Thin-profile spatial image display device and non-contact input device using the same

Abstract

To provide a thin spatial image display device that can form a clear spatial image despite its thin profile, and is excellent in terms of space saving and installation flexibility, as well as a non-contact input device using the same. [Solution] The non-contact input device 10 comprises an optical imaging means 18 having a light-receiving surface 16 and a light-emitting surface 17 parallel to each other, with a first light-reflecting surface and a second light-reflecting surface formed perpendicular to the light-receiving surface 16 and orthogonal to each other, and a flat plate-shaped image output means 20 whose display surface 19 is arranged parallel to the light-receiving surface 16, a thin spatial image display device 11 that displays a spatial image 12 with the optical imaging means 18 in the space on the light-emitting surface 17 side, with the optical imaging means 18 in between, and the front surface being symmetrical to the virtual display object 21 and inclined at an angle α with respect to the light-emitting surface 17, and a detection means 14 attached to the thin spatial image display device 11 that detects the position of an instruction means 13 that touches the spatial image 12.

Description

[Technical Field]

[0001] The present invention relates to a thin spatial image display device capable of displaying the original image of a spatial image by a flat plate-shaped image output means arranged parallel to the light-receiving surface of an optical imaging means, and a non-contact input device using the same. [Background technology]

[0002] As an example of a device that uses light (scattered light) emitted from the surface of an object (object to be displayed) to form a three-dimensional image (spatial image = real image) of that object in the air, a three-dimensional image forming device (optical imaging device) described in Patent Document 1 is known. This imaging device has first and second optical control panels formed inside two transparent flat plates, with numerous strip-shaped metal reflective surfaces arranged at a constant pitch perpendicular to one side of the transparent flat plates. The first and second optical control panels are placed in close contact with each other, with one side of each optical control panel facing the other, so that their respective light reflective surfaces are orthogonal. In this optical imaging device, as shown in Figures 3, 5, and 6 of Patent Document 1, the object image M' or N' formed in the air is generated at a position symmetrical to the object M or N with respect to the optical imaging device. This is also true when a display device such as a display is installed instead of the object M or N, and a spatial image of the image displayed on the display device is formed. Therefore, in this non-contact input device utilizing an optical imaging device, as shown in Figure 2 of Patent Document 2, for example, the angle a between the display that shows the image and the optical imaging means is equal to the angle a between the optical imaging means and the spatial image that is imaged in space. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2009 / 131128 [Patent Document 2] Utility Model Registration No. 3219968 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Thus, in order to tilt and project a spatial image in the space above the optical imaging device based on the image displayed on the display device, both the optical imaging device described in Patent Document 1 and the non-contact input device described in Patent Document 2 require the display device to be installed below the optical imaging device in an inclined position, thus requiring a large installation space. For this reason, optical imaging devices and non-contact input devices are large and lack installation flexibility, which has hindered their widespread adoption. This invention has been made in view of the above circumstances, and aims to provide a thin spatial image display device that can form a clear spatial image despite being thin, and is excellent in terms of space saving and installation flexibility, and a non-contact input device using the same. [Means for solving the problem]

[0005] A thin spatial image display device according to the first invention in line with the above objective is a thin spatial image display device comprising an optical imaging means having a light-receiving surface and a light-emitting surface parallel to each other, and a first light-reflecting surface and a second light-reflecting surface formed perpendicular to the light-receiving surface and orthogonal to each other, The optical imaging means includes a flat-plate image output means in which a display surface composed of multiple pixels arranged vertically and horizontally is arranged parallel to the light-receiving surface. Light emitted from a virtual display object whose front surface is inclined at an angle α with respect to the light-receiving surface of the optical imaging means and irradiated onto the light-receiving surface is output as light irradiated onto the light-receiving surface from a spatial image reproduction image displayed on the display surface of the flat-plate image output means. Of the light irradiated onto the light-receiving surface from the spatial image reproduction image, the light reflected once each by the first light-reflecting surface and the second light-reflecting surface displays a spatial image in the space on the light-emitting surface side of the optical imaging means, symmetrical to the virtual display object with respect to the optical imaging means and whose front surface is inclined at an angle α with respect to the light-emitting surface.

[0006] Here, two types of spatial image reproduction methods using light are known: ray reproduction and wavefront reproduction. The ray reproduction type spatial image reproduction method utilizes IP (Integral Photography) technology. For example, it reproduces the light emitted from each pixel that makes up an image displayed on a display means such as a 2D display as light rays traveling in a specific direction (hereinafter referred to as directional light rays), and an optical image (spatial image) can be formed in the air by this group of light rays. Methods for reproducing spatial images using directional light rays (ray reproduction type spatial image reproduction methods) include the pinhole array method, the lens array method, the layered display method, and the diffuse screen method. The wavefront reproduction type spatial image reproduction method is a method of recording and reproducing the wavefront of light, and is also called holography. During recording, a laser beam is shone on the subject (object to be displayed), and the interference fringes of the reflected light (object light) and the original laser beam (reference light) are recorded. During playback, the playback light (reference light) is irradiated onto the interference fringes displayed on a display means such as a spatial light modulator (SLM), and the optical image (spatial image) can be reproduced using the read-out diffracted light. By using the display means used in this ray playback type or wavefront playback type spatial image playback method as a flat-panel image output means, the spatial image display device can be made thinner.

[0007] The thin spatial image display device according to the first invention may be equipped with an image generation means for generating the spatial image reproduction image. Here, the image generation means may be built into the thin spatial image display device, or it may be attached externally to the thin spatial image display device, and the data of the spatial image reproduction image generated by the image generation means may be transmitted from the image generation means to the thin spatial image display device for use.

[0008] In the thin-type spatial image display device according to the first invention, the flat plate-like image output means is a light beam reproduction type image output means, and (a) an IP image panel that displays, on the display surface, as the spatial image reproduction image, an IP image composed of an element image group in which a plurality of element images generated based on the light beam information of the virtual display object obtained on an observation surface inclined at an angle α with respect to the front of the virtual display object by IP technology are grouped as a set, and (b) an IP filter provided one by one corresponding to each of the plurality of element images, having a plurality of light transmissive portions, and arranged in parallel with the light incident surface of the optical imaging means in front of the display surface of the IP image panel. Preferably, light emitted from each of the plurality of element images passes through each of the plurality of light transmissive portions corresponding to each of the plurality of element images and irradiates the light incident surface of the optical imaging means.

[0009] In the thin-type spatial image display device according to the first invention, it is preferable that each of the plurality of element images is configured in a rectangular shape when viewed from the front by a plurality of pixels on the display surface and arranged side by side vertically and horizontally on the display surface, and each of the plurality of light transmissive portions is formed in a pinhole shape.

[0010] In the thin-type spatial image display device according to the first invention, it is also possible that each of the plurality of element images is configured in a vertically long rectangular shape having a vertical dimension equal to the vertical dimension of the display surface when viewed from the front by a plurality of pixels on the display surface and arranged side by side horizontally on the display surface, and each of the plurality of light transmissive portions is formed in a vertically long slit shape.

[0011] In the thin-type spatial image display device according to the first invention, first to nth IP images composed of n types of different element image groups and complementary to each other are sequentially displayed on the IP image panel in a time-sharing manner. When the i-th IP image is displayed, light emitted from each of the plurality of element images constituting the i-th IP image may pass through each of the plurality of light transmissive portions corresponding to each of the plurality of element images constituting the i-th IP image and irradiate the light incident surface. However, n is an integer of 2 or more, and i is an integer from 1 to n.

[0012] In the thin space image display device according to the first invention, the IP image has a first partial IP image and a second partial IP image composed of two different element image groups, and pixels constituting each of the plurality of element images included in the first partial IP image and pixels constituting each of the plurality of element images included in the second partial IP image are such that the first partial IP image and the second partial IP image are simultaneously displayed on the IP image panel so as not to overlap, The flat plate image output means includes: (a) a polarizing means disposed between the IP image panel and the IP filter, linearly polarizing light emitted from the first partial IP image in a first direction and linearly polarizing light emitted from the second partial IP image in a second direction orthogonal to the first direction; and (b) a polarizer disposed on the optical imaging means side of the IP filter and having a polarization axis parallel to the first direction. The IP filter functions such that a range overlapping one or a plurality of pixels located at the center of each of the plurality of element images included in the first partial IP image when viewed from the front is a first light-transmitting portion, allowing light linearly polarized in the first direction by the polarizing means and light linearly polarized in the second direction by the polarizing means to pass through as they are, and a range overlapping one or a plurality of pixels located at the center of each of the plurality of element images included in the second partial IP image when viewed from the front is a second light-transmitting portion, linearly polarizing the light linearly polarized in the first direction by the polarizing means in the second direction and allowing it to pass through, and linearly polarizing the light linearly polarized in the second direction by the polarizing means in the first direction and allowing it to pass through.

[0013] In the thin space image display device according to the first invention, the polarizing means has a first polarizing alignment film, a second polarizing alignment film disposed opposite to the first polarizing alignment film, a polarizing liquid crystal layer filled with liquid crystal between the first polarizing alignment film and the second polarizing alignment film, and a polarizing driving unit capable of switching the alignment direction of the liquid crystal molecules of the polarizing liquid crystal layer in pixel units, and it is preferable that the alignment processing direction of the first polarizing alignment film and the alignment processing direction of the second polarizing alignment film are orthogonal to each other.

[0014] In the thin spatial image display device according to the first invention, the IP filter comprises a first alignment film for shutters, a second alignment film for shutters disposed opposite to the first alignment film for shutters, a liquid crystal layer for shutters in which liquid crystal is filled between the first alignment film for shutters and the second alignment film for shutters in a range that functions as at least the first and second light-transmitting portions, a shutter drive unit capable of switching the orientation direction of the liquid crystal molecules in the liquid crystal layer for shutters on a pixel-by-pixel basis, and a shielding portion that shields areas other than the range that functions as the first and second light-transmitting portions of the liquid crystal layer for shutters, wherein the orientation processing direction of the first alignment film for shutters and the orientation processing direction of the second alignment film for shutters are orthogonal to each other.

[0015] In the thin spatial image display device according to the first invention, the planar image output means is a wavefront regeneration type image output means, comprising: (a) a hologram display that displays on the display surface a hologram of the virtual display object recorded on a recording surface inclined at an angle α with respect to the front of the virtual display object by holography technology as the spatial image regeneration image; and (b) an illumination unit that irradiates the spatial image regeneration image with reference light. Light emitted from the reconstructed image of the virtual display object, which is reconstructed by irradiating the spatial image reproduction image with the reference light, may be irradiated onto the pre-printed light surface of the optical imaging means.

[0016] In the thin spatial image display device according to the first invention, it is preferable that the hologram is a computer-generated hologram and the hologram display is a spatial light modulator.

[0017] In the thin spatial image display device according to the first invention, it is preferable that the angle α = 45 ± 15 degrees.

[0018] A non-contact input device according to the second invention, which is in line with the above objective, is a non-contact input device using a thin spatial image display device according to the first invention, comprising the thin spatial image display device and a detection means attached to the thin spatial image display device for detecting the position of an indicator means that touches the spatial image. [Effects of the Invention]

[0019] The thin spatial image display device according to the first invention can display a spatial image (a spatial image tilted by an angle α with respect to the light-emitting surface) with a surface tilted at an angle α with respect to the light-emitting surface on the light-emitting surface side of the optical imaging means as the front, based on light irradiated toward the light-emitting surface from a flat plate-shaped image output means having a display surface parallel to the light-receiving surface of the optical imaging means, and is extremely compact and offers excellent flexibility in installation.

[0020] The non-contact input device according to the second invention uses a thin spatial image display device equipped with a flat plate-shaped image output means having a display surface parallel to the light-receiving surface of the optical imaging means, thereby being extremely thin, space-saving, and highly flexible in installation. [Brief explanation of the drawing]

[0021] [Figure 1] This is a perspective view showing a non-contact input device using a thin spatial image display device according to the first embodiment of the present invention. [Figure 2] This is a cross-sectional side view of the main part of the non-contact input device. [Figure 3] (A) and (B) are cross-sectional views parallel to the first and second light-reflecting surfaces, respectively, illustrating the operation of the optical imaging means in the thin-film spatial image display device. [Figure 4] This is a schematic side view illustrating the principle of the flat-panel image output means in the thin-panel spatial image display device. [Figure 5] This is a schematic side view illustrating the operation of the thin spatial image display device. [Figure 6] (A) is a front view of the main part of the flat plate image output means in the thin spatial image display device, and (B) is an enlarged front view of the element image displayed on the IP image panel of the flat plate image output means in the thin spatial image display device. [Figure 7] This is a front view of a key part showing a modified example of the flat-plate image output means in the thin-type spatial image display device. [Figure 8] This is a front view of the main part of the flat plate image output means in a thin spatial image display device according to a second embodiment of the present invention. [Figure 9] (A) and (B) are explanatory diagrams of the time-division drive of the flat plate image output means in the thin spatial image display device. [Figure 10] This is an explanatory diagram showing the operation of the flat plate image output means in a thin spatial image display device according to a third embodiment of the present invention. [Figure 11] This is a schematic exploded perspective view showing the configuration of the flat-panel image output means in the thin-type spatial image display device. [Figure 12] This is a schematic cross-sectional view of the main part of the thin spatial image display device, showing the operation of the flat-panel image output means. [Figure 13] This is a schematic side view illustrating the operation of a thin spatial image display device according to a fourth embodiment of the present invention. [Modes for carrying out the invention]

[0022] A non-contact input device using a thin spatial image display device according to the first embodiment of the present invention will be described with reference to the drawings. As shown in Figures 1 and 2, the non-contact input device 10 according to the first embodiment of the present invention comprises a thin spatial image display device 11 and a detection means 14 attached to the thin spatial image display device 11 for detecting the position of an instruction means 13 (in this case, a finger) such as a finger or touch pen that touches the spatial image 12.

[0023] As shown in Figure 2, the thin spatial image display device 11 includes an optical imaging means 18 having a light-receiving surface 16 and a light-emitting surface 17 that are parallel to each other, and a flat plate-shaped image output means 20 whose display surface 19 is arranged parallel to the light-receiving surface 16. This thin spatial image display device 11 displays a spatial image 12 in the space on the light-emitting surface 17 side of the optical imaging means 18, with the optical imaging means 18 in between, and the front of the image is a surface that is symmetrical to the virtual display target 21 and inclined at an angle α with respect to the light-emitting surface 17. Here, the angle α is preferably in the range of approximately 45 ± 15 degrees, but it is not limited to this range and can be selected as appropriate.

[0024] As shown in Figures 3(A) and (B), the optical imaging means 18 has a first light reflection surface 22 and a second light reflection surface 23 that are perpendicular to the light-receiving surface 16 and orthogonal to each other. In the manufacture of this optical imaging means 18, for example, a transparent resin is molded (for example, by injection molding, press molding, or roll molding, etc.) to produce a first molded body 27 on one side (here, the upper side) in which a plurality of trapezoidal grooves 26 are arranged in parallel at predetermined intervals, with one side being a vertical surface 24 and the other side being an inclined surface 25, and the grooves expanding toward the one side. A second molded body 31 is produced on the other side (here, the lower side) in which a plurality of trapezoidal grooves 30 are arranged in parallel at predetermined intervals, with one side being a vertical surface 28 and the other side being an inclined surface 29, and the grooves expanding toward the other side. Then, by covering the vertical surfaces 24 and 28 of the grooves 26 and 30 of the first molded body 27 and the second molded body 31 with a metal reflective film 33, a first optical control unit 35 having a plurality of first optical reflective surfaces 22 and a second optical control unit 36 ​​having a plurality of second optical reflective surfaces 23 are formed. As a result, the first light-reflecting surface 22 and the second light-reflecting surface 23 are each formed in a strip shape and arranged in parallel at a predetermined interval.

[0025] The metal reflective film 33 specularly reflects light and is made from a metal such as aluminum. It can cover the vertical surfaces 24 and 28 by methods such as sputtering, metal deposition, spraying of metal microparticles, ion beam irradiation, or plating. Then, transparent adhesive 37 is filled into each groove 26 of the first optical control unit 35 and each groove 30 of the second optical control unit 36, and with the grooves 26 and groove 30 facing each other, the first optical control unit 35 and the second optical control unit 36 ​​are stacked (overlapped) in the thickness direction and joined together and integrated so that the first optical reflective surface 22 and the second optical reflective surface 23 are orthogonal when viewed from above, thereby obtaining the optical imaging means 18.

[0026] Next, the operation of the optical imaging means 18 will be explained. As shown in Figures 3(A) and (B), in the optical imaging means 18, of the light emitted from an object (not shown) and irradiated onto the light-receiving surface 16, for example, light L1 and L2 enter the first optical control unit 35 from positions P11 and P21, respectively, are reflected once each at positions P12 and P22 on the first light-reflecting surface 22 and enter the second optical control unit 36, are reflected once each at positions P13 and P23 on the second light-reflecting surface 23, and are emitted into the air from the second optical control unit 36 ​​at positions P14 and P24 on the light-emitting surface 17.

[0027] Here, light rays L1 and L2 enter the transparent adhesive 37 from the first molded body 27 in Q1 and Q2 of Figure 3(B), and enter the second molded body 31 from the transparent adhesive 37 in S1 and S2 of Figure 3(A). However, the refractive indices η1 and η2 of the first molded body 27 and the second molded body 31 are the same and approximate (are almost equivalent to) the refractive index η3 of the transparent adhesive 37, so the effect of refraction is extremely small, and phenomena such as total internal reflection and spectral dispersion do not occur. Consequently, countless light rays emitted from the object and reflected once each by the first light reflection surface 22 and the second light reflection surface 23 of the optical imaging means 18 are imaged in the air, forming a spatial image (not shown) that is a real image of the object at a position symmetrical to the object with respect to the optical imaging means 18.

[0028] Although the light rays L1 and L2 are refracted at positions P11 and P21 on the light-receiving surface 16 and P14 and P24 on the light-emitting surface 17, respectively, the transparent resin (first molded body 27 and second molded body 31) that forms the base material of the first light control unit 35 and the second light control unit 36 ​​has the same refractive index and is homogeneous. Therefore, all light involved in the formation of the spatial image is refracted at a constant (same) angle at the light-receiving surface 16 and the light-emitting surface 17, regardless of the light-receiving and light-emitting positions, just like the light rays L1 and L2. Thus, these refractions do not affect the formation of the image. Furthermore, in Figures 3(A) and (B), the left side of the metal reflective film 33 is shown as the first light-reflecting surface 22 and the second light-reflecting surface 23. However, both the front and back sides (left and right sides in Figures 3(A) and (B)) of the metal reflective film 33 can function as the first and second light-reflecting surfaces. Depending on the arrangement of the first light-control unit 35 and the second light-control unit 36 ​​(reversal of front and back sides) or the direction of light entry, either the front or back side of the metal reflective film 33 can function as the first and second light-reflecting surfaces.

[0029] In conventional spatial image display devices and non-contact input devices utilizing such spatial image display devices, which combine the optical imaging means 18 with a display means such as a general liquid crystal display, in order to tilt and image (float) the spatial image in the space above the optical imaging means 18, the display means must be installed below the optical imaging means 18 in an inclined position. This increases the height (thickness) of the spatial image display device and the non-contact input device, resulting in problems with ease of installation and handling. In contrast, the non-contact input device 10 according to the first embodiment shown in Figures 1 and 2 achieves a compact non-contact input device 10 by using a flat plate image output means 20 that applies the technology of a light source regeneration type (IP method) spatial image reproduction method. Specifically, the light emitted from a virtual display target (for example, an image displayed on a display means such as a liquid crystal display) 21, whose front surface is inclined at an angle α with respect to the light-receiving surface 16 of the optical imaging means 18, and irradiated onto the light-receiving surface 16, is reproduced and output as light irradiated onto the light-receiving surface 16 from a spatial image reproduction image displayed on the display surface 19 of the flat plate image output means 20, thereby obtaining a compact non-contact input device 10.

[0030] The following describes the details of the thin spatial image display device 11. First, the principle of the flat-panel image output means 20 used in the thin-film spatial image display device 11 will be explained. The flat-panel image output means 20 is a light-ray regeneration type image output means, and the spatial image regeneration image displayed on the flat-panel image output means 20 is generated by applying conventionally known IP technology. As shown in Figure 4, a light-shielding panel 41 is placed horizontally in front of (above in Figure 4) a virtual display object 21 tilted at an angle α with respect to the horizontal plane. Multiple (in this case, three) pinholes 42a to 42c are formed in the light-shielding panel 41. Further in front of (above in Figure 4) the light-shielding panel 41, a photosensitive film 43 is placed parallel to the light-shielding panel 41. Numerous rays of light are shone from the surface of the virtual display object 21 toward the light-shielding panel 41. Here, of the numerous rays of light emitted from three object points 44 to 46 and shone in various directions, one ray 44a, 45a, and 46a each passes through the pinhole 42a, forming an elemental image 50a consisting of minute images 47a, 48a, and 49a on the photosensitive film 43.

[0031] Similarly, from the countless rays of light irradiated in various directions from each object point 44-46, one ray 44b, 45b, and 46b passing through the pinhole 42b forms an elemental image 50b consisting of minute images 47b, 48b, and 49b on the photosensitive film 43, and one ray 44c, 45c, and 46c passing through the pinhole 42c forms an elemental image 50c consisting of minute images 47c, 48c, and 49c on the photosensitive film 43. Then, by inverting these element images 50a to 50c by 180 degrees relative to the pinholes 42a to 42c, an IP image 52 is obtained, which consists of a group of element images, with multiple (in this case, three) element images 51 forming a set. By viewing the light emitted from each element image 51 through the pinholes 42a to 42c, the observer can observe a spatial image (real image) of the virtual display object 21 in which the unevenness (depth information) is correctly represented. At this time, the observation surface is a horizontal plane (a plane parallel to the light-shielding panel 41 and the photosensitive film 43) that is inclined at an angle α with respect to the front of the virtual display object 21, and the observer can observe the spatial image of the virtual display object 21 inclined at an angle α with respect to the horizontal plane on the observation surface.

[0032] By combining the flat-panel image output means 20, which was conceived using the above principles, with the optical imaging means 18 described earlier, the thin-panel spatial image display device 11 shown in Figures 2 and 5 can be obtained. Comparing Figure 4 and Figure 5, the flat image output means 20 includes an IP image panel 53 having a display surface 19 corresponding to the position of the IP image 52 in Figure 4, and an IP filter 54 positioned corresponding to the light-shielding panel 41 in Figure 4. The thin spatial image display device 11, on the other hand, includes an optical imaging means 18 instead of a photosensitive film 43.

[0033] As described above, the IP image panel 53 displays an IP image 52 on the display surface 19 as an image for spatial image reproduction. This IP image 52 is composed of a group of elemental images, each consisting of multiple elemental images 51 generated by IP technology based on ray information of the virtual display target 21 acquired by an observation plane tilted at an angle α with respect to the front of the virtual display target 21. The IP filter 54 has multiple light-transmitting sections 55, one for each of the multiple elemental images 51, and is positioned in front of the display surface 19 of the IP image panel 53 (above in Figure 5) and parallel to the light-receiving surface 16 of the optical imaging means 18. The multiple light-transmitting sections 55 of the IP filter 54 correspond to the pinholes 42a to 42c of the light-shielding panel 41 described above, and the light emitted from each of the multiple elemental images 51 passes through each of the multiple light-transmitting sections 55 corresponding to each of the multiple elemental images 51 and is irradiated onto the light-receiving surface 16 of the optical imaging means 18.

[0034] Of the light irradiated onto the light-receiving surface 16 of the optical imaging means 18 from the IP image 52 (image for spatial image reproduction), the light reflected once each by the first light-reflecting surface 22 and the second light-reflecting surface 23 allows for the display of a spatial image 12, as shown in Figure 5, in the space on the light-emitting surface 17 side of the optical imaging means 18, with the optical imaging means 18 in between, and with the surface facing forward being symmetrical to the virtual display target 21 and inclined at an angle α with respect to the light-emitting surface 17. In the actual flat plate image output means 20, as shown in Fig. 6(A), a plurality of element images 51 constituting the IP image 52 (image for spatial image reproduction) are displayed side by side vertically and horizontally on the display surface 19 of the IP image panel 53. Further, the display surface 19 of the IP image panel 53 is composed of a plurality of pixels 56 that are square when viewed from the front and arranged vertically and horizontally. In the present embodiment, as shown in Fig. 6(B), each region where one element image 51 is displayed contains 20 pixels 56 each vertically and horizontally. Therefore, the vertical dimension a of the element image 51 is equal to the horizontal dimension b of the element image 51, and the vertical pitch P py (= horizontal pitch P px ) of the pixel 56 of the IP image panel 53 is 20 times. As the IP image panel 53, a liquid crystal panel (liquid crystal display) is preferably used, but it is not limited thereto.

[0035] As shown in Fig. 6(A), the IP filter 54 is formed by forming one pinhole-shaped light-transmitting portion 55 corresponding to each of the plurality of element images 51 on the IP image 52 (corresponding to the center position of each element image 51) on the light-shielding plate 58. In the present embodiment, since one element image 51 is a square composed of 20 pixels 56 each vertically and horizontally, the vertical pitch P a of the light-transmitting portion 55 is equal to the horizontal pitch P b of the light-transmitting portion 55, and is also equal to the vertical dimension a and the horizontal dimension b ( = vertical pitch and horizontal pitch of the element image 51) of the element image 51, and is 20 times the vertical pitch P py (= horizontal pitch P px ) of the pixel 56 of the IP image panel 53. And the distance from the display surface 19 of the IP image panel 53 to the IP filter 54 is preferably in the range of 0.5 to 5 times (more preferably 1 to 2 times) the vertical pitch P a (= horizontal pitch P b ) of the light-transmitting portion 55. Also, the aperture diameter D H of the pinhole-shaped light-transmitting portion 55 is preferably about 1 to 2 times the vertical pitch P py (= horizontal pitch P px ) of the pixel 56, but is not limited to this range. Note that the vertical dimension a (= horizontal dimension b) of the element image 51 and the vertical pitch P of the light-transmitting portion 55a (=horizontal pitch P) b The vertical and horizontal dimensions (= vertical pitch P of the pixels) are selected as appropriate, and accordingly, the number of pixels 56 included in the element image 51 is also selected as appropriate. Furthermore, the pixels and element images only need to be composed of a rectangular shape (including squares and rectangles) when viewed from the front, and the vertical and horizontal dimensions of the pixels (= vertical pitch P of the pixels) are selected as appropriate. py and horizontal pitch P px ) and the vertical dimension a and horizontal dimension b of the element image (= vertical pitch P of the translucent part) a and horizontal pitch P b ) will be selected as appropriate.

[0036] With the thin spatial image display device 11 configured as described above, as shown in Figure 5, the light emitted from each of the multiple element images 51 on the IP image 52 displayed on the display surface 19 of the IP image panel 53, passing through the light-transmitting portion 55 of the IP filter 54 and irradiating the light-receiving surface 16 of the optical imaging means 18, is reflected once each by the first light-reflecting surface 22 and the second light-reflecting surface 23. This allows for the display of a spatial image 12 in the space on the light-emitting surface 17 side of the optical imaging means 18, with the optical imaging means 18 in between, and the front of the image being a surface that is symmetrical to the virtual display target 21 and inclined at an angle α with respect to the light-emitting surface 17.

[0037] Next, the detection means 14 will be described. As shown in Figures 1 and 2, the detection means 14 is positioned inside the housing 59 of the thin spatial image display device 11, parallel to the lower edge of the spatial image 12. An opening 60 parallel to the longitudinal direction of the detection means 14 is formed on the upper surface of the housing 59. The detection means 14 includes a light-emitting unit (not shown) that irradiates detection light through the opening 60 in a direction parallel to the spatial image 12 to form a detection surface 61 parallel to the spatial image 12, and a light-receiving unit (not shown) that receives reflected light reflected from the indicator means 13 when the indicator means 13 touches the detection surface 61 at a position that overlaps with the spatial image 12 when viewed from the front.

[0038] When the virtual display target 21 is an image displayed on a display means such as a liquid crystal display, the spatial image 12 becomes a planar image (two-dimensional image). Therefore, as shown in Figure 2, the spatial image 12 (image plane) and the detection surface 61 can be aligned, allowing the spatial image 12 to function as a contactless input screen. As a result, when a user looks at the spatial image 12 and indicates a predetermined position on the spatial image 12 with the instruction means 13, that position is detected by the detection means 14, and character input or a predetermined action (command) is executed in accordance with the indicated position. Note that the detection surface 61 does not need to coincide with the spatial image 12 (image plane); it may be positioned parallel to the spatial image 12, either in front of or behind it, with a gap between them.

[0039] As the detection means 14, a flat bar-shaped (strip-shaped) optical sensor such as a zForce® AIR touch sensor or AIRBAR® is preferably used. By scanning the surface of the spatial image 12 (detection surface 61) with detection light such as laser light or infrared light emitted from the detection means 14 (light-emitting part), the position of the indicating means 13 that indicates the spatial image 12 can be detected. In this embodiment, the detection means 14 is housed inside the housing 59, but for example, the detection means 14 can be installed on the outer upper surface of the housing 59 and the opening 60 can be omitted. Alternatively, the detection means 14 may be arranged parallel to the spatial image 12 on either the left or right side of the spatial image 12. In this case, the detection means 14 is rotatably held in the housing 59 and placed on the upper surface of the housing 59 when not in use, resulting in excellent compactness. The configuration of the detection means is not limited to this embodiment, and any means capable of detecting the position of the indicating means 13 that touches the spatial image 12 is acceptable. For example, as a detection means, a frame-shaped sensor (a type of optical proximity sensor) may be used, which is formed in a frame shape along the outer circumference of the spatial image 12 and has multiple light-emitting elements and light-receiving elements arranged around the spatial image 12, or an infrared motion sensor or the like may be used.

[0040] In contactless input devices, it is preferable to use a planar image (two-dimensional image) for the virtual display object and a planar image (two-dimensional image) for the spatial image. However, when using a thin spatial image display device alone, the virtual display object may be either a planar image (two-dimensional image) or a three-dimensional object (three-dimensional image). If the virtual display object is a three-dimensional object, the thin spatial image display device can display a three-dimensional spatial image. The spatial image reproduction image (IP image 52) can be generated by calculation using an image generation means, assuming that the CG image that will be the virtual object to be displayed is virtually captured by a camera. A conventionally known computer is preferably used as the image generation means. The CG image may be a wireframe or other image created using a computer from the beginning, or it may be a real-life image converted into a CG image. The image generation means may have some or all of its functions built into the thin spatial image display device 11, or it may be installed independently of the thin spatial image display device 11, connected to the thin spatial image display device 11 by wire or wireless, and configured to transmit only the data of the generated spatial image reproduction image to the thin spatial image display device 11.

[0041] Next, a modified example of the flat-plate image output means will be described with reference to Figure 7. Components similar to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted. The differences between the flat plate image output means 20A and the flat plate image output means 20 are, as shown in Figure 7, that the light-transmitting portion 55A of the IP filter 54A is formed in the shape of a vertically elongated slit, and that the multiple element images 51A that constitute the IP image 52A displayed on the IP image panel 53 are arranged horizontally in a rectangular shape, with a horizontal dimension W and a vertical dimension equal to the vertical dimension of the display surface 19 when viewed from the front.

[0042] Each light-transmitting portion 55A is positioned to correspond to each of the multiple elemental images 51A on the IP image 52A when viewed from the front (here, to the widthwise center position of each elemental image 51A). Therefore, the lateral pitch P of the light-transmitting portions 55A W This is equal to the horizontal dimension W of the element image 51A. The width D of the slit-shaped light-transmitting section 55A. WThis is a horizontal pitch P with 56 pixels. px It is preferable that it be about 1 to 2 times, but it is not limited to this range. Also, the vertical dimension of the light-transmitting portion 55A is equal to the vertical dimension of the display surface 19, similar to the vertical dimension of the element image 51A. Note that the horizontal dimension W of element image 51A and the horizontal pitch P of the light-transmitting portion 55A are also included. W The appropriate number of pixels is selected accordingly, and the number of pixels 56 included in the element drawing 51A is also selected accordingly.

[0043] In the flat-panel image output means 20, the rectangular element images 51 and the pinhole-shaped light-transmitting sections 55 are arranged two-dimensionally, vertically and horizontally, respectively. In contrast, in the flat-panel image output means 20A, the vertically elongated rectangular element images 51A and the slit-shaped light-transmitting sections 55A are arranged one-dimensionally, horizontally. Therefore, the flat-panel image output means 20A has a wider vertical viewing angle and higher brightness of the spatial image compared to the flat-panel image output means 20. Furthermore, the configuration of the IP image 52A is simplified in the flat-panel image output means 20A compared to the flat-panel image output means 20, and the number of element images 51A is reduced, resulting in improved display speed. Moreover, the IP filter 54A having the slit-shaped light-transmitting sections 55A is easier to manufacture and more mass-producible than the IP filter 54 having the pinhole-shaped light-transmitting sections 55. Based on the above, by using a flat-plate image output means 20A instead of the flat-plate image output means 20, an inexpensive thin-profile spatial image display device and a non-contact input device can be realized.

[0044] Next, with reference to Figures 8 and 9(A) and (B), the flat plate image output means 20B of the thin spatial image display device according to the second embodiment of the present invention will be described. Components similar to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted. The difference between the flat-panel image output means 20B and the flat-panel image output means 20 is that, as shown in Figures 9(A) and (B), a first IP image 52B and a second IP image 52C, composed of two different groups of elemental images that complement each other, are sequentially displayed on the IP image panel 53 in a time-division manner as spatial image reproduction images. As shown in Figures 9(A) and (B), the first IP image 52B and the second IP image 52C are each composed of multiple elemental images 51B and 51C arranged vertically and horizontally. In this embodiment, as shown in Figures 9(A) and (B), the area where each elemental image 51B and 51C is displayed contains four square pixels 56 in both the vertical and horizontal directions, and the vertical dimension a (= horizontal dimension b) of the elemental images 51B and 51C is equal to the vertical pitch P of the pixels 56 on the IP image panel 53. py (=horizontal pitch P) px This is four times the amount of the previous amount.

[0045] As shown in Figures 8 and 9(A) and (B), the IP filter 54B has a plurality of pinhole-shaped light-transmitting sections 55a and 55b arranged vertically and horizontally. The first light-transmitting group 62A, composed of the plurality of light-transmitting sections 55a, and the second light-transmitting group 62B, composed of the plurality of light-transmitting sections 55b, are driven (opened and closed) in a time-division manner, as shown in Figures 9(A) and (B). This allows the light-transmitting sections 55a and 55b to be selectively driven (opened and closed) to switch between allowing light to pass through and not allowing it to pass through. Figure 9(A) shows the state in which the light-transmitting sections 55a of the first light-transmitting group 62A are open and the light-transmitting sections 55b of the second light-transmitting group 62B are closed, and each of the plurality of light-transmitting sections 55a is arranged corresponding to each of the plurality of element images 51B that constitute the first IP image 52B (here, corresponding to the center position of each element image 51B). Furthermore, Figure 9(B) shows the state in which the light-transmitting portion 55a of the first light-transmitting group 62A is closed and the light-transmitting portion 55b of the second light-transmitting group 62B is open, with each of the multiple light-transmitting portions 55b being arranged to correspond to each of the multiple element images 51C that constitute the second IP image 52C (here, corresponding to the center position of each element image 51C). Conventional liquid crystal or PDLC type optical shutters are preferably used as such IP filters, but mechanical shutters (MEMS shutters) may also be used.

[0046] In this embodiment, as shown in Figures 9(A) and (B), each element image 51B and 51C is a square composed of 4 pixels 56 vertically and horizontally. Therefore, the vertical dimension a of element images 51B and 51C (= vertical pitch of element images 51B and 51C) is equal to the horizontal dimension b of element images 51B and 51C (= horizontal pitch of element images 51B and 51C), and the vertical pitch P of the pixels 56 of the IP image panel 53 is equal to the vertical pitch P of the pixels 56 of the IP image panel 53. py (=horizontal pitch P) px This is four times the amount of the previous amount. Furthermore, in this embodiment, as shown in Figure 8, the multiple light-transmitting portions 55a of the first light-transmitting group 62A have a vertical pitch P a , horizontal pitch P b (=P a The multiple light-transmitting sections 55b of the second light-transmitting group 62B are arranged vertically and horizontally, with a vertical pitch P a , horizontal pitch P b (=P a The second transparent group 62B is arranged vertically and horizontally relative to the first transparent group 55A, and P a / 2 and P in the lateral direction b / 2(=P a / 2) They are positioned offset. And, as shown in Figures 9(A) and (B), each of the light-transmitting parts 55a and 55b is positioned at the center of each element image 51B and 51C, so the vertical pitch P of the light-transmitting parts 55a and 55b shown in Figure 8 a (=horizontal pitch P) b ) is equal to the vertical dimension a (= horizontal dimension b) and the vertical pitch (= horizontal pitch) of element images 51B and 51C shown in Figures 9(A) and (B).

[0047] The thin spatial image display device using this flat-panel image output means 20B includes a display image manipulation means (not shown) for displaying a first IP image 52B and a second IP image 52C on an IP image panel 53, and a light-transmitting section manipulation means (not shown) for driving (opening / closing) the first light-transmitting group 62A (light-transmitting section 55a) and the second light-transmitting group 62B (light-transmitting section 55b) of the IP filter 54B. The display image manipulation means and the light-transmitting section manipulation means together constitute the control unit (not shown) of the thin spatial image display device. A conventionally known computer is preferably used as the control unit. By having the computer execute a predetermined program, the computer functions as both the display image manipulation means and the light-transmitting section manipulation means, and thus fulfills the role of the control unit of the thin spatial image display device. The control unit may be built into the thin spatial image display device, or it may be installed independently of the thin spatial image display device and connected to the thin spatial image display device by wire or wireless. Furthermore, the image generation means for generating the first IP image 52B and the second IP image 52C may be included in the control unit, or it may be connected to the thin spatial image display device by wire or wireless connection, independently of the control unit.

[0048] In the flat-panel image output means 20B configured as described above, as shown in Figures 9(A) and (B), the multiple light-transmitting sections 55a and 55b of the IP filter 54B are grouped into a first light-transmitting group 62A and a second light-transmitting group 62B, which are driven (opened and closed) in a time-division manner. When the first IP image 52B is displayed on the IP image panel 53, only the multiple light-transmitting sections 55a included in the first light-transmitting group 62A allow the light emitted from the first IP image 52B to pass through. When the second IP image 52C is displayed on the IP image panel 53, only the multiple light-transmitting sections 55b included in the second light-transmitting group 62B allow the light emitted from the second IP image 52C to pass through. In other words, by time-division driven the first light-transmitting group 62A and the second light-transmitting group 62B, the light emitted from each of the multiple element images 51B on the first IP image 52B passes only through the multiple light-transmitting sections 55a of the first light-transmitting group 62A, and the light emitted from each of the multiple element images 51C on the second IP image 52C passes only through the multiple light-transmitting sections 55b of the second light-transmitting group 62B.

[0049] The flat-panel image output means 20B switches the presence or absence (opening and closing) of light passing through the first light-transmitting group 62A and the second light-transmitting group 62B within the eye's afterimage retention time, displaying the first IP image 52B and the second IP image 52C with a time difference. As a result, the observer can observe a bright, high-definition spatial image in which the spatial image reproduced by light emitted from the first IP image 52B passing through the optical imaging means 18 and the spatial image reproduced by light emitted from the second IP image 52C passing through the optical imaging means 18 overlap within the eye's afterimage retention time. In this embodiment, the second light-transmitting group 62B is positioned vertically and horizontally relative to the first light-transmitting group 62A, respectively P a / 2(=P b / 2) By being offset, the translucent parts 55a and 55b are evenly distributed vertically and horizontally, and a uniform and homogeneous spatial image is reproduced. However, the number and arrangement of translucent parts included in the first translucent group and the second translucent group, as well as the direction and amount of the positional offset of the second translucent group relative to the first translucent group, can be appropriately selected. For example, the second translucent group may be offset by a predetermined amount (e.g., P) only in the vertical direction or only in the horizontal direction relative to the first translucent group. a / 2 or P b / 2) They may be positioned offset from each other.

[0050] In this embodiment, a first IP image and a second IP image are generated, each composed of two different sets of elemental images. These are then grouped into a first light-transmitting group and a second light-transmitting group, which open and close multiple light-transmitting sections of an IP filter in a time-division manner. The multiple light-transmitting sections contained in the first light-transmitting group and the second light-transmitting group are opened and closed sequentially for each group to display the first and second IP images in a time-division manner. However, the number of time divisions can be three or more. The number of time divisions can be appropriately selected (set) depending on the number, arrangement, and grouping of the light-transmitting sections, making it possible to display three or more IP images sequentially with a time difference.

[0051] Next, with reference to Figures 10 to 12, the flat plate image output means 20C of the thin spatial image display device according to the third embodiment of the present invention will be described. Components similar to those in the first and second embodiments are denoted by the same reference numerals and their descriptions are omitted. As shown in Figure 10, the IP image 52D displayed as a spatial image reproduction image on the IP image panel 53 of the flat image output means 20C consists of a first partial IP image 64A and a second partial IP image 64B. The first partial IP image 64A and the second partial IP image 64B are generated by the image generation means and consist of two different groups of elemental images.

[0052] As shown in Figure 10, the IP image panel 53 can display the IP image 52D (simultaneously displaying the first and second IP images 64A and 64B) by arranging the pixels 56 that constitute each of the multiple element images 51D included in the first partial IP image 64A and the pixels 56 that constitute each of the multiple element images 51E included in the second partial IP image 64B so that they do not overlap. At this time, linearly polarized light in a first direction is emitted from the first partial IP image 64A and the second partial IP image 64B. Here, the light emitted from an image displayed on a conventionally known liquid crystal panel (liquid crystal display) is generally linearly polarized in one direction parallel to the vertical or horizontal direction of the display surface when viewed from the front. Therefore, in the flat plate image output means 20C, by using an existing liquid crystal panel as the IP image panel 53, the first partial IP image 64A and the second partial IP image 64B can be displayed by linearly polarized light such that the direction parallel to the vertical or horizontal direction of the display surface 19 is the first direction.

[0053] In this embodiment, as shown in Figure 10, each area where element image 51D and element image 51E are displayed contains 4 pixels each in the vertical and horizontal directions, and element image 51D and element image 51E are displayed offset by 2 pixels in both the vertical and horizontal directions. In this embodiment, the pixels 56 constituting element image 51D and element image 51E are arranged in a checkerboard pattern (alternating) with a one-pixel offset in both the vertical and horizontal directions so as not to overlap. However, these arrangements are not limited to this embodiment and can be selected as appropriate. Furthermore, as shown in Figures 11 and 12, the flat image output means 20C is positioned between the IP image panel 53 and the IP filter 54C and includes a polarization means 65 that linearly polarizes the light emitted from the first partial IP image 64A in a first direction and the light emitted from the second partial IP image 64B in a second direction perpendicular to the first direction, and a polarizer 66 positioned on the optical imaging means 18 side of the IP filter 54C.

[0054] As shown in Figure 11, the polarization means 65 includes a first polarization alignment film 67a, a second polarization alignment film 67b positioned opposite the first polarization alignment film 67a, and a polarization liquid crystal layer 68 in which liquid crystal (not shown) is filled between the first polarization alignment film 67a and the second polarization alignment film 67b. The polarization means 65 also includes a polarization drive unit 69 that can switch the orientation direction of the liquid crystal molecules in the polarization liquid crystal layer 68 on a pixel-by-pixel basis. The polarization drive unit 69 includes a lower electrode 69a positioned on the light-receiving side (IP image panel 53 side) of the first polarization alignment film 67a and an upper electrode 69b positioned on the light-emitting side (IP filter 54C side) of the second polarization alignment film 67b.

[0055] The lower electrode 69a and the upper electrode 69b are formed by creating transparent electrodes 70a and 70b on a transparent substrate, respectively. The transparent electrode 70a of the lower electrode 69a and the transparent electrode 70b of the upper electrode 69b are arranged orthogonally. This allows for selective switching of the voltage on and off (presence or absence of voltage application) for the liquid crystal molecules of the polarizing liquid crystal layer 68 at a pixel 56 unit level. Furthermore, the orientation processing direction of the first polarizing alignment film 67a and the orientation processing direction of the second polarizing alignment film 67b are orthogonal to each other. Specifically, the orientation groove 71a formed in the first polarizing alignment film 67a and the orientation groove 71b of the second polarizing alignment film 67b are arranged orthogonally.

[0056] When the voltage between the lower electrode 69a and the upper electrode 69b is off (no voltage applied), the liquid crystal molecules of the polarizing liquid crystal layer 68 sandwiched between the first polarizing alignment film 67a and the second polarizing alignment film 67b align along the alignment groove 71a on the side of the first polarizing alignment film 67a and align along the alignment groove 71b on the side of the second polarizing alignment film 67b. As a result, when the voltage between the lower electrode 69a and the upper electrode 69b is off (no voltage applied), the alignment direction of the liquid crystal molecules of the polarizing liquid crystal layer 68 sandwiched between the first polarizing alignment film 67a and the second polarizing alignment film 67b is gradually twisted from the first polarizing alignment film 67a toward the second polarizing alignment film 67b, and is eventually twisted by 90 degrees. In this way, light passing through the polarizing liquid crystal layer 68, in which the alignment direction of the liquid crystal molecules is twisted by 90 degrees, is twisted by 90 degrees along the alignment direction of the liquid crystal molecules. Therefore, the direction of linear polarization rotates by 90 degrees before and after passing through the polarizing liquid crystal layer 68.

[0057] In contrast, when the voltage between the lower electrode 69a and the upper electrode 69b is ON (voltage applied), the liquid crystal molecules sandwiched between the first polarizing alignment film 67a and the second polarizing alignment film 67b align upright (along the electric field) so as to be perpendicular to the first polarizing alignment film 67a and the second polarizing alignment film 67b. Thus, light passing through the polarizing liquid crystal layer 68, where the alignment direction of the liquid crystal molecules is perpendicular to the first polarizing alignment film 67a and the second polarizing alignment film 67b, travels in a straight line along the alignment direction of the liquid crystal molecules, and therefore the direction of linear polarization does not change before and after passing through the polarizing liquid crystal layer 68.

[0058] The structure of the polarization drive unit 69 in the polarization means 65 can be appropriately selected and used from structures similar to those of conventionally known drive units in liquid crystal displays. In this embodiment, the transparent electrodes 70a are arranged along the column direction (vertically) and the transparent electrodes 70b are arranged along the row direction (horizontally), but the arrangement of the transparent electrodes 70a and 70b may be reversed. Also, in this embodiment, a simple matrix drive method is used as the drive method for the polarization drive unit 69, but an active matrix drive method (TFT) may also be used. In this embodiment, the orientation groove 71a of the first polarization orientation film 67a is oriented horizontally, and the orientation groove 71b of the second polarization orientation film 67b is oriented vertically. However, the orientation direction of the orientation grooves 71a and 71b is not limited to this, and it is sufficient if the orientation grooves 71a and 71b are orthogonal to each other.

[0059] As explained earlier, when the voltage between the lower electrode 69a and the upper electrode 69b is off (no voltage applied), the direction of linear polarization rotates by 90 degrees before and after passing through the polarizing liquid crystal layer 68. When the voltage between the lower electrode 69a and the upper electrode 69b is on (voltage applied), the direction of linear polarization does not change before and after passing through the polarizing liquid crystal layer 68. In this embodiment, since linearly polarized light is emitted from the first partial IP image 64A and the second partial IP image 64B, in Figure 12, by turning on the voltage between the lower electrode 69a and the upper electrode 69b corresponding to the pixels 56 used to display the first partial IP image 64A (voltage applied) and turning off the voltage between the lower electrode 69a and the upper electrode 69b corresponding to the pixels 56 used to display the second partial IP image 64B (voltage not applied), the light emitted from the first partial IP image 64A can be linearly polarized in the first direction (more precisely, the linearly polarized light in the first direction is allowed to pass through as is), and the light emitted from the second partial IP image 64B can be linearly polarized in the second direction perpendicular to the first direction.

[0060] The IP filter 54C shown in Figures 11 and 12 functions as a first light-transmitting section 55C, where, when viewed from the front, the area overlapping with one or more pixels 56 located at the center of each of the multiple element images 51D included in the first partial IP image 64A allows light linearly polarized in a first direction by the polarization means 65 and light linearly polarized in a second direction by the polarization means 65 to pass through as is. The second light-transmitting section 55D functions as a second light-transmitting section 55D, where, when viewed from the front, the area overlapping with one or more pixels 56 located at the center of each of the multiple element images 51E included in the second partial IP image 64B allows light linearly polarized in a first direction by the polarization means 65 to pass through after being linearly polarized in a second direction, and light linearly polarized in a second direction by the polarization means 65 to pass through after being linearly polarized in a first direction. In Figure 12, the direction of linear polarization in the first partial IP image 64A, the second partial IP image 64B, and the polarization means 65 is represented by the direction of the hatching, with the first direction being the horizontal direction and the second direction being the vertical direction. Also, in Figure 12, for explanatory purposes, the IP image panel 53 and the polarization means 65 are arranged separately, but in reality, they are arranged in close contact.

[0061] Next, the specific configuration of the IP filter 54C will be described. As shown in Figure 11, the IP filter 54C has a first alignment film 73a for the shutter, a second alignment film 73b for the shutter positioned opposite the first alignment film 73a for the shutter, and a liquid crystal layer 74 for the shutter in which liquid crystal (not shown) is filled between the first alignment film 73a and the second alignment film 73b for the shutter, in a range that functions as at least a first light-transmitting portion 55C and a second light-transmitting portion 55D. The IP filter 54C also has a shutter drive unit 75 that can switch the orientation direction of the liquid crystal molecules in the liquid crystal layer 74 on a pixel-by-pixel basis. The shutter drive unit 75 has a lower electrode 75a positioned on the light-receiving side (bottom side = polarizing means 65 side) of the first alignment film 73a for the shutter and an upper electrode 75b positioned on the light-emitting side (top side) of the second alignment film 73b for the shutter.

[0062] The lower electrode 75a and the upper electrode 75b are formed by creating transparent electrodes 76a and 76b on a transparent substrate, respectively. The transparent electrode 76a of the lower electrode 75a and the transparent electrode 76b of the upper electrode 75b are arranged orthogonally. This allows for selective switching of the voltage on and off (presence or absence of voltage application) for the liquid crystal molecules of the shutter liquid crystal layer 74 at a pixel 56 unit level. Furthermore, the orientation processing direction of the first alignment film 73a for the shutter and the orientation processing direction of the second alignment film 73b for the shutter are orthogonal to each other. Specifically, the alignment groove 77a formed in the first alignment film 73a for the shutter and the alignment groove 77b of the second alignment film 73b for the shutter are arranged orthogonally. In this embodiment, the alignment groove 77a is oriented horizontally and the alignment groove 77b is oriented vertically, but the arrangement direction of the alignment grooves 77a and 77b is not limited to this; it is sufficient that the alignment grooves 77a and 77b are orthogonal to each other.

[0063] Furthermore, as shown in Figure 12, the IP filter 54C has a shielding portion 78 that shields areas other than those that function as the first light-transmitting portion 55C and the second light-transmitting portion 55D of the liquid crystal layer 74 for the shutter. This shielding portion 78 only needs to be able to shield light. For example, through holes can be formed only in the areas that function as the first light-transmitting portion 55C and the second light-transmitting portion 55D of a non-transmitting plate material, and liquid crystal can be filled in these holes. A first alignment film 73a and a second alignment film 73b for the shutter can be placed on both sides of the plate, so that the areas other than those that function as the first light-transmitting portion 55C and the second light-transmitting portion 55D can function as the shielding portion 78. Alternatively, the entire space sandwiched between the first alignment film 73a and the second alignment film 73b for the shutter can be filled with liquid crystal, and the areas other than those functioning as the first light-transmitting portion 55C and the second light-transmitting portion 55D of the first alignment film 73a and the second alignment film 73b for the shutter can be colored, for example, black to function as a shielding portion 78.

[0064] As shown in Figures 11 and 12, the polarizer 66 is positioned on the optical imaging means 18 side of the IP filter 54C. As shown in Figure 11, the polarizer 66 has a polarization axis 79 parallel to the first direction. The polarizer 66 is a conventionally known type and can only allow linearly polarized light in the first direction parallel to the polarization axis 79 to pass through. Furthermore, as shown in Figures 11 and 12, the flat image output means 20C includes a spacer 80 positioned between the polarizing means 65 and the IP filter 54C. The spacer 80 is transparent and light-transmitting, allowing light that has passed through the polarizing means 65 to pass through without reflection, and a synthetic resin with low birefringence is preferably used.

[0065] The operation of the flat-panel image output means 20C, configured as described above, will now be explained. As shown in Figure 10, the IP image panel 53 displays IP image 52D (first partial IP image 64A + second partial IP image 64B) as an image for spatial image reproduction. At this time, as shown in Figure 12, the pixels 56 (solid hatched area) that constitute element image 51D included in the first partial IP image 64A and the pixels 56 (dashed hatched area) that constitute element image 51E included in the second partial IP image 64B are arranged so as not to overlap each other. Linearly polarized light in a first direction is emitted from the first partial IP image 64A and the second partial IP image 64B. As explained earlier, the polarization means 65 can linearly polarize the light emitted from the first partial IP image 64A in a first direction (more precisely, it can pass through the light that is linearly polarized in the first direction as is), and linearly polarize the light emitted from the second partial IP image 64B in a second direction perpendicular to the first direction.

[0066] Therefore, as shown in Figure 12, the light emitted from the first partial IP image 64A (solid line) passes through the polarization means 65, becomes linearly polarized in a first direction, passes through the spacer 80, and enters the IP filter 54C. The light emitted from the second partial IP image 64B (dashed line) passes through the polarization means 65, becomes linearly polarized in a second direction, passes through the spacer 80, and enters the IP filter 54C. In Figure 11, when the voltage between the lower electrode 75a and the upper electrode 75b of the IP filter 54C is ON (voltage applied), the liquid crystal molecules sandwiched between the first alignment film 73a and the second alignment film 73b for the shutter align upright (along the electric field) so as to be perpendicular to the first alignment film 73a and the second alignment film 73b for the shutter. Thus, light passing through the liquid crystal layer 74 for the shutter, where the alignment direction of the liquid crystal molecules is perpendicular to the first alignment film 73a and the second alignment film 73b for the shutter, travels in a straight line along the alignment direction of the liquid crystal molecules, and therefore the direction of linear polarization does not change before and after passing through the liquid crystal layer 74 for the shutter.

[0067] In contrast, when the voltage between the lower electrode 75a and the upper electrode 75b is off (no voltage applied), the liquid crystal molecules of the shutter liquid crystal layer 74 sandwiched between the first shutter alignment film 73a and the second shutter alignment film 73b align along the alignment groove 77a on the side of the first shutter alignment film 73a and align along the alignment groove 77b on the side of the second shutter alignment film 73b. As a result, when the voltage between the lower electrode 75a and the upper electrode 75b is off (no voltage applied), the alignment direction of the liquid crystal molecules of the shutter liquid crystal layer 74 sandwiched between the first shutter alignment film 73a and the second shutter alignment film 73b is gradually twisted from the first shutter alignment film 73a toward the second shutter alignment film 73b, and is finally twisted by 90 degrees. In this way, light passing through the shutter liquid crystal layer 74, in which the alignment direction of the liquid crystal molecules is twisted by 90 degrees, is twisted by 90 degrees along the alignment direction of the liquid crystal molecules. As a result, the direction of linear polarization rotates by 90 degrees before and after passing through the shutter liquid crystal layer 74.

[0068] Therefore, in the IP filter 54C of Figure 11, by setting the voltage between the lower electrode 75a and the upper electrode 75b corresponding to the first light-transmitting portion 55C to the ON state (voltage applied), the first light-transmitting portion 55C can pass through as is the light emitted from the first partial IP image 64A and linearly polarized in the first direction by the polarization means 65 (solid line) and the light emitted from the second partial IP image 64B and linearly polarized in the second direction by the polarization means 65 (dashed line), as shown in Figure 12. Furthermore, in the IP filter 54C shown in Figure 11, by setting the voltage between the lower electrode 75a and the upper electrode 75b corresponding to the second light-transmitting section 55D to the OFF state (no voltage applied), the second light-transmitting section 55D, as shown in Figure 12, can pass through light (solid line) emitted from the first partial IP image 64A and linearly polarized in the first direction by the polarization means 65 in a second direction after being linearly polarized in the second direction, and light (dashed line) emitted from the second partial IP image 64B and linearly polarized in the second direction by the polarization means 65 in a first direction after being linearly polarized in the first direction.

[0069] However, since a polarizer 66 that allows only light linearly polarized in the first direction to pass through is arranged on the light-emitting side of the IP filter 54C, of ​​the light passing through the first light-transmitting section 55C, only the light emitted from the first partial IP image 64A and that has passed through the first light-transmitting section 55C (liquid crystal layer 74 for shutter) while being linearly polarized in the first direction by the polarization means 65 (solid line) passes through the polarizer 66 and is emitted, while the light emitted from the second partial IP image 64B and that has passed through the first light-transmitting section 55C (liquid crystal layer 74 for shutter) while being linearly polarized in the second direction by the polarization means 65 (dashed line) cannot pass through the polarizer 66. Furthermore, of the light passing through the second light-transmitting section 55D, the light emitted from the first partial IP image 64A, linearly polarized in the first direction by the polarization means 65, and then linearly polarized in the second direction while passing through the second light-transmitting section 55D (solid line) cannot pass through the polarizer 66. Only the light emitted from the second partial IP image 64B, linearly polarized in the second direction by the polarization means 65, and then linearly polarized in the first direction while passing through the second light-transmitting section 55D (dashed line) passes through the polarizer 66 and is emitted. Furthermore, of the light that passes through the polarization means 65, any light that irradiates areas other than the first light-transmitting portion 55C and the second light-transmitting portion 55D of the IP filter 54C and does not contribute to the formation of a spatial image is shielded by the shielding portion 78, and therefore does not leak out to the outside of the IP filter 54C.

[0070] As described above, in the planar image output means 20C, by combining a liquid crystal shutter type IP filter 54C and a polarizer 66 that can select (switch) the polarization direction with the polarization means 65, ultimately, only the light emitted from the first partial IP image 64A is emitted from the first light-transmitting section 55C, and only the light emitted from the second partial IP image 64B is emitted from the second light-transmitting section 55D. As a result, the observer can observe a bright, high-definition spatial image in which the spatial image reproduced by the light emitted from the first partial IP image 64A passing through the optical imaging means 18 and the spatial image reproduced by the light emitted from the second partial IP image 64B passing through the optical imaging means 18 are superimposed.

[0071] Furthermore, the structure of the shutter drive unit 75 in the IP filter 54C can be appropriately selected and used from structures similar to those of conventionally known drive units in liquid crystal displays. In this embodiment, the transparent electrodes 76a are arranged along the column direction (vertically) and the transparent electrodes 76b are arranged along the row direction (horizontally), but the arrangement of transparent electrodes 76a and 76b may be reversed. In addition, in this embodiment, a simple matrix drive type image display drive unit is used, but an active matrix drive type (TFT) image display drive unit may also be used.

[0072] Next, with reference to Figure 13, a thin spatial image display device 11A according to the fourth embodiment of the present invention will be described. Note that components similar to those in the first to third embodiments are denoted by the same reference numerals and their descriptions are omitted. The difference between the thin spatial image display device 11A and the thin spatial image display device 11 is that the planar image output means 20D is a wavefront regeneration type image output means, and instead of the IP image panel 53 and IP filter 54, it is equipped with a hologram display 81 and an illumination unit 82.

[0073] The hologram (interference fringes) displayed on the display surface 19 of the hologram display 81 as an image for spatial image reproduction is recorded (generated) using conventionally known holography techniques. Generally, a hologram of the subject (object to be displayed) is obtained by irradiating the subject (object to be displayed) with laser light and recording the interference fringes of the reflected light (object light) and the original laser light (reference light) on a recording surface (photographic plate, hologram plate). In the thin spatial image display device 11A, as shown in Figure 13, the light emitted from a virtual display object 21 whose front surface is tilted at an angle α with respect to the light-receiving surface 16 of the optical imaging means 18 and irradiated onto the light-receiving surface 16 is output as light irradiated onto the light-receiving surface 16 from a spatial image reproduction image (hologram) displayed on the display surface 19 of the flat image output means 81. In this way, a spatial image 12 is displayed in the space on the light-emitting surface 17 side of the optical imaging means 18, with the optical imaging means 18 in between, symmetrical to the virtual display object 21, and with its front surface tilted at an angle α with respect to the light-emitting surface 17. In other words, the display surface 19 of the hologram display 81 displays a hologram of the virtual display object 21, which is recorded on a recording surface inclined at an angle α with respect to the front of the virtual display object 21, as an image for spatial image reproduction. Therefore, it is necessary to record (generate) the hologram of the virtual display object 21 so that the display surface 19 of the flat image output means 81 shown in Figure 13 coincides with the recording surface inclined at an angle α with respect to the front of the virtual display object 21.

[0074] As described above, the spatial image reproduction image (hologram) may be an analog hologram recorded (generated) by actually irradiating a subject (three-dimensional object, etc.) that will become the virtual display object 21 with laser light. However, it is preferable that it be a computer-generated hologram created using a computer based on numerical shape data of a fictional object that will become the virtual display object 21. The hologram display 81 can be any device capable of displaying (reproducing) a hologram (spatial image reproduction image) of the virtual display target 21, but a spatial light modulator (SLM) is preferably used as the hologram display 81.

[0075] When reference light from the illumination unit 82 is shone onto the spatial image reproduction image (hologram) displayed on the display surface 19 of the flat image output means 81, a reproduced image of the virtual display object 21 is reproduced. The light emitted from this reproduced image (spatial image reproduction image) corresponds to the reflected light from the virtual display object 21 and is shone onto the light-receiving surface 16 of the optical imaging means 18. Of the light shone onto the light-receiving surface 16, the light reflected once each by the first light-reflecting surface 22 and the second light-reflecting surface 23 displays a spatial image 12 in the space on the light-emitting surface 17 side of the optical imaging means 18, with the optical imaging means 18 in between, symmetrical to the virtual display object 21 and with the surface inclined at an angle α with respect to the light-emitting surface 17 as the front (see Figures 3(A) and (B)).

[0076] While LEDs are preferably used as the light source for the illumination unit 82, the invention is not limited to them. Furthermore, although this embodiment describes a reflective type hologram reproduction method in which the illumination unit 82 is positioned on the display surface 19 side of the flat plate image output means 81, the hologram reproduction method may also be a transmissive type in which the illumination unit 82 is positioned on the opposite side (back side) from the display surface 19 of the flat plate image output means 81. The spatial image reproduction image (hologram) displayed on the flat plate image output means 81 can be inverted front and back as needed, and the concavity (perspective) of the spatial image 12 can be reversed.

[0077] Although embodiments of the present invention have been described above, the present invention is not limited in any way to the configurations described in the embodiments described above, and includes other embodiments and modifications that can be considered within the scope of the matters described in the claims. Regarding the optical imaging means, as a method for integrating the first optical control unit and the second optical control unit, the first optical control unit and the second optical control unit may be positioned facing each other such that one side of the first optical control unit and the other side of the second optical control unit, that is, the sides on which the grooves are formed, face each other. A sheet-like transparent resin with a lower melting point than the first molded body and the second molded body may be sandwiched between them, and the unit may be heated and pressurized in a vacuum so that only the transparent resin melts and solidifies. Alternatively, the grooves of the first optical control unit and the second optical control unit may be filled separately with molten transparent resin, solidified, and molded into flat plates, which may then be joined together with a transparent adhesive or the like. In this case, in addition to the first optical control unit and the other side of the second optical control unit being positioned facing each other and joined, the first optical control unit and the other side of the second optical control unit may be positioned facing each other and joined together, or the other side of the first optical control unit and the one side of the second optical control unit may be positioned facing each other and joined together. Furthermore, instead of the first and second optical control units being formed separately from two transparent resin molded bodies and then joined together, the first and second optical control units may be formed on both sides of a single transparent resin molded body.

[0078] Furthermore, in the above embodiment, the optical imaging means described was one in which the multiple light-reflecting surfaces of the first and second optical control units are arranged in a straight line (parallel). However, a configuration may also be used that has a first optical control unit in which the multiple light-reflecting surfaces are arranged radially, and a second optical control unit in which the multiple light-reflecting surfaces are arranged concentrically. In this case, the radial light-reflecting surfaces of the first optical control unit are provided in a straight line with respect to a reference point X, while the concentric light-reflecting surfaces of the second optical control unit are curved along concentric circles centered on a reference point Y that coincides with the reference point X when viewed from above. However, at the points where the light-reflecting surfaces intersect when viewed from above, they are orthogonal. Therefore, a spatial image can be formed in the same manner as in the above embodiment.

[0079] Furthermore, as an optical imaging means, for example, as described in Japanese Patent Publication No. 5437436 (Figure 5), a configuration may be used in which first and second optical control units, each having a number of strip-shaped reflective surfaces formed perpendicularly (for example, at the same pitch) on one side surface, are superimposed so that their respective strip-shaped reflective surfaces are orthogonal when viewed from above. Alternatively, a two-sided corner reflector array may be used as an optical imaging means. In the above embodiment, the grooves of the first and second molded bodies (first and second optical control units) of the optical imaging means are formed in a trapezoidal cross-section. However, since the bottom surface of the groove is not an essential component of the optical imaging means, the dimensions (width) of the bottom surface do not need to be strictly controlled. It may be formed in a triangular cross-section with one side being a vertical surface and the other side being an inclined surface, expanding towards one side or the other. [Explanation of Symbols]

[0080] 10: Non-contact input device, 11, 11A: Thin spatial image display device, 12: Spatial image, 13: Indicating means, 14: Detection means, 16: Light-receiving surface, 17: Light-emitting surface, 18: Optical imaging means, 19: Display surface, 20, 20A, 20B, 20C, 20D: Flat plate image output means, 21: Virtual display object, 22: First light-reflecting surface, 23: Second light-reflecting surface, 24: Vertical surface, 25: Inclined surface, 26: Groove, 27: First molded body, 28: Vertical surface, 29: Inclined surface, 30: Groove, 31: Second molded body, 33: Metal reflective film 35: First light control unit, 36: Second light control unit, 37: Transparent adhesive, 41: Light-shielding panel, 42a~42c: Pinhole, 43: Photosensitive film, 44~46: Object dot, 44a~44c, 45a~45c, 46a~46c: Light rays, 47a~47c, 48a~48c, 49a~49c: Micro-image, 50a~50c: Elemental image, 51, 51A, 51B, 51C, 51D, 51E: Elemental image, 52, 52A, 52D: IP image, 52B: First IP image, 52C: Second IP image, 53: IP image panel, 54, 54A, 54B, 54C: IP filter, 55, 55a, 55b, 55A: light-transmitting section, 55C: first light-transmitting section, 55D: second light-transmitting section, 56: pixel, 58: light-shielding plate, 59: housing, 60: opening, 61: detection surface, 62A: first light-transmitting group, 62B: second light-transmitting group, 64A: first partial IP image, 64B: second partial IP image, 65: polarizing means, 66: polarizer, 67a: first polarizing alignment film, 67b: second polarizing alignment film, 68: polarizing liquid crystal layer, 69: polarizer 81: Hologram display, 82: Illumination unit

Claims

1. A thin spatial image display device comprising optical imaging means having a light-receiving surface and a light-emitting surface parallel to each other, and a first light-reflecting surface and a second light-reflecting surface formed perpendicular to the light-receiving surface and orthogonal to each other, A display surface composed of multiple pixels arranged vertically and horizontally is positioned parallel to the light-receiving surface of the optical imaging means, and a flat image output means outputs light emitted from a virtual display object whose front surface is tilted at an angle α with respect to the light-receiving surface and irradiates the light-receiving surface as light irradiated onto the light-receiving surface from a spatial image reproduction image displayed on the display surface. The flat plate image output means is a light ray reproduction type image output means, and comprises (a) an IP image panel that displays on the display surface as a spatial image reproduction image an IP image composed of a group of element images, each consisting of a set of multiple element images generated based on light ray information of the virtual display object acquired by IP technology on an observation surface inclined at an angle α with respect to the front of the virtual display object, and (b) an IP filter having a plurality of light-transmitting parts, one for each of the plurality of element images, and arranged in front of the display surface of the IP image panel parallel to the pre-printing light surface of the optical imaging means. A thin spatial image display device characterized in that, first to n IP images, each composed of n different elemental image groups that complement each other, are sequentially displayed on the IP image panel in a time-division manner, and when the i IP image is displayed, light emitted from each of the multiple elemental images constituting the i IP image passes through each of the multiple light-transmitting parts corresponding to each of the multiple elemental images constituting the i IP image and irradiates the front light surface of the optical imaging means, and the light irradiated onto the light-incoming surface is reflected once each by the first light-reflecting surface and the second light-reflecting surface, thereby displaying a spatial image with the optical imaging means sandwiched in the space on the light-emitting surface side of the optical imaging means, symmetrical to the virtual display object, and inclined at an angle α with respect to the light-emitting surface. However, n is an integer of 2 or more, and i is an integer from 1 to n.

2. A thin spatial image display device comprising optical imaging means having a light-receiving surface and a light-emitting surface parallel to each other, and a first light-reflecting surface and a second light-reflecting surface formed perpendicular to the light-receiving surface and orthogonal to each other, A display surface composed of multiple pixels arranged vertically and horizontally is positioned parallel to the light-receiving surface of the optical imaging means, and a flat image output means outputs light emitted from a virtual display object whose front surface is tilted at an angle α with respect to the light-receiving surface and irradiates the light-receiving surface as light irradiated onto the light-receiving surface from a spatial image reproduction image displayed on the display surface. The flat plate image output means is a light ray reproduction type image output means, and comprises (a) an IP image panel that displays on the display surface as a spatial image reproduction image an IP image composed of a group of element images, each consisting of a set of multiple element images generated based on light ray information of the virtual display object acquired by IP technology on an observation surface inclined at an angle α with respect to the front of the virtual display object, and (b) an IP filter having a plurality of light-transmitting parts, one for each of the plurality of element images, and arranged in front of the display surface of the IP image panel parallel to the pre-printing light surface of the optical imaging means. The IP image comprises a first partial IP image and a second partial IP image, each composed of two different sets of elemental images, wherein the pixels constituting each of the multiple elemental images included in the first partial IP image and the pixels constituting each of the multiple elemental images included in the second partial IP image are displayed simultaneously on the IP image panel such that they do not overlap. The planar image output means comprises (a) a polarization means disposed between the IP image panel and the IP filter, which linearly polarizes light emitted from the first partial IP image in a first direction and linearly polarizes light emitted from the second partial IP image in a second direction perpendicular to the first direction, and (b) a polarizer disposed on the optical imaging means side of the IP filter, which has a polarization axis parallel to the first direction. The IP filter functions as a first light-transmitting area in which, when viewed from the front, the area overlapping with one or more pixels located at the center of each of the multiple element images included in the first partial IP image allows light linearly polarized in the first direction by the polarization means and light linearly polarized in the second direction by the polarization means to pass through as is; and as a second light-transmitting area in which, when viewed from the front, the area overlapping with one or more pixels located at the center of each of the multiple element images included in the second partial IP image allows light linearly polarized in the first direction by the polarization means to pass through after being linearly polarized in the second direction, and light linearly polarized in the second direction by the polarization means to pass through after being linearly polarized in the first direction. A thin spatial image display device characterized in that light passes through the first light-transmitting portion and the second light-transmitting portion and is irradiated onto the light-ingress surface of the optical imaging means, and of the light irradiated onto the light-ingress surface, the light is reflected once each by the first light-reflecting surface and the second light-reflecting surface to display a spatial image in which the optical imaging means is sandwiched in the space on the light-emitting surface side of the optical imaging means, and the surface that is symmetrical to the virtual display object and inclined at an angle α with respect to the light-emitting surface is the front.

3. The thin spatial image display device according to claim 1 or 2, characterized by comprising an image generation means for generating the spatial image reproduction image.

4. The thin spatial image display device according to claim 1, characterized in that each of the multiple element images is configured in a rectangular shape when viewed from the front by a plurality of pixels on the display surface and is arranged vertically and horizontally on the display surface, and each of the multiple light-transmitting portions is formed in the shape of a pinhole.

5. The thin spatial image display device according to claim 1, wherein each of the multiple element images is configured in a vertically elongated rectangular shape with a vertical dimension equal to the vertical dimension of the display surface when viewed from the front, using a plurality of pixels on the display surface, and is arranged horizontally on the display surface, and each of the multiple light-transmitting portions is formed in a vertically elongated slit shape.

6. The spatial image display system according to claim 2, characterized in that the polarization means comprises a first polarization orientation film, a second polarization orientation film disposed opposite to the first polarization orientation film, a polarization liquid crystal layer in which liquid crystal is filled between the first polarization orientation film and the second polarization orientation film, and a polarization drive unit capable of switching the orientation direction of the liquid crystal molecules in the polarization liquid crystal layer on a pixel-by-pixel basis, and the orientation processing direction of the first polarization orientation film and the orientation processing direction of the second polarization orientation film are orthogonal to each other.

7. The IP filter comprises a first alignment film for shutters, a second alignment film for shutters positioned opposite the first alignment film for shutters, a liquid crystal layer for shutters in which liquid crystal is filled between the first alignment film for shutters and the second alignment film for shutters in a range that functions as at least the first and second light-transmitting portions, a shutter drive unit capable of switching the orientation direction of the liquid crystal molecules in the liquid crystal layer for shutters on a pixel-by-pixel basis, and a shielding portion that shields areas other than the range that functions as the first and second light-transmitting portions for shutters, wherein the orientation processing direction of the first alignment film for shutters and the orientation processing direction of the second alignment film for shutters are orthogonal to each other, as described in claim 2.

8. The thin spatial image display device according to claim 1 or 2, characterized in that the angle α = 45 ± 15 degrees.

9. A non-contact input device using a thin spatial image display device according to claim 1 or 2, characterized by comprising the thin spatial image display device and a detection means attached to the thin spatial image display device for detecting the position of an indicator means that touches the spatial image.

Images