Stereoscopic image display device

Abstract

Provided is a stereoscopic image display device capable of obtaining a sense of reality as if a displayed object is actually present at that place. The stereoscopic image display device comprises a display device, a camera for detecting the viewpoint position of a user watching the display device, and a rotating device for enabling the display device to rotate around a rotating shaft penetrating through the display surface of the display device. The rotating device enables the display device to rotate according to the movement of the position of the viewpoint of the user, so that the direction of the viewpoint of the user viewed from the display surface is kept unchanged. Furthermore, a three-dimensional object defined in a world coordinate system that does not move with respect to the real world will be displayed on a display device, and when a user viewpoint moves, an image of the three-dimensional object viewed from the user viewpoint direction will be displayed on the display device.

Description

Technical Field

[0001] The present invention relates to a stereoscopic image display device which effectively utilizes motion parallax. Background Art

[0002] An aerial image display device displays two-dimensional images in mid-air, while a stereoscopic display device displays three-dimensional information. While these two concepts are technically separate, the images displayed by an aerial image display device can also have a three-dimensional effect because they appear to float in mid-air. Stereoscopic images can also sometimes create a similar floating effect as aerial images.

[0003] Simply speaking of stereoscopic vision, there are many factors to consider. One of the most representative is binocular parallax. Research has shown that neurons that respond to binocular parallax exist in multiple visual areas, allowing us to calculate the relative distance between the point of gaze and the object. This allows us to obtain depth information.

[0004] Furthermore, even two-dimensional images viewed on a regular monitor can give the viewer a sense of front-to-back positioning and a sense of three-dimensionality due to factors such as perspective, occlusion, shadows, and textures. In other words, by determining the viewpoint, the virtual three-dimensional space constructed within the computer is rendered as a three-dimensional image. Even if the monitor is two-dimensional, it can be made to appear three-dimensional by expressing the depth of objects or adding shadows and highlights.

[0005]

Previous Technical Literature

[0006] For example, in 3D graphics, when objects displayed on a two-dimensional display are moved or rotated on the screen, a greater sense of three-dimensionality is achieved. This is due to motion parallax. Furthermore, technologies have been proposed for obtaining three-dimensional information from motion parallax information contained in two-dimensional images (Patent Documents 1 and 2).

[0007] As a method for utilizing this motion parallax in image display, a technology has been proposed that detects the movement of the user's viewpoint relative to the display, reproduces the image the user would see, and displays it on the display, thereby creating a sense of stereoscopic vision (Patent Document 3, etc.). However, with conventional displays that achieve motion parallax, the user must view the display interface from a certain angle as the viewpoint moves, making it impossible to achieve a natural sense of stereoscopic vision.

[0008] Therefore, an object of the present invention is to provide a stereoscopic image display device that can provide a natural stereoscopic effect by more effectively utilizing motion parallax, as if objects actually exist in space.

[0009]

Methods required to solve the problem

[0010] In addition, in a specific embodiment, it is characterized in that the display device is an aerial image display device that can display two-dimensional images in the air.

[0011] Moreover, in a specific embodiment, it is characterized in that the display device is an aerial image display device using a recursive transmission optical imaging element.

[0012] Effects of the Invention By adopting the stereoscopic image display device of the present invention, motion parallax can be more effectively utilized to achieve unprecedented realistic stereoscopic vision. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a perspective view showing an aerial image display device 1 as a stereoscopic image display device in the first embodiment of the present invention.

[0014] Figure 2 It is along Figure 1The cross-sectional view taken along line AA in FIG. 1 shows the aerial image display device 1 in use.

[0015] Figure 3 This is an explanatory diagram of how the user's viewpoint moves relative to the aerial image display device 1 in the first embodiment of the present invention.

[0016] exist Figure 4 Among them, (A1), (A2), and (A3) are plan views of the use status of the aerial image display device 1 of Example 1 of the present invention viewed from above, (B1), (B2), and (B3) are views corresponding to (A1), (A2), and (A3), which illustrate how the aerial image is displayed in the aerial image display device 1, and (C1), (C2), and (C3) are views of images displayed in the aerial image area G as aerial images in the aerial image display device 1.

[0017] Figure 5 It is a diagram for explaining perspective projection conversion performed in the aerial image display device 1 according to the second embodiment of the present invention.

[0018] Figure 6 This is a perspective view showing an aerial image display device 2 as a three-dimensional image display device in a third embodiment of the present invention.

[0019] Figure 7 This is a perspective view showing an aerial image display device 3 as a stereoscopic image display device in a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following describes a specific embodiment of the 3D image display device according to the present invention with reference to the accompanying drawings. In the following specific embodiment, the 3D image display device uses an aerial image display device having a recursive transmission type optical imaging element.

[0021] Example 1 [Structure of the aerial image display device] Figure 1 This is a perspective view showing an aerial image display device 1 as a stereoscopic image display device in the first embodiment of the present invention. Figure 2 It is along Figure 1 The cross-sectional view taken along line AA in FIG. 1 shows the aerial image display device 1 in use.

[0022] like Figure 1 and Figure 2As shown, essential components of the aerial image display device 1 include a liquid crystal display 10 and an optical plate 20. The aerial image display device 1 also includes components such as an information processing device 30 and a speaker 40 for controlling the liquid crystal display 10. The liquid crystal display 10, speaker 40, and information processing device 30 are housed within the lower housing 12 and are connected to each other via signal lines (not shown).

[0023] The information processing device 30 is essentially a small computer, consisting of a CPU (central processing unit), ROM (read-only memory), RAM (random access memory), a storage device for storing various programs and data, and input / output interfaces. These interfaces can be, for example, USB ports or wireless local area networks such as Wi-Fi. The information processing device 30 outputs video signals to the LCD 10, displaying the source of the aerial image. The information processing device 30 also outputs audio signals to the speaker 40, generating guidance voice and sound effects. The information processing device 30 can be a commercially available general-purpose small personal computer or tablet computer.

[0024] The LCD 10 is housed in a lower housing 12, which is rectangular in plan view and open at the top. It is supported substantially horizontally, with the display interface facing upward. The optical plate 20 is embedded in the upper housing 14, with its incident surface 21 facing downward and obliquely toward the display interface of the LCD 10. Here, the optical plate 20 is fixed at an angle of approximately 45 degrees to the LCD 10.

[0025] For example, the optical plate 20 may employ a recursive transmission optical imaging element (double-sided orthogonal reflector) as described in Japanese Patent Application Laid-Open No. 2011-175297. This optical imaging element is achieved by arranging a large number of mutually orthogonal planar light-reflecting portions at a constant pitch. Alternatively, a double-sided corner reflector with reflective surfaces formed on the side surfaces of a square hole, as described in Japanese Patent Application No. 4900618, may be employed.

[0026] Furthermore, the upper housing 14 constituting the aerial image display device 1 is designed to be easily detachable from the lower housing 12. If the upper housing 14 is detached, maintenance and adjustment of the interior of the lower housing 12 can be easily performed, and the height during transportation can be reduced.

[0027] like Figure 2 As shown, light from the display interface of the liquid crystal display 10 enters the optical plate 20, reflects twice within the optical plate 20, and is emitted to the opposite side. As a result, an aerial image G, which is the actual image, is formed in the space opposite the optical plate 20. In this case, in order to achieve a clearer aerial image G, it is desirable not to add external light to the light from the liquid crystal display 10.

[0028] The aerial image G here shows the image area displayed in the air when the image is displayed on the entire display interface of the liquid crystal display 10. When a three-dimensional object is displayed in the center of the display interface of the liquid crystal display 10, and no object is displayed in other areas (when other areas are displayed in black), only the three-dimensional object will be displayed in the air. Therefore, in the following description, "spatial image area G" will also be used instead of "spatial image G". Under normal circumstances, the display interface of the liquid crystal display 10 is rectangular, so the aerial image area G is also correspondingly rectangular. In addition, in this specification, the aerial image area G is referred to as the display surface of the aerial image display device 1.

[0029] Furthermore, a three-dimensional motion sensor 7 consisting of an infrared LED 72 and a pair of infrared cameras 74 is provided on the front side of the lower housing 12. This motion sensor 7 can accurately detect the user's hand movements in three dimensions. The detection range of the motion sensor 7 is determined by the emission angle of the infrared LED 72 and the viewing angle of the infrared camera 74. This motion sensor 7 can be a commercially available product, such as the Leap Motion Controller 2 from Ultraleap.

[0030] In particular, the three-dimensional motion sensor 7 is installed so that its tilt angle can be adjusted. That is, the motion sensor 7 is stored in a storage component in advance, and the storage component can be installed perpendicular to the Figure 2 The cross-sectional view of the paper is used as the rotation axis, and the device rotates within a certain angular range (here, ±20 degrees). Here, the center of the detection range of motion sensor 7 is adjusted to be offset from the center of the aerial image G toward the user. This adjustment maximizes the effective operation detection range.

[0031] In the past, such aerial image display devices were often used as input devices for administrative purposes, such as reception systems. Specifically, if a non-contact interface is displayed as the aerial image G, gestures can be used to perform operations, such as touching the non-contact interface with a finger. This operation is detected by the motion sensor 7, which consists of an infrared LED 72 and an infrared camera 74. The corresponding operation signal is sent to the information processing device 30, which performs the required processing. The operation interface includes, for example, controls such as buttons, checkboxes, and drop-down menus. This allows for a completely non-contact interface with the same ease of use as a traditional touch panel.

[0032] Furthermore, the aerial image display device 1 is placed on a motorized rotating platform 50 and can freely rotate 360 ​​degrees about a rotation axis R that passes vertically through the center of the aerial image area G (the center of both the width and height of the area). Specifically, the rotating platform 50 consists of a support platform 52, a rotating plate 56 pivoted on the support platform 52 via a rotating shaft 54, rollers 57 that rotatably support the rotating plate 56, and a drive device 58 that rotates the rotating plate 56. Thus, the rotating platform 50 serves as a rotating device that rotates the aerial image display device 1 mounted thereon.

[0033] The drive device 58 is connected to the information processing device 30 via a communication cable (not shown) for communication. The drive device 58 rotates the rotating plate 56 about the rotation axis 54 based on a control signal from the information processing device 30, and calculates the rotation angle of the rotating plate 56 and transmits it to the information processing device 30.

[0034] That is, the driving device 58 is provided with a motor with an encoder, which drives the rotating plate 56 to rotate around the rotating shaft 54 ​​and calculates the rotation angle of the rotating plate 56. Then, servo control is performed to accurately control the rotation of the aerial image display device 1.

[0035] Furthermore, a facial recognition camera 42 is provided above the optical plate 20. This facial recognition camera 42 captures an image of the user's face from the front of the aerial image display device 1 and detects the three-dimensional position of the user's eyes. This facial recognition camera 42 can be a 3D camera equipped with a depth sensor. For example, a Kinect (registered trademark) is used as this 3D camera.

[0036] Therefore, a facial recognition algorithm is built into the information processing device 30 to identify faces based on images captured by the facial recognition camera 42 and further identify eye positions. For example, the facial recognition algorithm can use YOLO, which has real-time processing capabilities. This allows detection of whether the user's viewpoint has moved left or right from directly in front of the aerial image display device 1.

[0037] Although not shown here, the aerial image display device 1 is placed on a table or the like at an appropriate height so that the aerial image can be viewed at eye level. A freely adjustable height lifting device is particularly suitable. An example of such a lifting device is the electric lifting device Mario N sold by Yamato Metal Manufacturing Co., Ltd.

[0038] [Coordinate system] Here, we will predefine the coordinate systems used in this specific embodiment. Coordinate systems can consider the world coordinate system, the camera coordinate system, and the device coordinate system. These definitions are roughly the same as those used in common coordinate systems, but with some extensions and modifications to the description.

[0039] First, let's introduce the world coordinate system. Generally speaking, the term "world coordinate system" refers to the coordinate system that defines the entire, immovable three-dimensional space within a computer. However, in this specification, this definition is used more broadly. In other words, if the computer itself rotates, the three-dimensional space within the computer will also rotate with it. However, in this specification, we consider a more absolutely stationary world coordinate system.

[0040] That is, even if the computer (the aerial image display device 1) itself rotates, the world coordinate system does not rotate and remains stationary relative to the external real world. Therefore, when the aerial image display device 1 rotates, other coordinate systems rotate relative to the external real world, but the world coordinate system does not. Instead, when viewed from the aerial image display device 1, the world coordinate system rotates in the opposite direction according to the detected rotation of the rotating plate 56.

[0041] The world coordinate system is a right-handed system, such as Figure 1 As shown, (x, y, z) is represented, with the vertical direction being the z-axis, the horizontal direction being the y-axis, and the depth direction being the x-axis. Origin O is located on the rotation axis 54 of the rotating plate 56. For ease of explanation, the center of the aerial image region G (the center of both the width and height of the region) is used as origin O.

[0042] Next, the device coordinate system is explained. The device coordinate system used here is the coordinate system on the display interface. Specifically, the coordinate is a coordinate of a position in the display interface with the aerial image area G as the display interface. The normal axis of the display interface is also added, and the coordinates are expressed as three-dimensional coordinates (x', y', z'). The device coordinate system (x', y', z') will rotate with the rotation of the rotating plate 56, but at a specified position on the rotating plate 56, the device coordinate system (x', y', z') and the world coordinate system (x, y, z) will coincide.

[0043] Next, we will explain the camera coordinate system. Here, this coordinate system is a three-dimensional coordinate system with the facial recognition camera 42 as its origin. In this specific embodiment, the camera coordinate values ​​of the center positions of the user's left and right eyes (here, the center position of the line segment connecting the left and right eyes, referred to as the viewpoint) detected by the facial recognition camera 42 are converted to the coordinate system of the aerial image area G (the device coordinate system (x', y', z')) for use. This can be accomplished through an affine transformation.

[0044] The user's viewpoint position is used to calculate the horizontal angle δ (refer to Figure 3 The coordinates of the viewpoint in the device coordinate system are (x', y', z') and the angle δ is calculated using the formula δ = atan(y' / x'). This angle δ is transmitted to the information processing device 30, which uses servo control to rotate the rotating plate 56 around the rotating shaft 54 ​​to reduce the angle δ to zero.

[0045] [Method for realizing stereoscopic images] The following describes a method for displaying a stereoscopic image using the aerial image display device 1 with reference to the accompanying drawings. First, the object (object) to be displayed as a stereoscopic image in the aerial image area G is modeled in the world coordinate system. As mentioned above, although the aerial image display device 1 rotates, the object is defined in the world coordinate system. Regardless of whether the aerial image display device 1 rotates, the object's position is determined relative to the real world (e.g., the room in which the aerial image display device 1 is located). For simplicity, a cube is used as an example object, which is kept stationary in the world coordinate system. Of course, the present invention is not limited to cubes and can be applied to any three-dimensional object.

[0046] Figure 4 (A1), (A2), and (A3) are top views of the aerial image display device 1 as viewed from above. Figure 4 In (A1), the user's viewpoint E is located in front of the aerial image display device 1 at the reference position. Figure 2 As shown, the position in which the back surface of the aerial image display device 1 faces the driving device 58 is set in advance as the reference position of the aerial image display device 1 .

[0047] Here, if the user moves slightly to the right, causing viewpoint E to move to the right from the front of aerial image display device 1, facial recognition camera 42 detects this movement (angle δ) and transmits (notifies) it to information processing device 30. Information processing device 30 then controls drive device 58 to rotate aerial image display device 1 in accordance with the movement of user viewpoint E, so that the user's viewpoint E after the movement is located in front of aerial image display device 1.

[0048] In other words, rotating plate 56 is rotated about rotation axis 54 so that the angle δ (= atan(y' / x')) between the front direction of aerial image display device 1 and the direction of the user's viewpoint, as viewed from rotation axis R, remains zero. This synchronizes the movement of aerial image display device 1 and the user's viewpoint E, maintaining a constant rotation angle Φ relative to the reference position, and ensuring that the user always faces the front of aerial image display device 1 (Figures 4 (A2) and (A3)).

[0049] Figure 4 (B1), (B2), (B3) and Figure 4 (A1), (A2), and (A3) correspond to the diagrams for explaining how an aerial image is displayed on the aerial image display device 1. In the diagram, the symbol C represents a cube, but this cube is only depicted as an object for the three-dimensional image display for convenience and is not an actual image. The image actually displayed as an aerial image in the aerial image area G is Figure 4 (C1), (C2), and (C3) in the .

[0050] The dotted line indicated by reference symbol G is a region where the aerial image of the display interface of the liquid crystal display 10 is projected. Figure 4 (C1), (C2), and (C3) are projection images of a cube C that is stationary in the world coordinate system on the aerial image area G, as viewed from the user's viewpoint E.

[0051] exist Figure 4 In (B1), the aerial image display device 1 is at the reference position, and the aerial image area at this time is represented by the reference symbol Go. In addition, the user's viewpoint E is located on the normal line of the aerial image area Go at the reference position. In this case, Figure 4 (C1) shows only the front side of cube C.

[0052] Here, as Figure 4 As shown in (B2), when the user's viewpoint E moves to the right, the aerial image display device 1 will rotate accordingly so that the aerial image area G faces the user's viewpoint E. Here is the rotation angle Φ relative to the aerial image area Go at the reference position. In this case, as Figure 4 The projection of (C2) will show a small part of the right side of cube C.

[0053] like Figure 4 As shown in (B3), when the user's viewpoint E moves further to the right, the aerial image display device 1 will also synchronize with it and rotate further. For example, when the rotation angle Φ is 45 degrees, as shown in Figure 4 As shown in (C3), the projected view of cube C will appear so that the front and right sides can be seen to an equal extent.

[0054] The aerial image area G is invisible to the user; all that's visible is the displayed object (here, a cube) floating in the air. To see the displayed object from the side, simply shift your viewpoint to the side, and the previously unseen side will appear. This provides the same experience as if the displayed object were actually there.

[0055] In this way, parallax caused by the movement of the observer's viewpoint, i.e., motion parallax, is achieved, thereby creating a motion depth effect, allowing the user to recognize the displayed object in a three-dimensional manner.

[0056] Example 2 In the first embodiment, the aerial image display device 1 rotates along with the user's viewpoint E, so that the user's viewpoint E is always in front of it. However, since the aerial image display device 1 rotates mechanically, it is difficult to perfectly synchronize the user's viewpoint E with the front of the aerial image display device 1. In other words, by utilizing the function of the driving device 58, Figure 3 Problems may arise with the angle δ, which should ideally be close to 0.

[0057] Furthermore, if motion parallax is implemented for the vertical movement of the user's viewpoint E, a sense of realism similar to that of a real object can be achieved. To achieve this mechanically, the aerial image display device 1 needs to be rotated about the y' axis in the above-mentioned coordinate system, but this increases the cost and the overall size of the device.

[0058] Therefore, in Example 2, the software is used to correct Figure 3 The angle δ in the image is the deviation between the user's viewpoint E and the front of the aerial image display device 1. The specific method is described below. Here, for simplicity, only the horizontal movement of the user's viewpoint E is considered.

[0059] exist Figure 5 In the illustration, when the user's viewpoint E moves laterally by only an angle θ relative to a stationary cube C in the world coordinate system, the aerial image display device 1 rotates accordingly. Originally, the angle between the aerial image area G and the reference aerial image area Go should be θ (see symbol Gt). However, due to mechanical rotational delay, this angle becomes a smaller angle Φ. In other words, the deviation is only an angle δ (=θ - Φ).

[0060] If, assuming the user's viewpoint E is at an angle θ, the cube C is drawn within the aerial image region G, the aerial image region G will be viewed from an oblique angle, resulting in a distorted image and a loss of three-dimensional effect. Therefore, a transformation is required to achieve a correct stereoscopic image when viewed from an oblique angle. This is done to create a visual illusion similar to the so-called image hump in road markings. This will be explained in detail below.

[0061] When the user's viewpoint E is located in front of the aerial image area G, the coordinates (device coordinates) of the projection surface (aerial image area G) are (y', z'), and the user's viewpoint E is located in the normal direction x'. However, due to the rotation delay of the aerial image display device 1, the user's viewpoint E is not located in the normal direction x' of the projection surface (aerial image area G).

[0062] Therefore, the perspective projection transformation is performed from the user's viewpoint E to the oblique aerial image region G of the cube C using the device coordinates. Assume that the coordinates of the user's viewpoint E in the device coordinates are (e x ,e y ,e z ), the coordinates of cube C are (c x ,c y ,c z If the intersection of the line connecting these two points and the projection plane (y'z' plane) is set to (p x , p y , p z ), p can be obtained as follows y With p z (p x Always 0).

[0063]

[0064]

[0065] Figure 5 The figure shows the projection of edges c1, c2, and c3 of a cube C onto points p1, p2, and p3 on the projection plane. Since the projection plane represents the aerial image region G, it can be directly output as the display image on the liquid crystal display 10. Furthermore, since displayed objects are generally opaque, hidden surface processing is performed to remove hidden lines and surfaces. Furthermore, since the coordinate system of a display device often has its origin in the upper left corner and requires adjustment of measurement units, it goes without saying that the output image will be appropriately transformed.

[0066] By using software to correct for the mechanical rotation delay, objects can be smoothly displayed to the user, allowing the object's shape to be perceived in a more natural, three-dimensional manner. In the above description, the software correction (the perspective projection transformation formula) is not limited to the horizontal direction. The parallax caused by the observer's viewpoint moving in the vertical and depth directions, that is, the motion parallax in the vertical and depth directions, is also achieved through a visual illusion effect. Of course, this is achieved within the viewing angle range of the vertical and depth directions. In this way, the depth of movement can be more effectively experienced.

[0067] Example 3 In Example 2, motion parallax is achieved by combining software correction with mechanical rotation of the aerial image display device 1. Motion parallax can also be achieved using software correction alone. However, when using a recursive transmissive or retroreflective display, the viewing angle is narrow, and software correction alone will limit the range within which the stereoscopic image can be viewed.

[0068] Therefore, in this third embodiment, motion parallax will be realized only by software correction in an aerial image display device with an expanded viewing angle.

[0069] Figure 6 This is a perspective view of an aerial image display device 2, which is a third embodiment of a three-dimensional image display device. This aerial image display device 2 comprises: a housing 60 with an M-shaped cross-section; a pair of left and right liquid crystal displays 70a and 70b arranged parallel to the inner sides of the housing 60; a pair of left and right optical plates 75a and 75b arranged at a 45-degree angle to the left and right liquid crystal displays 70a and 70b; a motion sensor 90 disposed on the outer sides of the optical plates 75a and 75b for detecting operation; a facial recognition camera 82 disposed on the upper portion of the housing 60; a speaker 89; and a control device (not shown) that processes the input and output signals of each of these elements. Here, the motion sensor 90 also comprises an infrared LED and an infrared camera. The functions of the motion sensor 90 and the facial recognition camera 82 are identical to those of the motion sensor 7 and facial recognition camera 42 in the first embodiment, and therefore will not be repeated.

[0070] The aerial image display device 2 is designed to be viewed while the user is standing. Since the vertical viewing angle of the aerial image display device 2 is not expanded, it is preferably viewed from the side. The housing 60 is supported by the legs 62 so that the aerial image is positioned at approximately eye level.

[0071] Here, the optical plates 75a and 75b each have the same rectangular shape, and are arranged so that one side of each plate contacts the other at a fixed angle (here, 90 degrees). A pair of liquid crystal displays 70a and 70b and a pair of optical plates 75a and 75b stand upright on either side. Overall, the liquid crystal displays 70a and 70b and the optical plates 75a and 75b are symmetrically arranged with respect to a plane bisecting the angle between the optical plates 75a and 75b, along the edges of the optical plates 75a and 75b.

[0072] Therefore, the image on the display screen of LCD 70a forms a real image at a symmetrical position with respect to optical plate 75a, and the image on the display screen of LCD 70b forms a real image at a symmetrical position with respect to optical plate 75b. These two real images partially overlap on the same plane, forming a single aerial image region Gx. However, the displays of LCDs 70a and 70b are controlled so that the overlapping portion of the two real images (the central portion of a single aerial image region Gx) appears as a single image. Consequently, compared to conventional aerial image display devices, aerial image region Gx is expanded, significantly increasing the viewing angle.

[0073] As in Example 2, objects are displayed in this aerial image region Gx. As the user's viewpoint moves, the objects undergo the aforementioned perspective projection transformation and are displayed in the aerial image region Gx. This creates a visual illusion, allowing the image to appear three-dimensional even when viewed from a certain angle.

[0074] Therefore, even without physically rotating the aerial image display device 2, it is possible to effectively experience the depth of motion at a wide viewing angle in the horizontal direction. Moreover, similar to the second embodiment, motion parallax is also achieved within the viewing angle range in the vertical direction.

[0075] Example 4 In Example 3, motion parallax is achieved in the vertical and horizontal directions by combining vertical viewing angle expansion with mechanical rotation. Figure 7 It is a perspective view showing an aerial image display device 3 constituting a stereoscopic image display device in a fourth embodiment of the present invention.

[0076] like Figure 7As shown, the aerial image display device 3 comprises a chair-shaped housing 13, a pair of liquid crystal displays 20a and 20b positioned within the housing at an angle of approximately 45 degrees to the horizontal, a pair of optical panels 25a and 25b positioned horizontally and vertically on the seat and backrest of the housing 13, respectively, a motion sensor 31 positioned on the front side for detecting operation, a speaker 39, and a control device (not shown) that processes the input and output signals of these components. The motion sensor 31 comprises a pair of infrared LEDs 32 and a pair of infrared cameras 34.

[0077] A pair of liquid crystal displays 20a, 20b and a pair of optical plates 25a, 25b hold Figure 6 The relative positional relationship between the liquid crystal displays 70a, 70b and the optical plates 75a, 75b of the aerial image display device 2 shown in the figure is tilted 90 degrees to the side. That is, the optical plates 25a, 25b each have the same rectangular shape and are configured so that one of their respective sides contacts each other at a fixed angle (here, 90 degrees). In addition, the liquid crystal displays 20a, 20b and the optical plates 25a, 25b are arranged relative to each other at a specified angle (here, 45 degrees). Overall, the liquid crystal displays 20a, 200b and the optical plates 25a, 25b pass through the joining edge of the optical plates 25a, 25b and are symmetrically arranged relative to a plane that bisects the angle between the optical plates 25a, 25b.

[0078] Therefore, the image on the display screen of LCD display 20a forms a real image at symmetrical positions with respect to optical plate 25a, and the image on the display screen of LCD display 20b forms a real image at symmetrical positions with respect to optical plate 25b. Furthermore, similar to the aerial image display device 1 of Example 1, the images on the display screens of LCD display 20a and LCD display 20b are formed on the same plane as a single aerial image area G. Aerial image area G is inclined at 45 degrees to the vertical. The overlapping portion of the two real images forms a single image. Thus, only the non-overlapping portion achieves an expanded vertical viewing angle.

[0079] As in Example 1, the infrared LED 32 and infrared camera 34 of the motion sensor 31 capture an image of the user's hand near the aerial image area G, and detect the position and movement of the user's hand. Furthermore, a facial recognition camera 42 is provided on the upper portion of the housing 13. As in Example 1, this captures an image of the user's face from the front of the aerial image display device 3 and detects the three-dimensional position of the user's eyes.

[0080] As in Example 1, the aerial image display device 3 is mounted on a motorized rotating platform 50 and is capable of 360-degree rotation about a rotation axis R that vertically passes through the center of the aerial image region G (the center of both the width and height of the region). The structure of the rotating platform 50 is the same as that of Example 1.

[0081] The method for displaying a 3D image on the aerial image display device 3 is the same as in Example 1 and will not be repeated here. Specifically, the information processing device controls the driving device 50 of the rotating stage 50 to rotate the aerial image display device 3 in accordance with the movement of the user's viewpoint, so that the user's viewpoint E is located in front of the aerial image display device 3.

[0082] The difference from the first embodiment is that the vertical viewing angle is enlarged. That is, the horizontal motion parallax is processed by mechanically rotating the aerial image display device 3, and the vertical motion parallax is processed by enlarging the viewing angle.

[0083] In the first embodiment, the aerial image region G stands vertically, but in the fourth embodiment, the aerial image region G is tilted by only 45 degrees, so that the image is viewed from diagonally above.

[0084]

Industrial Applicability

[0085] Here, a cube is used as an example object displayed on the aerial image display device 1, and is described as a stationary object in the world coordinate system. However, the present invention can be implemented even if the object undergoes any changes over time in the world coordinate system (e.g., rotation or deformation). For example, if the object is the Earth, its rotation relative to the world coordinate system can be viewed from various angles.

[0086] Furthermore, in the above-mentioned specific embodiment, the aerial image display device uses a recursive transmission optical imaging element. However, the present invention is not limited thereto, and an aerial image display device using a retroreflective optical imaging element may also be used.

[0087] Furthermore, the present invention aims to achieve a certain degree of effect even without using aerial images, and thus the present invention can also be implemented using a general-purpose display such as a liquid crystal display or an OLED display.

[0088] [Description of Reference Numerals] 1, 2, 3 Aerial image display device 7 Motion Sensor 10 LCD 12 Lower housing 13 Chair-shaped shell 14 Upper shell 20 optical plates 20a, 20b LCD 21 Incident surface 25a, 25b Optical plates 30 Information processing device 31 Motion Sensor 32 infrared LEDs 34 infrared cameras 39, 40 speakers 42 facial recognition cameras 50 Rotary Table 52 support platform 54 shaft 56 Rotating Plate 57 Roller 58 drive unit 60 shell 62 legs 70a, 70b LCD 72 infrared LEDs 74 infrared cameras 75a, 75b optical plates 82 facial recognition cameras 89 speakers 90 Motion Sensor 90 degrees (here G, Go, Gx aerial imaging area

Claims

1. A stereoscopic image display device, comprising: display device; a camera, disposed on the front of the display device, facing the display device, and detecting a viewpoint position of a user viewing the display device; A rotating device rotates the display device around a rotating axis; an information processing device connects the display device, the camera and the rotating device, receives the user viewpoint position from the camera and controls the rotation of the rotating device according to the movement of the user viewpoint position, so as to keep the direction of the user viewpoint viewed from the display surface unchanged, characterized in that the information processing device will display a three-dimensional object defined in a world coordinate system that does not move relative to the real world on the display device, and when the user viewpoint moves, the information processing device will display an image of the three-dimensional object observed from the direction of the user viewpoint on the display device.

2. The 3D image display device according to claim 1, wherein: The display device is an aerial image display device that can display two-dimensional images in the air.

3. The 3D image display device according to claim 2, wherein: The display device is an aerial image display device using a recursive transmission optical imaging element.

Images