pupil distance D1 is the axial distance from the first end face 21d to the pupil position PP, where the first end face 21d is the end of the second optical surface 21b of the lens component 21 closest to the pupil position PP on the axis. In this case, the first radius of curvature R1 of the reflecting surface of the polarizing optical element 25 opposite to the second optical surface 21b of the lens component 21, and the second radius of curvature R2 of the reflecting surface of the reflecting optical element 22 opposite to the first optical surface 21a of the lens component 21, are set as follows.

[0057] 0.8 ≤ R² / R₁ ≤ 1.2

[0058] Here, we consider a first radius of curvature R1 where the second optical surface 21b of the lens component 21 and the reflecting surface of the polarizing optical element 25 have the same or approximately the same shape. We also consider a second radius of curvature R2 where the first optical surface 21a of the lens component 21 and the reflecting surface of the reflecting optical element 22 have the same or approximately the same shape. Furthermore, if the first and second optical surfaces 21a and 21b of the lens component 21 are aspherical, we consider the first and second radii of curvature R1 and R2 as approximate radii of curvature.

[0059] It should be noted that the preferred ratio of radii of curvature (R2 / R1) satisfies the following conditions.

[0060] 1.0 ≤ R2 / R1 ≤ 1.2

[0061] As described above, in the first display optical system 103a, the image light ML emitted from the display 10 is incident three times on the wavelength plate element 24 disposed on the second optical surface 21b of the lens component 21. By being incident three times on the wavelength plate element 24, the image light ML can be converted into linearly polarized light of a predetermined direction, for example, converting horizontally polarized light into vertically polarized light, while simultaneously reflecting the light back. At this time, if the light is traced from the pupil position PP side, taking into account the light transmission and reflection angles at each field of view, it is possible to calculate as follows. Figure 6 The coordinates (z, r) of points P1~P6 and the angle of the incident light rays toward the wavelength plate element 24 are shown.

[0062] The following formula represents the field angle ray emitted from point P1.

[0063]

[0064] For the coordinates of point P2, the surface form of the second optical surface 21b is shown below (1).

[0065]

[0066] For simplification, the lens surface of the second optical surface 21b is set as a spherical surface to consider the ray angle relative to the normal direction of the lens surface. The gradient of the lens surface at point (z, r) is represented as follows by differentiating the surface equation (1) in the direction of radius r.

[0067]

[0068] Furthermore, the normal to the surface at point (z, r) is given by -1 / z'. If the refraction and reflection within the lens component 21 are calculated according to this formula, the light rays at each field of view can be plotted as curves, even without illustrations.

[0069] When considering the influence of the incident angle of light onto the wavelength plate element 24 (viewing angle characteristics), the polarized UV exposure direction (optical axis of the retardation plate) during the fabrication of the phase difference function of the wavelength plate element 24 becomes important. For example... Figure 7 As shown, as a comparative example, when plane wave exposure is performed in the optical axis AX direction of lens component 21, the liquid crystal molecules are aligned along the plane wave direction. It should be noted that... Figure 3 In the exposure apparatus 50 shown, plane wave exposure is performed to expose the object after the spherical wave forming lens 55 has been removed.

[0070] Figure 8 It is used as a comparative example. Figure 6 The graph shown illustrates the angle of incidence (relative to the optical axis AX) of the light rays passing through the wavelength plate element 24 exposed by the plane wave in the optical path from point P2 to point P4. Figure 8 The results show the calculation of the normal of the light incident angle (light passing angle) to the wavelength plate element 24 relative to the second optical surface 21b (the surface with the first radius of curvature R1) for the full field of view of the first display optical system 103a.

[0071] like Figure 8 As shown, for light rays at the edge of the field of view, the angle of incidence exceeds 50°. However, to obtain good image characteristics, the field of view characteristics of the wavelength plate element 24 need to support angles exceeding 50°. However, considering... Figure 9 The typical field of view characteristics of the wavelength plate element 24 shown are quite severe at 50°, with the wavelength plate element 24 deviating significantly from the target wavelength phase difference of 0.25.

[0072] Therefore, when exposing a spherical wave with the same radius of curvature as the first radius of curvature R1 so that the incident angle of the light incident on the wavelength plate element 24 follows the surface gradient of the first radius of curvature R1 corresponding to the second optical surface 21b, such as Figure 4As shown, the liquid crystal molecules are arranged in a manner that follows the gradient direction of the second optical surface 21b. The incident angle of light passing through the wavelength plate element 24 only needs to be considered as the angle relative to the normal direction of the surface with the first radius of curvature R1 corresponding to the second optical surface 21b. Figure 10 This is a graph showing the angle of incidence of light from the wavelength plate element 24 exposed to the spherical wave of this embodiment relative to the normal of the second optical surface 21b (the surface with the first radius of curvature R1) over the entire field of view. Figure 10 As shown, if with Figure 8 Compared to the comparative example shown, the angle of incidence of the light is less than 1 / 5, and such a field of view characteristic is considered realistic. Furthermore, the amount of phase difference between the wavelength plate element 24 and the target is also small.

[0073] On the other hand, such as Figure 2 As shown, the angle of incidence of light from the wavelength plate element 24 is determined by the focusing state of light within the first display optical system 103a, that is, the distribution of optical power from the pupil position PP to the optical surface of the image display panel 11. In particular, the ratio of the radii of curvature of the two reflective surfaces, specifically the ratio of the first radius of curvature R1 of the polarizing optical element 25 to the second radius of curvature R2 of the reflecting optical element 22, becomes important. Since the first radius of curvature R1 and the second radius of curvature R2 are determined by the F-number of the lens component 21, the ratio of the F-number and the radius of curvature (R2 / R1), as well as the F-number and the angle of incidence of light towards the wavelength plate element 24 (global and surface normal references) were studied.

[0074] Figure 11 This is a graph showing the relationship between the F-number and the ratio of the radius of curvature (R2 / R1). For example... Figure 11 As shown, if the F-number is less than 1.0, the desired optical properties cannot be obtained, and the design becomes difficult. Therefore, if verification is performed in the region with an F-number of 1.0 or higher, the ratio of radii of curvature (R2 / R1) satisfies the following condition.

[0075] 0.8 ≤ R² / R₁ ≤ 1.2

[0076] It should be noted that, when the F number is 1.0 or higher, the preferred ratio of curvature radii (R2 / R1) satisfies the following conditions.

[0077] 1.0 ≤ R2 / R1 ≤ 1.2

[0078] In addition, in the cases of plane wave exposure and spherical wave exposure, the number of incident rays on the opposing wavelength plate element 24 and the incident angle of the light at the end of the field of view are compared. Figure 12 Region BR1 is a graph showing the incident angle of light from the wavelength plate element 24 exposed to spherical waves in the light at the end of the field of view, as an example. Figure 12Region BR2 is a graph showing the incident angle of light from the plate element 24 at the wavelength of the plane wave exposed at the end of the field of view, as a comparative example. Figure 12 In this context, QWP represents wavelength plate element 24. For example... Figure 12 As shown in region BR1, when spherical wave exposure is performed with the surface normal as the reference, the incident angle is approximately 10° or less, except for cases with F-numbers of 0.9 and 1.0. On the other hand, as... Figure 12 As shown in region BR2, when plane wave exposure is performed with the optical axis AX as a reference, the incident angle to the wavelength plate element 24 is approximately 50° or more.

[0079] Next, simulations were used to compare the image characteristics displayed under plane wave and spherical wave exposures (specifically, brightness unevenness, color unevenness, and ghosting). In the simulations, the pupil position PP was calculated relative to the input information (refer to...). Figure 2 The output information is as follows: Specifically, between the input information and the output information about the image, the circular polarizer 16 (linear polarizer 14 and quarter-wavelength plate 15), the reflective optical element 22, the wavelength plate element 24, the polarizing optical element 25, the reflective optical element 22, the wavelength plate element 24, and the polarizing optical element 25 are processed sequentially. Specifically, for spectral intensity and polarization state, polarization calculations using the Stokes vector of the Mueller matrix are performed. It should be noted that the input information is the spectral intensity of the image light ML for the field of view. In addition, in the processing of each element 16, 22, 24, and 25, information such as the incident angle and polarization state is appropriately input.

[0080] Figure 13 It is a graph showing the results of comparing brightness unevenness, color unevenness, and ghosting (image light ratio) at each field of view (one side) position at each F number under plane wave exposure and spherical wave exposure. Figure 13 Region CR1 is a graph showing the brightness ratio at the field of view position of the embodiment. Figure 13 Region CR2 is a graph showing the brightness ratio at the field of view of the comparative example. Figure 13 Region CR3 is a graph illustrating the chromaticity variation at the field of view position of the embodiment. Figure 13 Region CR4 is a graph showing the chromaticity variation at the field of view of the comparative example. Figure 13 Region CR5 is a graph showing the ghosting ratio at the field of view position of the embodiment. Figure 13 Region CR6 is a graph showing the ghosting ratio at the field of view of the comparative example. The ghosting ratio is the ratio of the brightness of the ghost to the brightness of the image area or image light.

[0081] like Figure 13 As shown in regions CR1 and CR2, compared to plane wave exposure, spherical wave exposure improves brightness uniformity by 10% within the image. Figure 13 As shown in regions CR3 and CR4, although the influence of the viewing angle characteristics of the original wavelength plate element 24 is small, an improvement effect can still be seen for color unevenness. For chromaticity variation, if it exceeds 0.01, it reaches a level that can be visually confirmed as color unevenness. Figure 13 As shown in regions CR5 and CR6, for ghosting, under plane wave exposure, 60% of the image light ML is ghosting, while under spherical wave exposure, it can be reduced to about 1% to 2%, and a significant improvement can be expected.

[0082] (Example 1)

[0083] Hereinafter, Embodiment 1 of this embodiment will be described. The parameters of the first display optical system 103a of Embodiment 1 are shown below. The reference numerals are... Figure 2 and Figure 6 The corresponding reference numerals in the attached figures are shown.

[0084] FOV: 100°

[0085] Lens thickness D3: 7.3mm

[0086] The distance D2 from the pupil position PP to the center of the second optical surface 21b is 14.2 mm.

[0087] The first radius of curvature R1 of the second optical surface 21b is -21.40 mm.

[0088] The second radius of curvature R2 of the first optical surface 21a is -23.60 mm.

[0089] The ratio of radii of curvature (R2 / R1) = 1.103

[0090] (Example 2)

[0091] Hereinafter, Example 2 of this embodiment will be described. The parameters of the first display optical system 103a in Example 2 are shown below.

[0092] FOV: 100°

[0093] Lens thickness D3: 7.3mm

[0094] The distance D2 from the pupil position PP to the center of the second optical surface 21b is 13.3 mm.

[0095] The first radius of curvature R1 of the second optical surface 21b is 21.70 mm.

[0096] The second radius of curvature R2 of the first optical surface 21a is 21.64 mm.

[0097] The ratio of radii of curvature (R2 / R1) = 0.997

[0098] In embodiments 1 and 2, the configuration direction of the wavelength plate element 24, that is, the exposure direction of the polarized UV, is formed by spherical wave exposure along the normal direction of the curved surface of the second optical surface 21b. At this time, the incident angle of the light passing through the wavelength plate element 24 is as follows: Figure 10 As shown. Figure 10 As shown, for an incident angle of up to 8° across the entire field of view, the wavelength plate element 24 only needs to have a viewing angle characteristic of 8°. Therefore, the delay difference of the wavelength plate element 24 caused by the field of view is reduced, and phase changes occur approximately accurately across the entire wavelength range of the image light ML emitted from the image display panel 11. This suppresses brightness inconsistencies, color inconsistencies, and ghosting in the displayed image.

[0099] Furthermore, for the area through which light passes at the end of the field of view, if a spherical wave is used for exposure with an angle of less than ±5° relative to the normal angle of the surface gradient along the second optical surface 21b, the required field of view characteristics of the wavelength plate element 24 can be within the range of ±5°, thus improving image quality.

[0100] Figure 14 This diagram illustrates the verification of the field of view characteristics of the wavelength plate element 24. (See figure below.) Figure 14 As shown, the observation device 60 includes a camera 61, a first polarizing plate 62, a second polarizing plate 63, and a light source 64. The polarization direction of the first polarizing plate 62 is orthogonal to the polarization direction of the second polarizing plate 63. By clamping a lens member 21, on which a wavelength plate element 24, which is the object of observation, is disposed, between the first polarizing plate 62 and the second polarizing plate 63, and by moving the camera 61, the orthogonal Nicol pattern of the wavelength plate element 24 illuminated by the light source 64 is observed. This allows for the quantitative measurement of the phase difference of the wavelength plate element 24 on the second optical surface 21b. The pattern (phase difference) of the orthogonal Nicol pattern varies depending on the viewing angle. In the case of a sample exposed to spherical waves, if viewed from the front, the color appears to change between the center and the edge of the optical surface. Furthermore, in the case of a sample exposed to spherical waves, if viewed from an oblique angle, the edge of the optical surface appears to be the same color as the center of the optical surface in the case of frontal viewing, depending on the viewing angle. Based on the above, it can be seen that the phase difference between the center of the optical surface viewed from the front and the end of the optical surface viewed from the oblique direction is the same. On the other hand, in the case of a sample exposed to plane waves, if viewed from the front, the entire surface of the second optical surface 21b appears to be the same color.

[0101] Alternatively, the phase difference can also be measured using a phase difference measurement method. In this method, the input polarization state is varied among four polarization states (specifically, horizontally polarized light, vertically polarized light, right-circularly polarized light, and left-circularly polarized light), and each polarized light is incident on a lens component 21 equipped with a wavelength plate element 24. By measuring the intensity of light received in each polarization state, the phase change of the wavelength plate element 24 can be determined.

[0102] The virtual image display devices 100A and 100B and optical unit 100 of the first embodiment described above include: a display 10 that emits circularly polarized image light ML; and an optical component 20 that forms a virtual image by reflecting the image light ML back and forth twice. The optical component 20 includes: a lens component 21 having one or more lenses; a transmissive reflective optical element 22 disposed opposite to a first optical surface 21a of the lens component 21 near the display 10; and a reflective polarizing optical element 25 disposed opposite to a second optical surface 21b of the lens component 21 away from the display 10. The optical elements are arranged opposite each other and reflect image light ML, which is linearly polarized light in the first polarization direction; and a wavelength plate element 24, which is disposed between the reflective optical element 22 and the polarizing optical element 25, is formed of photocrosslinkable polymer liquid crystal material CS, which converts the image light ML passing through the reflective optical element 22 into linearly polarized light in the first polarization direction, and converts the image light ML reflected back and forth by the reflective optical element 22 into linearly polarized light in the second polarization direction. The wavelength plate element 24 has an orientation of less than d ± 5° with respect to the gradient normal angle d of the optical surface on which the wavelength plate element 24 is disposed.

[0103] In the aforementioned virtual image display device, by having the wavelength plate element 24 oriented along the gradient of the optical surface of the lens member 21, specifically the second optical surface 21b, the lens member 21 can substantially function as a wavelength plate along the shape of the optical surface. This suppresses the degradation of the displayed image quality (specifically, uneven brightness, uneven color, and ghosting).

[0104] It should be noted that the first polarization direction and the second polarization direction are used for convenience and can replace the specific definition of the direction. That is to say, in Figure 2 In the example shown, the polarizing optical element 25 reflects the first polarized light L1 as the first polarization direction in the X direction, but the polarizing optical element 25 can also reflect the first polarized light L1 as the first polarization direction in the Y direction.

[0105] [Second Implementation]

[0106] Hereinafter, the virtual image display device of the second embodiment will be described. It should be noted that the virtual image display device of the second embodiment is a device obtained by modifying part of the virtual image display device of the first embodiment, and the parts common to the virtual image display device of the first embodiment will be omitted from the description.

[0107] Figure 15 This is a side cross-sectional view illustrating the optical structure of the display optical systems 103a and 103b of the virtual image display devices 100A and 100B according to the second embodiment. (As shown...) Figure 15 As shown, in the first display optical system 103a, the lens component 21 of the optical component 20 is a meniscus lens with positive optical power as a whole, but has two or more lenses 121 and 221. That is, the lens component 21 has a first lens 121 and a second lens 221 sequentially from the display 10 side. The first lens 121 and the second lens 221 are lenses bonded together via the wavelength plate element 24.

[0108] The third optical surface 21f on the emission side of the first lens 121 is concave, and the fourth optical surface 21g on the incident side of the second lens 221 is convex. The radius of curvature of the fourth optical surface 21g is the same as or approximately the same as the radius of curvature of the third optical surface 21f. In this case, the wavelength plate element 24 has the shape of the third optical surface 21f and the fourth optical surface 21g following the curved surfaces. That is, the wavelength plate element 24 is disposed between the first optical surface 21a and the second optical surface 21b and is embedded inside the lens component 21.

[0109] The first radius of curvature R1 of the second optical surface 21b on the emission side of the lens component 21 and the second radius of curvature R2 of the first optical surface 21a on the incident side of the lens component 21 are set as follows.

[0110] 0.8 ≤ R² / R₁ ≤ 1.2

[0111] In addition, the preferred ratio of radii of curvature (R2 / R1) satisfies the following formula.

[0112] 1.0 ≤ R2 / R1 ≤ 1.2

[0113] A wavelength plate element 24 is formed by coating a photocrosslinkable polymeric liquid crystal material CS onto either the fourth optical surface 21g of the second lens 221 or the third optical surface 21f of the first lens 121, and then performing spherical wave exposure. In this case, Figure 4 In the spherical wave exposure shown, a roughly spherical wave is exposed relative to the optical surface of the lens component 21 coated with photocrosslinkable polymer liquid crystal material CS (in Figure 15In the example, the gradient normal angle d of the fourth optical surface 21g of the second lens 221 is d ± 5° or less. Either the first or second lens 121, 221 serves as a substrate, while the other functions as a cover glass. If the area around the lens component 21 is sealed with an adhesive or the like, the intrusion of moisture and the like can be prevented, and the deterioration of the wavelength plate element 24 can be suppressed.

[0114] If the refractive index is made different between the first lens 121 and the second lens 221, a lens effect can be produced between the glass materials, which can achieve further high resolution, and even miniaturization, thinning and weight reduction of the entire optical system.

[0115] It should be noted that when the lens component 21 is composed of two or more lenses, such as Figure 16 As shown, the wavelength plate element 24 can also be disposed between the second optical surface 21b and the polarizing optical element 25. Alternatively, a gap can be provided between the first lens 121 and the second lens 221. In this case, the wavelength plate element 24 is disposed, for example, on the second lens 221 on which the polarizing optical element 25 is disposed. Specifically, the wavelength plate element 24 is disposed on the fourth optical surface 21g on the incident side or the second optical surface 21b on the emission side of the second lens 221.

[0116] [Variations and others]

[0117] The present invention has been described above according to the embodiments, but the present invention is not limited to the above embodiments and can be implemented in various aspects without departing from its spirit, for example, the following modifications can also be made.

[0118] Figure 17 This diagram illustrates the fabrication of the wavelength plate element 24 in a modified example of the first embodiment. Figure 17 As shown, in the fabrication of the wavelength plate element 24, the refractive effect of the first optical surface 21a of the lens component 21 can be utilized to expose the photocrosslinked polymer liquid crystal material CS coated on the second optical surface 21b from the side of the first optical surface 21a, that is, the curved surface side of the second radius of curvature R2. In this case, the first and second radii of curvature R1 and R2 of the lens component 21 are adjusted such that the angle difference between the incident angle of the exposure light 9c and the gradient normal angle d is ±5° or less. The first and second radii of curvature R1 and R2 are set, for example, to satisfy the following formula.

[0119] R2 = 0.6 * R1

[0120] (Example 3)

[0121] Hereinafter, Embodiment 3 of the modified example will be described. The parameters of the first display optical system 103a of Embodiment 3 are shown below.

[0122] FOV: 100°

[0123] Lens thickness D3: 8.8mm

[0124] The distance D2 from the pupil position PP to the center of the second optical surface 21b is 13.3 mm.

[0125] The first radius of curvature R1 of the second optical surface 21b is 48.90 mm.

[0126] The second radius of curvature R2 of the first optical surface 21a is 29.50 mm.

[0127] The ratio of radii of curvature (R2 / R1) = 0.603

[0128] In the above embodiments, the lens component 21 assembled to the optical component 20 is merely an example, and can be configured to include one lens, or two lenses in a joined or separated state. Even when the lens component 21 is composed of two or more lenses, the ratio of the radii of curvature (R2 / R1) is considered with respect to the first radius of curvature R1 of the optical surface facing the reflecting surface of the polarizing optical element 25 and the second radius of curvature R2 of the optical surface facing the reflecting surface of the reflecting optical element 22.

[0129] Although not essential, the optical component 20 is preferably FOV 100° or higher, and the thickness of the rear emission surface 21c from the display 10 to the outer edge or center of the optical component 20 is preferably 20 mm or less.

[0130] The above assumes that the HMD200 is worn on the head for use, but the aforementioned virtual image display devices 100A and 100B can also be used as handheld displays for observation like binoculars without being worn on the head. In other words, in this invention, the head-mounted display also includes a handheld display.

[0131] Figure 2 The polarization states shown are examples. For instance, the image light ML emitted from the display 10 can be converted into left circularly polarized light. In this case, the polarizing optical element 25 needs to selectively reflect only linearly polarized light (vertically polarized light) with a polarization direction corresponding to the Y direction as the vertical direction, while selectively transmitting linearly polarized light (horizontally polarized light) with a polarization direction corresponding to the X direction as the horizontal direction.

[0132] The exposure of the photocrosslinked polymer liquid crystal material CS during the fabrication of the wavelength plate element 24 is not limited to the optical surface side on which the photocrosslinked polymer liquid crystal material CS is coated, but can also be performed from the optical surface side opposite to the optical surface on which the photocrosslinked polymer liquid crystal material CS is coated. In this case, the exposure is also performed such that the gradient normal angle d relative to the optical surface on which the wavelength plate element 24 is provided is d ± 5° or less.

[0133] The first virtual image display device specifically includes: a display that emits circularly polarized image light; and an optical component that forms a virtual image by reflecting the image light twice. The optical component includes: a lens component having one or more lenses; a transmissive reflective optical element disposed facing a first optical surface of the lens component near the display; a reflective polarizing optical element disposed facing a second optical surface of the lens component away from the display, and reflecting image light that is linearly polarized in a first polarization direction; and a wavelength plate element disposed between the reflective optical element and the polarizing optical element, formed of a photocrosslinkable polymer liquid crystal material, which converts the image light passing through the reflective optical element into linearly polarized light in the first polarization direction, and converts the image light reflected back and forth by the reflective optical element into linearly polarized light in the second polarization direction. The wavelength plate element has an orientation of d ± 5° or less with respect to the gradient normal angle d of the optical surface on which the wavelength plate element is disposed.

[0134] In the aforementioned virtual image display device, by having the wavelength plate element oriented with a gradient along the optical surface of the lens component, the lens component can substantially function as a wavelength plate with a shape along the optical surface. This allows for the suppression of image quality degradation of the displayed image (specifically, uneven brightness, uneven color, and ghosting).

[0135] In a specific virtual image display device, the lens component has an F-number of 1 or higher, and when the first curvature of the second optical surface is set to R1 and the second curvature of the first optical surface is set to R2, the following formula is satisfied.

[0136] 0.8 ≤ R² / R₁ ≤ 1.2

[0137] In this configuration, by satisfying the above equation through the first and second optical surfaces of the lens component, the radius of curvature of the reflective optical element (which is the reflective surface facing the first optical surface) and the radius of curvature of the polarizing optical element (which is the reflective surface facing the second optical surface) can be controlled, and the angular difference of light rays incident on the wavelength plate element three times can be reduced. This further improves the displayed image.

[0138] In a specific virtual image display device, a wavelength plate element is disposed between a second optical surface and a polarizing optical element.

[0139] In a specific virtual image display device, the lens component has two or more lenses, and the wavelength plate element is disposed between the first optical surface and the second optical surface.

[0140] In a specific virtual image display device, the first optical surface is convex and the second optical surface is concave. By making the first optical surface convex, the reflective optical element can have positive optical power, and by reducing the distance between the display and the optical components, the virtual image display device can be easily miniaturized. Furthermore, by making the second optical surface concave, the refraction of the principal rays on the second optical surface of the lens component can be reduced overall, making it easier to reduce aberrations of the optical components.

[0141] In specific virtual image display devices, the polarizing optical element can be any of a wire grid polarizer, a multilayer film, or a dielectric multilayer film. In this case, even if the optical surface is curved, it is relatively easy to form the polarizing optical element on the optical surface.

[0142] In a specific virtual image display device, the display has an image display panel and a polarization control component that makes the image light emitted from the image display panel circularly polarized.

[0143] In a specific virtual image display device, the polarization control component has a linear polarizing plate and a wavelength plate sequentially from the image display panel side.

[0144] In a specific virtual image display device, the lens component has a first end face extending from a second optical surface in a radial direction perpendicular to the optical axis, and a second end face orthogonal to the first end face. In this case, the first and second end faces function as positioning parts or positioning surfaces.

[0145] In a specific virtual image display device, the lens component has a first end face extending radially from a second optical surface in a direction perpendicular to the optical axis. The first end face is not provided with wavelength plate elements or polarizing optical elements, and its surface is exposed. In this case, the reflection of unwanted image light can be prevented.

[0146] The specific optical unit includes: a display that emits circularly polarized image light; and an optical component that forms a virtual image by reflecting the image light twice. The optical component includes: a lens component having one or more lenses; a transmissive reflective optical element disposed facing a first optical surface of the lens component near the display; a reflective polarizing optical element disposed facing a second optical surface of the lens component away from the display, and reflecting image light that is linearly polarized in a first polarization direction; and a wavelength plate element disposed between the reflective optical element and the polarizing optical element, formed of a photocrosslinkable polymer liquid crystal material, which converts the image light passing through the reflective optical element into linearly polarized light in a first polarization direction, and converts the image light reflected back and forth by the reflective optical element into linearly polarized light in a second polarization direction. The wavelength plate element has an orientation of d ± 5° or less relative to the gradient normal angle d of the optical surface on which the wavelength plate element is disposed.

Claims

1. A virtual image display device, characterized in that, have: A display that emits circularly polarized image light; and Optical components reflect the image light twice to form a virtual image. The optical component has: A lens component having one or more lenses; A transmissive reflective optical element is disposed facing the first optical surface of the lens component near the display. A reflective polarizing optical element is disposed opposite to a second optical surface of the lens component that is away from the display, and reflects image light that is linearly polarized as a first polarization direction. as well as A wavelength plate element, disposed between the reflective optical element and the polarizing optical element, is formed of a photocrosslinkable polymer liquid crystal material. It converts the image light passing through the reflective optical element into linearly polarized light with a first polarization direction, and converts the image light reflected back and forth by the reflective optical element into linearly polarized light with a second polarization direction. The wavelength plate element has an orientation of less than d ± 5° with respect to the gradient normal angle d of the optical surface on which the wavelength plate element is disposed.

2. The virtual image display device according to claim 1, wherein, The lens component has an F-number of 1 or higher, and when the first radius of curvature of the second optical surface is set to R1 and the second radius of curvature of the first optical surface is set to R2, the following equation is satisfied: 。 3. The virtual image display device according to claim 1, wherein, The wavelength plate element is disposed between the second optical surface and the polarizing optical element.

4. The virtual image display device according to claim 1, wherein, The lens component has two or more lenses. The wavelength plate element is disposed between the first optical surface and the second optical surface.

5. The virtual image display device according to claim 1, wherein, The first optical surface is a convex surface. The second optical surface is concave.

6. The virtual image display device according to claim 1, wherein, The polarizing optical element is any one of a wire grid polarizer, a multilayer film, and a dielectric multilayer film.

7. The virtual image display device according to claim 1, wherein, The display has an image display panel and a polarization control component, the polarization control component causing the image light emitted from the image display panel to be circularly polarized light.

8. The virtual image display device according to claim 7, wherein, The polarization control component has a linear polarizing plate and a wavelength plate sequentially from the image display panel side.

9. The virtual image display device according to claim 1, wherein, The lens component has a first end face extending from the second optical surface in a radial direction perpendicular to the optical axis, and a second end face orthogonal to the first end face.

10. The virtual image display device according to claim 1, wherein, The lens component has a first end face extending from the second optical surface in a radial direction perpendicular to the optical axis. The first end face is not provided with the wavelength plate element and the polarizing optical element, and the surface of the first end face is exposed.

11. An optical unit, characterized in that, have: A display that emits circularly polarized image light; and Optical components reflect the image light twice to form a virtual image. The optical component has: A lens component having one or more lenses; A transmissive reflective optical element is disposed facing the first optical surface of the lens component near the display. A reflective polarizing optical element is disposed opposite to a second optical surface of the lens component that is away from the display, and reflects image light that is linearly polarized as a first polarization direction. as well as A wavelength plate element, disposed between the reflective optical element and the polarizing optical element, is formed of a photocrosslinkable polymer liquid crystal material. It converts the image light passing through the reflective optical element into linearly polarized light with a first polarization direction, and converts the image light reflected back and forth by the reflective optical element into linearly polarized light with a second polarization direction. The wavelength plate element has an orientation of less than d ± 5° with respect to the gradient normal angle d of the optical surface on which the wavelength plate element is disposed.

Images