JP2012163702A - Parallax type three-dimensional aerial video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of displaying a video image formed by each of real mirror video image forming optical systems as a three-dimensional aerial video image having no distortion by parallax.SOLUTION: In the parallax type three-dimensional aerial video display device, real mirror video image forming optical systems 2A1 and 2A2 which can form real images of objects to be projected at a plane symmetrical position with respect to element plane surfaces S1 and S2 are arranged side by side therein, the same objects O1 and O2 to be projected are arranged so as to correspond to each of the image forming optical systems 2A1 and 2A2 at the same position with the angle relationship, and a real mirror video image P1 of the object O1 to be projected which is formed by the image forming optical system for a right eye that is the real mirror video image forming optical system 2A1 relatively arranged in the left side and corresponds to the image forming optical system 2A1, and a real mirror video image P2 of the object O2 to be projected which is formed by the image forming optical system for a left eye that is the real mirror video image forming optical system 2A2 relatively arranged in the right side and corresponds to the image forming optical system 2A2 are displayed at the same position so as to overlap each other.

Description

  The present invention relates to a display device that allows a stereoscopic aerial image without distortion to be viewed using parallax.

  In recent years, techniques for enabling viewing of stereoscopic images have been developed. For example, assuming that a convex lens or a concave mirror is used as the imaging optical system, a two-dimensional display capable of high-speed display is arranged inclined with respect to the optical axis of the optical system, and two-dimensional inclined with respect to the optical axis by a mirror scanner There has been proposed a stereoscopic display method of a three-dimensional image by a volume scanning method in which a three-dimensional image is formed by moving an image and displaying a cross-sectional image of a display object on a two-dimensional display accordingly (non-patent document). Reference 1). According to this method, since a three-dimensional real image is formed, a wearing object such as eyeglasses is unnecessary, and it can be said that it can satisfy all human stereoscopic perception factors.

  However, in the stereoscopic display method disclosed in Non-Patent Document 1, since a convex lens or a concave mirror is used as an optical system, the shape is distorted due to the aberration, and the localization is completely stabilized. Have difficulty.

  On the other hand, the present inventor, as an equal-magnification imaging optical system, uses a real mirror image forming element (hereinafter referred to as “two surfaces” as necessary) which is an optical element provided with a number of two-surface corner reflectors composed of two mirror surfaces. (Referred to as "Corner Reflector Array") (see Patent Document 1) and a real mirror image forming optical system (see Patent Document 2) using a retroreflector array having a retroreflective function and a half mirror. In addition, using an afocal lens array equipped with an afocal optical system with an infinite focal length, the element surface of the afocal lens element is used as a symmetry plane, and the image of the projection object is formed in the opposite space. A real mirror image forming optical system that has been realized has also been proposed (see Patent Document 3). These real mirror image forming optical systems have a plane-symmetrical position with respect to a symmetry plane (element surface of a two-surface corner reflector array, half mirror surface, element surface of an afocal lens array) in which the projection object is set in the optical system. The image is formed as a real image with the same magnification without distortion, and a two-dimensional real image can be observed if the projection object is two-dimensional, and a three-dimensional real image can be observed if the projection object is three-dimensional. It is.

  Then, the present inventor has devised a three-dimensional aerial image display device using a volume scanning method in order to provide a distortion-free three-dimensional aerial image display device to which each of the above-described real mirror image forming optical systems is applied ( (See Patent Document 4). In this three-dimensional aerial image display device, a display having a display surface for displaying an image as a projection object is arranged on the lower surface side of the symmetry surface of the real mirror image forming optical system, and the display is displayed on the display surface by driving means. On the other hand, it is operated so as to perform a motion including a vertical component, and the image displayed on the display surface is changed in synchronism with the operation of the display by the driving means. The image is formed as a stereoscopic image (hereinafter, sometimes referred to as “stereoscopic aerial image”).

  With such a volume scanning type three-dimensional aerial image display device, using a real mirror image forming optical system that forms an image of a projection object as a real image without distortion at a plane symmetrical position with respect to a symmetry plane, A display that moves three-dimensionally in a space on one side of the plane of symmetry, in other words, a real image displayed on a volumetric scanning three-dimensional display, and an aerial stereoscopic image that has no distortion in the other space. Can be displayed and observed.

International Publication No. 2007/116663 JP 2009-025776 A JP 2008-158114 A JP 2009-075483 A

“Volumetric display system based on three-dimensional scanning of inclined optical image”, Daisuke Miyazaki et al, Optic Express, Vol. 14 Issue 26, pp. 12760-12769

  However, the above-described volume scanning type three-dimensional aerial image display apparatus requires mechanical driving means for operating the display so as to perform a motion including a component in a direction perpendicular to the display surface.

  SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide an apparatus capable of displaying an image formed by each real mirror image forming optical system as a three-dimensional aerial image free from distortion due to parallax without using the driving means described above. Is.

  That is, according to the present invention, at least two real mirror image forming optical systems capable of forming a real image of a projection object at a plane-symmetrical position with respect to one geometric plane serving as a symmetry plane are arranged side by side. This is a three-dimensional aerial image display device in which projection objects are arranged corresponding to each system. Here, the real mirror image forming optical system forms an object to be projected as a real image without distortion at a plane symmetrical position with respect to the symmetry plane, and is constituted by the above-described two-surface corner reflector array, Or, it is appropriate to use a half mirror and retroreflector array, or a micro lens array (including an afocal lens array), but use other optical devices such as lenses and reflectors. It may be a configured optical system. For the projection object, for example, an image (two-dimensional) displayed on the screen is preferable, and when each projection object is the same image including the direction with respect to the real mirror image forming optical system, All real images formed by the real mirror image forming optical system are equal. Note that the projection object may be an object (three-dimensional).

  The three-dimensional aerial image display device according to the present invention causes the real mirror image forming optical system disposed relatively on the left side to function as the real mirror image forming optical system for the right eye, and is disposed relatively on the right side. The real mirror image forming optical system functions as a left-eye image forming optical system, and the corresponding real object image formed by the right-eye image forming optical system and the left-eye image forming optical system. It is characterized in that a real mirror image of a corresponding projection object imaged by the system is superimposed and displayed at the same position.

  According to such a parallax type three-dimensional aerial image display device, each real mirror image imaging optical system is used and is disposed in a space on one side of each symmetry plane so as to correspond to each imaging optical system. Since the real image of the projection is displayed so as to overlap with the other space as an undistorted image, a stereoscopic image can be observed using the parallax between the image by the right eye and the image by the left eye. In addition, the structure can be simplified as compared with the aspect using the mechanical drive means described above. Furthermore, in the three-dimensional aerial image display device of the present invention, a figure drawn on a plane without using a three-dimensional object or a three-dimensional image (including a three-dimensional image displayed by a volume scanning method) as a projection object. (Including pictures and characters) and images displayed on a flat display can be applied. Further, in the three-dimensional aerial image display device of the present invention, it is not necessary to arrange an article other than the projection object around the real mirror imaging optical system, so that the arrangement location of the projection object is greatly restricted. This increases the degree of freedom of arrangement of the projection object.

  In particular, in the parallax type three-dimensional aerial image display device of the present invention, if three or more real mirror image forming optical systems are arranged side by side, the same object disposed corresponding to the three or more image forming optical systems is arranged. Three or more real images of the projection can be displayed so as to overlap each other, and a stereoscopic aerial image can be observed from a plurality of viewpoints. That is, a real mirror image forming optical system that functions as a right eye imaging optical system at a certain viewpoint functions as a left eye imaging optical system at a different viewpoint.

  Based on the same principle, a parallax type three-dimensional aerial image display device in which a plurality of real mirror image optical systems are arranged in a ring shape can observe a three-dimensional aerial image from the entire periphery, and is versatile. Become.

  According to the present invention, a simple configuration in which a plurality of real mirror image forming optical systems that form a real image of a projection object at a plane-symmetrical position with respect to a certain geometric plane (symmetry plane) are arranged side by side relatively. The real image formed by the real mirror imaging optical system placed on the right side is viewed with the left eye, and the real image formed by the real mirror imaging optical system placed relatively on the left side is viewed with the right eye, thereby symmetric with binocular parallax. It is possible to provide a new method for displaying and observing a three-dimensional aerial image that can be observed as a three-dimensional aerial image without distortion in the space opposite to the surface.

1 is a diagram schematically showing a parallax stereoscopic aerial image display device according to a first embodiment of the present invention. The top view which shows typically the 2 surface corner reflector array which is a real mirror image formation optical system applied to the embodiment. FIG. 3 is a perspective view schematically showing an enlarged area A of FIG. 2. The figure which shows typically the image formation mode by the same 2 surface corner reflector array. The figure which shows schematically the parallax type | formula three-dimensional aerial image display apparatus which concerns on the modification of the embodiment. The figure which shows schematically the parallax type | formula three-dimensional aerial image display apparatus which concerns on another modification of the embodiment. FIG. 4 is a schematic perspective view showing another example of the two-surface corner reflector array applied to the embodiment, corresponding to FIG. 3. The side view which shows roughly the parallax type | formula three-dimensional aerial image display apparatus which concerns on 2nd Embodiment of this invention. The schematic front view which expands and shows a part of retro reflector array which is a real mirror image formation optical system applied to the embodiment. The figure which shows typically the mode of the reflection of the light ray by the retro-reflector array. The figure which shows roughly the parallax type | formula three-dimensional aerial image display apparatus which concerns on 3rd Embodiment of this invention. The figure which shows typically the structure of a micro lens array (afocal lens array) which is a real mirror image formation optical system applied to the embodiment, and an imaging mode.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  First Embodiment First, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a parallax type stereoscopic aerial image display device (hereinafter referred to as “three-dimensional aerial image display device”) X1 according to the present embodiment is a large number of types of real mirror image imaging optical systems. A plurality of (two in the illustrated example) real mirror image forming elements (hereinafter referred to as “two-sided corner reflector array”, which are indicated by reference numerals 2A1 and 2A2 in the figure) on which the two-sided corner reflector 1 is formed, Projection objects O1 and O2 arranged corresponding to the element planes S1 and S2 of the mirror image forming elements 2A1 and 2A2, respectively.

  In each of the two-surface corner reflector arrays 2A1 and 2A2, element planes S1 and S2 are planes substantially perpendicular to the two mirror surfaces 11 and 12 constituting the entire two-surface corner reflector 1, respectively. In each of these two-surface corner reflector arrays 2A1 and 2A2, real mirror images P1 and P2 of the projections O1 and O2 are formed at plane-symmetric positions with the element planes S1 and S2 as symmetry planes. In this embodiment, two-surface corner reflector arrays 2A1 and 2A2 having an isosceles triangle shape in plan view or a substantially isosceles triangle shape in plan view are applied, and each of these two-surface corner reflector arrays 2A1 and 2A2 is substantially fan-shaped in plan view. Are arranged side by side (in the example shown in the figure, one of the two equal sides in the two-surface corner reflector arrays 2A1 and 2A2 is arranged by joining the long sides). In the present embodiment, these two-surface corner reflector arrays 2A1 and 2A2 are arranged in a plane (on the same flat plate). Therefore, the element surfaces of these two-surface corner reflector arrays 2A1 and 2A2 are set on the same plane.

  Then, by arranging the independent projections O1 and O2 on one side (downward in the illustrated example) of the element planes S1 and S2 so as to correspond to the respective two-surface corner reflector arrays 2A1 and 2A2, the other of the element planes S1 is arranged. A real mirror image P1 of the projection object O1 is formed on the side (upper in the illustrated example) through the two-surface corner reflector array 2A1, and a two-surface corner reflector array is formed on the other side (upper in the illustrated example) of the element plane S2. A real mirror image P2 of the projection object O2 is formed through 2A2. Then, the relative position and relative angle of the projection object O1 with respect to the two-surface corner reflector array 2A1 and the relative position and relative angle of the projection object O2 with respect to the two-surface corner reflector array 2A2 are set to be the same. The real mirror image P1 of the projection object O1 that can be observed through the reflector array 2A1 and the real mirror image P2 of the projection object O2 that can be observed through the two-surface corner reflector array 2A2 are formed as real images so as to overlap spatially. it can. Here, the two-surface corner reflector array 2A1, which is a real mirror image-forming optical system disposed relatively to the left as viewed from the observer W, functions as the right-eye imaging optical system of the present invention, and is relatively A two-surface corner reflector array 2A2, which is a real mirror image imaging optical system arranged on the right side, functions as the left-eye imaging optical system of the present invention. As a result, when the real mirror images P1 and P2 overlapping in the air are observed with both eyes, a stereoscopic image floating in the air due to parallax can be observed. In order to give binocular parallax, for example, when the observation distance is 30 cm, the center angle (angle between two equal sides) of each of the two-surface corner reflector arrays 2A1 and 2A2 may be set to 11 degrees or less. Incidentally, in this embodiment, the center angle of each of the two-surface corner reflector arrays 2A1 and 2A2 is set to 10 degrees.

  Hereinafter, the specific configuration and imaging mode of each part will be described. In the following description, when the two two-sided corner reflector arrays 2A1 and 2A2 and the element planes S1 and S2 are collectively referred to, reference numerals 2A and S are used.

  As shown in FIGS. 2 and 3 (FIG. 3 is an enlarged view of a region A in FIG. 2), each two-sided corner reflector array 2A includes a flat base 21 and a flat base surface. In order to form a large number of holes 22 penetrating through the wall perpendicularly to each other and to use the inner wall surface of each hole 22 as the two-surface corner reflector 1, the mirror surface 11 , 12 are formed. The base 21 is applied with an isosceles triangular shape in a planar view having a thickness of 50 to 200 μm, for example, 100 μm in the present embodiment. However, in FIG. 2 and FIG. A square shape is shown. Note that. The thickness, planar shape, and planar dimensions of the base 21 can be set as appropriate.

  Each of the two-surface corner reflector arrays 2A has a plane substantially perpendicular to the two mirror surfaces 11 and 12 as an element plane S. The projection plane is located at a plane-symmetrical position with the element plane S as a symmetry plane. The real mirror image is formed. In the present embodiment, the two-surface corner reflector 1 is very small compared to the entire two-surface corner reflector array 2A. Therefore, in FIG. 1, the entire set of the two-surface corner reflectors 1 is represented in gray, and the direction of the inner angle is indicated. It is schematically represented by a V shape. Further, as shown in FIG. 3, each two-sided corner reflector 1 is formed using physical and optical holes 22 formed in the base 21 in order to transmit light. In the present embodiment, first, a large number of holes 22 having a substantially rectangular shape in plan view (specifically, a square shape in the present embodiment) are formed in the base 21, and smooth mirror surfaces are formed on two adjacent inner wall surfaces orthogonal to each other among the holes 22. The mirror surfaces 11 and 12 are processed to form a two-surface corner reflector 1 that functions as a reflecting surface. In addition, it is preferable to suppress a part of the inner wall surface of the hole 22 other than the two-surface corner reflector 1 from being subjected to mirror surface treatment so that light cannot be reflected, or to prevent multiple reflected light by providing an angle. . Each two-surface corner reflector 1 is formed on the base 21 so that the inner angles formed by the mirror surfaces 11 and 12 are all in the same direction. Hereinafter, the direction of the inner angle of the mirror surfaces 11 and 12 may be referred to as the direction (direction) of the dihedral corner reflector 1. In the present embodiment, the orientations of the two-surface corner reflector 1 are all set to the center direction of the two-surface corner reflector array 2A (intersection of two equal sides). In forming the mirror surfaces 11 and 12, in the present embodiment, a metal mold is first created, and the inner wall surface on which the mirror surfaces 11 and 12 are to be formed is subjected to nanoscale cutting processing to form the mirror surfaces. The surface roughness is 10 nm or less, and the surface is uniformly mirrored with respect to the visible light spectrum region.

  Specifically, each of the mirror surfaces 11 and 12 constituting each two-sided corner reflector 1 has a side of, for example, 50 to 200 μm, and in this embodiment, 100 μm corresponding to the thickness of the base 21. A plurality of substrates are formed at a predetermined pitch on a single substrate 21 by a nanoimprint method or an electroforming method in which the conventional press method is applied to the nanoscale. In the present embodiment, all the two-surface corner reflectors 1 are aligned on regular lattice points assumed on the element plane S and face the same direction. In addition, the transmittance | permeability can be improved by setting the separation | spacing dimension of adjacent 2 surface corner reflectors 1 as small as possible. In addition, a portion of the base 21 other than the portion where the two-surface corner reflector 1 is formed is subjected to a light shielding process, and a transparent reinforcing material having a thin plate shape (not shown) is provided on the upper and lower surfaces of the base 21. In the present embodiment, a two-surface corner reflector array 2A in which tens of thousands to hundreds of thousands of such two-surface corner reflectors 1 are provided on a base 21 having an isosceles triangle shape in plan view is employed.

  In addition, when the base | substrate 21 is formed with metals, such as aluminum and nickel, by the electroforming method, if the surface roughness of a metal mold | die is small enough, the mirror surface 11 and 12 will become a mirror surface naturally by it. When the substrate 21 is made of resin or the like using the nanoimprint method, it is necessary to perform mirror coating by sputtering or the like in order to create the mirror surfaces 11 and 12.

  The double-sided corner reflector 1 formed on the base 21 in this way reflects light entering the hole 22 from the front surface side (or back surface side) of the base 21 by one mirror surface (11 or 12) and further reflects the reflected light. Is reflected by the other mirror surface (12 or 11) and passes to the back surface side (or front surface side) of the base plate 21. The light entrance path and the light emission path are symmetrical with respect to the base plate 21. Therefore, by forming a large number of two-sided corner reflectors 1 on the base 21 as described above, the two-sided corner reflector array 2A functions. That is, the element plane S of the two-surface corner reflector array 2A (assuming a plane that passes through the central portion of the thickness of the base 21 and is orthogonal to each mirror surface and is indicated by an imaginary line in FIG. It becomes a symmetric plane that forms a real image of the projection object on the side as a mirror image (real mirror image) at a plane symmetric position on the other side.

  Here, an image formation mode by the two-surface corner reflector array 2A will be briefly described along with a path of light emitted from the point light source o as a projection object. 4 (a) is a schematic plan view, and FIG. 4 (b) is a schematic side view. As shown in FIG. 4 (b), light emitted from a point light source o (indicated by an arrow and a solid line). The two-sided corner reflector 1 travels from the back side to the front side of the sheet when passing through a hole 22 (omitted in the figure) formed in the base 21 (omitted in the figure) of the two-sided corner reflector array 2A. Is reflected by one mirror surface 11 (or 12) constituting the light source and further reflected by the other mirror surface 12 (or 11) and then transmitted through the element plane S (rays of transmitted light are indicated by broken lines). The point light source o passes through the element plane S of 2A (see FIG. 4B) while spreading in a plane symmetrical position (position o in the figure). That is, in the end, the transmitted light gathers at a plane symmetric position with respect to the element plane S of the point light source o and forms an image as a real mirror image p.

  In the present embodiment, as shown in FIG. 1, as the projections O1 and O2 disposed below the two-surface corner reflector arrays 2A1 and 2A2, the lower sides of the two-surface corner reflector arrays 2A1 and 2A2, respectively. The images displayed on the display areas (display surfaces) 3a1 and 3a2 of the respective displays 31 and 32 are applied. That is, the images O1 and O2 displayed on the display surfaces 3a1 and 3a2 of the displays 31 and 32 are three-dimensionally represented as real images (real mirror images) P1 and P2 of mirror images by the two-surface corner reflector arrays 2A1 and 2A2 in this embodiment. This is a projection object from which an aerial image is formed.

  Each display 31 and 32 has the same or substantially the same planar shape as the two-surface corner reflector array 2A. The display surfaces 3a1 and 3a2 formed on the front surface (upper surface) side of the displays 31 and 32 may be curved surfaces. However, as long as the display surfaces 3a1 and 3a2 are substantially flat, appropriate known displays can be appropriately used. The relative position and relative angle of the projection object O1 with respect to the two-surface corner reflector array 2A1 and the relative position and relative angle of the projection object O2 with respect to the two-surface corner reflector array 2A2 are the same. The relative position and relative angle of the display 31 with respect to the array 2A1 and the relative position and relative angle of the display 32 with respect to the two-sided corner reflector array 2A2 are set to be the same. As a result, the real image P1 of the projection object O1 that can be observed through the two-surface corner reflector array 2A1 and the real image P2 of the projection object O2 that can be observed through the two-surface corner reflector array 2A2 are spatially overlapped. Can be imaged.

  In this embodiment, as shown in FIG. 1, displays 31 and 32 in which the display surfaces 3a1 and 3a2 have a planar shape are adopted, and the display surfaces 3a1 and 3a2 are elements in the space on the lower surface side of the two-surface corner reflector array 2A. It arrange | positions so that it may become an arbitrary angle with respect to plane S1, S2, for example, 90 degree | times (perpendicular). Further, in the present embodiment, the displays 31 and 32 are arranged such that the central portion (intersection of two equal sides in each display 31 and 32) is in contact with the central portion (intersection of two equal sides) of the two-surface corner reflector array 2A. Arranged in the state. Note that the orientation of the displays 31 and 32 is not necessarily limited to this, and the image O1 displayed on the display surfaces 3a1 and 3a2 when viewed from a certain viewpoint on the upper surface side of the two-surface corner reflector arrays 2A1 and 2A2. , O2 can be appropriately set as long as the real image (real mirror images P1, P2) can be seen.

  Next, an operation of the parallax type 3D aerial image display device X1 according to the present embodiment will be described. Through the two-surface corner reflector array 2A1 which is disposed on the left side relative to the observer W among the two two-surface corner reflector arrays 2A1 and 2A2, the display surface 3a1 is plane-symmetric with respect to the element plane S1 of the two-surface corner reflector array 2A1. At the position, an image of the same figure as the image O1 is formed as a real mirror image P1 of the image O1 displayed on the display surface 3a1. Further, the display surface 3a2 is displayed on the display surface 3a2 at a plane-symmetrical position of the display surface 3a2 with respect to the element plane S2 of the two-surface corner reflector array 2A2 through the two-surface corner reflector array 2A2 that is disposed on the right side as viewed from the observer W. As an actual mirror image P2 of the image O2, an image having the same figure as the image O2 is formed. These real mirror images P1 and P2 are imaged at spatially overlapping positions (in this embodiment, the upper space at the center of the two-surface corner reflector arrays 2A1 and 2A2), and the observer W is the right-eye and the two-surface corner reflector. When viewing the real mirror image P1 imaged through the array 2A1 and viewing the real mirror image P2 imaged through the two-plane corner reflector array 2A2 with the left eye, a stereoscopic aerial image can be observed by binocular parallax.

  As described above, according to the three-dimensional aerial image display device X1 of the present embodiment, the images O1 and O2 displayed on the display surfaces 3a1 and 3a2 of the displays 31 and 32 are respectively transmitted through the two-surface corner reflector arrays 2A1 and 2A2. Real images P1 and P2 having no distortion at the planes of symmetry with respect to the element planes S1 and S2 can be displayed as a three-dimensional aerial image by a parallax method, and the image can be floated in an empty space to move up and down the viewpoint. It is possible to provide a new 3D video presentation style called 3D aerial video that does not move.

  In addition, the stereoscopic aerial image display device X1 according to the present embodiment can display a stereoscopic image based on parallax, and the positions of the real mirror images P1 and P2 coincide with the presentation position of the stereoscopic image, so that only a small number of parallax images can be displayed. Even if it is not, it is possible to eliminate the inconsistency between the congestion and the focus.

  In addition, the parallax type stereoscopic aerial image display device X1 of the present embodiment regards a real image formed through one two-plane corner reflector array 2A as being observed with one eye, and two two like the above-described embodiment. When the surface corner reflector arrays 2A1 and 2A2 are arranged side by side, the real images P1 and P2 formed through the two surface corner reflector arrays 2A1 and 2A2 are displayed as stereoscopic aerial images using a parallax method. Therefore, when the two two-surface corner reflector arrays 2A1 and 2A2 are arranged side by side, the viewpoint is limited to a certain direction, but the same configuration as the two-surface corner reflector array 2A used in the above embodiment is used. When three or more are arranged side by side in a ring or partial ring (fan shape) and the same projection object is arranged in the same position and angular relationship corresponding to each two-sided corner reflector array 2A, from a plurality of viewpoints A three-dimensional aerial image display device capable of observing a three-dimensional aerial image is also possible. That is, the two-surface corner reflector array that functions as the right-eye imaging optical system among the two two-surface corner reflector arrays that display a stereoscopic aerial image that can be observed from a predetermined viewpoint, displays a stereoscopic aerial image that can be observed from different viewpoints. Of the two two-surface corner reflector arrays to be displayed, the left-eye imaging optical system may function. That is, in the stereoscopic aerial image display device of the present embodiment, the number obtained by subtracting 1 from the number of the two-sided corner reflector array 2A arranged in a plurality is the number of viewpoints that can observe a three-dimensional aerial image using binocular parallax. Accordingly, it is possible to simultaneously observe a stereoscopic aerial image having the same shape from a plurality of viewpoints, and it is possible to easily realize a multi-viewpoint of the stereoscopic aerial image.

  In addition, a plurality of two-sided corner reflector arrays arranged in an annular shape or a partial annular shape (fan shape) are arranged in a posture in which the center portion (intersection of two equal sides) side is recessed from the anti-center portion side, It is also possible to arrange the part side in a posture that is recessed from the center part (the intersection of two equal sides) side. In these cases, the element planes (target planes) of the adjacent two-sided corner reflector arrays are not formed on the same plane, but the real mirror images of the projections formed through the two-sided corner reflectors overlap in the air. If set, an aerial stereoscopic image can be observed by parallax.

  Further, as shown in FIG. 5, a mirror M is arranged in a posture orthogonal to the element plane S on the side where the projection object O is arranged (lower side in the illustrated example) in the two-surface corner reflector array 2A. The stereoscopic aerial mirror image display device X2 in which the display 3 ′ is arranged at a predetermined angle with respect to can also be configured. 5 shows the arrangement of the mirror M and the projection object O (display 3 ′) with respect to one two-sided corner reflector 2A for convenience of explanation, two or more two-sided surfaces according to FIG. The three-dimensional aerial mirror image display device X2 is configured by arranging the corner reflectors 2A and arranging the mirror M and the projection object O (display 3 ′) corresponding to each of the two-surface corner reflectors 2A. Further, the two-sided corner reflector 2A itself is the same as the two-sided corner reflector 2A in the above-described embodiment.

  Specifically, as shown in FIG. 5, when the display 3 ′ is arranged at an arbitrary angle on the outside (on the opposite side of the center) with the mirror M as a boundary, an image (display in the illustrated example) is displayed on the display 3 ′. The virtual image V of the projection object O) displayed on the 3 ′ display surface 3a ′ is displayed at the surface target position (center side) with respect to the mirror M, and this virtual image V passes through the mirror M and the two-surface corner reflector array 2A. A real image (real mirror image) P is displayed at the surface target position with respect to the element plane S of the two-surface corner reflector array 2A. Therefore, through the two-surface corner reflector array 2A arranged in two or more, the image O displayed on each display 3 ′ is positioned in a plane-symmetrical position with respect to the element plane S of the virtual image V on the upper side of each two-surface corner reflector array 2A. As the real mirror image P ′, images of the same figure as the image O are formed. Each of these real mirror images P forms an image at a spatially overlapping position, and the observer W can observe as a stereoscopic aerial image by binocular parallax.

  Even such a stereoscopic aerial image display device X2 can display an aerial stereoscopic image above the two-sided corner reflector array 2A by the above-described parallax method. With such an aspect, it is possible to apply a planar shape larger than the planar shape of the two-sided corner reflector array 2A as the display 3 ′ (projected object O) and the two-sided corner reflector array. Since it is not necessary to arrange the display 3 ′ on the center side of 2A, a wide free space can be secured below the center side.

  In the stereoscopic aerial mirror image display device X3 shown in FIG. 6, three or more two-surface corner reflector arrays 2A are arranged side by side in an annular shape or a partial annular shape (annular shape in the illustrated example), and each two-surface corner reflector array is arranged. When the mirror M and the display 3 ′ are respectively arranged corresponding to 2A, a real image P that can be observed for each of a plurality of viewpoints is formed above the two-sided corner reflector array 2A. It can be observed as a three-dimensional aerial image. FIG. 6 schematically shows a case where a quadrangular image O displayed on the entire display surface of the display 3 ′ is imaged as a real mirror image P on the upper side of the two-surface corner reflector array 2A. The mirror image P is intentionally shown larger than the projection object (image O).

  Further, in each of the above-described embodiments, the two-surface corner reflector that constitutes the two-surface corner reflector array only needs to have two orthogonal reflecting surfaces, and the reflecting surface may be a substance that reflects light such as metal. It is possible to use phenomena such as reflection by an end face or film having a flatness with a specular accuracy of 5 mm and total reflection at a boundary having flatness with a specular accuracy between transparent media having different refractive indexes. More specifically, for example, in the above-described embodiment, as shown in FIGS. 2 and 3, in the two-sided corner reflector array 2 </ b> A, a square hole 22 is formed in the thin plate-like base 21, and the hole A two-sided corner reflector is formed by two adjacent ones of the inner peripheral walls of the glass plate, but instead of such a configuration, as shown in an enlarged view in FIG. A two-sided corner reflector array 2A ′ may be formed in which a two-sided corner reflector 1 ′ is formed in each of the two 23 and a large number of such cylindrical bodies 23 are formed in a grid pattern. In this case, the two-surface corner reflector 1 ′ can be formed also by an aspect in which two orthogonal surfaces among the inner wall surfaces of each cylindrical body 23 are mirror surface elements 11 ′ and 12 ′. In this case, similarly to the above-described embodiment, the light reflected twice by the two-surface corner reflector 1 ′ passes through a point that is plane-symmetric with respect to the surface direction of the substrate 21, that is, the element plane S ′. A three-dimensional aerial image can be formed in a space opposite to the element plane S ′.

  It should be noted that the inner wall surface other than the mirror surface elements 11 ′ and 12 ′ of the cylindrical body 23 is not a mirror surface, or an angle other than perpendicular to the element plane S ′ is provided, thereby eliminating excessive reflection and making it clearer. A good image can be obtained. The two mirror surfaces 11 ′ and 12 ′ constituting the two-surface corner reflector 1 ′ can use total reflection or can use reflection by a reflection film. In particular, when the total reflection of the mirror surfaces 11 ′ and 12 ′ is used, it can be expected that multiple reflections are less likely to occur because there is a critical angle for total reflection. Furthermore, it is also possible to attach a metal reflection film to two surfaces of a cylindrical body on which a mirror surface is to be formed, and bond the cylindrical bodies to each other. In this case, it is necessary to take measures against multiple reflections such as non-specularization to a surface other than the mirror surface, but a two-surface corner reflector array having a high aperture ratio and a high transmittance can be obtained.

  In addition, the two specular elements constituting the two-surface corner reflector may be arranged with a gap between each other without being in contact with each other as long as two orthogonal reflecting surfaces can be formed. The specific configuration of each part is not limited to the above-described embodiment, such as the shape of the display optical system or the two-surface corner reflector array can be freely set, and various modifications can be made.

  Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. The three-dimensional aerial image display device X4 according to the present embodiment uses the real mirror image forming optical system in the first embodiment from the two-surface corner reflector array 2A to the real mirror image using the half mirror 5 and the retro reflector array 6. It has a configuration replaced with the imaging optical system 2B. For convenience of explanation, FIG. 8 shows one real mirror image forming optical system 2B and the arrangement of the projection object O (display 3) with respect to this real mirror image forming optical system 2B. By copying and arranging two or more real mirror image forming optical systems 2B side by side, and arranging each projection object O (display 3) corresponding to each real mirror image forming optical system 2B, the three-dimensional air A real mirror image display device X4 is configured. The display 3 has a configuration similar to that of the first embodiment, but the planar shape may be a triangular shape, a quadrangular shape, or other shapes.

  As shown in FIG. 8, the real mirror image forming optical system 2 </ b> B applied in the present embodiment has a display in which the half mirror surface 51 of the half mirror 5 is a symmetrical surface and is disposed in a space on the lower surface side of the half mirror surface 51. 3 is reflected by the half mirror surface 51, is then retroreflected by the retroreflector array 6, returns to the incident direction, and is transmitted through the half mirror surface 51. A mirror image P is formed at a plane symmetrical position with respect to the half mirror surface 51 as a symmetrical plane of the set over time. Here, “retroreflection” refers to a phenomenon in which reflected light is reflected (reversely reflected) in a direction in which incident light is incident. The incident light and the reflected light are parallel and opposite to each other. A retro-reflector array 6 is an array of retro-reflectors having such a retroreflective action.

  Any type of retroreflector array 6 can be used as long as it strictly reflects back incident light, and a retroreflective film or a retroreflective coating may be applied to the surface of the material. Moreover, the shape may be a curved surface as shown in FIG. 8, or may be a flat surface. For example, the retroreflector array 6 shown in an enlarged part of the front view in FIG. 9A is a corner cube array that is a set of corner cubes using one corner of a rectangular parallelepiped. The individual retro-reflectors 61 form a regular triangle when the mirror surfaces 61a, 61b, 61c forming three isosceles right-angled isosceles triangles are gathered at one point and viewed from the front. The mirror surfaces 61a, 61b, 61c are orthogonal to each other to form a corner cube. In addition, the retroreflector array 6 shown in an enlarged part of the front view in FIG. 4B is also a corner cube array that is a set of corner cubes that use one corner of the rectangular parallelepiped. Each retroreflector 61 forms a regular hexagon when the mirror surfaces 61a, 61b, 61c forming three squares of the same shape and the same size are gathered at one point and viewed from the front, and these three mirror surfaces 61a, 61b and 61c are orthogonal to each other. The retroreflector array 6 is different in shape from the retroreflector array 6 shown in FIG. 10A and 10B, the retroreflector array 6 shown in FIGS. 9A and 9B will be described as an example. Light incident on one of the mirror surfaces (for example, 61a) By reflecting on the other mirror surfaces (61b, 61c), the light is reflected in the original direction in which the light has entered the retroreflector 61. The paths of the incident light and the outgoing light with respect to the retroreflector array 6 are not strictly overlapping but are parallel to each other. However, when the retroreflector 61 is sufficiently smaller than the retroreflector array 6, the paths of the incident light and the outgoing light. May be considered as overlapping. The difference between these two types of corner cube arrays is that the mirror surface is isosceles triangle is relatively easy to create, but the reflectivity is slightly lower, and the mirror surface is square is slightly easier to create than the isosceles triangle. While difficult, it has a high reflectivity.

  In addition to the corner cube array described above, a retroreflector array 6 that retroreflects light rays with three mirror surfaces (“corner reflector” in a broad sense) can be employed. Although not shown, for example, as a unit retroreflective element, two mirror surfaces of three mirror surfaces are orthogonal to each other, and another mirror surface is 90 / N degrees with respect to the other two mirror surfaces (where N is an integer) And acute angle retroreflectors having angles of 90 degrees, 60 degrees, and 45 degrees formed by the adjacent mirror surfaces of the three mirror surfaces are suitable as the retroreflective element 3 applied to the present embodiment. In addition, a cat's eye retro reflector or the like can be used as a unit retroreflective element. These retro-reflector arrays may be planar or bent or curved. In the example of FIG. 8, the partially spherical retroreflector array 6 is arranged outside the display 3. However, if the light emitted from the image O on the display surface 31 and reflected by the half mirror 5 can be retroreflected. The shape and arrangement position of the retro reflector array 6 can be set as appropriate.

  On the other hand, the half mirror 5 can use, for example, a thin reflective film coated on one surface of a transparent thin plate such as a transparent resin or glass. By applying anti-reflection treatment (AR coating) to the opposite surface of the transparent thin plate, it is possible to prevent the observed real mirror image P from being doubled. In addition, on the actual upper surface of the half mirror 5, a visual field control film or a visual field is used as a visual line control means that transmits a light beam in a specific direction and blocks a light beam in another specific direction or diffuses only a light beam in a specific direction. An optical film 52 such as a corner adjusting film can be attached and provided. Specifically, the optical film 52 prevents the light directly transmitted through the half mirror 5 from reaching the position other than the predetermined viewpoint through the optical mirror 52, thereby allowing the display 3 to be displayed from other than the predetermined viewpoint through the half mirror 5. While preventing the image O of the display surface 3 from being directly observable, only the light rays in the direction that passes through the half mirror 6 after being reflected once by the half mirror 5 described later and retroreflected by the retroreflector array 6 are used. By transmitting, only the real image P of the video O can be observed from a specific viewpoint.

  As in the case of the first embodiment, at least two real mirror image forming optical systems 2B constituted by the half mirror 5 and the retroreflector array 6 are arranged side by side and correspond to the real mirror image forming optical system 2B. In the three-dimensional aerial image display device X4 in which the same projection object O is disposed at the same position and angular relationship, the right-eye imaging optical system that is the real mirror image imaging optical system 2B disposed relatively on the left side. A real mirror image of the corresponding projection object imaged by the system, and a corresponding projection image formed by the left-eye imaging optical system which is the real mirror image imaging optical system 2B disposed relatively on the right side. The real mirror image can be superimposed and displayed at the same position, and the stereoscopic aerial image can be imaged in the space on the upper surface side of the half mirror 5 by the parallax and observed.

  <Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. The three-dimensional aerial image display device X5 according to the present embodiment is an application of a microlens array 2C (the microlens arrays 2C1 and 2C2 shown in FIG. 11 are collectively referred to as 2C) as a real mirror image forming optical system. The display 3 (the displays 31 and 32 shown in FIG. 11 are collectively referred to as 3) has a configuration similar to that of the first embodiment, and has an arbitrary planar shape. FIG. 11 shows the display 3 having a substantially rectangular shape in plan view. In the present embodiment, the display 3 is opposed to the microlens array 2C (in FIG. 11, the display surface 3a1 of the display 31 and the element plane S3 of the microlens array 2C1 are parallel to each other, the display surface 3a2 of the display 32, The microlens array 2C2 is disposed at a position parallel to the element plane S4.

  As shown in FIG. 12, the microlens array 2C is configured by arranging a large number of microlenses 7 on one element plane S (element planes S3 and S4 shown in FIG. 11 are collectively referred to as S). The microlens 7 may be either a non-focal type or a focal side. The non-focal-side microlens is referred to as an afocal lens. Specifically, the microlens 7 includes two lenses 71 and 72 that share an optical axis g perpendicular to the element plane S and are spaced from each other by focal lengths fs and fe. In this example, convex lenses are applied as the lenses 71 and 72. As a result, light incident on the lenses 71 from one side of the element plane S is emitted from the other pair of lenses 72 and collected at a position that is plane-symmetric with respect to the element plane S. Shine. That is, the images O1 and O2 displayed on the display surfaces 3a1 and 3a2 of the displays 31 and 32 serving as the light sources in FIG. 11 are imaged at plane symmetry positions with respect to the element planes S3 and S4. Note that, when the projection object is formed as a real image at a plane-symmetrical position with respect to the element plane S using the microlens array 2C, the viewing angle is limited to a direction near the element plane S.

  As in the first embodiment, at least two (two in the illustrated example) such real mirror image forming optical systems 2C are arranged side by side, and correspond to each of the real mirror image forming optical systems 2C1 and 2C2. By configuring the three-dimensional aerial image display device X5 in which the same projections O1 and O2 are disposed at the same position and angle relationship, respectively, the real mirror image imaging optical system 2C1 disposed relatively on the left side. A real mirror image P1 of the corresponding projection object O1 imaged by a certain right eye imaging optical system is connected by a left eye imaging optical system which is a real mirror image imaging optical system 2C2 disposed on the right side. The real image P2 of the corresponding projection O2 to be imaged can be superimposed and displayed at the same position, and the stereoscopic aerial image is connected to the space on the upper surface side of the real image imaging optical systems 2C1 and 2C2 by parallax. It is possible to image and observe It is.

  In addition, this invention is not limited to embodiment mentioned above. In each example described above, an image displayed on a display is used as a projection object. However, an object (three-dimensional) itself can be applied as a projection object. However, the depth of the observed real image is reversed from the depth of the projection object. In addition, when applying an image displayed on a display as an object to be projected, not only a display in a general sense of displaying an image on a screen but also a screen that displays an image projected by a projector or the like. It can also be adopted. Further, the display surface of the display may be a curved surface as well as a flat surface.

  In addition, when the real mirror image forming optical system is composed of a two-sided corner reflector array, the mirror surface in each two-sided corner reflector has a glossy surface such as metal or resin regardless of whether it is solid or liquid. A material that reflects on a flat surface formed of a certain substance or a material that reflects or totally reflects on a flat boundary surface between transparent media having different refractive indexes can be used. Further, when the mirror surface is configured by total reflection, undesired multiple reflection by a plurality of mirror surfaces is likely to exceed the critical angle of total reflection, so that it can be expected to be naturally suppressed. The mirror surface may be formed on a very small part of the inner wall of the optical hole as long as there is no functional problem, or may be constituted by a plurality of unit mirror surfaces arranged in parallel. In other words, the latter aspect means that one mirror surface may be divided into a plurality of unit mirror surfaces. In this case, the unit mirror surfaces do not necessarily have to be on the same plane as long as they are parallel to each other. Further, each unit mirror surface is allowed to be either in contact with or apart from each other. Further, when light is transmitted from one side of the element plane of the two-sided corner reflector array to the other side, it is only necessary to reflect the light once by two mirror surfaces, so that the two mirror surfaces orthogonal to each other in the two-sided corner reflector are separated from each other. It may be an embodiment.

  Furthermore, when a two-surface corner reflector array is applied as a real mirror image forming optical system in the present invention, in addition to the above-described two-surface corner reflector array (2A, etc.), mirror surfaces that are perpendicular to the element surface and parallel to each other A two-sided corner reflector array having a structure in which two slit mirror arrays each having a vertical axis are stacked so that the mirror surfaces are vertical may be employed.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  The present invention can be used as a display device that displays a video displayed on a display as a three-dimensional video floating in the air due to parallax.

X1, X2, X3, X4, X5 ... Parallax type stereoscopic aerial image display device S (S1, S2), S3, S4 ... Symmetry plane (element plane)
O (O1, O2) ... Projected object P (P1, P2) ... Real mirror image 2A (2A1, 2A2), 2A ', 2B, 2C (2C1, 2C2) ... Real mirror image imaging optical system

Claims (3)

Arranging at least two real mirror image-forming optical systems that can form a real image of a projection object at a plane-symmetrical position with respect to a certain geometric plane as a symmetry plane;
A projection object is arranged for each imaging optical system,
A real mirror image of the corresponding projection imaged by the right-eye imaging optical system which is the real mirror video imaging optical system disposed relatively on the left side;
The actual mirror image of the corresponding projection image formed by the left-eye imaging optical system, which is the actual mirror image imaging optical system disposed relatively on the right side, is superimposed and displayed at the same position. A parallax type three-dimensional aerial image display device. The parallax-type three-dimensional aerial image display device according to claim 1, wherein three or more real mirror image forming optical systems are arranged side by side. The parallax type three-dimensional aerial image display device according to claim 1, wherein the plurality of real mirror image optical systems are arranged in a ring shape.

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