Optical device

Abstract

The present invention provides an optical device capable of adjusting the position of an enlarged virtual image according to the user's vision. The optical device (100) of the present invention comprises: a display (110) that displays an image; and an optical system (300) that has a first transmissive reflection surface (321) and a second transmissive reflection surface (311) that are arranged on the downstream side and the upstream side of the optical axis (L) of the display (110), respectively, and the image is enlarged by at least the second transmissive reflection surface (311). The optical device uses a moving device (410) to drive the second transmissive reflection surface (311) along the optical axis (L) relative to the first transmissive reflection surface (321), or to change the surface shape or lens magnification of the second transmissive reflection surface (311) having a variable surface shape or a variable lens magnification. In this way, the optical path can be folded back twice between the first transmissive reflection surface (321) and the second transmissive reflection surface (311), and the position of the enlarged virtual image can be adjusted according to the user's vision.

Description

Technical Field

[0001] The present invention relates to an optical device for generating an enlarged virtual image of an image. Background Art

[0002] An optical device is known that adopts immersive virtual reality (VR) technology, uses a thinned triple pass (Japanese original: Triple Pass) optical module that folds the light path twice by two reflective surfaces to enlarge the image displayed on the display panel and project the enlarged virtual image (for example, refer to Patent Document 1).

[0003] Patent Document 1: International Publication No. 2018 / 150773 Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] However, there is currently no optical device that can adjust the position of the magnified virtual image according to the user's vision.

[0006] (II) Technical solution

[0007] (Item 1)

[0008] The optical device may include a display for displaying images.

[0009] The optical device may include an optical system having a first transmissive reflective surface and a second transmissive reflective surface arranged on a downstream side and an upstream side, respectively, on an optical axis of the display, wherein at least the second transmissive reflective surface magnifies the image.

[0010] The optical device may include a moving device that moves at least one of the first transflective surface, the second transflective surface, and the display along the optical axis.

[0011] (Item 2)

[0012] The moving device can move the second transmissive reflective surface along the optical axis relative to the first transmissive reflective surface.

[0013] (Item 3)

[0014] The moving device can move the display and the second transmissive reflective surface while maintaining a relative position relationship.

[0015] (Item 4)

[0016] The second transflective surface may be a curved surface.

[0017] (Item 5)

[0018] The curved surface may be an aspherical surface in which a curved surface angle increases or decreases according to a distance from a center.

[0019] (Item 6)

[0020] The second transflective reflective surface may be a semi-reflective mirror surface provided on the lens element.

[0021] The ratio of the focal length of the optical system relative to the focal length of the lens element may be in the range of 0.166 to 0.317.

[0022] (Item 7)

[0023] The ratio may be in the range of 0.173 to 0.317 relative to diopter +2, in the range of 0.170 to 0.299 relative to diopter -1, and in the range of 0.166 to 0.279 relative to diopter -5.

[0024] (Item 8)

[0025] The optical device may be provided with a display which displays an image.

[0026] The optical device may include an optical system having a first transmissive reflective surface and a second transmissive reflective surface arranged on the downstream and upstream sides, respectively, on the optical axis of the display, wherein the second transmissive reflective surface having a variable surface shape or a variable lens magnification magnifies the image.

[0027] (Item 9)

[0028] The variable surface shape may be formed into an aspherical shape in which the curved surface angle increases or decreases according to the distance from the center.

[0029] (Item 10)

[0030] The variable lens power can be generated in a manner comparable to an aspherical surface in which the curved surface angle increases or decreases according to the distance from the center.

[0031] (Item 11)

[0032] The optical device may further include a diffractive optical element disposed between the display and the second transmissive reflective surface.

[0033] (Item 12)

[0034] The diffractive optical element may further include a GPH element which compensates for the wavelength dispersion of the optical system.

[0035] (Item 13)

[0036] The diffractive optical element may include an unnecessary light eliminating element for eliminating unnecessary light on the downstream side of the GPH element.

[0037] (Item 14)

[0038] The unnecessary light removing element may include a λ / 4 plate and a linear polarizing plate.

[0039] (Item 15)

[0040] The optical device may further include a control device that changes a distortion correction value of an image according to a state of the optical system.

[0041] In addition, the above summary of the invention does not list all the features of the present invention. In addition, sub-combinations of these feature groups can also constitute other inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The structure of the optical device according to this embodiment is schematically shown.

[0043] Figure 2A An example of the surface shape of the half mirror surface (HM) of the lens is shown.

[0044] Figure 2B An example of the cone angle characteristics of a light beam after reflection by a half mirror (HM) of a lens is shown.

[0045] Figure 3A Shows the overall structure of the mobile device.

[0046] Figure 3B An exploded structure of a mobile device is shown.

[0047] Figure 4A The principle of lens movement using a moving device is shown (minimum separation state).

[0048] Figure 4B The principle of lens movement using the moving device is shown (extended state).

[0049] Figure 4C The principle of lens movement using a moving device is shown (maximum separation state).

[0050] Figure 5A The entire structure of a mobile device according to a first modified example is shown.

[0051] Figure 5B An exploded structure of a mobile device according to a first modification is shown.

[0052] Fig. 6A The principle of lens movement using the moving device of the first modification (minimum separation state) is described.

[0053] Figure 6B The principle (extended state) of lens movement using the moving device of the first modified example is described.

[0054] Figure 6CThe principle of lens movement using the moving device of the first modified example (maximum separation state) is described.

[0055] Fig. 7A The entire structure of a mobile device according to a second modified example is shown.

[0056] Figure 7B An exploded structure of a mobile device according to a second modification is shown.

[0057] Fig. 8A The principle of lens movement using the moving device of the second modification (minimum separation state) is shown.

[0058] Figure 8B The principle of lens movement using the moving device of the second modified example (extended state) is described.

[0059] Figure 8C The principle of lens movement using the moving device of the second modification (maximum separation state) is described.

[0060] Fig. 9A The figure shows changes in field curvature when the distance (air distance) between the reflective polarizing plate and the half mirror surface is changed (the air distance is small).

[0061] Fig. 9B The figure shows the field curvature when the distance (air distance) between the reflective polarizing plate and the half mirror surface is changed (the air distance is medium).

[0062] Fig. 9C The figure shows the field curvature when the distance (air distance) between the reflective polarizing plate and the half mirror surface is changed (the air distance is large).

[0063] Fig. 10A The definition of the ray interval in the optical device is shown.

[0064] Fig. 10B Show Fig. 10A The cone angle of the rays in each ray interval shown.

[0065] Fig.11 The change of the field curvature with respect to the air distance at each diopter is shown.

[0066] Fig. 12A Detailed structures of the diffractive optical element, lens, and filter included in the optical devices of Models 1 to 3 are shown.

[0067] Fig. 12B The detailed structures of filters A to C are shown.

[0068] Fig.13A The detailed design of the optical device of Example 1 is shown.

[0069] Fig. 13B The lateral aberration detected at a diopter of +2 in the optical device of Example 1 is shown.

[0070] Fig. 13C The following is a diagram showing lateral aberrations detected at a diopter of -1 in the optical device of Example 1.

[0071] Fig.13D The lateral aberration detected at a diopter of -5 in the optical device of Example 1 is shown.

[0072] Fig.13E The spherical aberration detected at a diopter of +2 in the optical device of Example 1 is shown.

[0073] Fig.13F The spherical aberration detected at a diopter of -1 in the optical device of Example 1 is shown.

[0074] Figure 13G The spherical aberration detected at a diopter of -5 in the optical device of Example 1 is shown.

[0075] Fig.13H The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of +2 in the optical device of Example 1.

[0076] Fig.13I The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -1 in the optical device of Example 1.

[0077] Fig.13J The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -5 in the optical device of Example 1.

[0078] Fig.14A The detailed design of the optical device of Example 2 is shown.

[0079] Fig. 14B The lateral aberration detected at a diopter of +2 in the optical device of Example 2 is shown.

[0080] Fig. 14C The following shows the lateral aberration detected at a diopter of -1 in the optical device of Example 2.

[0081] Fig.14D The following diagram shows the lateral aberration detected at a diopter of -5 in the optical device of Example 2.

[0082] Fig.14E The spherical aberration detected at a diopter of +2 in the optical device of Example 2 is shown.

[0083] Fig.14F The spherical aberration detected at a diopter of -1 in the optical device of Example 2 is shown.

[0084] Figure 14G The spherical aberration detected at a diopter of -5 in the optical device of Example 2 is shown.

[0085] Fig.14H The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of +2 in the optical device of Example 2.

[0086] Fig.14I The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -1 in the optical device of Example 2.

[0087] Fig.14J The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -5 in the optical device of Example 2.

[0088] Fig.15A The detailed design of the optical device of Example 3 is shown.

[0089] Fig. 15B The lateral aberration detected at a diopter of +2 in the optical device of Example 3 is shown.

[0090] Fig. 15C The following is a diagram showing lateral aberration detected at a diopter of -1 in the optical device of Example 3.

[0091] Fig.15D The lateral aberration detected at a diopter of -5 in the optical device of Example 3 is shown.

[0092] Fig.15E The spherical aberration detected at a diopter of +2 in the optical device of Example 3 is shown.

[0093] Fig.15F The spherical aberration detected at a diopter of -1 in the optical device of Example 3 is shown.

[0094] Figure 15G The spherical aberration detected at a diopter of -5 in the optical device of Example 3 is shown.

[0095] Fig.15H The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of +2 in the optical device of Example 3.

[0096] Fig.15I The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -1 in the optical device of Example 3.

[0097] Fig.15J The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -5 in the optical device of Example 3.

[0098] Fig.16AThe detailed design of the optical device of Example 4 is shown.

[0099] Fig. 16B The lateral aberration detected at a diopter of +2 in the optical device of Example 4 is shown.

[0100] Fig. 16C The following is a diagram showing lateral aberration detected at a diopter of -1 in the optical device of Example 4.

[0101] Fig.16D The lateral aberration detected at a diopter of -5 in the optical device of Example 4 is shown.

[0102] Fig.16E The spherical aberration detected at a diopter of +2 in the optical device of Example 4 is shown.

[0103] Fig.16F The spherical aberration detected at a diopter of -1 in the optical device of Example 4 is shown.

[0104] Figure 16G The spherical aberration detected at a diopter of -5 in the optical device of Example 4 is shown.

[0105] Fig.16H The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of +2 in the optical device of Example 4.

[0106] Fig.16I The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -1 in the optical device of Example 4.

[0107] Fig.16J The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -5 in the optical device of Example 4.

[0108] Fig.17A The detailed design of the optical device of Example 5 is shown.

[0109] Fig. 17B The lateral aberration detected at a diopter of +2 in the optical device of Example 5 is shown.

[0110] Fig. 17C The lateral aberration detected at a diopter of -1 in the optical device of Example 5 is shown.

[0111] Fig.17D The lateral aberration detected at a diopter of -5 in the optical device of Example 5 is shown.

[0112] Fig.17E The spherical aberration detected at a diopter of +2 in the optical device of Example 5 is shown.

[0113] Fig.17FThe spherical aberration detected at a diopter of -1 in the optical device of Example 5 is shown.

[0114] Figure 17G The spherical aberration detected at a diopter of -5 in the optical device of Example 5 is shown.

[0115] Fig.17H The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of +2 in the optical device of Example 5.

[0116] Fig.17I The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -1 in the optical device of Example 5.

[0117] Fig.17J The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -5 in the optical device of Example 5.

[0118] Fig.18A The detailed design of the optical device of Example 6 is shown.

[0119] Fig.18B The lateral aberration detected at a diopter of +2 in the optical device of Example 6 is shown.

[0120] Fig.18C The lateral aberration detected at a diopter of -1 in the optical device of Example 6 is shown.

[0121] Fig.18D The lateral aberration detected at a diopter of -5 in the optical device of Example 6 is shown.

[0122] Fig.18E The spherical aberration detected at a diopter of +2 in the optical device of Example 6 is shown.

[0123] Fig.18F The spherical aberration detected at a diopter of -1 in the optical device of Example 6 is shown.

[0124] Figure 18G The spherical aberration detected at a diopter of -5 in the optical device of Example 6 is shown.

[0125] Fig.18H The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of +2 in the optical device of Example 6.

[0126] Fig.18I The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -1 in the optical device of Example 6.

[0127] Fig.18J The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -5 in the optical device of Example 6.

[0128] Fig.19A The detailed design of the optical device of Example 7 is shown.

[0129] Fig.19B The lateral aberration detected at a diopter of +2 in the optical device of Example 7 is shown.

[0130] Fig.19C The lateral aberration detected at a diopter of -1 in the optical device of Example 7 is shown.

[0131] Fig.19D The lateral aberration detected at a diopter of -5 in the optical device of Example 7 is shown.

[0132] Fig.19E The spherical aberration detected at a diopter of +2 in the optical device of Example 7 is shown.

[0133] Fig.19F The spherical aberration detected at a diopter of -1 in the optical device of Example 7 is shown.

[0134] Figure 19G The spherical aberration detected at a diopter of -5 in the optical device of Example 7 is shown.

[0135] Fig.19H The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of +2 in the optical device of Example 7.

[0136] Fig.19I The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -1 in the optical device of Example 7.

[0137] Fig.19J The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -5 in the optical device of Example 7.

[0138] Fig. 20A The detailed design of the optical device of Example 8 is shown.

[0139] Fig. 20B The lateral aberration detected at a diopter of +2 in the optical device of Example 8 is shown.

[0140] Fig. 20C The lateral aberration detected at a diopter of -1 in the optical device of Example 8 is shown.

[0141] Fig.20D The lateral aberration detected at a diopter of -5 in the optical device of Example 8 is shown.

[0142] Fig.20E The spherical aberration detected at a diopter of +2 in the optical device of Example 8 is shown.

[0143] Fig.20F The spherical aberration detected at a diopter of -1 in the optical device of Example 8 is shown.

[0144] Figure 20G The spherical aberration detected at a diopter of -5 in the optical device of Example 8 is shown.

[0145] Fig. 20H The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of +2 in the optical device of Example 8.

[0146] Fig.20I The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -1 in the optical device of Example 8.

[0147] Fig. 20J The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -5 in the optical device of Example 8.

[0148] Fig.21A The detailed design of the optical device of Example 9 is shown.

[0149] Fig. 21B The lateral aberration detected at a diopter of +2 in the optical device of Example 9 is shown.

[0150] Fig. 21C The lateral aberration detected at a diopter of -1 in the optical device of Example 9 is shown.

[0151] Fig.21D The figure shows the lateral aberration detected at a diopter of -5 in the optical device of Example 9.

[0152] Fig.21E The spherical aberration detected at a diopter of +2 in the optical device of Example 9 is shown.

[0153] Fig.21F The spherical aberration detected at a diopter of -1 in the optical device of Example 9 is shown.

[0154] Figure 21G The spherical aberration detected at a diopter of -5 in the optical device of Example 9 is shown.

[0155] Fig.21H The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of +2 in the optical device of Example 9.

[0156] Fig.21I The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -1 in the optical device of Example 9.

[0157] Fig.21JThe figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -5 in the optical device of Example 9.

[0158] Fig.22A The detailed design of the optical device of Example 10 is shown.

[0159] Fig. 22B The lateral aberration detected at a diopter of +2 in the optical device of Example 10 is shown.

[0160] Fig. 22C The lateral aberration detected at a diopter of -1 in the optical device of Example 10 is shown.

[0161] Fig.22D The lateral aberration detected at a diopter of -5 in the optical device of Example 10 is shown.

[0162] Fig.22E The spherical aberration detected at a diopter of +2 in the optical device of Example 10 is shown.

[0163] Fig.22F The spherical aberration detected at a diopter of -1 in the optical device of Example 10 is shown.

[0164] Figure 22G The spherical aberration detected at a diopter of -5 in the optical device of Example 10 is shown.

[0165] Fig.22H The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of +2 in the optical device of Example 10.

[0166] Fig.22I The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -1 in the optical device of Example 10.

[0167] Fig.22J The figure shows the field curvature (left figure) and image distortion (right figure) detected at a diopter of -5 in the optical device of Example 10.

[0168] Fig.23 The structure of an optical device according to a modified example is schematically shown. DETAILED DESCRIPTION

[0169] The present invention will be described below by way of the embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all combinations of features described in the embodiments are essential to the solution of the invention.

[0170] exist Figure 11 and 2 show a schematic diagram of the structure of the optical device 100 of the present embodiment. The optical device 100 is a device for generating an enlarged virtual image of an image, for example, for immersive virtual reality (VR) technology. The optical device 100 includes: a display 110, a diffractive optical element 200, an optical system 300, a control device 390, and a housing 400. In addition, the image light 50 emitted from the display 110 is guided to the user's eye (single eye) 30 via the diffractive optical element 200 and the optical system 300. Here, the display 110 side is referred to as the upstream side on the optical axis L of the image light 50, and the user's eye 30 side is referred to as the downstream side. In addition, according to the electric field vibration trajectory when observing the upstream side from the downstream side, the polarized light of the image light 50 is divided into: horizontal linear polarized light, vertical linear polarized light, left-handed (also called counterclockwise) circularly polarized light, and right-handed (also called clockwise) circularly polarized light.

[0171] The display 110 is a device for displaying an image. The display 110 can be, for example, a liquid crystal display device composed of a display device, a light source, and a liquid crystal panel, wherein the display device is composed of an organic light emitting diode (OLED). The image can be one or more images constituting a still image or a moving image, or a color image consisting of three colors of red, green, and blue. The display 110 emits image light 50 constituting the image from the display surface. In the case of a color image, the various colors can be emitted in a time-sharing manner, or they can be overlapped or spatially divided in units of pixels and emitted simultaneously.

[0172] The diffractive optical element 200 includes a plurality of elements for processing the image light 50. The diffractive optical element 200 is disposed on the downstream side of the display 110, and includes a first GPH element, a first λ / 4 plate, a CSF element, a second λ / 4 plate, a second GPH element, a third λ / 4 plate, a first polarizing plate, and a fourth λ / 4 plate (none of which are shown) which are overlapped in order from the upstream side to the downstream side.

[0173] The first and second GPH (geometric phase hologram) elements are elements that distribute the light of polymeric liquid crystal into a specific pattern, and change the polarization direction of the incident light while using the diffraction phenomenon to produce a lens effect (diffusion or focusing effect) to output a diffracted light. In the case of incident unpolarized light, the first and second GPH elements diffuse and output the left-handed circularly polarized light beam, and focus and output the right-handed circularly polarized light beam. In the case of incident right-handed circularly polarized light, the first and second GPH elements flip the polarization direction to left-handed circularly polarized light, diffuse and output the light beam, and flip to right-handed circularly polarized light, focus and output the light beam. By using the first and second GPH elements, the wavelength dispersion of the refraction angle relative to the image light 50 and the chromatic aberration associated therewith can be compensated.

[0174] The first to fourth λ / 4 plates are elements that modulate the two polarized light components of the image light 50 by giving a phase difference of a quarter wavelength. The λ / 4 plates modulate linear polarization into circular polarization, and modulate circular polarization into linear polarization.

[0175] CSF (wavelength selective polarization conversion) elements are elements that rotate the polarization direction by 90 degrees only in a specific wavelength region. For example, CSF elements modulate vertical linear polarization into horizontal linear polarization, and modulate horizontal linear polarization into vertical linear polarization.

[0176] The first polarizing plate is an element that absorbs one of mutually orthogonal linear polarized light and transmits the other (so-called linear polarizing plate). As an example, the first polarizing plate transmits vertical linear polarized light and absorbs horizontal linear polarized light.

[0177] The optical system 300 is a three-pass optical system that is thinned by folding the optical path twice by two reflecting surfaces, and includes a filter 320 and a lens 310 arranged on the downstream and upstream sides of the optical axis L. The optical system 300 uses the lens 310 to diffuse the image light 50 to enlarge the image.

[0178] The filter 320 includes a plurality of elements for processing the image light 50. The filter 320 is disposed downstream of the lens 310 and includes a fifth λ / 4 plate (not shown), a reflective polarizing plate 321, and a second polarizing plate (not shown) stacked in order from upstream to downstream.

[0179] The fifth λ / 4 plate is an element that modulates the two polarized light components of the image light 50 that has passed through the lens 310 by giving a phase difference of a quarter wavelength.

[0180] The reflective polarizing plate 321 is an example of a first transmissive reflective surface, and is an element that reflects one of mutually orthogonal linear polarized lights and transmits the other linear polarized light. As an example, the reflective polarizing plate 321 transmits vertical linear polarized light and reflects horizontal linear polarized light.

[0181] The second polarizing plate 320 is an element that absorbs one of mutually orthogonal linear polarized lights and transmits the other. As an example, the second polarizing plate 320 transmits vertical linear polarized lights and absorbs horizontal linear polarized lights.

[0182] The lens 310 is an element that diffuses the image light 50 to magnify the image. The lens 310 is designed to have a diopter (the reciprocal of the focal length value in meters) of an arbitrary value within the range of, for example, -5 to +2. The lens 310 has a semi-reflective mirror surface 311 as an example of a second transmissive reflective surface on one surface on its upstream side. The semi-reflective mirror surface 311 is a curved surface whose curved surface angle increases or decreases according to the distance from the center, and is particularly an aspherical surface.

[0183] Figure 2A An example of the surface shape of the half mirror surface (HM) 311 of the lens 310 is shown. Here, the solid line represents the aspherical shape of the half mirror surface (HM) 311 using the surface position Z relative to the surface diameter. The dotted line represents the change amount Δθ of the curved surface angle of the half mirror surface (HM) 311 relative to the surface diameter. For the surface shape of the half mirror surface 311, the surface position Z deviates as it moves away from the center to the outside, but the change amount Δθ of the curved surface angle tends to decrease as it moves away from the center to the outside.

[0184] Figure 2B An example of the cone angle characteristics of the light beam after being reflected by the half-mirror (HM) 311 of the lens 310 is shown. Here, the solid line represents the cone angle of the light beam after being reflected by the half-mirror (HM) 311 relative to the reflection position. It should be noted that the width of the light beam before reflection is set to 5 mm, and the cone angle is set to the infinite condition (parallel). The dotted line represents the change in the cone angle of the light beam after being reflected by the half-mirror (HM) 311 relative to the reflection position. For the cone angle of the light beam, the farther away from the center of the half-mirror 311, the smaller it is, and the change tends to increase.

[0185] Since the change amount Δθ of the curved surface angle of the half mirror surface 311 tends to decrease as it moves away from the center toward the outside, the change amount of the cone angle of the light beam after being reflected by the half mirror surface 311 tends to increase as it moves away from the center toward the outside. Therefore, by moving the half mirror surface 311 along the optical axis direction and thus changing the reflection position of the image light 50 on the half mirror surface 311 in the surface diameter direction, the field curvature can be corrected.

[0186] In addition, instead of the lens 310 , a lens element that combines an optical element including a plurality of lenses and produces a lens effect on the image light 50 may be used.

[0187] The control device 390 controls each part of the optical device 100. The control device 390 can drive the lens 310 along the optical axis L direction by rotating a guide ring 430 of a moving device 410 described later using a rotary motor or an actuator (not shown) included in the housing 400, for example.

[0188] In addition, the control device 390 changes the distortion correction value of the image according to the state of the optical system 300, for example, according to the diopter of the optical system 300. For example, in the three-pass optical system 300, there is a tendency for the virtual image to have pincushion distortion (original Japanese text: thread-winding distortion). Therefore, the control device 390 displays on the display 110 an image of a barrel shape whose distortion is an amount that cancels out the pincushion distortion of the optical system 300, thereby correcting the distortion. Here, the distortion of the optical system 300 is measured in advance using a camera or the like, and the amount of distortion for generating an image of barrel distortion that cancels out this distortion is stored as a distortion correction value in the control device 390. When the degree of distortion of the optical system 300 varies for each diopter, the distortion is measured for each diopter, and the distortion correction value is stored in the control device 390. The control device 390 corrects the distortion of the diopter selected by the user by inputting the distortion correction value corresponding to the diopter of the optical system 390 to the display 110 and causing the display 110 to display an image of barrel distortion corresponding to this distortion correction value.

[0189] The housing 400 houses the display 110, the diffractive optical element 200, and the optical system 300. The housing 400 holds the moving device 410, which moves the lens 310 (especially the semi-reflective mirror surface 311) along the optical axis L relative to the filter 320 (especially the reflective polarizing plate 321). By moving the lens 310 relative to the filter 320, the folding length of the optical path of the image light 50 between them is changed, so that the position of the magnified virtual image can be changed. The structure of the moving device 410 will be further described later.

[0190] The principle by which the optical device 100 guides the image light 50 of the display 110 to the user's eye 30 will be described.

[0191] The display 110 generates and outputs image light 50 that is non-polarized light. By making the image light 50 non-polarized light, it is possible to prevent uneven brightness from occurring when the image light 50 passes through the first GPH for correcting chromatic aberration.

[0192] The image light 50 output from the display 110 enters the diffractive optical element 200. In the diffractive optical element 200, the image light 50 first enters the first GPH element. As a result, one of the ±first diffracted lights of the unpolarized image light 50 is diffused and output as left-handed circularly polarized light, and the other is focused and output as right-handed circularly polarized light. The image light 50 then enters the first λ / 4 plate. As a result, the left-handed circularly polarized image light 50 is modulated into horizontal linear polarized light, and the right-handed circularly polarized image light 50 is modulated into vertical linear polarized light. The image light 50 then enters the CSF. As a result, the horizontal linear polarized image light 50 in a specific wavelength region is modulated into vertical linear polarized light, and is output together with the vertical linear polarized image light 50 outside the specific wavelength region. The vertical linear polarized image light 50 in the specific wavelength region is modulated into horizontal linear polarized light, and then removed by the first polarizing plate. Thus, according to the wavelength region, either the diffuse light or the focused light output from the first GPH element is output from the diffractive optical element 200, that is, the optical path is changed according to the wavelength region, thereby correcting the chromatic aberration. Hereinafter, only the vertical linear polarized light image light 50 output from the CSF will be described.

[0193] The image light 50 then enters the second λ / 4 plate. As a result, the image light 50 of the vertical linear polarization is modulated into left-handed circular polarization. The image light 50 then enters the second GPH element. As a result, the image light 50 of the left-handed circular polarization is modulated into right-handed circular polarization by the focusing effect. The image light 50 then enters the third λ / 4 plate. As a result, the image light 50 of the right-handed circular polarization is modulated into the linear polarization of the vertical direction. The image light 50 then enters the first polarizing plate. The image light 50 of the vertical linear polarization is transmitted through the first polarizing plate, and the useless light of the horizontal linear polarization is absorbed by the first polarizing plate. The image light 50 then enters the fourth λ / 4 plate. As a result, the image light 50 of the vertical linear polarization is modulated into left-handed circular polarization. In this way, the image light 50 is modulated into left-handed circular polarization and the chromatic aberration is compensated, and is output from the diffractive optical element 200 to the downstream side.

[0194] In addition, in the optical device 100 of the present embodiment, the image light 50 modulated into the linear polarized light in the vertical direction by the first λ / 4 plate and the CSF element in the diffractive optical element 200 is used, and the image light 50 modulated into the linear polarized light in the horizontal direction is removed as useless light by the first polarizing plate. However, it is also possible to use the image light 50 modulated into the linear polarized light in the horizontal direction by the first λ / 4 plate and the CSF element in the diffractive optical element 200, and the image light 50 modulated into the linear polarized light in the vertical direction is removed as useless light by the first polarizing plate.

[0195] The image light 50 output from the diffractive optical element 200 enters the optical system 300. In the optical system 300, the image light 50 is first incident on the lens 310. Thus, regardless of the polarization state, the image light 50 of half intensity is transmitted through the half mirror surface 311, amplified by the lens action and output to the downstream side, and the image light 50 of the remaining half intensity is reflected by the half mirror surface 311.

[0196] The image light 50 then enters the optical filter 320. In the optical filter 320, the image light 50 first enters the fifth λ / 4 plate. As a result, the image light 50, which is left-handed circularly polarized light, is modulated into horizontally linearly polarized light. The image light 50 then enters the reflective polarizing plate. As a result, the image light 50, which is horizontally linearly polarized light, is reflected. The image light 50 enters the fifth λ / 4 plate again. As a result, the image light 50, which is horizontally linearly polarized light, is modulated into right-handed circularly polarized light. In this way, the image light 50 is reflected by the optical filter 320 and output to the upstream side.

[0197] Image light 50 enters lens 310 from the downstream side. Image light 50 is amplified by the lens effect, half of the intensity of image light 50 is further amplified by the lens effect by being reflected by half mirror 311 and output to the downstream side, and the remaining half of the intensity of image light 50 passes through half mirror 311.

[0198] The image light 50 is incident on the filter 320 again. In the filter 320, the image light 50 first enters the fifth λ / 4 plate. As a result, the right-handed circularly polarized image light 50 is modulated into a vertically linearly polarized light. The image light 50 then enters the reflective polarizing plate. The vertically linearly polarized image light 50 is transmitted through the reflective polarizing plate. The image light 50 then enters the second polarizing plate. The vertically linearly polarized image light 50 is transmitted through the second polarizing plate, and the useless light of the horizontally linearly polarized light is absorbed by the second polarizing plate. The diffused image light 50 is output from the filter 320 to the downstream side.

[0199] Thus, after passing through the lens 310 once in the optical system 300 , the image light 50 is reflected by the filter 320 and reciprocates in the lens 310 , and is further amplified by the lens action of the lens 310 , output to the downstream side, and then guided to the user's eye 30 .

[0200] Figure 3A and Figure 3B The overall structure and the exploded structure of the mobile device 410 are shown respectively. The mobile device 410 includes a first housing 420 , a second housing 440 , and a guide ring 430 .

[0201] The first housing 420 is a housing capable of accommodating the second housing 440 in a manner extending into its internal space 420a. The first housing 420 includes a main body 421, and first and second flanges 422 and 423. The main body 421 has a cylindrical shape including an internal space 420a, and a slit 421a extending in the axial direction is provided on the side. The first flange 422 is formed by protruding outward from one end of the main body 421, and extends inward to form a circular opening 422a smaller than the inner diameter of the main body 421. The second flange 423 is formed by protruding outward from the other end of the main body 421.

[0202] The second housing 440 is a housing for housing the lens 310 and the like. In the present embodiment, the second housing 440 houses the display 110, the diffractive optical element 200, and the lens 310 in order from the front to the back of the drawing. The second housing 440 is formed into a bottomed cylindrical shape having an outer diameter equal to or slightly smaller than the inner diameter of the main body 421, and a guide pin 441 is provided on the side surface.

[0203] The guide ring 430 is a member for guiding the movement of the second housing 440 in the first housing 420. The guide ring 430 is cylindrical and has a spirally extending slit 430a on the side thereof. The cylindrical shape has an inner diameter equal to or slightly larger than the outer diameter of the main body 421.

[0204] The mobile device 410 is assembled as follows. First, the guide pin 441 of the second housing 440 is inserted into the slit 421a of the main body 421, and the second housing 440 is inserted into the internal space 420a of the first housing 420. The second housing 440 is positioned by abutting against the inner edge of the first flange 422 in the first housing 420. Then, the guide pin 441 protruding upward from the slit 421a of the main body 421 is inserted into the slit 430a of the guide ring 430, and the outer periphery of the main body 421 between the first flange 422 and the second flange 423 is embedded in the guide ring 430.

[0205] Furthermore, the optical filter 320 is fixed to the downstream side of the moving device 410 in the housing 400 .

[0206] from FIG. 4A to FIG. 4C The principle of lens movement using the moving device 410 is shown. Figure 4A In the state shown in FIG. 4 (minimum separation state), the guide pin 441 is located on one side of the slit 430a of the guide ring 430. At this time, the second housing 440 is retracted into the first housing 420. That is, the lens 310 is closest to the filter 320. Next, as shown in FIG. Figure 4BAs shown in (extended state), by rotating the side surface of the guide ring 430 near the drawing upward, the guide pin 441 is guided by the spiral slit 430a and moves to the right in the slit 421a of the main body 421, and the second shell 440 extends from the first shell 420 to the right in the drawing. Figure 4C As shown in the maximum separation state, by making the guide pin 441 reach the other side of the slit 430a of the guide ring 430, the second housing 440 is extended to the maximum extent from the first housing 420. In other words, the lens 310 and the filter 320 are separated to the maximum extent. Conversely, by rotating the side of the guide ring 430 near the drawing downward, the guide pin 441 is guided by the spiral slit 430a and moves to the left in the slit 421a of the main body 421, and the second housing 440 is as shown in the maximum separation state. Figure 4A (minimum separation state) and retreat into the first housing 420.

[0207] Therefore, the moving device 410 maintains the relative positional relationship among the display 110 , the diffractive optical element 200 , and the lens 310 (half mirror 311 ), and moves them relative to the filter 320 (reflective polarizing plate 321 ).

[0208] exist Figure 5A and Figure 5B 2 and 3 show the overall structure and the exploded structure of the moving device 411 of the first modified example. The moving device 411 includes a first housing 420 , a second housing 440 , a guide ring 431 , and a second flange portion 423 .

[0209] The first housing 420 includes the above-mentioned main body portion 421 and the first flange portion 422 .

[0210] The second housing 440 is configured similarly to the above-described second housing 440 .

[0211] The guide ring 431 is in a cylindrical shape, and is provided with a slit 431a extending in a spiral shape and open on one side toward one end of the cylinder. The cylindrical shape has an inner diameter equal to or slightly larger than the outer diameter of the main body 421. In addition, the side of the slit 431a open toward one end of the cylinder is called an open end, and the portion of the slit 431a extending in a spiral shape is called a spiral portion.

[0212] The second flange 423 is formed into an annular shape as a separate component from the first housing 420. The inner diameter of the second flange 423 is equal to the inner diameter of the main body 421, and the outer diameter of the second flange 423 is larger than the outer diameter of the main body 421.

[0213] The moving device 411 is assembled as follows. First, the guide pin 441 of the second housing 440 is inserted into the slit 421a of the main body 421, and the second housing 440 is inserted into the internal space 420a of the first housing 420. The second housing 440 is positioned by abutting against the inner edge of the first flange 422 in the first housing 420. Next, the guide pin 441 protruding upward from the slit 421a of the main body 421 is inserted into the guide ring 431 from the open end of the slit 431a, and the guide ring 431 is rotated relative to the first housing 420 so that the guide pin 441 enters the spiral portion of the slit 431a. Finally, the second flange 423 is fixed to the end of the main body 421 by bonding, welding, screwing, etc. Thus, the guide ring 431 is embedded in the outer periphery of the main body 421 between the first flange 422 and the second flange 423.

[0214] from FIG. 6A to FIG. 6C The principle of lens movement using the moving device 411 is shown. Fig. 6A In the state shown in FIG. 4 (minimum separation state), the guide pin 441 is located on one side of the slit 431a of the guide ring 431. At this time, the second housing 440 is retracted into the first housing 420. That is, the lens 310 is closest to the filter 320. Next, as shown in FIG. Figure 6B As shown in (extended state), by rotating the side surface of the guide ring 431 near the drawing upward, the guide pin 441 is guided by the spiral portion of the slit 431a and moves to the right in the drawing in the slit 421a of the main body 421, and the second housing 440 extends from the first housing 420 to the right in the drawing. Figure 6C As shown in the maximum separation state, by making the guide pin 441 reach the other side of the slit 431a of the guide ring 431, the second housing 440 is extended to the maximum extent from the first housing 420. In other words, the lens 310 and the filter 320 are separated to the maximum extent. Conversely, by rotating the side of the guide ring 431 near the drawing downward, the guide pin 441 is guided by the spiral part of the slit 431a and moves to the left in the drawing in the slit 421a of the main body 421, and the second housing 440 is as shown in the maximum separation state. Fig. 6A (minimum separation state) and retreat into the first housing 420.

[0215] Therefore, similarly to the moving device 410 , the moving device 411 maintains the relative positional relationship among the display 110 , the diffractive optical element 200 , and the lens 310 (half mirror 311 ) and moves them relative to the filter 320 (reflective polarizing plate 321 ).

[0216] exist Fig. 7A and Figure 7B2 and 3 show the overall structure and the exploded structure of the moving device 412 of the second modified example. The moving device 412 includes a first housing 420 , a second housing 440 , a guide ring 432 , and a second flange portion 423 .

[0217] The first housing 420, the second housing 440, and the second flange 423 are configured similarly to those of the moving device 411 of the first modification. The guide pin 441 of the second housing 440 is formed slightly lower than the guide pin in the first modification.

[0218] The guide ring 432 is cylindrical in shape and has a spirally extending slit 432a and a groove-shaped tunnel portion 432b provided on the inner surface from one side of the slit 432a toward one end of the cylinder. The cylinder has an inner diameter that is equal to or slightly larger than the outer diameter of the main body 421. The thickness of the tunnel portion 432b is thinner than other portions.

[0219] In addition, a spiral groove may be formed on the inner surface of the guide ring 432 instead of the slit 432a. The groove is connected to the tunnel 432b on one side. Thus, the second housing 440 is sealed in the first housing 420 by the guide ring 432, and foreign matter such as dust can be prevented from mixing in.

[0220] The moving device 412 is assembled as follows. First, the guide pin 441 of the second shell 440 is inserted into the slit 421a of the main body 421, and the second shell 440 is inserted into the internal space 420a of the first shell 420. The second shell 440 is positioned in the first shell 420 by abutting against the inner edge of the first flange portion 422. Next, the guide pin 441 protruding upward from the slit 421a of the main body 421 is entered into the slit 432a through the tunnel portion 432b of the guide ring 432, and the guide ring 432 is rotated relative to the first shell 420, so that the guide pin 441 moves in the depth direction of the slit 432a. Finally, the second flange portion 423 is fixed to the end of the main body 421 by bonding, welding, screw fixing, etc. As a result, the guide ring 432 is embedded in the outer periphery of the main body 421 between the first flange portion 422 and the second flange 423.

[0221] from FIG. 8A to FIG. 8C The principle of lens movement using the moving device 412 is shown. First, Fig. 8A In the state shown in FIG. 4 (minimum separation state), the guide pin 441 is located on one side of the slit 432a of the guide ring 432. At this time, the second housing 440 is retracted into the first housing 420. That is, the lens 310 is closest to the filter 320. Next, as shown in FIG. Figure 8BAs shown in (extended state), by rotating the side surface of the guide ring 432 near the drawing upward, the guide pin 441 is guided by the slit 432a and moves to the right in the slit 421a of the main body 421, and the second shell 440 extends from the first shell 420 to the right in the drawing. Figure 8C As shown in the maximum separation state, the guide pin 441 reaches the other side of the slit 432a of the guide ring 432, so that the second housing 440 is extended to the maximum extent from the first housing 420. In other words, the lens 310 and the filter 320 are separated to the maximum extent. Conversely, by rotating the side of the guide ring 432 near the drawing downward, the guide pin 441 is guided by the slit 432a and moves to the left in the drawing in the slit 421a of the main body 421, and the second housing 440 is as shown in the maximum separation state. Fig. 8A (minimum separation state) and retreat into the first housing 420.

[0222] Therefore, similarly to the moving device 410 , the moving device 412 maintains the relative positional relationship among the display 110 , the diffractive optical element 200 , and the lens 310 (half mirror 311 ) and moves them relative to the filter 320 (reflective polarizing plate 321 ).

[0223] In the optical device 100, it is necessary to make the image curvature of the virtual image displayed at the virtual image position converge within the focal depth of the optical system 300. However, in the case of the three-pass type optical system 300, there is a problem that the image curvature does not converge within the focal depth due to the shallow focal depth. Therefore, in the optical device 100 of this embodiment, the moving device 410 is used to move the lens 310 (half-reflecting mirror surface 311) relative to the filter 320 (reflective polarizing plate 321) along the optical axis L, and the distance between the reflective polarizing plate 321 and the half-reflecting mirror surface 311 is changed to adjust the image curvature, so that it can converge within the focal depth for each diopter.

[0224] exist FIG. 9A to FIG. 9C, the ray trajectory and the change of the image plane curvature when the refractive power of the optical system 300 is uniquely set and the lens 310 (half-reflecting mirror 311) is moved relative to the filter 320 (reflective polarizing plate 321) along the optical axis L to change the distance a (referred to as the spatial distance or air distance) between the reflective polarizing plate 321 and the half-reflecting mirror 311. It should be noted that, by using the ray reverse tracing simulation, the light is drawn from the virtual image position to the eye box, and the light is retro-reflected in the eye box and follows the ray trajectory toward the display 110, and the curvature of the image plane of the display image is analyzed. In addition, in this example, the refractive power of the optical system 300 is set to -3. In each figure, the light (referred to as the central light 51) that is horizontally reflected from the eye box to the upstream side and reaches the center of the display surface of the display 110 and the light (referred to as the peripheral light 52) ​​that is reflected obliquely upward from the eye box to the upstream side and reaches the upper end of the display 110 are shown.

[0225] exist Fig. 9A The light trajectory when the air distance a=1.5 mm and the image plane curvature on the display surface of the display 110 are shown in the figure. In addition, the image plane curvature is shown at the position in the direction of the optical axis L where the light is most focused. Here, the solid line represents the image plane curvature on the tangential plane, and the dotted line represents the image plane curvature on the sagittal plane. The area marked with section lines represents the range of focal diopter of the optical system 300, and the image plane curvature needs to be converged within this range. The central light 51 reflected horizontally from the eye box to the upstream side passes through the filter 320, enters the lens 310 and is reflected at the center of the semi-reflective mirror 311, is focused and transmitted to the downstream side, is reflected at the reflective polarizer 321 in the filter 320, is further focused through the lens 310, and reaches the center of the display 110 via the diffractive optical element 200. The peripheral light 52 reflected obliquely upward from the eye box to the upstream side passes through the filter 320, enters the lens 310, and is reflected on the upper side of the half-reflecting mirror 311, where it is condensed and transmitted obliquely downward to the downstream side, where it is reflected by the reflective polarizing plate 321 in the filter 320, further condensed by passing through the lens 310, and reaches the upper end of the display 110 via the diffractive optical element 200. The image plane tends to be formed on the downstream side at the periphery relative to the center of the display 110, slightly beyond the range of the depth of focus.

[0226] exist Fig. 9B, the light trajectory and the image curvature on the display surface of the display 110 when the air distance a=1.7 mm are shown. The central light 51 reflected horizontally from the eye box to the upstream side is focused in the same manner as when the air distance a=1.5 mm, and reaches the center of the display 110 along the same optical path. The peripheral light 52 reflected obliquely upward from the eye box to the upstream side passes through the filter 320, enters the lens 310, and is reflected on the upper side of the half-reflective mirror 311, where it is focused and transmitted obliquely downward to the downstream side, reflected by the reflective polarizing plate 321 in the filter 320, further focused by passing through the lens 310, and reaches the upper side of the display 110 via the diffractive optical element 200. The image curvature is small and is contained within the focal depth.

[0227] exist Fig. 9C , the light trajectory and the image curvature on the display surface of the display 110 when the air distance a=1.9 mm are shown. The central light 51 reflected horizontally from the eye box to the upstream side is focused in the same manner as in the case of the air distance a=1.5 mm, and reaches the center of the display 110 along the same optical path. The peripheral light 52 reflected obliquely upward from the eye box to the upstream side passes through the filter 320, enters the lens 310, and is reflected on the upper side of the half-reflective mirror 311, where it is focused and transmitted obliquely downward to the downstream side, reflected by the reflective polarizing plate 321 in the filter 320, further focused by passing through the lens 310, and reaches the upper side of the display 110 via the diffractive optical element 200. The image plane tends to be imaged on the upstream side at the periphery relative to the center of the display 110, slightly exceeding the range of the depth of focus.

[0228] Fig. 10A The definition of the light interval in the optical device 100 is shown. Here, 1 of the light interval represents the interval from the eye box to the exit surface of the filter 320, 2 represents the interval from the incident surface of the filter 320 to the exit surface of the lens 310, 3 represents the interval from the exit surface of the lens 310 to the incident surface (half-mirror surface 311) of the lens 310, 4 represents the interval from the incident surface (half-mirror surface 311) of the lens 310 to the exit surface of the lens 310, 5 represents the interval from the exit surface of the lens 310 to the incident surface of the filter 320, 6 represents the interval from the incident surface of the filter 320 to the exit surface of the lens 310, 7 represents the interval from the exit surface of the lens 310 to the incident surface of the lens 310, 8 represents the interval from the incident surface of the lens 310 to the exit surface of the diffractive optical element 200, and 9 represents the interval from the incident surface of the diffractive optical element 200 to the exit surface of the display 110. In addition, although Fig. 10A In the figure, the light interval is defined for the peripheral light 52 , but the same definition is also applied to the central light 51 .

[0229] Fig. 10B Indicated in Fig. 10AThe cone angles of the central light 51 and the peripheral light 52 in each light interval 1 to 9 in the optical device 100 defined in FIG. The cone angle of the central light 51 is equal when the air distance a=1.5, 1.7, and 1.9 mm, is zero in the light intervals 1 and 2, increases in intervals 3 and 4, that is, it expands due to entering the lens 310, is constant in intervals 5 and 6, decreases in interval 7, increases again in interval 8, and reaches the display 110 at the maximum angle in interval 9. The cone angle of the peripheral light 52 is the same as the cone angle of the central light 51. It should be noted that the cone angle of the peripheral light 52 will differ according to the air distance after the peripheral light 52 enters interval 4 of the lens 310. That is, the larger the air distance, the peripheral light 52 enters the upper side of the semi-reflective mirror 311, thereby the cone angle becomes smaller, and the peripheral light 52 is focused farther away. The smaller the air distance is, the more the ambient light 52 enters the lower side of the half-reflective mirror 311 , whereby the cone angle becomes larger and the ambient light 52 is focused closer.

[0230] By changing the air distance, the focus position of the light beam at the periphery of the image can be changed forward or backward relative to the focus position of the light beam at the center of the image, thereby adjusting the image plane curvature. Figure 2B As shown in FIG. 1 , the closer to the periphery of the half mirror surface 311 , the greater the change in the cone angle. Therefore, the field curvature can be corrected by changing the air distance.

[0231] Fig.11 The figure shows the change of the image plane curvature with respect to the air distance when the diopters are -5, -3, -1, and +2, respectively. The image plane curvature decreases as the air distance increases, and is the minimum at a certain air distance, and increases as the air distance further increases. For each diopter, there is an air distance that minimizes the image plane curvature. Therefore, it can be seen that by roughly selecting the diopters according to the user's visual acuity to design the optical system 300, and moving the optical system 300 relative to the filter 320, the image plane curvature can be minimized more precisely according to the visual acuity.

[0232] exist Fig. 12ADetailed structures of the diffractive optical element 200, lens 310, and filter 320 included in the optical device 100 of models 1 to 3 are shown in FIG. In model 1, the diffractive optical element 200 is constructed in such a manner that a GPL (GPH lens) element, a filter A, a GPL element, and a filter B are sequentially overlapped from the upstream side to the downstream side. The lens 310 is constructed in such a manner that a half mirror and a biconvex lens are sequentially overlapped from the upstream side to the downstream side. The filter 320 is constructed in such a manner that a λ / 4 plate, a reflective polarizing plate, and a polarizing plate are sequentially overlapped from the upstream side to the downstream side. In the optical device 100 of model 1, the diffractive optical element 200 is constructed in the same manner as the diffractive optical element 200 of the above-mentioned embodiment, and chromatic aberration is suppressed by using two GPH elements (GPL elements) and a CSF element. In model 2, the diffractive optical element 200 is constructed by a filter C. The lens 310 is constructed in such a manner that a half-mirror, a biconvex lens, and a concave meniscus lens are overlapped in sequence from the upstream side to the downstream side. The filter 320 is constructed in the same manner as in model 1. In the optical device 100 of model 2, the diffractive optical element 200 does not include a GPH element (GPL element) and a CSF element, and only the structure of the lens 310 is used to suppress chromatic aberration. In model 3, the diffractive optical element 200 is constructed in such a manner that a GPL element and a filter B are overlapped in sequence from the upstream side to the downstream side. The lens 310 is constructed in the same manner as in model 2. The filter 320 is constructed in the same manner as in model 1. In the optical device 100 of model 3, the diffractive optical element 200 does not include a CSF element, and only the GPH element (GPL element) is used to suppress chromatic aberration.

[0233] Fig. 12B The detailed structures of the optical filters A to C are shown. Each optical filter is configured such that the elements listed in the right column are stacked in order from the upstream side to the downstream side.

[0234] Fig.13A The detailed design of the optical device 100 of the first embodiment is shown. In the first embodiment, Fig. 12AThe optical device 100 is designed according to various parameters assigned to the lens specifications, aspheric coefficients, GPL data, and variable interval data of the model 1. In the optical device 100, the lens 310 is designed by applying the lens parameters to the lens structure of the model 1, so that its focal length B is uniquely determined, and the focal length A of the entire optical system 300 is determined by adjusting the air distance, etc., so that the position of the magnified virtual image can be adjusted according to the user's diopter. Therefore, it is considered that the detailed structure of the optical device 100 can be characterized by the ratio A / B of the focal length A of the entire optical system 300 to the focal length B of the lens 310. In this example, the ratio A / B is given as 0.183, 0.176, and 0.168 for diopter +2, -1, and -5, respectively. In addition, the diopter X represents the state where the magnified virtual image of the optical system appears at a position 1 / X [m] away from the eye box on the optical axis. It should be noted that the sign is set to be positive when the image appears on the downstream side of the optical system.

[0235] Fig. 13B , Fig. 13C and Fig.13D The following diagrams show the lateral aberrations detected for diopter +2, -1, and -5 (ratio A / B = 0.183, 0.176, 0.168) in the optical device 100 of Example 1. Here, the upper left group of figures show aberrations at the center of the image, the upper right group of figures show aberrations at the center of the upper and lower ends of the image, the lower left group of figures show aberrations at the center of the left and right ends, and the lower right group of figures show aberrations at the diagonals. Py and Px are coordinates on the aperture plane (at the position of the eye box) (the maximum scale is 4 mm), and ey and ex are the aberration amounts on the tangential plane and the sagittal plane, respectively (the maximum scale is shown in each figure). The solid line represents the aberration for a wavelength of 0.515 μm, the dotted line represents the aberration for a wavelength of 0.528 μm, and the single-point dashed line represents the aberration for a wavelength of 0.544 μm.

[0236] Fig.13E , Fig.13F and Figure 13G The spherical aberration on the optical axis detected for diopter +2, -1, and -5 (ratio A / B = 0.183, 0.176, 0.168) in the optical device 100 of Example 1 is shown. Here, the vertical axis is the normalized pupil coordinate at the position of the eye box (the maximum scale is 4 mm), and the horizontal axis is the aberration amount. In each figure, the solid line represents the aberration for the wavelength of 0.515μm, the dotted line represents the aberration for the wavelength of 0.528μm, and the single-dot chain line represents the aberration for the wavelength of 0.544μm.

[0237] Fig.13H , Fig.13I and Fig.13JThe figure shows the field curvature (left figure) and image distortion (right figure) detected for diopter +2, -1, and -5 (ratio A / B=0.183, 0.176, 0.168) in the optical device 100 of Example 1. FIG. 9A to FIG. 9C Similarly, the image plane curvature is shown on the horizontal axis for the position relative to the center on the display surface 110 of the vertical axis (the outermost position is set to 1.0). The image plane curvature on the tangential plane and the image plane curvature on the sagittal plane are shown respectively. The image distortion is shown on the horizontal axis for the position on the diagonal relative to the center on the display surface 110 of the vertical axis. In each figure, the solid line represents the image plane curvature and image distortion for a wavelength of 0.515μm, the dotted line represents the image plane curvature and image distortion for a wavelength of 0.528μm, and the single-point chain line represents the image plane curvature and image distortion for a wavelength of 0.544μm.

[0238] exist Fig.13H In (diopter +2, ratio A / B = 0.183), the image plane is imaged on the downstream side at the periphery relative to the center of the display 110 on the tangential plane, and is imaged on the upstream side at the periphery relative to the center of the display 110 on the radial plane. Image distortion indicates negative distortion at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0239] exist Fig.13I (Diopter -1, ratio A / B = 0.176), the image plane is formed slightly upstream of the center of the display 110 on the tangential plane, and formed upstream of the center of the display 110 on the radial plane. The image distortion is negative distortion at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0240] exist Fig.13J (Diopter -5, ratio A / B = 0.168), the image plane forms an image on the downstream side of the periphery relative to the center of the display 110 on the tangential plane and the radial plane. In addition, the wavelength dependence of the image plane curvature is very small. The image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion becomes barrel-shaped.

[0241] In the optical device 100 of Example 1, for diopter +2, -1, and -5 (ratio A / B=0.183, 0.176, 0.168), the field curvature is within the range of ±0.2 mm, and the maximum image distortion is about -3%.

[0242] Fig.14A The detailed design of the optical device 100 of Example 2 is shown. In Example 2, Fig. 12AThe optical device 100 is designed according to various parameters assigned to the lens specifications, aspheric coefficients, GPL data, and variable interval data for the model 1. In this example, the ratio A / B is given as 0.210, 0.202, and 0.193 for diopter +2, -1, and -5, respectively.

[0243] Fig. 14B , Fig. 14C and Fig.14D The following diagrams show the lateral aberrations detected for diopter +2, -1, and -5 (ratio A / B = 0.210, 0.202, 0.193) in the optical device 100 of Example 2. Here, the upper left group of figures show aberrations at the center of the image, the upper right group of figures show aberrations at the center of the upper and lower ends of the image, the lower left group of figures show aberrations at the center of the left and right ends, and the lower right group of figures show aberrations at the diagonals. Py and Px are coordinates on the aperture plane (at the position of the eye box) (the maximum scale is 4 mm), and ey and ex are the aberration amounts on the tangential plane and the sagittal plane, respectively (the maximum scale is shown in each figure). The solid line represents the aberration for a wavelength of 0.515 μm, the dotted line represents the aberration for a wavelength of 0.528 μm, and the single-point dashed line represents the aberration for a wavelength of 0.544 μm.

[0244] Fig.14E , Fig.14F and Figure 14G The spherical aberration on the optical axis detected for diopter +2, -1, and -5 (ratio A / B = 0.210, 0.202, 0.193) in the optical device 100 of Example 2 is shown. Here, the vertical axis is the normalized pupil coordinate at the position of the eye box (the maximum scale is 4 mm), and the horizontal axis is the aberration amount. In each figure, the solid line represents the aberration for the wavelength of 0.515μm, the dotted line represents the aberration for the wavelength of 0.528μm, and the single-dot chain line represents the aberration for the wavelength of 0.544μm.

[0245] Fig.14H , Fig.14I and Fig.14J The figure shows the field curvature (left figure) and image distortion (right figure) detected for diopter +2, -1, and -5 (ratio A / B=0.210, 0.202, 0.193) in the optical device 100 of Example 2. FIG. 9A to FIG. 9CSimilarly, the image plane curvature is shown on the horizontal axis for the position relative to the center on the display surface 110 of the vertical axis (the outermost position is set to 1.0). The image plane curvature on the tangential plane and the image plane curvature on the sagittal plane are shown respectively. The image distortion is shown on the horizontal axis for the position on the diagonal relative to the center on the display surface 110 of the vertical axis. In each figure, the solid line represents the image plane curvature and image distortion for a wavelength of 0.515μm, the dotted line represents the image plane curvature and image distortion for a wavelength of 0.528μm, and the single-point chain line represents the image plane curvature and image distortion for a wavelength of 0.544μm.

[0246] exist Fig.14H In (diopter +2, ratio A / B = 0.210), the image plane is imaged on the downstream side at the periphery relative to the center of the display 110 on the tangential plane, and is imaged on the upstream side at the periphery relative to the center of the display 110 on the radial plane. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0247] exist Fig.14I (Diopter -1, ratio A / B = 0.202), the image plane is formed slightly upstream of the center of the display 110 on the tangential plane, and formed upstream of the center of the display 110 on the radial plane. The image distortion is negative distortion at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0248] exist Fig.14J (Diopter -5, ratio A / B = 0.193), the image plane is imaged on the upstream side of the periphery relative to the center of the display 110 on the tangential plane and the radial plane. In addition, the wavelength dependence of the image plane curvature is basically not found. The image distortion shows that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0249] In the optical device 100 of Example 2, for diopter +2, -1, and -5 (ratio A / B=0.210, 0.202, 0.193), the field curvature is within the range of ±0.2 mm, and the maximum image distortion is about -3%.

[0250] Fig.15A The detailed design of the optical device 100 of Example 3 is shown. In Example 3, Fig. 12A The optical device 100 is designed according to various parameters assigned to the lens specifications, aspheric coefficients, GPL data, and variable interval data for the model 1. In this example, the ratio A / B is given as 0.283, 0.270, and 0.254 for diopter +2, -1, and -5, respectively.

[0251] Fig. 15B , Fig. 15C and Fig.15DThe following diagrams show the lateral aberrations detected for diopter +2, -1, and -5 (ratio A / B = 0.283, 0.270, 0.254) in the optical device 100 of Example 3. Here, the upper left group of figures shows the aberrations at the center of the image, the upper right group of figures shows the aberrations at the center of the upper and lower ends of the image, the lower left group of figures shows the aberrations at the center of the left and right ends, and the lower right group of figures shows the aberrations at the diagonals. Py and Px are coordinates on the aperture plane (at the position of the eye box) (the maximum scale is 4 mm), and ey and ex are the aberration amounts on the tangential plane and the sagittal plane, respectively (the maximum scale is shown in each figure). The solid line represents the aberrations for a wavelength of 0.515 μm, the dotted line represents the aberrations for a wavelength of 0.528 μm, and the single-point dashed line represents the aberrations for a wavelength of 0.544 μm.

[0252] Fig.15E , Fig.15F and Figure 15G The spherical aberration on the optical axis detected for diopter +2, -1, and -5 (ratio A / B = 0.283, 0.270, 0.254) in the optical device 100 of Example 3 is shown. Here, the vertical axis is the normalized pupil coordinates at the position of the eye box (the maximum scale is 4 mm), and the horizontal axis is the aberration amount. In each figure, the solid line represents the aberration for the wavelength of 0.515μm, the dotted line represents the aberration for the wavelength of 0.528μm, and the single-dot chain line represents the aberration for the wavelength of 0.544μm.

[0253] Fig.15H , Fig.15I and Fig.15J The figure shows the field curvature (left figure) and image distortion (right figure) detected for diopter +2, -1, and -5 (ratio A / B=0.283, 0.270, 0.254) in the optical device 100 of Example 3. FIG. 9A to FIG. 9C Similarly, the image plane curvature is shown on the horizontal axis for the position relative to the center on the display surface 110 of the vertical axis (the outermost position is set to 1.0). The image plane curvature on the tangential plane and the image plane curvature on the sagittal plane are shown respectively. The image distortion is shown on the horizontal axis for the position on the diagonal relative to the center on the display surface 110 of the vertical axis. In each figure, the solid line represents the image plane curvature and image distortion for a wavelength of 0.515μm, the dotted line represents the image plane curvature and image distortion for a wavelength of 0.528μm, and the single-point chain line represents the image plane curvature and image distortion for a wavelength of 0.544μm.

[0254] exist Fig.15H In (diopter +2, ratio A / B=0.283), the image plane is formed on the downstream side in the tangential plane and the sagittal plane relative to the center of the display 110. The image distortion is negative distortion in the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0255] exist Fig.15I (diopter -1, ratio A / B = 0.270), the image plane is formed slightly downstream in the periphery relative to the center of the display 110 on the tangential plane, and is formed downstream in the periphery relative to the center of the display 110 on the radial plane. Image distortion indicates that the distortion is negative in the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0256] exist Fig.15J In (diopter -5, ratio A / B = 0.254), the image plane forms an image on the upstream side of the periphery relative to the center of the display 110 on the tangential plane, and is substantially not distorted on the radial plane. Image distortion indicates negative distortion at the periphery relative to the center of the display 110, that is, the image is distorted into a barrel shape.

[0257] In the optical device 100 of Example 3, for diopter +2, -1, and -5 (ratio A / B=0.283, 0.270, 0.254), the field curvature is within the range of ±0.2 mm, and the maximum image distortion is about -3%.

[0258] Fig.16A The detailed design of the optical device 100 of Example 4 is shown. In Example 4, Fig. 12A The optical device 100 is designed according to various parameters assigned to the lens specifications, aspheric coefficients, GPL data, and variable interval data for the model 1. In this example, the ratio A / B is given as 0.317, 0.299, and 0.279 for diopters +2, -1, and -5, respectively.

[0259] Fig. 16B , Fig. 16C and Fig.16D The following diagrams show the lateral aberrations detected for diopter +2, -1, and -5 (ratio A / B = 0.317, 0.299, 0.279) in the optical device 100 of Example 4. Here, the upper left group of figures shows the aberrations at the center of the image, the upper right group of figures shows the aberrations at the center of the upper and lower ends of the image, the lower left group of figures shows the aberrations at the center of the left and right ends, and the lower right group of figures shows the aberrations at the diagonals. Py and Px are coordinates on the aperture plane (at the position of the eye box) (the maximum scale is 4 mm), and ey and ex are the aberration amounts on the tangential plane and the sagittal plane, respectively (the maximum scale is shown in each figure). The solid line represents the aberrations for a wavelength of 0.515 μm, the dotted line represents the aberrations for a wavelength of 0.528 μm, and the single-point dashed line represents the aberrations for a wavelength of 0.544 μm.

[0260] Fig.16E , Fig.16F and Figure 16GThe spherical aberration on the optical axis detected for diopter +2, -1, and -5 (ratio A / B = 0.317, 0.299, 0.279) in the optical device 100 of Example 4 is shown. Here, the vertical axis is the normalized pupil coordinate at the position of the eye box (the maximum scale is 4 mm), and the horizontal axis is the aberration amount. In each figure, the solid line represents the aberration for the wavelength of 0.515μm, the dotted line represents the aberration for the wavelength of 0.528μm, and the single-dot chain line represents the aberration for the wavelength of 0.544μm.

[0261] Fig.16H , Fig.16I and Fig.16J The figure shows the field curvature (left figure) and image distortion (right figure) detected for diopter +2, -1, and -5 (ratio A / B=0.317, 0.299, 0.279) in the optical device 100 of Example 4. FIG. 9A to FIG. 9C Similarly, the image plane curvature is shown on the horizontal axis for the position relative to the center on the display surface 110 of the vertical axis (the outermost position is set to 1.0). The image plane curvature on the tangential plane and the image plane curvature on the sagittal plane are shown respectively. The image distortion is shown on the horizontal axis for the position on the diagonal relative to the center on the display surface 110 of the vertical axis. In each figure, the solid line represents the image plane curvature and image distortion for a wavelength of 0.515μm, the dotted line represents the image plane curvature and image distortion for a wavelength of 0.528μm, and the single-point chain line represents the image plane curvature and image distortion for a wavelength of 0.544μm.

[0262] exist Fig.16H In (diopter +2, ratio A / B=0.317), the image plane forms an image on the downstream side in the tangential and sagittal planes relative to the center of the display 110. The image distortion is negative in the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0263] exist Fig.16I (Diopter -1, ratio A / B = 0.299), the image plane is formed slightly downstream in the periphery relative to the center of the display 110 on the tangential plane, and is formed downstream in the periphery relative to the center of the display 110 on the radial plane. Image distortion indicates that the distortion is negative in the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0264] exist Fig.16J In (diopter -5, ratio A / B = 0.279), the image plane is imaged on the upstream side of the periphery relative to the center of the display 110 on the tangential plane, and is imaged on the downstream side of the periphery relative to the center of the display 110 on the radial plane. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0265] In the optical device 100 of Example 4, for diopter +2, -1, and -5 (ratio A / B=0.317, 0.299, 0.279), the field curvature is within the range of ±0.2 mm, and the maximum image distortion is about -3%.

[0266] Fig.17A The detailed design of the optical device 100 of Example 5 is shown. In Example 5, Fig. 12A The optical device 100 is designed according to various parameters assigned to the lens specifications, aspheric coefficients, GPL data, and variable interval data for the model 2. In this example, the ratio A / B is given as 0.179, 0.175, and 0.171 for diopter +2, -1, and -5, respectively.

[0267] Fig. 17B , Fig. 17C and Fig.17D The following diagrams show the lateral aberrations detected for diopter +2, -1, and -5 (ratio A / B = 0.179, 0.175, 0.171) in the optical device 100 of Example 5. Here, the upper left group of figures show aberrations at the center of the image, the upper right group of figures show aberrations at the center of the upper and lower ends of the image, the lower left group of figures show aberrations at the center of the left and right ends, and the lower right group of figures show aberrations at the diagonals. Py and Px are coordinates on the aperture plane (at the position of the eye box) (the maximum scale is 4 mm), and ey and ex are the aberration amounts on the tangential plane and the sagittal plane, respectively (the maximum scale is shown in each figure). The solid line represents the aberration for a wavelength of 0.515 μm, the dotted line represents the aberration for a wavelength of 0.528 μm, and the single-dot chain line represents the aberration for a wavelength of 0.544 μm.

[0268] Fig.17E , Fig.17F and Figure 17G The spherical aberration on the optical axis detected for the diopter +2, -1, and -5 (ratio A / B = 0.179, 0.175, 0.171) in the optical device 100 of Example 5 is shown. Here, the vertical axis is the normalized pupil coordinate at the position of the eye box (the maximum scale is 4 mm), and the horizontal axis is the aberration amount. In each figure, the solid line represents the aberration for the wavelength of 0.515μm, the dotted line represents the aberration for the wavelength of 0.528μm, and the single-dot chain line represents the aberration for the wavelength of 0.544μm.

[0269] Fig.17H , Fig.17I and Fig.17J The figure shows the field curvature (left figure) and image distortion (right figure) detected for diopter +2, -1, and -5 (ratio A / B=0.179, 0.175, 0.171) in the optical device 100 of Example 5. FIG. 9A to FIG. 9CSimilarly, the image plane curvature is shown on the horizontal axis for the position relative to the center on the display surface 110 of the vertical axis (the outermost position is set to 1.0). The image plane curvature on the tangential plane and the image plane curvature on the sagittal plane are shown respectively. The image distortion is shown on the horizontal axis for the position on the diagonal relative to the center on the display surface 110 of the vertical axis. In each figure, the solid line represents the image plane curvature and image distortion for a wavelength of 0.515μm, the dotted line represents the image plane curvature and image distortion for a wavelength of 0.528μm, and the single-point chain line represents the image plane curvature and image distortion for a wavelength of 0.544μm.

[0270] exist Fig.17H In (diopter +2, ratio A / B = 0.179), the image plane vibrates greatly on the tangential plane according to the position from the center of the display 110, and forms an image on the downstream side of the periphery relative to the center, and vibrates gently on the radial plane according to the position from the center of the display 110, and forms an image slightly upstream of the center of the periphery. Image distortion indicates that the distortion is negative on the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0271] exist Fig.17I In (diopter -1, ratio A / B = 0.175), the image plane vibrates greatly on the tangential plane according to the position from the center of the display 110, and forms an image on the downstream side at the periphery relative to the center, and vibrates gently on the radial plane according to the position from the center of the display 110, and forms an image on the upstream side at the periphery relative to the center. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0272] exist Fig.17J In (diopter -5, ratio A / B = 0.171), the image plane vibrates greatly on the tangential plane according to the position from the center of the display 110, and forms an image on the upstream side at the periphery relative to the center, and changes gently on the radial plane according to the position from the center of the display 110, and forms an image on the upstream side at the periphery relative to the center. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion becomes barrel-shaped.

[0273] In the optical device 100 of Example 5, for diopter +2, -1, and -5 (ratio A / B=0.179, 0.175, 0.171), the field curvature is within the range of ±0.2 mm, and the maximum image distortion is about -2%.

[0274] Fig.18A The detailed design of the optical device 100 of Example 6 is shown. In Example 6, Fig. 12AThe optical device 100 is designed according to various parameters assigned to the lens specifications, aspheric coefficients, GPL data, and variable interval data for the model 2. In this example, the ratio A / B is given as 0.204, 0.201, and 0.196 for diopter +2, -1, and -5, respectively.

[0275] Fig.18B , Fig.18C and Fig.18D The following diagrams show the lateral aberrations detected for diopter +2, -1, and -5 (ratio A / B = 0.204, 0.201, and 0.196) in the optical device 100 of Example 6. Here, the upper left group of figures shows the aberrations at the center of the image, the upper right group of figures shows the aberrations at the center of the upper and lower ends of the image, the lower left group of figures shows the aberrations at the center of the left and right ends, and the lower right group of figures shows the aberrations at the diagonals. Py and Px are coordinates on the aperture plane (at the position of the eye box) (the maximum scale is 4 mm), and ey and ex are the aberration amounts on the tangential plane and the sagittal plane, respectively (the maximum scale is shown in each figure). The solid line represents the aberrations for a wavelength of 0.515 μm, the dotted line represents the aberrations for a wavelength of 0.528 μm, and the single-point dashed line represents the aberrations for a wavelength of 0.544 μm.

[0276] Fig.18E , Fig.18F and Figure 18G The spherical aberration on the optical axis detected for diopter +2, -1, and -5 (ratio A / B = 0.204, 0.201, 0.196) in the optical device 100 of Example 6 is shown. Here, the vertical axis is the normalized pupil coordinate at the position of the eye box (the maximum scale is 4 mm), and the horizontal axis is the aberration amount. In each figure, the solid line represents the aberration for the wavelength of 0.515μm, the dotted line represents the aberration for the wavelength of 0.528μm, and the single-dot chain line represents the aberration for the wavelength of 0.544μm.

[0277] Fig.18H , Fig.18I and Fig.18J The figure shows the field curvature (left figure) and image distortion (right figure) detected for diopter +2, -1, and -5 (ratio A / B=0.204, 0.201, 0.196) in the optical device 100 of Example 6. FIG. 9A to FIG. 9CSimilarly, the image plane curvature is shown on the horizontal axis for the position relative to the center on the display surface 110 of the vertical axis (the outermost position is set to 1.0). The image plane curvature on the tangential plane and the image plane curvature on the sagittal plane are shown respectively. The image distortion is shown on the horizontal axis for the position on the diagonal relative to the center on the display surface 110 of the vertical axis. In each figure, the solid line represents the image plane curvature and image distortion for a wavelength of 0.515μm, the dotted line represents the image plane curvature and image distortion for a wavelength of 0.528μm, and the single-point chain line represents the image plane curvature and image distortion for a wavelength of 0.544μm.

[0278] exist Fig.18H In (diopter +2, ratio A / B = 0.204), the image plane vibrates greatly in the tangential plane according to the position from the center of the display 110, and forms an image on the downstream side at the periphery relative to the center, and changes gently in the radial plane according to the position from the center of the display 110, and forms an image slightly downstream at the periphery relative to the center. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0279] exist Fig.18I In (diopter -1, ratio A / B = 0.201), the image plane greatly vibrates on the tangential plane according to the position from the center of the display 110, and forms an image on the downstream side at the periphery relative to the center, and gently changes on the radial plane according to the position from the center of the display 110, and forms an image on the upstream side at the periphery relative to the center. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion becomes barrel-shaped.

[0280] exist Fig.18J In (diopter -5, ratio A / B = 0.196), the image plane changes gently on the tangential plane according to the position from the center of the display 110, and forms an image on the upstream side at the periphery relative to the center, and changes gently on the radial plane according to the position from the center of the display 110, and forms an image on the upstream side at the periphery relative to the center. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion becomes barrel-shaped.

[0281] In the optical device 100 of Example 6, for diopter +2, -1, and -5 (ratio A / B=0.204, 0.201, 0.196), the field curvature is within the range of ±0.2 mm, and the maximum image distortion is about -3%.

[0282] Fig.19A The detailed design of the optical device 100 of Example 7 is shown. In Example 7, Fig. 12AThe optical device 100 is designed according to various parameters assigned to the lens specifications, aspheric coefficients, GPL data, and variable interval data for the model 2. In this example, the ratio A / B is given as 0.289, 0.280, and 0.269 for diopter +2, -1, and -5, respectively.

[0283] Fig.19B , Fig.19C and Fig.19D The following diagrams show the lateral aberrations detected for diopter +2, -1, and -5 (ratio A / B = 0.289, 0.280, and 0.269) in the optical device 100 of Example 7. Here, the upper left group of figures show aberrations at the center of the image, the upper right group of figures show aberrations at the center of the upper and lower ends of the image, the lower left group of figures show aberrations at the center of the left and right ends, and the lower right group of figures show aberrations at the diagonals. Py and Px are coordinates on the aperture plane (at the position of the eye box) (the maximum scale is 4 mm), and ey and ex are the aberration amounts on the tangential plane and the sagittal plane, respectively (the maximum scale is shown in each figure). The solid line represents the aberration for a wavelength of 0.515 μm, the dotted line represents the aberration for a wavelength of 0.528 μm, and the single-point dashed line represents the aberration for a wavelength of 0.544 μm.

[0284] Fig.19E , Fig.19F and Figure 19G The spherical aberration on the optical axis detected for diopter +2, -1, and -5 (ratio A / B = 0.289, 0.280, 0.269) in the optical device 100 of Example 7 is shown. Here, the vertical axis is the normalized pupil coordinate at the position of the eye box (the maximum scale is 4 mm), and the horizontal axis is the aberration amount. In each figure, the solid line represents the aberration for the wavelength of 0.515μm, the dotted line represents the aberration for the wavelength of 0.528μm, and the single-dot chain line represents the aberration for the wavelength of 0.544μm.

[0285] Fig.19H , Fig.19I and Fig.19J The figure shows the field curvature (left figure) and image distortion (right figure) detected for diopter +2, -1, and -5 (ratio A / B=0.289, 0.280, 0.269) in the optical device 100 of Example 7. FIG. 9A to FIG. 9CSimilarly, the image plane curvature is shown on the horizontal axis for the position relative to the center on the display surface 110 of the vertical axis (the outermost position is set to 1.0). The image plane curvature on the tangential plane and the image plane curvature on the sagittal plane are shown respectively. The image distortion is shown on the horizontal axis for the position on the diagonal relative to the center on the display surface 110 of the vertical axis. In each figure, the solid line represents the image plane curvature and image distortion for a wavelength of 0.515μm, the dotted line represents the image plane curvature and image distortion for a wavelength of 0.528μm, and the single-point chain line represents the image plane curvature and image distortion for a wavelength of 0.544μm.

[0286] exist Fig.19H In (diopter +2, ratio A / B = 0.289), the image plane greatly vibrates on the tangential plane according to the position from the center of the display 110, and forms an image on the downstream side at the periphery relative to the center, and gently changes on the radial plane according to the position from the center of the display 110, and forms an image slightly downstream at the periphery relative to the center. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0287] exist Fig.19I In (diopter -1, ratio A / B = 0.280), the image plane vibrates greatly on the tangential plane according to the position from the center of the display 110, and forms an image on the upstream side of the periphery relative to the center, and gently changes on the radial plane according to the position from the center of the display 110, and forms an image slightly downstream of the center at the periphery. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0288] exist Fig.19J In (diopter -5, ratio A / B = 0.269), the image plane changes gently on the tangential plane according to the position from the center of the display 110, and forms an image on the upstream side of the periphery relative to the center, and does not change substantially on the radial plane relative to the position from the center of the display 110, and forms an image at a constant position. Image distortion indicates that the distortion is negative on the periphery relative to the center of the display 110, that is, the image distortion becomes barrel-shaped.

[0289] In the optical device 100 of Example 7, with respect to the diopter +2, -1, and -5

[0290] (ratio A / B = 0.289, 0.280, 0.269), the image plane curvature is within the range of ±0.2mm, and the maximum image distortion is about -2%.

[0291] Fig. 20A The detailed design of the optical device 100 of Example 8 is shown. In Example 8, Fig. 12AThe optical device 100 is designed according to various parameters assigned to the lens specifications, aspheric coefficients, GPL data, and variable interval data for the model 3. In this example, the ratio A / B is given as 0.173, 0.170, and 0.166 for diopter +2, -1, and -5, respectively.

[0292] Fig. 20B , Fig. 20C and Fig.20D The following diagrams show the lateral aberrations detected for diopter +2, -1, and -5 (ratio A / B = 0.173, 0.170, 0.166) in the optical device 100 of Example 8. Here, the upper left group of figures show aberrations at the center of the image, the upper right group of figures show aberrations at the center of the upper and lower ends of the image, the lower left group of figures show aberrations at the center of the left and right ends, and the lower right group of figures show aberrations at the diagonals. Py and Px are coordinates on the aperture plane (at the position of the eye box) (the maximum scale is 4 mm), and ey and ex are the aberration amounts on the tangential plane and the sagittal plane, respectively (the maximum scale is shown in each figure). The solid line represents the aberration for a wavelength of 0.515 μm, the dotted line represents the aberration for a wavelength of 0.528 μm, and the single-point dashed line represents the aberration for a wavelength of 0.544 μm.

[0293] Fig.20E , Fig.20F and Figure 20G The spherical aberration on the optical axis detected for diopter +2, -1, and -5 (ratio A / B = 0.173, 0.170, 0.166) in the optical device 100 of Example 8 is shown. Here, the vertical axis is the normalized pupil coordinate at the position of the eye box (the maximum scale is 4 mm), and the horizontal axis is the aberration amount. In each figure, the solid line represents the aberration for the wavelength of 0.515μm, the dotted line represents the aberration for the wavelength of 0.528μm, and the single-dot chain line represents the aberration for the wavelength of 0.544μm.

[0294] Fig. 20H , Fig.20I and Fig. 20J The figure shows the field curvature (left figure) and image distortion (right figure) detected for diopter +2, -1, and -5 (ratio A / B = 0.173, 0.170, 0.166) in the optical device 100 of Example 8. FIG. 9A to FIG. 9CSimilarly, the image plane curvature is shown on the horizontal axis for the position relative to the center on the display surface 110 of the vertical axis (the outermost position is set to 1.0). The image plane curvature on the tangential plane and the image plane curvature on the sagittal plane are shown respectively. The image distortion is shown on the horizontal axis for the position on the diagonal relative to the center on the display surface 110 of the vertical axis. In each figure, the solid line represents the image plane curvature and image distortion for a wavelength of 0.515μm, the dotted line represents the image plane curvature and image distortion for a wavelength of 0.528μm, and the single-point chain line represents the image plane curvature and image distortion for a wavelength of 0.544μm.

[0295] exist Fig. 20H In (diopter +2, ratio A / B = 0.173), the image plane greatly vibrates on the tangential plane according to the position from the center of the display 110, and forms an image on the downstream side of the periphery relative to the center, and gently changes on the radial plane according to the position from the center of the display 110, and forms an image slightly upstream of the center of the periphery. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0296] exist Fig.20I In (diopter -1, ratio A / B = 0.170), the image plane vibrates greatly on the tangential plane according to the position from the center of the display 110, and forms an image on the upstream side at the periphery relative to the center, and gently changes on the radial plane according to the position from the center of the display 110, and forms an image on the downstream side at the periphery relative to the center. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion becomes barrel-shaped.

[0297] exist Fig. 20J In (diopter -5, ratio A / B = 0.166), the image plane changes greatly on the tangential plane according to the position from the center of the display 110, and forms an image on the upstream side at the periphery relative to the center, and changes gently on the radial plane according to the position from the center of the display 110, and forms an image on the upstream side at the periphery relative to the center. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion becomes barrel-shaped.

[0298] In the optical device 100 of Example 8, for diopter +2, -1, and -5 (ratio A / B=0.173, 0.170, 0.166), the field curvature is within the range of ±0.2 mm, and the maximum image distortion is about -2%.

[0299] Fig.21A The detailed design of the optical device 100 of Example 9 is shown. In Example 9, Fig. 12AThe optical device 100 is designed according to various parameters assigned to the lens specifications, aspheric coefficients, GPL data, and variable interval data for the model 3. In this example, the ratio A / B is given as 0.215, 0.210, and 0.203 for diopter +2, -1, and -5, respectively.

[0300] Fig. 21B , Fig. 21C and Fig.21D The following diagrams show the lateral aberrations detected for diopter +2, -1, and -5 (ratio A / B = 0.215, 0.210, and 0.203) in the optical device 100 of Example 9. Here, the upper left group of figures show aberrations at the center of the image, the upper right group of figures show aberrations at the center of the upper and lower ends of the image, the lower left group of figures show aberrations at the center of the left and right ends, and the lower right group of figures show aberrations at the diagonals. Py and Px are coordinates on the aperture plane (at the position of the eye box) (the maximum scale is 4 mm), and ey and ex are the aberration amounts on the tangential plane and the sagittal plane, respectively (the maximum scale is shown in each figure). The solid line represents the aberration for a wavelength of 0.515 μm, the dotted line represents the aberration for a wavelength of 0.528 μm, and the single-point dashed line represents the aberration for a wavelength of 0.544 μm.

[0301] Fig.21E , Fig.21F and Figure 21G The spherical aberration on the optical axis detected for the diopter +2, -1, and -5 (ratio A / B = 0.215, 0.210, 0.203) in the optical device 100 of Example 9 is shown. Here, the vertical axis is the normalized pupil coordinate at the position of the eye box (the maximum scale is 4 mm), and the horizontal axis is the aberration amount. In each figure, the solid line represents the aberration for the wavelength of 0.515μm, the dotted line represents the aberration for the wavelength of 0.528μm, and the single-dot chain line represents the aberration for the wavelength of 0.544μm.

[0302] Fig.21H , Fig.21I and Fig.21J The figure shows the field curvature (left figure) and image distortion (right figure) detected for diopter +2, -1, and -5 (ratio A / B=0.215, 0.210, 0.203) in the optical device 100 of Example 9. FIG. 9A to FIG. 9CSimilarly, the image plane curvature is shown on the horizontal axis for the position relative to the center on the display surface 110 of the vertical axis (the outermost position is set to 1.0). The image plane curvature on the tangential plane and the image plane curvature on the sagittal plane are shown respectively. The image distortion is shown on the horizontal axis for the position on the diagonal relative to the center on the display surface 110 of the vertical axis. In each figure, the solid line represents the image plane curvature and image distortion for a wavelength of 0.515μm, the dotted line represents the image plane curvature and image distortion for a wavelength of 0.528μm, and the single-point chain line represents the image plane curvature and image distortion for a wavelength of 0.544μm.

[0303] exist Fig.21H In (diopter +2, ratio A / B = 0.215), the image plane vibrates greatly in the tangential plane according to the position from the center of the display 110, and forms an image on the downstream side at the periphery relative to the center, and changes gently in the radial plane according to the position from the center of the display 110, and forms an image slightly downstream at the periphery relative to the center. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0304] exist Fig.21I In (diopter -1, ratio A / B = 0.210), the image plane vibrates greatly on the tangential plane according to the position from the center of the display 110, and forms an image on the downstream side at the periphery relative to the center, and changes gently on the radial plane according to the position from the center of the display 110, and forms an image on the upstream side at the periphery relative to the center. Image distortion indicates that the distortion is negative at the periphery relative to the center of the display 110, that is, the image distortion becomes barrel-shaped.

[0305] exist Fig.21J (Diopter -5, ratio A / B = 0.203), the image plane changes gently in the tangential plane according to the position from the center of the display 110, and forms an image on the upstream side of the periphery relative to the center, and changes gently in the radial plane according to the position from the center of the display 110, and forms an image on the upstream side of the periphery relative to the center. In addition, basically no wavelength dependence is found. Image distortion shows negative distortion in the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0306] In the optical device 100 of Example 9, for diopter +2, -1, and -5 (ratio A / B=0.215, 0.210, 0.203), the field curvature is within the range of ±0.2 mm, and the maximum image distortion is about -2%.

[0307] Fig.22A The detailed design of the optical device 100 of the embodiment 10 is shown. In the embodiment 10, Fig. 12AThe optical device 100 is designed according to various parameters assigned to the lens specifications, aspheric coefficients, GPL data, and variable interval data for the model 3. In this example, the ratio A / B is given as 0.301, 0.280, and 0.257 for diopter +2, -1, and -5, respectively.

[0308] Fig. 22B , Fig. 22C and Fig.22D The following diagrams show the lateral aberrations detected for diopter +2, -1, and -5 (ratio A / B = 0.301, 0.280, and 0.257) in the optical device 100 of Example 10. Here, the upper left group of figures show aberrations at the center of the image, the upper right group of figures show aberrations at the center of the upper and lower ends of the image, the lower left group of figures show aberrations at the center of the left and right ends, and the lower right group of figures show aberrations at the diagonals. Py and Px are coordinates on the aperture plane (at the position of the eye box) (the maximum scale is 4 mm), and ey and ex are the aberration amounts on the tangential plane and the sagittal plane, respectively (the maximum scale is shown in each figure). The solid line represents the aberration for a wavelength of 0.515 μm, the dotted line represents the aberration for a wavelength of 0.528 μm, and the single-point dashed line represents the aberration for a wavelength of 0.544 μm.

[0309] Fig.22E , Fig.22F and Figure 22G The spherical aberration on the optical axis detected for diopter +2, -1, and -5 (ratio A / B = 0.301, 0.280, 0.257) in the optical device 100 of Example 10 is shown. Here, the vertical axis is the normalized pupil coordinate at the position of the eye box (the maximum scale is 4 mm), and the horizontal axis is the aberration amount. In each figure, the solid line represents the aberration for the wavelength of 0.515μm, the dotted line represents the aberration for the wavelength of 0.528μm, and the single-dot chain line represents the aberration for the wavelength of 0.544μm.

[0310] Fig.22H , Fig.22I and Fig.22J The figure shows the field curvature (left figure) and image distortion (right figure) detected for diopter +2, -1, and -5 (ratio A / B=0.301, 0.280, 0.257) in the optical device 100 of Example 10. FIG. 9A to FIG. 9CSimilarly, the image plane curvature is shown on the horizontal axis for the position relative to the center on the display surface 110 of the vertical axis (the outermost position is set to 1.0). The image plane curvature on the tangential plane and the image plane curvature on the sagittal plane are shown respectively. The image distortion is shown on the horizontal axis for the position on the diagonal relative to the center on the display surface 110 of the vertical axis. In each figure, the solid line represents the image plane curvature and image distortion for a wavelength of 0.515μm, the dotted line represents the image plane curvature and image distortion for a wavelength of 0.528μm, and the single-point chain line represents the image plane curvature and image distortion for a wavelength of 0.544μm.

[0311] exist Fig.22H (diopter +2, ratio A / B = 0.301), the image plane vibrates greatly in the tangential plane according to the position from the center of the display 110, and forms an image on the downstream side at the periphery relative to the center, and changes gently in the radial plane according to the position from the center of the display 110, and forms an image on the downstream side at the periphery relative to the center. In addition, wavelength dependence is basically not found. Image distortion shows negative distortion at the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0312] exist Fig.22I (Diopter -1, ratio A / B = 0.280), the image plane vibrates greatly on the tangential plane according to the position from the center of the display 110, and forms an image on the upstream side of the periphery relative to the center, and gently changes on the radial plane according to the position from the center of the display 110, and forms an image slightly downstream of the center of the periphery. In addition, basically no wavelength dependence is found. Image distortion shows negative distortion on the periphery relative to the center of the display 110, that is, the image distortion is barrel-shaped.

[0313] exist Fig.22J (Diopter -5, ratio A / B = 0.257), the image plane changes gently on the tangential plane according to the position from the center of the display 110, and forms an image on the upstream side of the periphery relative to the center, and does not change on the radial plane, and forms an image at a substantially constant position. In addition, basically no wavelength dependence is found. Image distortion shows negative distortion in the periphery relative to the center of the display 110, that is, the image distortion becomes barrel-shaped.

[0314] In the optical device 100 of Example 10, for diopter +2, -1, and -5 (ratio A / B=0.301, 0.280, 0.257), the field curvature is within the range of ±0.2 mm, and the maximum image distortion is about -2%.

[0315] Based on the results of the image plane curvature and image distortion in Examples 1 to 10, by making the ratio A / B of the focal length A of the entire optical system 300 relative to the focal length B of the lens 310 within the range of 0.166 to 0.317, or by making the ratio A / B within the range of 0.173 to 0.317 for the diopter +2, making the ratio A / B within the range of 0.170 to 0.299 for the diopter -1, and making the ratio A / B within the range of 0.166 to 0.279 for the diopter -5, it is possible to obtain good imaging characteristics regardless of the detailed design of the lens 310, and regardless of whether chromatic aberration correction is performed using the GPH element (GPL element) and the CSF element, etc., and the detailed design of the diffractive optical element 200.

[0316] In addition, regarding the Fig. 12A In the embodiments 1 to 4 of the optical device 100 designed by the model 1, the results of the embodiment 2 are compared with the results of the embodiment 1, and it can be seen that the lateral aberration, spherical aberration, field curvature, and image distortion are relatively good. The results of the embodiment 3 are compared with the results of the embodiment 4, and it can be seen that the lateral aberration, spherical aberration, field curvature, and image distortion are relatively good. Therefore, it can be seen that in terms of the ratio A / B of the focal length A of the entire optical system 300 to the focal length B of the lens 310, there is a range in which good imaging characteristics can be obtained, and relatively good imaging characteristics can be obtained within the above range relative to those outside the range.

[0317] In addition, the optical device 100 of the present embodiment maintains the relative positional relationship of the display 110, the diffractive optical element 200, and the lens 310 (half-reflecting mirror surface 311) by using the moving device 410, and moves them relative to the filter 320 (reflective polarizing plate 321), but as long as at least the separation distance between the filter 320 (reflective polarizing plate 321) and the lens 310 (half-reflecting mirror surface 311) can be changed, a structure in which the display 110, the diffractive optical element 200, the lens 310, and the filter 320 are moved may be adopted. For example, the lens 310 may be moved relative to the filter 320 and the display 110 may be moved relative to the lens 310. Without being limited to this, the relative positions of the filter 320 and the lens 310 may be maintained, and the display 110 may be moved relative to them.

[0318] The optical device 100 of this embodiment includes a display 110 for displaying an image, an optical system 300, and a moving device 410, wherein the optical system 300 includes a filter 320 (reflective polarizing plate 321) and a lens 310 (half-mirror surface 311) arranged on the downstream side and the upstream side, respectively, on the optical axis L of the display 110, and at least the lens 310 (half-mirror surface 311) magnifies the image, and the moving device 410 moves at least one of the filter 320, the lens 310, and the display 110 along the optical axis L. Thus, by folding the optical path twice between the filter 320 and the lens 310 included in the optical system 300 and magnifying the image by the lens 310 (half-mirror surface 311), the position of the magnified virtual image can be adjusted according to the user's visual acuity.

[0319] In addition, the optical system 300 and the moving device 410 in the optical device 100 of this embodiment are an example of a diopter optical system and a diopter adjustment mechanism for adjusting the position of the magnified virtual image according to the user's vision. By having them, the optical device 100 can be small, light and thin and have high optical performance within the diopter adjustment range.

[0320] In addition, although the optical device 100 of this embodiment moves the lens 310 (half mirror 311) relative to the filter 320 (reflective polarizing plate 321), a lens having a variable surface shape or a variable lens power may be used instead of the movable lens 310.

[0321] Fig.23 The structure of an optical device 101 according to a modified example is schematically shown. The optical device 100 includes a display 110 , a diffractive optical element 200 , an optical system 300 , a control device 390 , and a housing 400 .

[0322] The display 110 and the diffractive optical element 200 are configured similarly to those in the above-described embodiment.

[0323] The optical system 300 is a three-pass optical system that is thinned by folding the optical path twice by two reflecting surfaces, and includes a filter 320 and a lens 330 that are arranged on the downstream side and the upstream side, respectively, on the optical axis L. The optical system 300 diffuses the image light 50 to enlarge the image by changing the variable surface shape or lens magnification of the lens 330.

[0324] The optical filter 320 is configured similarly to the above-described embodiment.

[0325] As the lens 330, for example, a liquid lens can be used, which changes the shape of the boundary surface between liquids with different refractive indices by adjusting the applied voltage, thereby realizing a variable surface shape. In this case, a half-reflecting mirror surface 331 is provided as an example of a second transmissive reflective surface on the end surface on the upstream side of the lens 330. Here, the variable surface shape is formed into an aspherical shape in which the curved surface angle increases or decreases according to the distance from the center. For example, Figure 2A As shown, the surface shape is formed such that the surface position Z shifts as it moves away from the center toward the outside, and the amount of change Δθ of the curved surface angle tends to decrease as it moves away from the center toward the outside.

[0326] In addition, as the lens 330, a liquid crystal lens can be used, which effectively changes the refractive index by adjusting the orientation of the liquid crystal by adjusting the applied voltage, thereby realizing a variable lens magnification. In this case, a half-reflective mirror surface 331 as an example of a second transmissive reflective surface is provided on the end surface on the upstream side of the lens 330. Here, the variable lens magnification is generated in a manner equivalent to an aspherical surface whose curved surface angle increases or decreases according to the distance from the center. For example, Figure 2A As shown, it is generated in a manner corresponding to a surface shape in which the position Z shifts as the surface moves away from the center toward the outside, and the amount of change Δθ of the curved surface angle tends to decrease as it moves away from the center toward the outside.

[0327] The control device 390 is a device that controls each unit constituting the optical device 101. The control device 390 adjusts the applied voltage to the lens 330 to control the variable surface shape or the variable lens power.

[0328] The housing 400 accommodates the display 110 , the diffractive optical element 200 , and the optical system 300 .

[0329] The principle by which the optical device 101 guides the image light 50 of the display 110 toward the eye 30 of the user will be described.

[0330] Display 110 generates image light 50 which is unpolarized light.

[0331] The image light 50 output from the display 110 enters the diffractive optical element 200. The image light 50 is modulated into right-handed circularly polarized light and chromatic aberration is compensated, and is output to the downstream side from the diffractive optical element 200. The details are the same as those of the above embodiment.

[0332] The image light 50 output from the diffractive optical element 200 enters the optical system 300. In the optical system 300, the image light 50 is first incident on the lens 330. Thus, regardless of the polarization state, the image light 50 of half intensity is transmitted through the half mirror surface 331, amplified by the lens action and output to the downstream side, and the image light 50 of the remaining half intensity is reflected by the half mirror surface 331.

[0333] The image light 50 then enters the optical filter 320. The image light 50 is modulated into left-handed circularly polarized light and is reflected and output to the upstream side from the optical filter 320. The details are the same as those of the above-described embodiment.

[0334] The image light 50 enters the lens 330 from the downstream side. Thus, the image light 50 is amplified by the lens effect, half of the intensity of the image light 50 is reflected by the half mirror 331, further amplified by the lens effect and output to the downstream side, and the remaining half of the intensity of the image light 50 is transmitted through the half mirror 331.

[0335] The image light 50 is incident again on the filter 320. The image light 50 is modulated into horizontal linear polarized light, passes through the filter 320, and is output to the downstream side. The details are the same as those in the above embodiment.

[0336] After passing through the lens 330 once in the optical system 300 , the image light 50 is reflected by the filter 320 and reciprocates in the lens 330 , and is further amplified by the lens action of the lens 330 , output to the downstream side, and then guided to the user's eye 30 .

[0337] In addition, the optical device 100 of this embodiment amplifies the image light 50 of the display 110 and guides it to one eye 30 of the user, and adjusts the position of the amplified virtual image. In other words, the optical device 100 includes the diffractive optical element 200 and the optical system 300 for only one of the left eye and the right eye 30. It is also possible to configure a binocular optical device in the following manner: the optical device 100, that is, the diffractive optical element 200 and the optical system 300 of the above-mentioned structure are respectively provided for the two eyes 30.

[0338] In addition, the optical device 100 of this embodiment is configured to use immersive virtual reality (VR) technology to amplify the image light 50 of the display 110 and guide it to the user's eyes 30, but can also be configured to use augmented reality (AR) technology to superimpose the image light 50 of the display 110 with external light and guide it to the user's eyes 30.

[0339] The present invention has been described above using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. According to the description of the claims, the above-mentioned changes or improvements are also included in the technical scope of the present invention.

[0340] It should be noted that the execution order of each process such as actions, sequences, steps, and stages in the devices, systems, programs, and methods shown in the claims, specifications, and drawings can be implemented in any order unless "before" or "prior to" is specifically stated, and the output of the pre-processing is not used for the post-processing. Even if the action flow in the claims, specifications, and drawings is described using "first" or "next" for convenience, it does not have to be implemented in that order.

[0341] Description of Reference Numerals

[0342] 30-eye; 50-image light; 51-central light; 52-peripheral light; 100, 101-optical device; 110-display; 200-diffractive optical element; 300-optical system; 310-lens; 311-semi-reflective mirror; 320-filter; 321-reflective polarizing plate; 330-lens; 331-semi-reflective mirror; 390-control device; 400-housing; 410, 411, 412-moving device; 420-first shell; 420a-inner space; 421-main body; 421a-slit; 422-first flange; 422a-opening; 423-second flange; 430, 431, 432-guide ring; 430a, 431a, 432a-slit; 432b-tunnel; 440-second shell; 441-guide pin; L-optical axis.

Claims

1. An optical device for generating a magnified virtual image of an image, wherein: The optical device comprises: a display that outputs image light that forms an image; an optical system that magnifies the image and includes a first transmissive reflection surface and a second transmissive reflection surface arranged on an optical axis of the display on an eye point side and a display side, respectively, and a lens element in which the second transmissive reflection surface is provided on one surface on the display side, the first transmissive reflection surface transmitting or reflecting at least a portion of the image light, and the second transmissive reflection surface being an aspherical curved surface in which a change amount of a curved surface angle continuously increases or decreases according to a distance from a center, and transmitting or reflecting at least a portion of the image light; A moving device is configured to relatively move at least the second transmissive reflective surface along the optical axis relative to the first transmissive reflective surface.

2. The optical device according to claim 1, characterized in that The moving device further moves the display while maintaining a relative positional relationship with the second transmissive reflective surface.

3. The optical device according to claim 1 or 2, characterized in that: The first transflective surface reflects at least a portion of the image light that has transmitted the second transflective surface, and transmits at least a portion of the image light that has been reflected by the second transflective surface.

4. The optical device according to claim 3, characterized in that The first transmissive reflective surface is a polarizing element that reflects one of mutually orthogonal linear polarized lights and transmits the other.

5. The optical device according to claim 1, characterized in that The second transmissive reflective surface transmits at least a portion of the image light emitted from the display, and reflects a portion of the image light reflected by the first transmissive reflective surface and returned.

6. The optical device according to claim 2, characterized in that The second transmissive reflective surface transmits at least a portion of the image light emitted from the display, and reflects a portion of the image light reflected by the first transmissive reflective surface and returned.

7. The optical device according to claim 3, characterized in that The second transmissive reflective surface transmits at least a portion of the image light emitted from the display, and reflects a portion of the image light reflected by the first transmissive reflective surface and returned.

8. The optical device according to claim 4, characterized in that The second transmissive reflective surface transmits at least a portion of the image light emitted from the display, and reflects a portion of the image light reflected by the first transmissive reflective surface and returned.

9. The optical device according to any one of claims 1, 2 and 4 to 8, characterized in that: The optical device further includes a diffractive optical element disposed between the display and the second transmissive reflective surface.

10. The optical device according to claim 3, characterized in that The optical device further includes a diffractive optical element disposed between the display and the second transmissive reflective surface.

11. The optical device according to claim 9, characterized in that The diffractive optical element includes a GPH element that compensates for the wavelength dispersion of the optical system.

12. The optical device according to claim 10, characterized in that The diffractive optical element includes a GPH element that compensates for the wavelength dispersion of the optical system.

13. The optical device according to claim 11, characterized in that The diffractive optical element includes an unnecessary light removing element that removes unnecessary light on the eye point side of the GPH element.

14. The optical device according to claim 12, characterized in that The diffractive optical element includes an unnecessary light removing element that removes unnecessary light on the eye point side of the GPH element.

15. The optical device according to claim 13, characterized in that The unnecessary light removing element includes a λ / 4 plate and a linear polarizing plate.

16. The optical device according to claim 14, characterized in that The unnecessary light removing element includes a λ / 4 plate and a linear polarizing plate.

17. The optical device according to any one of claims 1, 2, 4 to 8 and 10 to 14, characterized in that The optical device further includes a control device that changes a distortion correction value of the image according to a state of the optical system.

18. The optical device according to claim 3, characterized in that The optical device further includes a control device that changes a distortion correction value of the image according to a state of the optical system.

19. The optical device according to claim 9, characterized in that The optical device further includes a control device that changes a distortion correction value of the image according to a state of the optical system.

20. The optical device according to any one of claims 1, 2, 4 to 8 and 10 to 14, characterized in that The optical device further includes a housing that accommodates the display and the optical system. The first transmissive reflective surface is held by the housing, and the second transmissive reflective surface moves along the optical axis in the housing.

21. The optical device according to claim 3, characterized in that The optical device further includes a housing that accommodates the display and the optical system. The first transmissive reflective surface is held by the housing, and the second transmissive reflective surface moves along the optical axis in the housing.

22. The optical device according to claim 9, characterized in that The optical device further includes a housing that accommodates the display and the optical system. The first transmissive reflective surface is held by the housing, and the second transmissive reflective surface moves along the optical axis in the housing.

Images