Virtual image display device and optical unit

Abstract

To increase the angle of view while avoiding an increase in the size of the entire optical system.SOLUTION: Virtual image display devices 100A, 100B, and an optical unit 100 each include: an illumination device 10a; a projection optical system 12 that forms illumination light IL emitted from the illumination device 10a into an image; a transmission type imager 22 that is arranged at an image formation position of the illumination light IL, and forms video light ML corresponding to the illumination light IL; a mirror for illumination light 14 that selectively reflects the illumination light IL from the projection optical system 12 toward the transmission type imager 22; and a polarizing lens 50 that is arranged on a face side of the transmission type imager 22 and the mirror for illumination light 14, and has a refractive power selectively acting on polarized light of the video light ML.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a virtual image display device and an optical unit that enable the observation of a virtual image, and more particularly to a see-through type virtual image display device that enables the viewing of an external image. [Background technology]

[0002] A known see-through virtual image display device that enables viewing of the outside world includes a liquid crystal panel having an image display area and a transparent display area surrounding the image display area, and a light guide plate that guides backlight incident from a light source to an edge of the panel. The light guide plate has a light-emitting area that irradiates the image display area of ​​the liquid crystal panel with the backlight and a light-transmitting area that transmits ambient light (Patent Document 1). This display device is configured so that ambient light reaches the viewer through the light-transmitting area of ​​the light guide plate and the transparent display area of ​​the liquid crystal panel, and also so that ambient light reaches the viewer by passing through the light-emitting area of ​​the light guide plate and the image display area of ​​the liquid crystal panel during periods when backlight is not irradiated onto the image display area. This configuration achieves a see-through display in which image light and ambient light are superimposed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2016 / 056298 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above device, the light-emitting area of ​​the light guide plate is processed by forming dots and applying scattering material, etc., and since ambient light passing through the image display area of ​​the liquid crystal panel passes through the processed light-emitting area, the see-through transmittance decreases near the center of the field of view corresponding to the image display area. [Means for solving the problem]

[0005] A virtual image display device according to one aspect of the present invention includes an illumination device, a projection optical system that forms an image of illumination light emitted from the illumination device, a transmissive imager that is disposed at the imaging position of the illumination light and forms image light corresponding to the illumination light, an illumination light mirror that selectively reflects the illumination light from the projection optical system toward the transmissive imager, and a polarized lens that is disposed on the face side of the transmissive imager and has a refractive power that selectively acts on the polarization of the image light. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 2 is an external perspective view illustrating a wearing state of the virtual image display device of the first embodiment. [Figure 2] FIG. 2 is a side view illustrating the optical structure of a display optical system. [Figure 3] FIG. 2 is a conceptual perspective view illustrating the optical structure of a display optical system. [Figure 4] FIG. 2 is a conceptual perspective view illustrating the arrangement of an image forming optical system and a composite display member. [Figure 5] FIG. 2 is a diagram illustrating the angular characteristics of a dielectric multilayer mirror. [Figure 6] FIG. 2 is a conceptual enlarged perspective view illustrating a sub-pixel of a composite display member. [Figure 7A] FIG. 2 is a plan view illustrating a light blocking member. [Figure 7B] FIG. 1 is a plan view illustrating a transmission type imager. [Figure 7C] FIG. 2 is a plan view illustrating a patterned polarization member. [Figure 8] 10A and 10B are diagrams illustrating the irradiation state of sub-pixel spots in a pixel block. [Figure 9] FIG. 10 is a diagram illustrating a virtual image display device according to a modified example. [Figure 10] FIG. 10 is a conceptual diagram illustrating an optical operation in a modified example. [Figure 11] FIG. 10 is a diagram illustrating a virtual image display device according to a second embodiment. [Figure 12] 1 is a diagram illustrating wavelength characteristics of reflection and transmission of a dielectric multilayer mirror. FIG. [Figure 13] 10A and 10B are diagrams illustrating the irradiation state of sub-pixel spots in a pixel block. [Figure 14] FIG. 10 is a diagram illustrating a virtual image display device according to a third embodiment. [Figure 15] 10A and 10B are diagrams illustrating the irradiation state of sub-pixel spots in a pixel block. DETAILED DESCRIPTION OF THE INVENTION

[0007] [First embodiment] Hereinafter, a virtual image display device and the like according to a first embodiment of the present invention will be described with reference to FIGS.

[0008] FIG. 1 is a perspective view illustrating a state in which a head-mounted display, i.e., a head-mounted display device 200, is worn. The head-mounted display device (hereinafter also referred to as HMD) 200 allows an observer or wearer US wearing it to recognize an image as a virtual image. In FIG. 1 and other figures, X, Y, and Z represent a Cartesian coordinate system, with the +X direction corresponding to the lateral direction in which the eyes EY of the observer or wearer US wearing the HMD 200 are aligned, the +Y direction corresponding to the upward direction perpendicular to the lateral direction in which the eyes EY are aligned for the wearer US, and the +Z direction corresponding to the forward or front direction for the wearer US. The ±Y directions are parallel to the vertical axis or vertical direction.

[0009] The HMD 200 includes a first virtual image display device 100A for the right eye, a second virtual image display device 100B for the left eye, a pair of temples 100C supporting the virtual image display devices 100A and 100B, and a user terminal 90 serving as an information terminal. The first virtual image display device 100A includes a first display driver 102a disposed at the top, a first display optical system 103a that covers the area in front of the user's eyes, and a light-transmitting cover 104a that covers the first display optical system 103a on the outside or front side. The second virtual image display device 100B includes a second display driver 102b disposed at the top, a second display optical system 103b that covers the area in front of the user's eyes, and a light-transmitting cover 104b that covers the second display optical system 103b on the outside or front side. The HMD 200, which combines the first virtual image display device 100A and the second virtual image display device 100B, can also be considered a virtual image display device in a broad sense. The pair of temples 100C are wearing members or support devices 106 that are worn on the head of the wearer US. The temples 100C support the upper end sides of the pair of display optical systems 103a, 103b and the upper end sides of the pair of light-transmitting covers 104a, 104b via display driving units 102a, 102b that are integrated in appearance. The combination of the pair of display driving units 102a, 102b is called the driving device 102. The combination of the pair of light-transmitting covers 104a, 104b is called the shade 104.

[0010] FIG. 2 is a conceptual side view illustrating the structure of the first display optical system 103a, FIG. 3 is a conceptual perspective view mainly illustrating the illumination optical system of the first display optical system 103a, and FIG. 4 is a conceptual perspective view mainly illustrating the observation optical system of the first display optical system 103a.

[0011] The first display optical system 103a includes an image-forming optical system 10, a composite display element 20, and a polarizing lens 50. The main body of the image-forming optical system 10 is disposed above the composite display element 20 so that illumination light IL is irradiated onto the transmissive imager 22 of the composite display element 20. The transmissive imager 22 functions as a screen for the illumination light IL from the image-forming optical system 10. The composite display element 20 and the polarizing lens 50 are disposed apart from each other along the optical axis AX. An illumination light mirror 14 of the image-forming optical system 10 is disposed between the composite display element 20 and the polarizing lens 50 and near the polarizing lens 50. In the first display optical system 103a, the distance between the polarizing lens 50 and the eye EY is, for example, approximately 10 mm to 20 mm. The distance between the polarizing lens 50 and the composite display element 20 or the transmissive imager 22 is, for example, approximately 10 mm to 25 mm.

[0012] The image forming optical system 10 forms a two-dimensional image and emits blue illumination light IL from this image. The image forming optical system 10 includes an image display panel 11, a projection optical system 12, an illumination light mirror 14, and a display control device 88. The image forming optical system 10 projects the blue emission light emitted from the display surface 11d of the image display panel 11 as illumination light IL onto a two-dimensionally arranged display area 22e provided on the projection surface DS of the transmissive imager 22. In the display area 22e of the transmissive imager 22, blue image light ML corresponding to the illumination light IL and green and red image light ML as fluorescence are formed, and these image lights ML are emitted toward the polarizing lens 50. In other words, a color image to be displayed is formed on the projection surface DS of the transmissive imager 22 and can be viewed from the polarizing lens 50 side, i.e., the wearer US side.

[0013] The image display panel 11 is a self-luminous image light generating device and functions as an illumination device 10a that emits blue illumination light IL. The image display panel 11 is, for example, an organic EL (organic electro-luminescence) display, and forms blue still or moving images on a two-dimensional display surface 11d. The image display panel 11 is driven by a display control device 88 to perform display operations. The image display panel 11 is not limited to an organic EL display, and can be replaced with a display device that uses an inorganic EL, an organic LED, an LED array, a laser array, a quantum dot light-emitting element, or the like.

[0014] The projection optical system 12 includes a lens 12a and a prism mirror 12b. The projection optical system 12 is an imaging optical system that projects an image on the display surface 11d of the image display panel 11 onto the projection surface DS of the transmissive imager 22 via an illumination light mirror 14, with the display surface 11d and the projection surface DS being in a conjugate relationship. The illumination light mirror 14 is an angle-selective mirror MR1 that reflects illumination light IL having an incident angle equal to or greater than a predetermined angle, and selectively reflects illumination light IL from the image display panel 11 while transmitting video light ML and external light OL.

[0015] In the projection optical system 12, the lens 12a receives the illumination light IL emitted from the image display panel 11 and directs it to the prism mirror 12b. The entrance surface 12i of the lens 12a is, for example, a flat surface or a free-form surface, and the exit surface 12j of the lens 12a is, for example, a free-form surface. The entrance surface 12i and the exit surface 12j are not limited to flat surfaces or free-form surfaces, and can also be aspherical. The exit surface 12j is asymmetric about the optical axis AX in the vertical or up-down direction, which is parallel to the YZ plane and intersects with the optical axis AX, and is symmetric about the optical axis AX in the horizontal or X direction. The lens 12a is made of, for example, resin, but can also be made of glass. An anti-reflection coating can be formed on the optical surfaces 12i and 12j of the lens 12a.

[0016] Prism mirror 12b is an optical component that combines a mirror and a lens and has a refracting and reflecting function, and refracts and reflects illumination light IL from lens 12a. Prism mirror 12b has incident surface 12p, a refractive surface located on the light exit side of lens 12a, reflecting surface 12r that bends the optical axis AX, and exit surface 12q, a refractive surface located opposite reflecting surface 12r and oriented symmetrically with respect to incident surface 12p. Prism mirror 12b reflects illumination light IL incident from behind lens 12a in a direction tilted downward and rearward. Incident surface 12p, reflecting surface 12r, and exit surface 12q that constitute prism mirror 12b are asymmetrical about optical axis AX in the vertical direction, which is parallel to the YZ plane and intersects with optical axis AX, and are symmetrical about optical axis AX in the horizontal or X direction. The entrance surface 12p, the reflection surface 12r, and the exit surface 12q of the prism mirror 12b are, for example, free-form surfaces. The entrance surface 12p, the reflection surface 12r, and the exit surface 12q are not limited to free-form surfaces, but can also be aspherical. The prism mirror 12b is formed, for example, from resin, but can also be made of glass. The reflection surface 12r is not limited to one that reflects the image light ML by total reflection, but can also be a reflection surface made of a metal film or a dielectric multilayer film. In this case, a reflection film made of a single layer or a multilayer film made of a metal such as Al or Ag is formed on the reflection surface 12r by vapor deposition or the like, or a sheet-like reflection film made of metal is attached. Although detailed illustration is omitted, an anti-reflection film can be formed on the entrance surface 12p and the exit surface 12q.

[0017] The illumination light mirror 14 has a dielectric multilayer mirror 14d, equivalent to the angle-selective mirror MR1, provided on one surface 14s of a light-transmitting flat plate 14a. The dielectric multilayer mirror 14d reflects illumination light IL with an incident angle of, for example, 40° or more, and transmits image light ML and external light OL with an incident angle of, for example, 30° or more. The dielectric multilayer mirror 14d is made of multiple dielectric layers whose materials and thicknesses are adjusted based on the wavelength and incident angle of the illumination light IL. An anti-reflection film can be formed on the other surface 14t of the flat plate 14a. The dielectric multilayer mirror 14d is formed in a region of the flat plate 14a that is at least a predetermined height above the optical axis AX, taking into account the incidence range of the illumination light IL.

[0018] The illumination light mirror 14 is disposed between the composite display member 20 and the polarizing lens 50. This allows the composite display member 20 and the polarizing lens 50 to be made relatively large to ensure a wide angle of view for the image light ML, while narrowing the distance between the composite display member 20 and the polarizing lens 50, thereby enabling the virtual image display device 100A to be made thinner and lighter.

[0019] 5 is a diagram illustrating the angular characteristics of reflection and transmission of the dielectric multilayer mirror 14d shown in FIG. 2 and other figures. The dielectric multilayer mirror 14d exhibits a reflectance of 90% or more when blue illumination light IL having a wavelength of 460 nm is incident at an incident angle of 40° or more, and exhibits a transmittance of 90% or more when blue image light ML having a wavelength of 460 nm is incident at an incident angle of 35° or less. In other words, the blue illumination light IL incident at an incident angle of 40° or more is reflected by the dielectric multilayer mirror 14d with almost no loss and enters the transmissive imager 22 of the composite display member 20. On the other hand, most of the blue, red, and green image light ML illuminated by the illumination light IL and scattered by the scatterers in the display area 22e of the transmissive imager 22 or wavelength-converted by the phosphors is incident on the dielectric multilayer mirror 14d at an incident angle of 30° or less and is transmitted through the dielectric multilayer mirror 14d with almost no reflection.

[0020] 2 etc., the composite display member 20 is a plate-like member extending parallel to the XY plane perpendicular to the optical axis AX. The composite display member 20 has a structure in which, from the external world side, a light-blocking member 21, a transmissive imager 22, and a polarizing member 23 are laminated and integrated by a frame (not shown). In the example shown, in order to form discrete spots of illumination light IL on the transmissive imager 22 of the composite display member 20, the illumination light IL incident from the image-forming optical system 10 is arranged to pass through the polarizing member 23 and then enter the transmissive imager 22.

[0021] 4, the composite display member 20 is composed of a plurality of repeating units 20a arranged in a matrix along the XY plane. Each repeating unit 20a includes a pixel PE, which is a unit that forms an image in the layer of the transmissive imager 22. Each pixel PE includes a set of four sub-pixels PEa.

[0022] The polarizing lens 50 shown in FIG. 2 and elsewhere selectively acts on the image light ML, functioning like a lens. In other words, the polarizing lens 50 is an optical element that acts as a lens for specific polarization components. The polarizing lens 50 is a plate-shaped component placed on the face side of the composite display element 20 and the illumination light mirror 14, covering the front of the eyes. The polarizing lens 50 is placed on the pupil position PP side, i.e., the -Z side, of the composite display element 20 and the illumination light mirror 14, and extends parallel to the XY plane. The polarizing lens 50 functions as a convex lens with positive refractive power for the image light ML. In other words, the polarizing lens 50 is a single lens that comprehensively images the multiple pixels PE that make up the composite display element 20, collectively focusing the light corresponding to each pixel PE. Meanwhile, the polarizing lens 50 functions as a parallel plate for external light OL.

[0023] Specifically, the polarized lens 50 is a liquid crystal lens. The polarized lens 50 has a refractive power set for each annular portion RA that selectively acts on the polarized light of the image light ML (see FIG. 4). The polarized lens 50 has a liquid crystal layer 53 sandwiched between a pair of substrates 51 and 52 with a transparent electrode layer (not shown) interposed therebetween. The group of annular portions RA are arranged symmetrically and concentrically around the optical axis AX. Of the group of annular portions RA, the peripheral annular portions RA that are farther from the optical axis AX have a narrower radial width about the optical axis AX than the central annular portion RA through which the optical axis AX passes. In other words, the radial width of the annular portions RA is narrower the closer they are to the periphery. The liquid crystal layer 53 has an adjusted birefringence or retardation distribution for each annular portion RA. The liquid crystal layer 53 gradually decreases the refractive index by reducing birefringence or retardation from the central annular zone RA through which the optical axis AX passes to the outer edge annular zone RA, for example, with respect to the first polarization direction, i.e., the first polarization P1 of the image light ML. Furthermore, the liquid crystal layer 53 has a uniform refractive index in each annular zone RA, for example, with respect to the second polarization direction, i.e., the second polarization P2 of the external light OL. The liquid crystal layer 53 is formed, for example, by stabilizing a liquid crystal material. The liquid crystal layer 53 is solidified by ultraviolet curing, thermal curing, or the like while the liquid crystal is aligned.

[0024] Polarizing lens 50 acts on first polarized light in the horizontal direction (horizontally polarized light) and does not act on second polarized light in the vertical or perpendicular direction (vertically polarized light), allowing it to pass through almost unchanged. Polarizing lens 50, which acts on horizontally polarized light, has a focal point on or near the projection surface DS (see FIG. 2) of composite display member 20, or has a refractive power close to that point, so that horizontally polarized image light ML that passes through polarizing lens 50 is collimated to be almost parallel, passes through pupil position PP (see FIG. 2), and enters eye EY as a light ray from a distance.

[0025] Returning to FIG. 1, the second display optical system 103b is optically identical to the first display optical system 103a, or is a left-right inversion of the first display optical system 103a, and a detailed description thereof will be omitted.

[0026] In the first virtual image display device 100A or the second virtual image display device 100B, the optical device excluding the display control device 88 is called an optical unit 100.

[0027] Fig. 6 is a partially enlarged perspective view illustrating a repeat unit 20a of the composite display member 20. Fig. 6 shows an area of ​​the repeat unit 20a corresponding to one sub-pixel PEa. Here, axis AXa is an axis parallel to the optical axis AX shown in Fig. 1.

[0028] The light-shielding member 21 suppresses external light OL from entering the display region 22e of the transmissive imager 22. The light-shielding member 21 includes a rectangular light-shielding layer 21b provided on one surface 21s of a light-transmitting flat plate 21a. As shown in FIG. 7A, the entire light-shielding member 21 includes a large number of light-shielding layers 21b arranged in a matrix along the XY plane and arranged discretely. That is, all the light-shielding layers 21b constituting the light-shielding member 21 are spaced apart from one another and arranged two-dimensionally periodically in the horizontal X direction and the vertical Y direction. Each light-shielding layer 21b is formed in a region corresponding to a sub-pixel PEa in each repeat unit 20a and suppresses external light OL from entering the display region 22e. The light-transmitting region A1 of the light-shielding member 21, where no light-shielding layer 21b is provided, transmits external light OL.

[0029] The light-shielding layer 21b of the light-shielding member 21 is formed of a light-absorbing paint or other substance, and can be applied to the desired location using, for example, an inkjet method. The light-shielding layer 21b may be formed of a paint of a color other than black, as long as the material has a light-absorbing or light-reflecting property. Furthermore, the light-shielding layer 21b may be formed by forming a metal pattern on the flat plate 21a at the location where the light-shielding layer 21b is to be formed using photoresist technology or the like, and then oxidizing the metal pattern to enhance its absorbency. The light-shielding layer 21b may also be a mirror formed of a reflective substance such as a metal film.

[0030] The transmissive imager 22 shown in FIG. 6 etc. receives ultraviolet illumination light IL emitted from the image formation optical system 10 shown in FIG. 3 and generates image light ML by scattering or by wavelength conversion of fluorescence. The transmissive imager 22 has, on a light-transmitting flat plate 22a, a display region 22e that is a blue scatterer or a display region 22e that is a phosphor that generates red and green fluorescence from blue light, as a sub-pixel PEa. The display region 22e or the sub-pixel PEa has a polygonal or circular outline when viewed from the -Z side. The display region 22e of the transmissive imager 22 is located on the projection surface DS, and is illuminated by a sub-pixel spot SP from the image display panel 11. Of the illumination light IL irradiated onto the sub-pixel spot SP, light that enters the display area 22e is converted into red, green, or blue image light ML and is dispersed toward the eye EY or the -Z side, and light that enters the light-transmitting area A2 other than the display area 22e is transmitted or reflected and does not proceed toward the eye EY.

[0031] As shown in FIG. 8 , in the transmissive imager 22, each repeat unit 20a, i.e., one pixel display region 22p, is provided with three types of display regions 22e: a red fluorescent region 22r, a pair of green fluorescent regions 22g, and a blue scattering region 22b. The red fluorescent region 22r emits red image light MLr by fluorescence emission at a timing and brightness required for display in response to illumination light IL or sub-pixel spots SP from the image formation optical system 10. The pair of green fluorescent regions 22g emit green image light MLg by fluorescence emission at a timing and brightness required for display in response to illumination light IL or sub-pixel spots SP from the image formation optical system 10. The blue scattering region 22b emits blue image light MLb at a timing and brightness required for display in response to illumination light IL or sub-pixel spots SP from the image formation optical system 10. 7B, a large number of pixels PE, each of which has a set of three fluorescent regions 22r, 22g and one scattering region 22b, are arranged in a matrix along the XY plane in the entire transmission-type imager 22. In other words, all of the pixels PE constituting the transmission-type imager 22, or all of the sets of regions 22r, 22g, and 22b, are arranged two-dimensionally and periodically in the horizontal X direction and the vertical Y direction. The light-transmitting region A2 of the transmission-type imager 22, which does not have regions 22r, 22g, and 22b, transmits external light OL.

[0032] The scattering region 22b of the display region 22e has a structure such as a nanostructure that scatters light toward the eye EY. The scattering region 22b has a polygonal or circular outline when viewed from the front. The nanostructure of the display region 22e or the scattering region 22b is formed by nanoimprint lithography, photolithography, or the like. The scattering region 22b can also be formed by applying a scattering material. The red fluorescent region 22r is formed by applying a fluorescent material, and when irradiated with blue illumination light IL having a wavelength of 460 nm, for example, it emits image light MLr having a wavelength of 610 nm through fluorescent conversion. The green fluorescent region 22g is formed by applying a fluorescent material, and when irradiated with blue illumination light IL having a wavelength of 460 nm, it emits image light MLr having a wavelength of 510 nm through fluorescent conversion.

[0033] In the above, blue scattering region 22b is a first display region DR1 that scatters blue illumination light IL and emits blue image light MLb. Green fluorescent region 22g is a second display region DR2 that is excited by blue illumination light IL to generate green fluorescence and emit it as image light MLg, and red fluorescent region 22r is a third display region DR3 that is excited by blue illumination light IL to generate red fluorescence and emit it as image light MLr. In other words, transmissive imager 22 generates blue, green, and red image light ML through scattering and fluorescence, enabling the observation of a color display image.

[0034] The polarizing member 23 shown in FIG. 6 and other figures has a pattern combining two types of polarizing elements and restricts the image light ML and the external light OL to a first polarization direction and a second polarization direction, respectively. By passing through the polarizing member 23, the polarization direction of the image light ML and the polarization direction of the external light OL become different. The polarizing member 23 is formed by providing a first polarizing element 60 and a second polarizing element 70 on a light-transmitting flat plate 23a. As shown in FIG. 7C , the entire polarizing member 23 includes a large number of first polarizing regions 23b, i.e., first polarizing elements 60, which are arranged in a matrix along the XY plane and are discretely arranged. That is, the first polarizing elements 60 constituting the polarizing member 23 are spaced apart from one another and are periodically arranged two-dimensionally in the horizontal X direction and vertical Y direction. Meanwhile, second polarizing elements 70 are formed in the second polarizing regions 23c of the entire polarizing member 23 where no first polarizing elements 60 are provided. The first polarizing element 60 limits the image light ML emitted from the display region 22e of the transmissive imager 22 to horizontally polarized light in a first polarization direction. The second polarizing element 70 limits the external light OL to vertically polarized light in a second polarization direction that is perpendicular to the first polarization direction. Both polarizing elements 60, 70 are, for example, wire-grid polarizing elements, and have polarization characteristics that correspond to the pattern direction of a fine metallic grid made of aluminum or the like.

[0035] Regarding the optical path, illumination light IL from the image display panel 11 passes through the projection optical system 12, is condensed, and is reflected by the illumination light mirror 14. The condensed light is incident as a sub-pixel spot SP on the display region 22e or the sub-pixel PEa formed on the projection surface DS of the transmissive imager 22. At this time, the image formed on the display surface 11d of the image display panel 11 is projected onto the projection surface DS of the transmissive imager 22. Image light ML emitted in the −Z direction from the first display region DR1, the second display region DR2, and the third display region DR3 of the display region 22e illuminated by the illumination light IL passes through the polarizing member 23 and is converted into horizontally polarized light in a first polarization direction. The image light ML then passes through the illumination light mirror 14 arranged in the −Z direction and enters the polarizing lens 50. Note that external light OL passes through the polarizing member 23 of the composite display member 20 and is limited to vertically polarized light in a second polarization direction. When horizontally polarized light and vertically polarized light are incident on the polarized lens 50, the polarized lens 50 selectively acts as a lens for horizontally polarized light in one direction (first polarized light P1) due to the distribution of refractive index, and has no effect on vertically polarized light in the other direction (second polarized light P2), transmitting the light substantially unchanged (see FIG. 6). Here, the horizontally polarized light in one direction is specifically image light ML having a polarization plane along the horizontal direction, and the polarized light in the other direction is specifically outside light OL having a polarization plane along the vertical direction. In other words, a wearer US wearing the first virtual image display device 100A can observe a virtual image formed by the image light ML superimposed on an outside world image, enabling AR display.

[0036] Although the image formed on the display surface 11d of the image display panel 11 and the image projected onto the projection surface DS of the transmissive imager 22 correspond one-to-one, they are not necessarily similar. In this case, if the image formed on the display surface 11d is given an opposite distortion in advance, the distortion of the image projected onto the projection surface DS can be offset.

[0037] FIG. 9 illustrates a modified example of the first display optical system 103a or optical unit 100 shown in FIG. 2 and other figures. In this case, a quarter-wave plate 41 is disposed upstream of the polarizing lens 150, between the polarizing lens 150 and the illumination light mirror 14. The polarizing lens 150 includes a first optical member 5a having an internal reflective optical surface R1, a quarter-wave plate 5b that converts the polarization state of the image light ML to linearly polarized light or circularly polarized light, and a second optical member 5c that includes a polarizing reflective layer R2. The reflective optical surface R1 of the first optical member 5a is a Fresnel-type half mirror and has refractive power equivalent to that of a reflective surface that is concave toward the pupil position PP. The polarizing reflective layer R2 of the second optical member 5c is formed on an optical surface such as an aspherical surface and reflects vertically polarized light. Specifically, the polarizing reflective layer R2 is a wire-grid polarizing element.

[0038] Referring to FIG. 10 , the image light ML from the composite display element 20 is horizontally polarized light and becomes right-handed circularly polarized light after passing through the quarter-wave plate 41. The image light ML enters the first optical element 5a of the polarizing lens 150, partially transmits through the reflective optical surface R1, and enters the quarter-wave plate 5b in the forward direction. The image light ML that passes through the quarter-wave plate 5b is converted to vertically polarized light, enters the second optical element 5c, is mostly reflected by the polarizing reflective layer R2, and then enters the quarter-wave plate 5b again. The image light ML that passes through the quarter-wave plate 5b in the reverse direction is converted to right-handed circularly polarized light, enters the first optical element 5a, and is partially reflected by the reflective optical surface R1. The image light ML that is reflected by the reflective optical surface R1 is converted to left-handed circularly polarized light and enters the quarter-wave plate 5b in the forward direction. The image light ML that passes through the quarter-wave plate 5b is converted to horizontally polarized light, enters the second optical element 22, and passes through the polarizing reflective layer R2. The image light ML emitted from the second optical member 22 is collimated by the lens action and enters the pupil position PP where the eye EY of the wearer US is located. Meanwhile, the outside light OL is limited to vertical polarization after passing through the composite display member 20 and becomes left-handed circularly polarized light after passing through the quarter-wave plate 41. The left-handed circularly polarized outside light OL enters the first optical member 21, partially transmits through the reflective optical surface R1, and enters the quarter-wave plate 5b. The outside light OL that passes through the quarter-wave plate 5b is converted to horizontally polarized light, enters the second optical member 5c, and passes through the polarized reflective layer R2. In this way, the specific component of the outside light OL that passes through the composite display member 20 passes through the polarized lens 150, but the polarized lens 150 does not exert a lens effect on the outside light OL.

[0039] 9 is not limited to a Fresnel-type half mirror, but may be a half mirror formed along a continuous concave surface. Also, by replacing the quarter-wave plate 5b with a half-wave plate and the polarized reflective layer R2 with a cholesteric liquid crystal layer, it is possible to collimate the image light ML and make it incident on the pupil position PP, and to allow the outside light OL to pass through without causing a lens action on the outside light OL.

[0040] Although not shown in the figures, the image display panel 11 can be replaced with a scanning illumination device 10a. In this case, the illumination device 10a includes a laser light source and a micromirror. The scanning illumination device 10a emits modulated light from the laser light source and two-dimensionally scans the spot-shaped modulated light as illumination light IL by changing the angle of the micromirror. This allows the illumination light IL to be projected onto the display area 22e of the transmissive imager 22 via the projection optical system 12. In other words, the trajectory of the spot-shaped modulated light moving on the transmissive imager 22 by scanning corresponds to the image to be displayed.

[0041] The virtual image display devices 100A, 100B and optical unit 100 of the first embodiment described above include an illumination device 10a, a projection optical system 12 that forms an image of illumination light IL emitted from the illumination device 10a, a transmissive imager 22 that is arranged at the imaging position of the illumination light IL and forms image light ML corresponding to the illumination light IL, an illumination light mirror 14 that selectively reflects the illumination light IL from the projection optical system 12 toward the transmissive imager 22, and a polarized lens 50 that is arranged on the face side of the transmissive imager 22 and the illumination light mirror 14 and has a refractive power that selectively acts on the polarization of the image light ML.

[0042] In the virtual image display devices 100A, 100B and optical unit 100, the illumination light mirror 14 selectively reflects the illumination light IL from the projection optical system 12 toward the transmissive imager 22, so that the transmissive imager 22 forms image light ML corresponding to the illumination light IL, and the image light ML from the transmissive imager 22 can be observed through the polarized lens 50. Components of the outside light OL that are different from the polarization of the image light ML pass through the polarized lens 50 without being affected by the refractive power of the polarized lens 50, so that the wearer US of the virtual image display devices 100A, 100B can observe a virtual image formed by the image light ML superimposed on an image of the outside world.

[0043] Second Embodiment The virtual image display device of the second embodiment will be described below. Note that the virtual image display device of the second embodiment is a partial modification of the virtual image display device of the first embodiment, and a description of parts common to the virtual image display device of the first embodiment will be omitted.

[0044] 11, the first display optical system 103a includes an image forming optical system 10, a composite display member 20, and a polarizing lens 50. The image forming optical system 10 has an image display panel 211 that emits ultraviolet illumination light IL as an illumination device 10a. The dielectric multilayer film mirror 214d formed on the illumination light mirror 14 is a dichroic mirror, i.e., a wavelength-selective mirror MR2, which reflects ultraviolet illumination light IL and transmits visible image light ML and external light OL.

[0045] 12 is a diagram illustrating the wavelength characteristics of reflection and transmission of the dielectric multilayer mirror 214d, along with the wavelength characteristics of the emission intensity of the illumination light IL and the like emitted from the image display panel 211. The dielectric multilayer mirror 214d exhibits a reflectance of 90% or more in a wavelength range of approximately 400 nm or less and a transmittance of 90% or more in a wavelength range of approximately 410 nm or more. In other words, the illumination light IL, whose intensity peak is at approximately 340 nm and whose full width at half maximum is approximately 20 nm, is reflected by the dielectric multilayer mirror 214d with almost no loss and enters the transmissive imager 22 of the composite display member 20. On the other hand, the red, green, and blue image light ML, which is illuminated by the illumination light IL and wavelength-converted by the phosphors in the display region 22e of the transmissive imager 22, has intensity peaks at wavelengths of 610 nm, 510 nm, and 460 nm, and is transmitted through the dielectric multilayer mirror 214d with almost no reflection.

[0046] 13 , in the transmissive imager 22, each repeat unit 20a, i.e., one pixel display region 22p, is provided with three types of display regions 22e: specifically, a red fluorescent region 22r, a pair of green fluorescent regions 22g, and a blue fluorescent region 222b. The red fluorescent region 22r emits fluorescence-converted red image light MLr in response to illumination light IL or the sub-pixel spots SP from the image formation optical system 10. The pair of green fluorescent regions 22g emit fluorescence-converted green image light MLg in response to illumination light IL or the sub-pixel spots SP from the image formation optical system 10. The blue fluorescent region 222b emits fluorescence-converted blue image light MLb in response to illumination light IL or the sub-pixel spots SP from the image formation optical system 10.

[0047] In the above, blue fluorescent region 222b is a first display region DR1 that is excited by ultraviolet illumination light IL to generate blue fluorescence and emit it as image light MLb. Green fluorescent region 22g is a second display region DR2 that is excited by ultraviolet illumination light IL to generate green fluorescence and emit it as image light MLg, and red fluorescent region 22r is a third display region DR3 that is excited by ultraviolet illumination light IL to generate red fluorescence and emit it as image light MLr. In other words, transmissive imager 22 generates blue, green, and red image light MLb, MLg, and MLr by fluorescent emission, enabling color image observation.

[0048] Third Embodiment The virtual image display device of the third embodiment will be described below. Note that the virtual image display device of the third embodiment is a partial modification of the virtual image display device of the first embodiment, and a description of parts common to the virtual image display device of the first embodiment will be omitted.

[0049] 14, the first display optical system 103a includes an image forming optical system 10, a composite display member 20, and a polarizing lens 50. The image forming optical system 10 has an image display panel 311 as an illumination device 10a that emits illumination light IL in the visible range including blue, green, and red. The illumination light mirror 14 is an angle-selective mirror MR1, and the dielectric multilayer film mirror 14d of the illumination light mirror 14 reflects illumination light IL in the visible range with an incident angle of, for example, 40° or more, and transmits video light ML and external light OL in the visible range with an incident angle of, for example, 30° or more.

[0050] The dielectric multilayer mirror 14d exhibits a reflectance of 90% or more when blue, green, and red illumination light IL is incident at an incident angle of 40° or more, and exhibits a transmittance of 90% or more when blue, green, and red image light ML is incident at an incident angle of 30° or less. In other words, the illumination light IL of each color incident at an incident angle of 40° or more is reflected by the dielectric multilayer mirror 14d with almost no loss and enters the transmissive imager 22 of the composite display member 20. On the other hand, most of the blue, red, and green image light ML illuminated by the illumination light IL and scattered by the scatterers in the display region 22e of the transmissive imager 22 is incident on the dielectric multilayer mirror 14d at an incident angle of 30° or less and is transmitted through the dielectric multilayer mirror 14d with almost no reflection.

[0051] 15, in the transmissive imager 22, each repeat unit 20a, i.e., one pixel display region 22p, is provided with three types of display regions 22e: specifically, a red scattering region 322r, a pair of green scattering regions 322g, and a blue scattering region 22b. The red scattering region 322r emits red image light MLr by scattering the illumination light IL or the sub-pixel spots SP from the image forming optical system 10. The pair of green scattering regions 322g emit green image light MLg by scattering the illumination light IL or the sub-pixel spots SP from the image forming optical system 10. The blue scattering region 22b emits blue image light MLb by scattering the illumination light IL or the sub-pixel spots SP from the image forming optical system 10.

[0052] In the above, the blue scattering region 22b is a first display region DR1 that scatters blue illumination light IL and emits it as blue image light MLb. The green scattering region 322g is a second display region DR2 that scatters green illumination light IL and emits it as green image light MLg. The red scattering region 322r is a third display region DR3 that scatters red illumination light IL and emits it as red image light MLr. In other words, the transmissive imager 22 forms blue, green, and red image light MLb, MLg, and MLr by scattering, allowing for the observation of a color display image.

[0053] [Variations and Others] The present invention has been described above in accordance with the embodiments, but the present invention is not limited to the above embodiments and can be implemented in various forms without departing from the spirit of the invention, and for example, the following modifications are also possible.

[0054] In the above embodiment, the lens 12a and the prism mirror 12b of the projection optical system 12 are merely examples, and the projection optical system 12 can be configured with a variety of optical elements including lenses or mirrors.

[0055] In the above, the composite display element 20 has been described as being formed by preparing the light-shielding element 21, the transmissive imager 22, and the polarizing element 23 separately and stacking them together, but it is also possible to make an optical element in which the optical elements that make up these elements are integrally incorporated.

[0056] In the above description, it is assumed that the HMD 200 is used by being worn on the head, but the virtual image display devices 100A and 100B can also be used as handheld displays that are not worn on the head but are peered into like binoculars. In other words, in the present invention, the head-mounted display also includes a handheld display.

[0057] In the above embodiment, the arrangement and size of the pixel PE or sub-pixel PEa can be changed as appropriate so that a sufficient see-through region exists in one pixel.

[0058] In a specific embodiment, the virtual image display device includes an illumination device, a projection optical system that forms an image of illumination light emitted from the illumination device, a transmissive imager that is arranged at the imaging position of the illumination light and forms image light corresponding to the illumination light, an illumination light mirror that selectively reflects the illumination light from the projection optical system toward the transmissive imager, and a polarized lens that is arranged on the face side of the transmissive imager and the illumination light mirror and has a refractive power that selectively acts on the polarization of the image light.

[0059] In the virtual image display device, the illumination light mirror selectively reflects illumination light from the projection optical system toward the transmissive imager, which then forms image light corresponding to the illumination light, and the image light from the transmissive imager can be observed through the polarized lens. Components of outside light that are different from the polarization of the image light pass through the polarized lens without being affected by the refractive power of the polarized lens, allowing the wearer of the virtual image display device to observe a virtual image created by the image light superimposed on an image of the outside world.

[0060] In a specific embodiment of the virtual image display device, the transmissive imager has a display area that is discretely arranged two-dimensionally and forms image light, and a light-transmitting area that is provided around the display area. An image corresponding to the image light is formed in the display area, and external light passes through the light-transmitting area.

[0061] In a specific aspect, the virtual image display device includes a polarizing member having a first polarization region disposed on the face side of the transmissive imager opposite the display region and restricting image light from the display region to a first polarization direction, and a second polarization region disposed on the outside world side of the first polarization region and restricting outside world light to a second polarization direction different from that of the first polarization region. In this case, the image light passes through the first polarization region and is restricted to polarization in the first polarization direction that is affected by the refractive power of the polarizing lens, while the outside world light passes through the second polarization region and is restricted to polarization in the second polarization direction that is not affected by the refractive power of the polarizing lens.

[0062] In a specific aspect of the virtual image display device, the lighting device emits blue illumination light, the illumination mirror reflects the blue illumination light at a predetermined angle or more and transmits image light at a predetermined angle or less, and the transmissive imager has, as display regions, a first display region that scatters the blue illumination light and emits it as image light, and a second display region that is excited by the blue illumination light to generate fluorescence and emit it as image light. In this case, the illumination mirror reflects the illumination light and transmits the scattered blue illumination light and the excited fluorescent image light.

[0063] In a specific embodiment of the virtual image display device, the second display region of the transmissive imager is excited by blue illumination light to generate green fluorescence and emit it as image light, and the transmissive imager further has a third display region that is excited by blue illumination light to generate red fluorescence and emit it as image light. In this case, the transmissive imager forms three colors of image light, blue, green, and red, by scattering and fluorescent emission, allowing for color display image observation.

[0064] In a specific aspect of the virtual image display device, the lighting device emits ultraviolet illumination light, the illumination mirror reflects the ultraviolet illumination light and transmits visible light, and the transmissive imager has a first display region as a display region that is excited by the ultraviolet illumination light to generate fluorescence and emits the fluorescence as image light. In this case, the illumination mirror reflects the illumination light and transmits the excited fluorescent image light.

[0065] In a specific embodiment of the virtual image display device, the first display region of the transmissive imager is excited by illumination light in the ultraviolet range to generate blue fluorescence and emit it as image light, and the transmissive imager further has a second display region that is excited by illumination light in the ultraviolet range to generate green fluorescence and emit it as image light, and a third display region that is excited by illumination light in the ultraviolet range to generate red fluorescence and emit it as image light. In this case, the transmissive imager forms image light of three colors, blue, green, and red, by fluorescent emission, allowing for the observation of a color display image.

[0066] In a specific aspect of the virtual image display device, the lighting device emits illumination light in the visible range, the illumination mirror reflects the illumination light in the visible range at a predetermined incident angle or more and transmits image light in the visible range at an incident angle or less, and the transmissive imager has a first display region as a display region that scatters the illumination light in the visible range and emits it as image light. In this case, the illumination mirror reflects the illumination light and transmits the scattered image light in the visible range.

[0067] In a specific embodiment of the virtual image display device, the first display region of the transmissive imager scatters blue illumination light and outputs it as image light, and the transmissive imager further has a second display region that scatters green illumination light and outputs it as image light, and a third display region that scatters red illumination light and outputs it as image light. In this case, the transmissive imager forms image light of three colors, blue, green, and red, by scattering, allowing for the observation of a color display image.

[0068] In a specific embodiment of the virtual image display device, the polarized lens has a liquid crystal layer sandwiched between a pair of substrates.

[0069] In a specific embodiment, the optical unit includes an illumination device, a projection optical system that forms an image of illumination light emitted from the illumination device, a transmissive imager that is arranged at the imaging position of the illumination light and forms image light corresponding to the illumination light, an illumination light mirror that selectively reflects the illumination light from the projection optical system toward the transmissive imager, and a polarized lens that is arranged on the face side of the transmissive imager and the illumination light mirror and has a refractive power that selectively acts on the polarization of the image light.

[0070] In the optical unit, the illumination light mirror selectively reflects illumination light from the projection optical system toward the transmissive imager, which then forms image light corresponding to the illumination light. The image light from the transmissive imager can be observed through the polarizing lens. Components of outside light that are different in polarization from the image light pass through the polarizing lens without being affected by the refractive power of the polarizing lens, allowing the wearer of the virtual image display device to observe a virtual image created by the image light superimposed on an image of the outside world. [Explanation of symbols]

[0071] 10...image forming optical system, 10a...illumination device, 11,211,311...image display panel, 11d...display surface, 12...projection optical system, 12a...lens, 12b...prism mirror, 14...mirror for illumination light, 14a...flat plate, 14d, 214d...dielectric multilayer mirror, 20...composite display member, 20a...repeating unit, 21...light-shielding member, 21b...light-shielding layer, 22...transmissive imager, 22p...pixel display area, 22e...display area, 22b...scattering area, 22g, 22r...fluorescent area, 222g, 222r...fluorescent area, 322g, 322r...scattering area, 23...polarizing member, 50, 150...polarizing lens, 60, 70...polarizing element, 88...display control control device, 90...user terminal, 100...optical unit, 100A, 100B...virtual image display device, 102...driver, 102a, 102b...display drive unit, 103a, 103b...display optical system, 106...support device, 200...head-mounted display device, A1, A2...light transmission area, AX...optical axis, DS...projection surface, EY...eye, IL...illumination light, ML...image light, MLb, MLg, MLr...image light, MR1...angle selection mirror, MR2...wavelength selection mirror, OL...external light, P1...first polarization, P2...second polarization, PE...pixel, PEa...subpixel, PP...pupil position, R1...reflective optical surface, R2...polarized reflection layer, SP...subpixel spot, US...wearer

Claims

1. A lighting device; a projection optical system that forms an image of the illumination light emitted from the illumination device; a transmission imager disposed at an imaging position of the illumination light and forming image light corresponding to the illumination light; an illumination light mirror that selectively reflects the illumination light from the projection optical system toward the transmission imager; a polarizing lens disposed on a face side of the transmission imager and the illumination light mirror, the polarizing lens having a refractive power that selectively acts on the polarization of the image light; A virtual image display device comprising:

2. The transmissive imager has a display area that is discretely arranged two-dimensionally and forms image light, and a light-transmitting area that is provided around the display area. The virtual image display device according to claim 1 .

3. a polarizing member having a first polarizing region that is disposed on the face side of the transmissive imager opposite a display region and that limits the image light from the display region to a first polarization direction, and a second polarizing region that is disposed on the outside world side from the position of the first polarizing region and that limits outside light to a second polarization direction different from that of the first polarizing region; The virtual image display device according to claim 1 .

4. the illumination device emits blue illumination light; the illumination light mirror reflects the blue illumination light having an incident angle equal to or greater than a predetermined angle and transmits the image light having an incident angle equal to or smaller than the predetermined angle; the transmissive imager has, as the display regions, a first display region that scatters the blue illumination light and emits the scattered light as the image light, and a second display region that is excited by the blue illumination light to generate fluorescence and emits the fluorescence as the image light. The virtual image display device according to claim 2 .

5. the second display region of the transmissive imager is excited by the blue illumination light to generate green fluorescence and emit the green fluorescence as the image light; the transmissive imager further includes a third display region that is excited by the blue illumination light to generate red fluorescence and emit the red fluorescence as the image light; The virtual image display device according to claim 4 .

6. the illumination device emits the illumination light in the ultraviolet range, the illumination light mirror reflects the illumination light in the ultraviolet range and transmits light in the visible range; the transmissive imager has, as the display region, a first display region that is excited by the illumination light in the ultraviolet region to generate fluorescence and emit the fluorescence as the image light; The virtual image display device according to claim 2 .

7. the first display region of the transmissive imager is excited by the illumination light in the ultraviolet range to generate blue fluorescence and emit the blue fluorescence as the image light; the transmissive imager further includes a second display region that is excited by the illumination light in the ultraviolet range to generate green fluorescence and emit the green fluorescence as the image light, and a third display region that is excited by the illumination light in the ultraviolet range to generate red fluorescence and emit the red fluorescence as the image light. The virtual image display device according to claim 6 .

8. the illumination device emits the illumination light in the visible range; the illumination light mirror reflects the illumination light in a visible range equal to or greater than a predetermined angle of incidence and transmits the image light in a visible range equal to or less than the predetermined angle of incidence; the transmissive imager has, as the display region, a first display region that scatters the illumination light in a visible range and emits the scattered light as the image light; The virtual image display device according to claim 2 .

9. the first display region of the transmissive imager scatters the blue illumination light and emits it as the image light; the transmissive imager further includes a second display region that scatters the green illumination light and emits the light as the image light, and a third display region that scatters the red illumination light and emits the light as the image light. The virtual image display device according to claim 8 .

10. The polarized lens has a liquid crystal layer sandwiched between a pair of substrates. The virtual image display device according to claim 1 .

11. A lighting device; a projection optical system that forms an image of the illumination light emitted from the illumination device; a transmission imager disposed at an imaging position of the illumination light and forming image light corresponding to the illumination light; an illumination light mirror that selectively reflects the illumination light from the projection optical system toward the transmission imager; a polarizing lens disposed on a face side of the transmission imager and the illumination light mirror, the polarizing lens having a refractive power that selectively acts on the polarization of the image light; An optical unit comprising:

Images