Airborne video display device

Abstract

To provide a more suitable airborne video display device so that this invention contributes to the Sustainable Development Goals (SDGs) of "3: Health and well-being for all", "9: Let's create a foundation for industrial and technological innovation", and "11: Create a city where people can continue to live".SOLUTION: The airborne video display device installed in an airborne video display system is provided with a video processing unit, a display unit for displaying the video processed by the video processing unit, and an optical system for generating an airborne video based on the video displayed by the display unit. The airborne video display device forms an airborne image from the side of a vehicle parked at a position corresponding to a service facility provided in the airborne image display system toward occupants of the vehicle, wherein the airborne image is formed near a position for placing an order or paying a bill for the service facility in a traveling direction of the vehicle.SELECTED DRAWING: Figure 15A

Description

[Technical field]

[0001] The present invention relates to a floating-in-the-air image display device. [Background technology]

[0002] The airborne information display technology is disclosed in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-128722 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the disclosure of Patent Document 1 does not sufficiently consider configurations for obtaining practical brightness and quality for the floating image, or configurations for allowing users to more enjoyably view the floating image.

[0005] An object of the present invention is to provide a more suitable floating-in-the-air image display device. [Means for solving the problem]

[0006] In order to solve the above problem, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above problem, but to give one example, the floating image display device provided in the floating image display system has an image processing unit, a display unit that displays an image processed by the image processing unit, and an optical system that generates a floating image based on the image displayed by the display unit, and forms the floating image from the side of a vehicle parked at a position corresponding to a service facility provided in the floating image display system toward the occupant of the vehicle, and the floating image is formed in the traveling direction of the vehicle near a position for placing an order with the service facility or a position for making a payment. Effect of the Invention

[0007] According to the present invention, a more suitable space floating image display device can be realized. Other objects, configurations and effects will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing an example of a usage form of a space floating image display device according to an embodiment of the present invention; [Figure 2A] 1 is a diagram showing an example of a main part configuration and a retroreflection part configuration of a space floating image display device according to an embodiment of the present invention; [Figure 2B] 1 is a diagram showing an example of a main part configuration and a retroreflection part configuration of a space floating image display device according to an embodiment of the present invention; [Figure 2C] 1 is a diagram showing an example of a main part configuration and a retroreflection part configuration of a space floating image display device according to an embodiment of the present invention; [Figure 2D] 1 is a diagram showing an example of a main part configuration and a retroreflection part configuration of a floating-in-the-air image display device according to an embodiment of the present invention; [Figure 2E] 1 is a projection diagram of a retroreflector constituting a floating-in-the-air image display device according to an embodiment of the present invention; [Figure 2F]FIG. 2 is a top view of a retroreflector constituting a floating-in-the-air image display device according to an embodiment of the present invention. [Figure 2G] FIG. 2 is a perspective view showing a corner reflector constituting a retroreflector constituting a floating-in-the-air image display device according to an embodiment of the present invention. [Figure 2H] FIG. 2 is a top view showing a corner reflector constituting a retroreflector constituting a floating-in-the-air image display device according to an embodiment of the present invention. [Figure 2I] 1 is a side view showing a corner reflector constituting a retroreflector constituting a floating-in-the-air image display device according to an embodiment of the present invention; FIG. [Diagram 3] 1 is a diagram showing a configuration example of a space floating image display device according to an embodiment of the present invention; [Figure 4A] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4B] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4C] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4D] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4E] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4F] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4G] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4H] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4I] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4J] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4K]FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4L] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4M] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4N] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 4O] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a cross-sectional view showing an example of a specific configuration of a light source device according to an embodiment of the present invention. [Figure 6] FIG. 2 is a cross-sectional view showing an example of a specific configuration of a light source device according to an embodiment of the present invention. [Figure 7] FIG. 2 is a cross-sectional view showing an example of a specific configuration of a light source device according to an embodiment of the present invention. [Figure 8] 1 is a layout diagram showing a main part of a space floating image display device according to an embodiment of the present invention; [Figure 9] 1 is a cross-sectional view showing a configuration of a display device according to an embodiment of the present invention. [Figure 10] 1 is a cross-sectional view showing a configuration of a display device according to an embodiment of the present invention. [Figure 11] 1 is an explanatory diagram for explaining a light source diffusion characteristic of an image display device according to an embodiment of the present invention. [Figure 12] 1 is an explanatory diagram for explaining the diffusion characteristics of a video display device according to an embodiment of the present invention; [Figure 13A] 1 is a diagram illustrating an example of a problem to be solved by image processing according to an embodiment of the present invention; [Figure 13B] FIG. 4 is an explanatory diagram of an example of image processing according to an embodiment of the present invention. [Figure 13C] FIG. 4 is an explanatory diagram of an example of a video display process according to an embodiment of the present invention. [Figure 13D] FIG. 4 is an explanatory diagram of an example of a video display process according to an embodiment of the present invention. [Figure 14] 1 is a diagram showing an example of a main part configuration and a retroreflection part configuration of a space floating image display device according to an embodiment of the present invention; [Figure 15A] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 15B] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 16] FIG. 2 is a diagram showing an example of a floating image in space viewed from inside a vehicle according to an embodiment of the present invention. [Figure 17A] FIG. 2 is a diagram illustrating an example of a floating image in space according to an embodiment of the present invention. [Figure 17B] FIG. 2 is a diagram illustrating an example of a floating image in space according to an embodiment of the present invention. [Figure 18A] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 18B] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 19] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 20] FIG. 2 is a diagram showing an example of a floating image in space viewed from inside a vehicle according to an embodiment of the present invention. [Figure 21] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 22] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 23] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 24] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Diagram 25] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 26] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 27]FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 28] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. [Figure 29] FIG. 1 is a diagram showing an example of a configuration of a space floating image display device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the description of the embodiments, and various changes and modifications can be made by those skilled in the art within the scope of the technical ideas disclosed in this specification. In addition, in all the drawings for explaining the present invention, the same reference numerals are given to parts having the same functions, and repeated explanations thereof may be omitted.

[0010] The following embodiment relates to an image display device capable of transmitting an image produced by image light from an image emission source through a transparent member that divides a space, such as glass, and displaying the image as a floating image outside the transparent member. In the following description of the embodiment, an image floating in space is expressed by the term "floating image in space". Instead of this term, it is also acceptable to express it as "aerial image", "spatial image", "floating image in space", "floating optical image of a displayed image", "floating optical image of a displayed image", etc. The term "floating image in space" that is mainly used in the description of the embodiment is used as a representative example of these terms.

[0011] According to the following embodiment, for example, a suitable image display device can be realized for bank ATMs, station ticket vending machines, digital signage, etc. For example, currently, touch panels are usually used in bank ATMs, station ticket vending machines, etc., but by using a transparent glass surface or a light-transmitting plate material, high-resolution image information can be displayed in a space-floating state on the glass surface or light-transmitting plate material. At this time, by making the divergence angle of the emitted image light small, that is, an acute angle, and further aligning it with a specific polarization, only the normal reflected light is efficiently reflected by the retroreflector, so that the light utilization efficiency is high, and ghost images that occur in addition to the main space-floating image, which was a problem in the conventional retroreflection method, can be suppressed, and a clear space-floating image can be obtained. In addition, a device including the light source of this embodiment can provide a novel and highly usable space-floating image display device (space-floating image display system) that can significantly reduce power consumption. In addition, for example, a space-floating image display device for vehicles that can display a so-called unidirectional space-floating image that can be viewed inside and / or outside the vehicle can be provided. <Example 1>

[0012] <An example of how the space floating image display device can be used> FIG. 1 is a diagram showing an example of a usage form of a space-floating image display device according to an embodiment of the present invention, and is a diagram showing the overall configuration of the space-floating image display device according to this embodiment. The specific configuration of the space-floating image display device will be described in detail using FIG. 2 and the like, but light with a narrow-angle directional characteristic and specific polarization is emitted from the image display device 1 as an image light beam, and is once incident on the retroreflector 2 after reflection in the optical system in the space-floating image display device, and is retroreflected and transmitted through a transparent member 100 (glass, etc.), forming a real aerial image (space-floating image 3) on the outside of the glass surface. In the following embodiment, the retroreflector 2 (retroreflector) is used as an example of the retroreflector. However, the retroreflector 2 of the present invention is not limited to a flat plate, and is used as an example of a concept including a sheet-like retroreflector attached to a flat or non-flat member, and an entire assembly in which a sheet-like retroreflector is attached to a flat or non-flat member. Furthermore, since the light rays reflected by the retroreflector 2 have the optical property of forming an image, the retroreflector 2 may be expressed as an imaging optical member or an imaging optical plate.

[0013] In addition, in a store or the like, a space is divided by a show window (also called "window glass") 105, which is a light-transmitting member such as glass. According to the space floating image display device of this embodiment, it is possible to transmit the floating image through such a transparent member and display it in one direction to the outside and / or inside of the store (space).

[0014] 1, the inside of the window glass 105 (inside the store) is shown in the depth direction, and the outside (for example, the sidewalk) is shown in the foreground. On the other hand, by providing the window glass 105 with a means for reflecting a specific polarized wave, it is possible to form an aerial image at a desired position inside the store.

[0015] <Example of optical system configuration for space floating image display device> Fig. 2A is a diagram showing an example of the configuration of an optical system of a space-floating image display device according to an embodiment of the present invention. The configuration of the space-floating image display device will be described in more detail with reference to Fig. 2A. As shown in Fig. 2A(1), a display device 1 that diverges specific polarized image light at a narrow angle is provided in the oblique direction of a transparent member 100 such as glass. The display device 1 includes a liquid crystal display panel 11 and a light source device 13 that generates specific polarized light having a narrow-angle diffusion characteristic.

[0016] The image light of a specific polarization from the display device 1 is reflected by a polarization separation member 101 (in the figure, the polarization separation member 101 is formed into a sheet shape and adhered to the transparent member 100) having a film that selectively reflects the image light of a specific polarization provided on a transparent member 100, and enters the retroreflector 2. A λ / 4 plate 21 is provided on the image light incidence surface of the retroreflector 2. The image light is made to pass through the λ / 4 plate 21 twice, when it enters the retroreflector 2 and when it leaves, and is polarized and converted from the specific polarization to the other polarization. Here, the polarization separation member 101 that selectively reflects the image light of a specific polarization has a property of transmitting the polarized light of the other polarization that has been polarized and converted, so the image light of the specific polarization after polarization conversion passes through the polarization separation member 101. The image light that has passed through the polarization separation member 101 forms a space floating image 3, which is a real image, outside the transparent member 100. 2A shows an example in which the chief ray of the image light incident on the retroreflector 2 is incident at an angle of 90° to the retroreflector 2. However, the incident angle of the chief ray of the image light on the retroreflector 2 is not limited to 90°, and may be, for example, 90°±15°.

[0017] Here, a first example of the polarization design in the optical system of FIG. 2A will be described. For example, the display device 1 may be configured to emit S-polarized image light to the polarization separation member 101, and the polarization separation member 101 may have the property of reflecting S-polarized light and transmitting P-polarized light. In this case, the S-polarized image light that reaches the polarization separation member 101 from the display device 1 is reflected by the polarization separation member 101 and travels toward the retroreflector 2. When the image light is reflected by the retroreflector 2, it passes through the λ / 4 plate 21 provided on the incident surface of the retroreflector 2 twice, so that the image light is converted from S-polarized light to P-polarized light. The image light converted to P-polarized light travels again toward the polarization separation member 101. Here, the polarization separation member 101 has the property of reflecting S-polarized light and transmitting P-polarized light, so that the P-polarized image light passes through the polarization separation member 101 and then through the transparent member 100. The image light transmitted through the transparent member 100 is generated by the retroreflector 2, and therefore forms a floating image 3, which is an optical image of the image displayed on the display device 1, at a position that is in a mirror relationship with the image displayed on the display device 1 with respect to the polarization separation member 101. This polarization design allows the floating image 3 to be formed appropriately.

[0018] Next, a second example of the polarization design in the optical system of FIG. 2A will be described. For example, the display device 1 may be configured to emit P-polarized image light to the polarization separation member 101, and the polarization separation member 101 may have a property of reflecting P-polarized light and transmitting S-polarized light. In this case, the P-polarized image light that reaches the polarization separation member 101 from the display device 1 is reflected by the polarization separation member 101 and travels toward the retroreflector 2. When the image light is reflected by the retroreflector 2, it passes through the λ / 4 plate 21 provided on the incident surface of the retroreflector 2 twice, so that the image light is converted from P-polarized light to S-polarized light. The image light converted to S-polarized light travels again toward the polarization separation member 101. Here, the polarization separation member 101 has a property of reflecting P-polarized light and transmitting S-polarized light, so that the S-polarized image light passes through the polarization separation member 101 and then through the transparent member 100. The image light transmitted through the transparent member 100 is generated by the retroreflector 2, and therefore forms a floating image 3, which is an optical image of the image displayed on the display device 1, at a position that is in a mirror relationship with the image displayed on the display device 1 with respect to the polarization separation member 101. This polarization design allows the floating image 3 to be formed appropriately.

[0019] The light forming the floating image 3 is a collection of light rays that converge from the retroreflector 2 to the optical image of the floating image 3, and these light rays continue to travel straight even after passing through the optical image of the floating image 3. Therefore, the floating image 3 is an image with high directivity, unlike the diffuse image light formed on a screen by a general projector or the like. Therefore, in the configuration of FIG. 2A, when a user views the floating image 3 from the direction of the arrow A, the floating image 3 is viewed as a bright image. However, when another person views the floating image 3 from the direction of the arrow B, the floating image 3 cannot be viewed as an image at all. This characteristic is very suitable for use in a system that displays images that require high security or highly confidential images that should be kept secret from people facing the user.

[0020] Depending on the performance of the retroreflector 2, the polarization axis of the image light after reflection may become uneven. Also, the reflection angle may become uneven. Such uneven light may not maintain the polarization state and traveling angle assumed in the design. For example, light with such a polarization state and traveling angle that is not assumed in the design may re-enter the image display surface side of the liquid crystal display panel 11 directly from the position of the retroreflector 2 without passing through the polarization separation member. Such light with a polarization state and traveling angle that is not assumed in the design may re-enter the image display surface side of the liquid crystal display panel 11 after being reflected by a component in the space floating image display device. Such light that re-enters the image display surface side of the liquid crystal display panel 11 may be re-reflected by the image display surface of the liquid crystal display panel 11 that constitutes the display device 1, generating a ghost image and possibly degrading the image quality of the space floating image. Therefore, in this embodiment, an absorbing polarizing plate 12 may be provided on the image display surface of the display device 1. The image light emitted from the display device 1 is transmitted through the absorptive polarizing plate 12, and the reflected light returning from the polarization separation member 101 is absorbed by the absorptive polarizing plate 12, thereby suppressing the re-reflection. This makes it possible to prevent degradation of image quality due to ghost images of spatially floating images. Specifically, if the display device 1 is configured to emit S-polarized image light to the polarization separation member 101, the absorptive polarizing plate 12 may be a polarizing plate that absorbs P-polarized light. Also, if the display device 1 is configured to emit P-polarized image light to the polarization separation member 101, the absorptive polarizing plate 12 may be a polarizing plate that absorbs S-polarized light.

[0021] The above-mentioned polarization separation member 101 may be formed, for example, of a reflective polarizing plate or a metal multilayer film that reflects a specific polarized wave.

[0022] 2A(2) shows an example of the surface shape of a retroreflector as a representative retroreflector 2. A ray of light incident on the interior of regularly arranged hexagonal prisms is reflected by the walls and bottoms of the hexagonal prisms and emitted as retroreflected light in a direction corresponding to the incident light, and a real floating image is displayed based on the image displayed on the display device 1.

[0023] The resolution of this floating image in space depends not only on the resolution of the liquid crystal display panel 11, but also on the outer shape D and pitch P of the retroreflector 2 shown in Fig. 2A(2). For example, when using a 7-inch WUXGA (1920 x 1200 pixels) liquid crystal display panel, even if one pixel (one triplet) is about 80 μm, if the diameter D of the retroreflector is 240 μm and the pitch is 300 μm, one pixel of the floating image in space will be equivalent to 300 μm. For this reason, the effective resolution of the floating image in space will be reduced to about 1 / 3.

[0024] Therefore, in order to make the resolution of the spatial floating image equal to that of the display device 1, it is desirable to make the diameter and pitch of the retroreflective portion close to one pixel of the liquid crystal display panel. On the other hand, in order to suppress the occurrence of moire due to the retroreflective plate and the pixels of the liquid crystal display panel, it is preferable to design the pitch ratio of each to be a different integer multiple of one pixel. In addition, it is preferable to arrange the shape so that none of the sides of the retroreflective portion overlaps with any of the sides of one pixel of the liquid crystal display panel.

[0025] The surface shape of the retroreflector according to this embodiment is not limited to the above example. It may have various surface shapes that realize retroreflection. Specifically, a retroreflection element in which triangular pyramid prisms, hexagonal pyramid prisms, other polygonal prisms, or a combination of these are periodically arranged may be provided on the surface of the retroreflector of this embodiment. Alternatively, a retroreflection element in which these prisms are periodically arranged to form a cube corner may be provided on the surface of the retroreflector of this embodiment. These can also be expressed as a corner reflector array or a multifaceted reflector array. Alternatively, a capsule lens type retroreflection element in which glass beads are periodically arranged may be provided on the surface of the retroreflector of this embodiment. The detailed configuration of these retroreflection elements can be achieved by using existing technology, so a detailed description will be omitted. Specifically, the techniques disclosed in Japanese Patent Application Laid-Open Nos. 2001-33609, 2001-264525, 2005-181555, 2008-70898, and 2009-229942 may be used.

[0026] <Another configuration example 1 of the optical system of the space floating image display device> Another example of the configuration of the optical system of the space floating image display device will be described with reference to Fig. 2B. In Fig. 2B, the components with the same reference numerals as Fig. 2A have the same functions and configurations as Fig. 2A. For such components, repeated explanations will be omitted to simplify the explanation.

[0027] In the optical system of FIG. 2B, as in FIG. 2A, image light of a specific polarization is output from the display device 1. The image light of a specific polarization output from the display device 1 is input to the polarization separation member 101B. The polarization separation member 101B is a member that selectively transmits the image light of a specific polarization. Unlike the polarization separation member 101 of FIG. 2A, the polarization separation member 101B is not integrated with the transparent member 100, but has an independent plate-like shape. Therefore, the polarization separation member 101B may be expressed as a polarization separation plate. The polarization separation member 101B may be configured as a reflective polarizing plate configured by attaching a polarization separation sheet to a transparent member, for example. Alternatively, the transparent member may be formed of a metal multilayer film that selectively transmits a specific polarization and reflects a polarization of another specific polarization. In FIG. 2B, the polarization separation member 101B is configured to transmit the image light of a specific polarization output from the display device 1.

[0028] The image light transmitted through the polarization separation member 101B is incident on the retroreflector 2. A λ / 4 plate 21 is provided on the image light incident surface of the retroreflector. The image light is polarized and converted from a specific polarization to the other polarization by passing through the λ / 4 plate 21 twice, when it enters the retroreflector and when it leaves the retroreflector. Here, the polarization separation member 101B has a property of reflecting the polarized light of the other polarization converted by the λ / 4 plate 21, so that the image light after polarization conversion is reflected by the polarization separation member 101B. The image light reflected by the polarization separation member 101B passes through the transparent member 100 and forms a space floating image 3, which is a real image, outside the transparent member 100.

[0029] Here, a first example of the polarization design in the optical system of FIG. 2B will be described. For example, the display device 1 may be configured to emit P-polarized image light to the polarization separation member 101B, and the polarization separation member 101B may have a property of reflecting S-polarized light and transmitting P-polarized light. In this case, the P-polarized image light that reaches the polarization separation member 101B from the display device 1 passes through the polarization separation member 101B and travels toward the retroreflector 2. When the image light is reflected by the retroreflector 2, it passes through the λ / 4 plate 21 provided on the incident surface of the retroreflector 2 twice, so that the image light is converted from P-polarized light to S-polarized light. The image light converted to S-polarized light travels again toward the polarization separation member 101B. Here, the polarization separation member 101B has a property of reflecting S-polarized light and transmitting P-polarized light, so that the S-polarized image light is reflected by the polarization separation member 101 and passes through the transparent member 100. Since the image light transmitted through the transparent member 100 is generated by the retroreflector 2, it forms a space-floating image 3, which is an optical image of the display image of the display device 1, at a position that is in a mirror relationship with the display image of the display device 1 with respect to the polarization separation member 101B. This polarization design allows the space-floating image 3 to be formed appropriately.

[0030] Next, a second example of the polarization design in the optical system of FIG. 2B will be described. For example, the display device 1 may be configured to emit S-polarized image light to the polarization separation member 101B, which may have the property of reflecting P-polarized light and transmitting S-polarized light. In this case, the S-polarized image light reaching the polarization separation member 101B from the display device 1 passes through the polarization separation member 101B and travels toward the retroreflector 2. When the image light is reflected by the retroreflector 2, it passes through the λ / 4 plate 21 provided on the incident surface of the retroreflector 2 twice, so that the image light is converted from S-polarized light to P-polarized light. The image light converted to P-polarized light travels again toward the polarization separation member 101B. Here, the polarization separation member 101B has the property of reflecting P-polarized light and transmitting S-polarized light, so that the P-polarized image light is reflected by the polarization separation member 101 and passes through the transparent member 100. The image light transmitted through the transparent member 100 is generated by the retroreflector 2, and therefore forms a space-floating image 3, which is an optical image of the display image of the display device 1, at a position that is in a mirror relationship with the display image of the display device 1 with respect to the polarization separation member 101B. With this polarization design, the space-floating image 3 can be formed suitably.

[0031] In FIG. 2B, the image display surface of the display device 1 and the surface of the retroreflector 2 are arranged parallel to each other. The polarization separation member 101B is arranged at an angle α (for example, 30°) with respect to the image display surface of the display device 1 and the surface of the retroreflector 2. Then, in the reflection of the polarization separation member 101B, the traveling direction of the image light reflected by the polarization separation member 101B (the direction of the chief ray of the image light) differs from the traveling direction of the image light incident from the retroreflector 2 (the direction of the chief ray of the image light) by an angle β (for example, 60°). By configuring in this way, in the optical system of FIG. 2B, the image light is output at a predetermined angle shown in the figure toward the outside of the transparent member 100, and the space-floating image 3, which is a real image, is formed. In the configuration of FIG. 2B, when a user views the space-floating image 3 from the direction of the arrow A, the space-floating image 3 is viewed as a bright image. However, when another person views the space-floating image 3 from the direction of the arrow B, the space-floating image 3 cannot be viewed as an image at all. This characteristic is extremely suitable for use in a system that displays images that require high security or highly confidential images that should be concealed from people directly facing the user.

[0032] As described above, the optical system in FIG. 2B is an optical system with a different configuration from the optical system in FIG. 2A, but can form a suitable floating-in-space image in the same way as the optical system in FIG. 2A.

[0033] An absorptive polarizing plate may be provided on the surface of the transparent member 100 facing the polarization separation member 101B. The absorptive polarizing plate may transmit the polarized wave of the image light from the polarization separation member 101B and absorb the polarized wave that is 90° out of phase with the polarized wave of the image light from the polarization separation member 101B. In this way, the image light for forming the space-floating image 3 is sufficiently transmitted, while the external light incident from the space-floating image 3 side of the transparent member 100 can be reduced by about 50%. This makes it possible to reduce stray light in the optical system of FIG. 2B due to the external light incident from the space-floating image 3 side of the transparent member 100.

[0034] <Another configuration example 2 of the optical system of the space floating image display device> Another example of the configuration of the optical system of the space floating image display device will be described with reference to Fig. 2C. In Fig. 2C, the components with the same reference numerals as Fig. 2B have the same functions and configurations as Fig. 2B. For the sake of simplicity, the description of such components will not be repeated.

[0035] The only difference between the optical system in Fig. 2B and the optical system in Fig. 2C is the arrangement angle of the polarization separation member 101B with respect to the image display surface of the display device 1 and the surface of the retroreflector 2. All other configurations are the same as those of the optical system in Fig. 2B, so repeated explanations will be omitted. The polarization design of the optical system in Fig. 2C is also the same as that of the optical system in Fig. 2B, so repeated explanations will be omitted.

[0036] In the optical system of FIG. 2C, the polarization separation member 101B is arranged at an angle α with respect to the image display surface of the display device 1 and the surface of the retroreflector 2. In FIG. 2C, the angle α is 45°. With this configuration, in the reflection of the polarization separation member 101B, the angle β between the traveling direction of the image light reflected by the polarization separation member 101B (direction of the chief ray of the image light) and the traveling direction of the image light incident from the retroreflector 2 (direction of the chief ray of the image light) is 90°. With this configuration, the image display surface of the display device 1 and the surface of the retroreflector 2 are perpendicular to the traveling direction of the image light reflected by the polarization separation member 101B, and the angular relationship of the surfaces constituting the optical system can be simplified. If the surface of the transparent member 100 is arranged so as to be perpendicular to the traveling direction of the image light reflected by the polarization separation member 101B, the angular relationship of the surfaces constituting the optical system can be further simplified. In the configuration of FIG. 2C, when a user views the image from the direction of the arrow A, the floating image 3 is perceived as a bright image. However, when another person views the image from the direction of the arrow B, the floating image 3 cannot be seen as an image at all. This characteristic is very suitable for use in a system that displays images that require high security or highly confidential images that should be concealed from people directly facing the user.

[0037] As described above, the optical system of Fig. 2C can form a suitable floating image in space similar to the optical system of Fig. 2A and Fig. 2B, even though the optical system of Fig. 2C has a different configuration from the optical system of Fig. 2A and Fig. 2B. In addition, the angles of the surfaces constituting the optical system can be made simpler.

[0038] An absorptive polarizing plate may be provided on the surface of the transparent member 100 facing the polarization separation member 101B. The absorptive polarizing plate may transmit the polarized wave of the image light from the polarization separation member 101B and absorb the polarized wave that is 90° out of phase with the polarized wave of the image light from the polarization separation member 101B. In this way, the image light for forming the space-floating image 3 is sufficiently transmitted, while the external light incident from the space-floating image 3 side of the transparent member 100 can be reduced by about 50%. This makes it possible to reduce stray light in the optical system of FIG. 2C due to the external light incident from the space-floating image 3 side of the transparent member 100.

[0039] <Other Configuration Example 3 of the Optical System of the Space Floating Image Display Device> Another example of the configuration of the optical system of the space floating image display device will be described with reference to FIG. 2D. The optical system of FIG. 2D is an optical system using a retroreflector 5 different from the retroreflector 2 used in FIG. 2A to FIG. 2C. Another example of the configuration 3 of the optical system will be described in more detail below with reference to FIG. 2D to FIG. 2I. In FIG. 2D, components with the same reference numerals as those in FIG. 2A to FIG. 2C have the same functions and configurations. Such components will not be described repeatedly in order to simplify the explanation.

[0040] 2D is a diagram showing an example of a main part configuration and a retroreflection part configuration of a space floating image display device according to an embodiment of the present invention. A display device 10 that emits image light is provided in an oblique direction of a transparent member 100 such as glass. The display device 10 includes a liquid crystal display panel 11 and a light source device 13 that generates light.

[0041] A chief ray 9020 representing a light beam emitted from the display device 10 travels toward the retroreflector 5 and is incident on the retroreflector 5 at an incident angle α. The incident angle α may be, for example, 45°. However, the incident angle α is not limited to 45°, and may be, for example, 45°±15°.

[0042] The retroreflector 5 is an optical member having an optical property of retroreflecting light rays in at least some directions. In addition, since the reflected light rays have an optical property of forming an image, the retroreflector 5 may be expressed as an imaging optical member or an imaging optical plate.

[0043] 2E, 2F, etc., the principal ray 9020 travels in the z direction and is retroreflected in the x and y directions by the retroreflector 5. As a result, the reflected ray 9021 travels in a direction away from the retroreflector 5 along an optical path mirror-symmetrical to the principal ray 9020 with respect to the retroreflector 5, passes through the transparent member 100, and forms the floating image 3 as a real image on the imaging plane.

[0044] The light beam forming the floating image 3 is a collection of light rays that converge from the retroreflector 5 to the optical image of the floating image 3, and these light rays continue to travel straight even after passing through the optical image of the floating image 3. Therefore, the floating image 3 is an image with high directivity, unlike a diffuse image formed on a screen by a general projector or the like. Therefore, in the configuration of FIG. 2, when a user views the floating image 3 from the direction of the arrow A, the floating image 3 is viewed as a bright image. However, when another person views the floating image 3 from the direction of the arrow B, the floating image 3 cannot be viewed as an image at all. This characteristic is suitable for use in a system that displays images that require high security or highly confidential images that should be concealed from people facing the user.

[0045] An example of the configuration of the retroreflector 5 will be described with reference to Figs. 2E and 2F. The retroreflector 5 has a configuration in which a plurality of corner reflectors 9040 are arranged in an array on the surface of a transparent member 50. This may be called a corner reflector array or a multi-surface reflector array. The specific configuration of the corner reflector 9040 will be described in detail with reference to Figs. 2G, 2H, and 2I. The light rays 9111, 9112, 9113, and 9114 emitted from the light source 9110 are reflected twice by the two mirror surfaces 9041 and 9042 of the corner reflector 9040, and become reflected light rays 9121, 9122, 9123, and 9124. This double reflection is a retroreflection that turns back in the same direction as the incident direction (travels in a direction rotated by 180°) in the x and y directions, and a regular reflection in which the incident angle and the reflection angle match due to total reflection in the z direction.

[0046] That is, the light rays 9111 to 9114 generate reflected light rays 9121 to 9124 on a straight line symmetrical in the z direction with respect to the corner reflector 9040, and form an aerial real image 9120. The light rays 9111 to 9114 emitted from the light source 9110 are four light rays representative of the diffused light from the light source 9110, and although the light rays incident on the retroreflector 5 are not limited to these depending on the diffusion characteristics of the light source 9110, all the incident light rays cause similar reflection and form an aerial real image 9120. To make the drawing easier to see, the position of the light source 9110 and the position of the aerial real image 9120 in the x direction are shown shifted, but in reality the position of the light source 9110 and the position of the aerial real image 9120 in the x direction are the same position, and are overlapped when viewed from the z direction.

[0047] Next, the configuration and effect of the corner reflector 9040 constituting the retroreflector 5 will be described with reference to Figures 2G, 2H, and 2I. The corner reflector 9040 is a rectangular parallelepiped with only two specific faces being mirror faces 9041 and 9042, and the other four faces being made of transparent materials. The retroreflector 5 has a configuration in which the corner reflectors 9040 are arrayed so that the corresponding mirror faces face the same direction.

[0048] When viewed from the top (+z direction), a light ray 9111 emitted from a light source 9110 enters a mirror surface 9041 (or a mirror surface 9042) at a specific angle of incidence, is totally reflected at a reflection point 9130, and then is totally reflected again at a reflection point 9132 on the mirror surface 9042 (or a mirror surface 9041).

[0049] If the angle of incidence of the light ray 9111 with respect to the mirror surface 9041 (or the mirror surface 9042) is θ, the angle of incidence of the first reflected light ray 9131 reflected by the mirror surface 9041 (or the mirror surface 9042) with respect to the mirror surface 9042 (or the mirror surface 9041) can be expressed as 90°-θ. Therefore, with respect to the light ray 9111, the second reflected light ray 9121 is rotated by 2θ by the first reflection and by 2×(90°-θ) by the second reflection, resulting in a total inversion optical path of 180°. On the other hand, when viewed from the side (the direction halfway between -x and -y), total reflection in the z direction occurs only once. Therefore, with respect to the light ray 9111, if the angle of incidence with respect to the mirror surface 9041 or the mirror surface 9042 is φ, the reflected light ray 9121 is rotated by 2×φ by one reflection.

[0050] As a result, the light beam incident on the corner reflector 9040 undergoes retroreflection with an inverted optical path in the x and y directions, and undergoes regular reflection due to total reflection in the z direction. Considering the retroreflector 5, similar reflections occur in each optical path, so that an image is formed at a point symmetrical with respect to the z axis direction due to an inverted optical path that has convergence in the x and y directions.

[0051] 2A to 2C, the retroreflector 2 has retroreflection characteristics in three axial directions. As a result, when an incident light beam with diffusivity is incident on the retroreflector 2, the reflected light beam with convergence travels toward the side of the retroreflector 2 where the light source of the incident light is present. The reflected light beam with convergence forms an image in the air to form a space floating image 3. The traveling direction of the main ray of the reflected light beam with convergence reflected from the retroreflector 2 is the opposite direction to the traveling direction of the main ray of the incident light beam with diffusivity that is incident on the retroreflector 2.

[0052] 2D, the retroreflector 5 has biaxial retroreflection properties and is specular in the other axial direction. As a result, when a diffusive incident light beam is incident on the retroreflector 5, the convergent reflected light beam reflected by the corner reflector array travels toward the side opposite to the side where the light source of the incident light is present with respect to the retroreflector 5. The convergent reflected light beam forms an image in the air to form the space floating image 3.

[0053] The traveling direction of the chief ray of the convergent reflected light beam reflected by the corner reflector array of the retroreflector 5 is not the opposite direction to the traveling direction of the chief ray of the diffusive incident light beam incident on the retroreflector 5. The normal direction component of the plate-shaped surface of the retroreflector 5 in the traveling direction of the chief ray of the diffusive incident light beam incident on the retroreflector 5 and the normal direction component of the plate-shaped surface of the retroreflector 5 in the traveling direction of the chief ray after being reflected by the retroreflector 5 to become a convergent reflected light beam proceed in a straight line without changing before and after reflection by the corner reflector array.

[0054] That is, the diffusive incident light beam is converted into a convergent reflected light beam by reflection on the retroreflector 5, but in the normal direction of the plate-shaped surface of the retroreflector 5, the light beam travels as if passing through the retroreflector 5. Here, the diffusive incident light beam incident on the retroreflector 5 and the convergent reflected light beam emerging from the retroreflector 5 are geometrically symmetrical with respect to the plate-shaped surface of the retroreflector 5.

[0055] The resolution of the space-floating image formed by the light beam from the image output unit 10 depends heavily on the diameter D and pitch P (not shown) of the retroreflector 5 shown in Figures 2E and 2F, in addition to the resolution of the liquid crystal display panel 11. For example, when a 7-inch WUXGA (1920 x 1200 pixels) liquid crystal display panel is used, even if one pixel (one triplet) is about 80 μm, if the diameter D of the retroreflector is 240 μm and the pitch P is 300 μm, one pixel of the space-floating image will be equivalent to 300 μm. For this reason, the effective resolution of the space-floating image is reduced to about 1 / 3.

[0056] Therefore, in order to make the resolution of the spatial floating image equal to that of the display device 10, it is desirable to make the diameter D and pitch P of the retroreflective portion close to one pixel of the liquid crystal display panel. On the other hand, in order to suppress the occurrence of moire due to the retroreflective plate and the pixels of the liquid crystal display panel, it is preferable to design the pitch ratio of each to be a different integer multiple of one pixel. In addition, it is preferable to arrange the shape so that none of the sides of the retroreflective portion overlaps with any of the sides of one pixel of the liquid crystal display panel.

[0057] The shape of the retroreflector (imaging optical plate) according to this embodiment is not limited to the above example. It may have various shapes that realize retroreflection. Specifically, it may be various cubic corner bodies, corner reflector arrays, slit mirror arrays, two-sided corner reflector arrays, polyhedral reflector arrays, or shapes in which a combination of their reflective surfaces is periodically arranged. Alternatively, a capsule lens type retroreflection element in which glass beads are periodically arranged may be provided on the surface of the retroreflection plate of this embodiment. Since the detailed configuration of these retroreflection elements can be achieved by using existing technology, detailed description will be omitted. Specifically, it is possible to use the technology disclosed in JP2017-33005A, JP2019-133110A, JP2017-67933A, WO2009 / 131128A, etc.

[0058] 2D, the image light emitted from the display device 10 may be in any polarization state. It does not matter whether it is S-polarized or P-polarized.

[0059] As described above, the optical system of FIG. 2D is an optical system that uses a different retroreflector from the optical systems of FIGS. 2A to 2C, but it can form a more suitable floating-in-space image, similar to the optical system of FIGS. 2A to 2C.

[0060] According to the optical systems of FIGS. 2A, 2B, 2C, and 2D described above, it is possible to provide brighter and higher quality floating images in space.

[0061] <<Block diagram of the internal configuration of the space floating image display device>>

[0062] Next, a description will be given of a block diagram of the internal configuration of the space-floating image display device 1000. Fig. 3 is a block diagram showing an example of the internal configuration of the space-floating image display device 1000.

[0063] The space floating image display device 1000 includes a retroreflection unit 1101, an image display unit 1102, a light guide 1104, a light source 1105, a power source 1106, an external power source input interface 1111, an operation input unit 1107, a non-volatile memory 1108, a memory 1109, a control unit 1110, an image signal input unit 1131, an audio signal input unit 1133, a communication unit 1132, an air operation detection sensor 1351, an air operation detection unit 1350, an audio output unit 1140, a microphone 1139, an image control unit 1160, a storage unit 1170, an imaging unit 1180, etc. In addition, the space floating image display device 1000 may include a removable media interface 1134, an attitude sensor 1113, a transmissive self-luminous image display device 1650, a second display device 1680, or a secondary battery 1112.

[0064] Each component of the space floating image display device 1000 is disposed in a housing 1190. Note that the imaging unit 1180 and the mid-air operation detection sensor 1351 shown in FIG.

[0065] The retroreflector 1101 in Fig. 3 corresponds to the retroreflector 2 in Fig. 2A, Fig. 2B, and Fig. 2C. The retroreflector 1101 retroreflects light modulated by the image display unit 1102. Of the light reflected from the retroreflector 1101, the light outputted to the outside of the space-floating image display device 1000 forms the space-floating image 3.

[0066] Image display unit 1102 in Fig. 3 corresponds to liquid crystal display panel 11 in Fig. 2A, Fig. 2B, and Fig. 2C. Light source 1105 in Fig. 3 corresponds to light source device 13 in Fig. 2A, Fig. 2B, and Fig. 2C. Image display unit 1102, light guide 1104, and light source 1105 in Fig. 3 correspond to display device 1 in Fig. 2A, Fig. 2B, and Fig. 2C.

[0067] The video display unit 1102 is a display unit that generates a video by modulating transmitted light based on a video signal input under the control of a video control unit 1160 described later. The video display unit 1102 corresponds to the liquid crystal display panel 11 in Figs. 2A, 2B, and 2C. For example, a transmissive liquid crystal panel is used as the video display unit 1102. Alternatively, for example, a reflective liquid crystal panel that modulates reflected light or a DMD (Digital Micromirror Device: registered trademark) panel may be used as the video display unit 1102.

[0068] The light source 1105 generates light for the image display unit 1102 and is a solid-state light source such as an LED light source or a laser light source. The power source 1106 converts an AC current input from the outside via the external power input interface 1111 into a DC current and supplies power to the light source 1105. The power source 1106 also supplies the necessary DC current to each unit in the space-floating image display device 1000. The secondary battery 1112 stores the power supplied from the power source 1106. The secondary battery 1112 also supplies power to the light source 1105 and other components that require power when power is not supplied from the outside via the external power input interface 1111. That is, when the space-floating image display device 1000 includes the secondary battery 1112, the user can use the space-floating image display device 1000 even when power is not supplied from the outside.

[0069] The light guide 1104 guides the light generated by the light source 1105 and irradiates the image display unit 1102. The combination of the light guide 1104 and the light source 1105 can be called a backlight of the image display unit 1102. The light guide 1104 may be mainly made of glass. The light guide 1104 may be mainly made of plastic. The light guide 1104 may be made of a mirror. There are various types of combination of the light guide 1104 and the light source 1105. Specific configuration examples of the combination of the light guide 1104 and the light source 1105 will be described in detail later.

[0070] The aerial operation detection sensor 1351 is a sensor that detects an operation of the floating-in-space image 3 by a finger of the user 230. The aerial operation detection sensor 1351 senses, for example, a range that overlaps with the entire display range of the floating-in-space image 3. Note that the aerial operation detection sensor 1351 may only sense a range that overlaps with at least a portion of the display range of the floating-in-space image 3.

[0071] Specific examples of the aerial operation detection sensor 1351 include a distance sensor using invisible light such as infrared light, an invisible light laser, ultrasonic waves, etc. The aerial operation detection sensor 1351 may be configured to detect coordinates on a two-dimensional plane by combining a plurality of sensors. The aerial operation detection sensor 1351 may be configured with a ToF (Time of Flight) LiDAR (Light Detection and Ranging) or an image sensor.

[0072] The mid-air operation detection sensor 1351 only needs to be capable of sensing to detect a touch operation or the like performed by a user with a finger on an object displayed as the floating-in-space image 3. Such sensing can be performed using existing technology.

[0073] The aerial operation detection unit 1350 acquires a sensing signal from the aerial operation detection sensor 1351, and performs operations such as determining whether or not the finger of the user 230 has touched an object in the floating in space image 3 and calculating the position (contact position) where the finger of the user 230 has touched the object based on the sensing signal. The aerial operation detection unit 1350 is configured with a circuit such as an FPGA (Field Programmable Gate Array). Some of the functions of the aerial operation detection unit 1350 may be realized by software using a spatial operation detection program executed by the control unit 1110, for example.

[0074] The aerial operation detection sensor 1351 and the aerial operation detection unit 1350 may be configured to be built into the space-floating image display device 1000, or may be provided externally separately from the space-floating image display device 1000. When provided separately from the space-floating image display device 1000, the aerial operation detection sensor 1351 and the aerial operation detection unit 1350 are configured to transmit information and signals to the space-floating image display device 1000 via a wired or wireless communication connection path or image signal transmission path.

[0075] Also, the aerial operation detection sensor 1351 and the aerial operation detection unit 1350 may be provided separately. This makes it possible to build a system in which the air-floating image display device 1000 without the aerial operation detection function is used as the main body, and only the aerial operation detection function can be added as an option. Also, a configuration in which only the aerial operation detection sensor 1351 is provided separately, and the aerial operation detection unit 1350 is built into the air-floating image display device 1000 may be used. In cases in which it is desired to more freely arrange the aerial operation detection sensor 1351 relative to the installation position of the air-floating image display device 1000, a configuration in which only the aerial operation detection sensor 1351 is provided separately is advantageous.

[0076] The imaging unit 1180 is a camera having an image sensor, and captures the space near the floating-in-space image 3 and / or the face, arms, fingers, etc. of the user 230. A plurality of imaging units 1180 may be provided. By using a plurality of imaging units 1180 or an imaging unit with a depth sensor, the mid-air operation detection unit 1350 can be assisted in the detection process of the touch operation of the floating-in-space image 3 by the user 230. The imaging unit 1180 may be provided separately from the floating-in-space image display device 1000. When the imaging unit 1180 is provided separately from the floating-in-space image display device 1000, it is sufficient to configure it so that an imaging signal can be transmitted to the floating-in-space image display device 1000 via a wired or wireless communication connection path or the like.

[0077] For example, if the aerial operation detection sensor 1351 is configured as an object intrusion sensor that detects whether or not an object has intruded into a plane (intrusion detection plane) including the display surface of the floating image 3, the aerial operation detection sensor 1351 may not be able to detect information such as how far an object (e.g., a user's finger) that has not intruded into the intrusion detection plane is from the intrusion detection plane, or how close the object is to the intrusion detection plane.

[0078] In such a case, the distance between the object and the intrusion detection plane can be calculated by using information such as object depth calculation information based on the captured images of the multiple imaging units 1180 and object depth information by the depth sensor. These pieces of information and various pieces of information such as the distance between the object and the intrusion detection plane are used for various display controls for the floating in space image 3.

[0079] Furthermore, without using the aerial operation detection sensor 1351, the aerial operation detection section 1350 may detect a touch operation on the floating-in-space image 3 by the user 230 based on the captured image by the imaging section 1180.

[0080] Also, the imaging unit 1180 may capture an image of the face of the user 230 operating the floating image 3, and the control unit 1110 may perform an identification process for the user 230. Furthermore, in order to determine whether or not a third person is standing around or behind the user 230 operating the floating image 3 and peeking at the operation of the user 230 on the floating image 3, the imaging unit 1180 may capture an image of a range including the user 230 operating the floating image 3 and the surrounding area of ​​the user 230.

[0081] The operation input unit 1107 is, for example, an operation button, a signal receiving unit such as a remote controller, or an infrared light receiving unit, and inputs a signal for an operation different from the air operation (touch operation) by the user 230. In addition to the above-mentioned user 230 who touches the space floating image 3, the operation input unit 1107 may be used by, for example, an administrator to operate the space floating image display device 1000.

[0082] The video signal input unit 1131 is connected to an external video output device and inputs video data. Various digital video input interfaces are possible for the video signal input unit 1131. For example, the video signal input unit 1131 may be configured with a video input interface conforming to the HDMI (registered trademark) (High-Definition Multimedia Interface) standard, a video input interface conforming to the DVI (Digital Visual Interface) standard, or a video input interface conforming to the DisplayPort standard.

[0083] Alternatively, an analog video input interface such as analog RGB or composite video may be provided. The audio signal input unit 1133 inputs audio data by connecting an external audio output device. The audio signal input unit 1133 may be configured with an audio input interface conforming to the HDMI standard, an optical digital terminal interface, a coaxial digital terminal interface, or the like. In the case of an interface conforming to the HDMI standard, the video signal input unit 1131 and the audio signal input unit 1133 may be configured as an interface in which a terminal and a cable are integrated. The audio output unit 1140 is capable of outputting audio based on the audio data input to the audio signal input unit 1133. The audio output unit 1140 may be configured with a speaker.

[0084] The audio output unit 1140 may output built-in operation sounds or error warning sounds. Alternatively, the audio output unit 1140 may be configured to output a digital signal to an external device, like the Audio Return Channel function defined in the HDMI standard. The microphone 1139 is a microphone that collects sounds around the space floating image display device 1000, converts them into signals, and generates audio signals. The microphone may record a person's voice, such as a user's voice, and the control unit 1110, which will be described later, may perform voice recognition processing on the generated audio signal to obtain text information from the audio signal.

[0085] The non-volatile memory 1108 stores various data used by the space-floating image display device 1000. The data stored in the non-volatile memory 1108 includes, for example, data for various operations to be displayed on the space-floating image 3, display icons, data of objects to be operated by user operations, layout information, etc. The memory 1109 stores image data to be displayed as the space-floating image 3, data for controlling the device, etc.

[0086] The control unit 1110 controls the operation of each unit connected to it. In addition, the control unit 1110 may perform calculation processing based on information obtained from each unit in the space floating image display device 1000 in cooperation with a program stored in the memory 1109.

[0087] The communication unit 1132 communicates with external devices, external servers, and the like via a wired or wireless communication interface. When the communication unit 1132 has a wired communication interface, the wired communication interface may be, for example, an Ethernet LAN interface. When the communication unit 1132 has a wireless communication interface, the communication unit 1132 may be, for example, a Wi-Fi communication interface, a Bluetooth communication interface, or a mobile communication interface such as 4G or 5G. Various data such as video data, image data, and audio data are transmitted and received by communication via the communication unit 1132.

[0088] The removable media interface 1134 is an interface for connecting a removable recording medium (removable media). The removable recording medium (removable media) may be composed of a semiconductor element memory such as a solid state drive (SSD), a magnetic recording medium recording device such as a hard disk drive (HDD), or an optical recording medium such as an optical disk. The removable media interface 1134 is capable of reading out various information such as various data such as video data, image data, and audio data recorded on the removable recording medium. The video data, image data, and the like recorded on the removable recording medium are output as a space floating image 3 via the video display unit 1102 and the retroreflection unit 1101.

[0089] The storage unit 1170 is a storage device that records various information such as various data such as video data, image data, and audio data. The storage unit 1170 may be configured with a magnetic recording medium recording device such as a hard disk drive (HDD) or a semiconductor element memory such as a solid state drive (SSD). For example, various information such as various data such as video data, image data, and audio data may be recorded in advance in the storage unit 1170 at the time of product shipment. In addition, the storage unit 1170 may record various information such as various data such as video data, image data, and audio data acquired from an external device, an external server, etc. via the communication unit 1132.

[0090] The video data, image data, etc. recorded in the storage unit 1170 are output as the space floating image 3 via the video display unit 1102 and the retroreflection unit 1101. The video data, image data, etc. of the display icons and objects for the user to operate, which are displayed as the space floating image 3, are also recorded in the storage unit 1170.

[0091] Layout information of display icons and objects displayed as the space floating image 3, various metadata information related to the objects, and the like are also recorded in the storage unit 1170. The audio data recorded in the storage unit 1170 is output as audio from the audio output unit 1140, for example.

[0092] The video control unit 1160 performs various controls related to the video signal input to the video display unit 1102. The video control unit 1160 may be called a video processing circuit, and may be configured with hardware such as an ASIC, an FPGA, or a video processor. The video control unit 1160 may also be called a video processing unit or an image processing unit. The video control unit 1160 performs control of video switching, such as determining which video signal to input to the video display unit 1102, between the video signal to be stored in the memory 1109 and the video signal (video data) input to the video signal input unit 1131, for example.

[0093] In addition, the image control unit 1160 may generate a superimposed image signal by superimposing the image signal to be stored in memory 1109 and the image signal input from the image signal input unit 1131, and input the superimposed image signal to the image display unit 1102, thereby performing control to form a composite image as a floating-in-space image 3.

[0094] Furthermore, the video control unit 1160 may control image processing of the video signal input from the video signal input unit 1131, the video signal to be stored in the memory 1109, etc. Examples of image processing include scaling processing for enlarging, reducing, transforming, etc. an image, brightness adjustment processing for changing the luminance, contrast adjustment processing for changing the contrast curve of the image, and Retinex processing for decomposing an image into light components and changing the weighting of each component.

[0095] Furthermore, the video control unit 1160 may perform special effect video processing or the like for assisting the aerial operation (touch operation) of the user 230 on the video signal input to the video display unit 1102. The special effect video processing is performed, for example, based on the detection result of the touch operation of the user 230 by the aerial operation detection unit 1350 or the captured image of the user 230 by the imaging unit 1180.

[0096] The attitude sensor 1113 is a sensor composed of a gravity sensor, an acceleration sensor, or a combination of these, and can detect the attitude in which the space-floating image display device 1000 is installed. Based on the attitude detection result of the attitude sensor 1113, the control unit 1110 may control the operation of each connected unit. For example, when an undesirable attitude as a user's usage state is detected, the control unit 1110 may perform control to stop displaying the image displayed by the image display unit 1102 and display an error message to the user. Alternatively, when the attitude sensor 1113 detects that the installation attitude of the space-floating image display device 1000 has changed, the control unit 1110 may perform control to rotate the display direction of the image displayed by the image display unit 1102.

[0097] As explained above, various functions are installed in the space-floating image display device 1000. However, the space-floating image display device 1000 does not need to have all of these functions, and can have any configuration as long as it has the function of forming the space-floating image 3.

[0098] <Example of the configuration of a space floating image display device> Next, a configuration example of the space-floating image display device will be described. The layout of the components of the space-floating image display device according to this embodiment can be various depending on the usage form. Each layout of Fig. 4A to Fig. 4M will be described below. In addition, in each example of Fig. 4A to Fig. 4M, the thick line surrounding the space-floating image display device 1000 shows an example of the housing structure of the space-floating image display device 1000.

[0099] FIG. 4A is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 shown in FIG. 4A is equipped with an optical system corresponding to the optical system of FIG. 2A. The space-floating image display device 1000 shown in FIG. 4A is installed horizontally so that the surface on which the space-floating image 3 is formed faces upward. That is, in FIG. 4A, the space-floating image display device 1000 has a transparent member 100 installed on the upper surface of the device. The space-floating image 3 is formed above the surface of the transparent member 100 of the space-floating image display device 1000. The light of the space-floating image 3 travels diagonally upward. When the mid-air operation detection sensor 1351 is provided as shown in the figure, it is possible to detect the operation of the space-floating image 3 by the finger of the user 230. Note that the x direction is the left-right direction as seen from the user, the y direction is the front-back direction (depth direction) as seen from the user, and the z direction is the up-down direction (vertical direction). Hereinafter, the definitions of the x-direction, y-direction, and z-direction are the same in each diagram of FIG. 4, so repeated explanation will be omitted.

[0100] FIG. 4B is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 shown in FIG. 4B is equipped with an optical system corresponding to the optical system of FIG. 2A. The space-floating image display device 1000 shown in FIG. 4B is installed vertically so that the surface on which the space-floating image 3 is formed faces the front of the space-floating image display device 1000 (the direction of the user 230). That is, in FIG. 4B, the space-floating image display device is installed with the transparent member 100 on the front side of the device (the direction of the user 230). The space-floating image 3 is formed on the user 230 side with respect to the surface of the transparent member 100 of the space-floating image display device 1000. The light of the space-floating image 3 travels in an oblique upward direction. When the midair operation detection sensor 1351 is provided as shown in the figure, it is possible to detect the operation of the space-floating image 3 by the finger of the user 230. 4B, the mid-air operation detection sensor 1351 can use the reflection of sensing light by the user's nail for touch detection by sensing the finger of the user 230 from above. Generally, the nail has a higher reflectivity than the pad of the finger, so that the accuracy of touch detection can be improved by configuring in this way.

[0101] FIG. 4C is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 shown in FIG. 4C is equipped with an optical system corresponding to the optical system of FIG. 2B. The space-floating image display device 1000 shown in FIG. 4C is installed horizontally so that the surface on which the space-floating image 3 is formed faces upward. That is, in FIG. 4C, the space-floating image display device 1000 has a transparent member 100 installed on the upper surface of the device. The space-floating image 3 is formed above the surface of the transparent member 100 of the space-floating image display device 1000. The light of the space-floating image 3 travels diagonally upward. When the mid-air operation detection sensor 1351 is provided as shown in the figure, it is possible to detect the operation of the space-floating image 3 by the finger of the user 230.

[0102] FIG. 4D is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 shown in FIG. 4D is equipped with an optical system corresponding to the optical system of FIG. 2B. The space-floating image display device 1000 shown in FIG. 4D is installed vertically so that the surface on which the space-floating image 3 is formed faces the front of the space-floating image display device 1000 (the direction of the user 230). That is, in FIG. 4D, the space-floating image display device 1000 is installed with the transparent member 100 on the front side of the device (the direction of the user 230). The space-floating image 3 is formed on the user 230 side with respect to the surface of the transparent member 100 of the space-floating image display device 1000. The light of the space-floating image 3 travels in an oblique upward direction. When the midair operation detection sensor 1351 is provided as shown in the figure, it is possible to detect the operation of the space-floating image 3 by the finger of the user 230. 4D, the mid-air operation detection sensor 1351 can use the reflection of sensing light by the user's nail for touch detection by sensing the finger of the user 230 from above. Generally, the nail has a higher reflectivity than the pad of the finger, so that the accuracy of touch detection can be improved by configuring in this way.

[0103] FIG. 4E is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 shown in FIG. 4E is equipped with an optical system corresponding to the optical system of FIG. 2C. The space-floating image display device 1000 shown in FIG. 4E is installed horizontally so that the surface on which the space-floating image 3 is formed faces upward. That is, in FIG. 4E, the space-floating image display device 1000 has a transparent member 100 installed on the upper surface of the device. The space-floating image 3 is formed above the surface of the transparent member 100 of the space-floating image display device 1000. The light of the space-floating image 3 travels directly upward. When the mid-air operation detection sensor 1351 is provided as shown in the figure, it is possible to detect the operation of the space-floating image 3 by the finger of the user 230.

[0104] FIG. 4F is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 shown in FIG. 4F is equipped with an optical system corresponding to the optical system of FIG. 2C. The space-floating image display device 1000 shown in FIG. 4F is installed vertically so that the surface on which the space-floating image 3 is formed faces the front of the space-floating image display device 1000 (the direction of the user 230). That is, in FIG. 4F, the space-floating image display device 1000 is installed with the transparent member 100 on the front side of the device (the direction of the user 230). The space-floating image 3 is formed on the user 230 side with respect to the surface of the transparent member 100 of the space-floating image display device 1000. The light of the space-floating image 3 travels toward the user. When the midair operation detection sensor 1351 is provided as shown in the figure, it is possible to detect the operation of the space-floating image 3 by the finger of the user 230.

[0105] FIG. 4G is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 shown in FIG. 4G is equipped with an optical system corresponding to the optical system of FIG. 2C. In the optical system of the space-floating image display device shown in FIG. 4A to FIG. 4F, the central optical path of the image light emitted from the display device 1 was on the yz plane. That is, in the optical system of the space-floating image display device shown in FIG. 4A to FIG. 4F, the image light traveled in the front-back direction and the up-down direction as seen from the user. In contrast, in the optical system of the space-floating image display device shown in FIG. 4G, the central optical path of the image light emitted from the display device 1 is on the xy plane. That is, in the optical system of the space-floating image display device shown in FIG. 4G, the image light travels in the left-right direction and the front-back direction as seen from the user. In the space-floating image display device 1000 shown in FIG. 4G, the surface on the side on which the space-floating image 3 is formed is installed so as to face the front of the device (the direction of the user 230). That is, in Fig. 4G, the space-floating image display device 1000 has the transparent member 100 installed on the front side of the device (toward the user 230). The space-floating image 3 is formed on the user side of the surface of the transparent member 100 of the space-floating image display device 1000. The light of the space-floating image 3 travels toward the user. If the mid-air operation detection sensor 1351 is provided as shown in the figure, it can detect the operation of the space-floating image 3 by the finger of the user 230.

[0106] FIG. 4H is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 of FIG. 4H is different from the space-floating image display device of FIG. 4G in that it has a window having a transparent plate 100B such as glass or plastic on the back side of the device (opposite the position where the user 230 views the space-floating image 3, i.e., opposite the traveling direction of the image light of the space-floating image 3 toward the user 230). The other configurations are the same as those of the space-floating image display device of FIG. 4G, so repeated explanations will be omitted. The space-floating image display device 1000 of FIG. 4H has a window having a transparent plate 100B at a position opposite the traveling direction of the image light of the space-floating image 3 with respect to the space-floating image 3. Therefore, when the user 230 views the space-floating image 3, the user 230 can recognize the scenery behind the space-floating image display device 1000 as the background of the space-floating image 3. Therefore, the user 230 can recognize the space floating image 3 as floating in the air in front of the scenery behind the space floating image display device 1000. This can further emphasize the feeling of floating in the air of the space floating image 3.

[0107] Depending on the polarization distribution of the image light output from the display device 1 and the performance of the polarization separation member 101B, a part of the image light output from the display device 1 may be reflected by the polarization separation member 101B and directed toward the transparent plate 100B. Depending on the coating performance of the surface of the transparent plate 100B, this light may be reflected again by the surface of the transparent plate 100B and may be visually recognized by the user as stray light. Therefore, in order to prevent this stray light, the transparent plate 100B may not be provided on the window on the back of the space floating image display device 1000.

[0108] Fig. 4I is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 in Fig. 4I is different from the space-floating image display device in Fig. 4H in that a light-shielding door 1410 is provided in the window of the transparent plate 100B arranged on the back of the device (opposite the position where the user 230 views the space-floating image 3). The other configurations are the same as those of the space-floating image display device in Fig. 4H, so repeated explanations will be omitted.

[0109] The opening and closing door 1410 of the space-floating image display device 1000 in FIG. 4I has, for example, a light-shielding plate, and is provided with a mechanism for moving (sliding) the light-shielding plate, a mechanism for rotating the light-shielding plate, or a mechanism for attaching and detaching the light-shielding plate, so that the window (rear window) of the transparent plate 100B located at the back side of the space-floating image display device 1000 can be switched between an open state and a light-shielding state. The movement (sliding) and rotation of the light-shielding plate by the opening and closing door 1410 may be electrically driven by a motor (not shown). The motor may be controlled by the control unit 1110 in FIG. 3. Note that, in the example of FIG. 4I, an example in which the opening and closing door 1410 has two light-shielding plates is disclosed. In contrast, the number of light-shielding plates of the opening and closing door 1410 may be one.

[0110] For example, when the scenery seen through the window of the transparent plate 100B of the space-floating image display device 1000 is outdoors, the brightness of sunlight varies depending on the weather. When the sunlight outdoors is strong, the background of the space-floating image 3 may become too bright, and the user 230 may experience a decrease in visibility of the space-floating image 3. In such a case, if the rear window is put into a light-shielding state by moving (sliding), rotating, or attaching the light-shielding plate of the opening and closing door 1410, the background of the space-floating image 3 becomes dark, and the visibility of the space-floating image 3 can be relatively improved. Such a shielding operation by the light-shielding plate of the opening and closing door 1410 may be directly performed by the force of the hand of the user 230. In response to an operation input via the operation input unit 1107 of FIG. 3, the control unit 1110 may control a motor (not shown) to perform a shielding operation by the light-shielding plate of the opening and closing door 1410.

[0111] In addition, an illuminance sensor may be provided on the rear side (opposite side of the user 230) of the space-floating image display device 1000, such as near the rear window, to measure the brightness of the space beyond the rear window. In this case, the control unit 1110 in FIG. 3 may control a motor (not shown) to perform the opening and closing operation of the light shielding plate of the opening and closing door 1410 according to the detection result of the illuminance sensor. By controlling the opening and closing operation of the light shielding plate of the opening and closing door 1410 in this way, it is possible to more suitably maintain the visibility of the space-floating image 3 even if the user 230 does not manually open and close the light shielding plate of the opening and closing door 1410.

[0112] Also, the light shielding plate by the opening and closing door 1410 may be manually detachable. Depending on the use purpose and installation environment of the space floating image display device 1000, the user can select whether the rear window is opened or shielded. If the rear window is to be used in a light shielded state for a long period of time, the removable light shielding plate may be fixed in the light shielded state. If the rear window is to be used in an open state for a long period of time, the removable light shielding plate may be removed. The light shielding plate may be attached and detached using a screw, a hook structure, or a fitting structure.

[0113] In the example of the space-floating image display device 1000 in FIG. 4I, depending on the polarization distribution of the image light output from the display device 1 and the performance of the polarization separation member 101B, a part of the image light output from the display device 1 may be reflected by the polarization separation member 101B and directed toward the transparent plate 100B. Depending on the coating performance of the surface of the transparent plate 100B, this light may be reflected again by the surface of the transparent plate 100B and may be visually recognized by the user as stray light. Therefore, in order to prevent the stray light, the window on the back of the space-floating image display device 1000 may be configured without providing the transparent plate 100B. The above-mentioned opening and closing door 1410 may be provided on the window that does not have the transparent plate 100B. In order to prevent the stray light, it is desirable that the surface of the light shielding plate of the above-mentioned opening and closing door 1410 on the inside of the housing has a coating or material with low light reflectance.

[0114] Fig. 4J is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 of Fig. 4J is different from the space-floating image display device of Fig. 4H in that an electronically controlled transmittance variable device 1620 is arranged on the rear side window instead of the transparent plate 100B made of glass or plastic. The other configurations are the same as those of the space-floating image display device of Fig. 4H, so repeated explanations will be omitted. An example of the electronically controlled transmittance variable device 1620 is a liquid crystal shutter.

[0115] That is, the liquid crystal shutter can control the transmitted light by controlling the voltage of the liquid crystal element sandwiched between two polarizing plates. Therefore, if the liquid crystal shutter is controlled to increase the transmittance, the scenery through the rear window can be seen through the background of the floating image 3. Also, if the liquid crystal shutter is controlled to increase the transmittance, the scenery through the rear window can be hidden as the background of the floating image 3. In addition, since the liquid crystal shutter can control the intermediate length, it can also be set to a state of transmittance of 50% or the like. For example, the control unit 1110 can control the transmittance of the electronically controlled transmittance variable device 1620 in response to an operation input via the operation input unit 1107 in Fig. 3. With this configuration, in cases where a view through the rear window is desired as the background of the floating image in space 3, but the view through the rear window as the background is too bright and reduces the visibility of the floating image in space 3, it is possible to adjust the transmittance of the electronically controlled transmittance variable device 1620 to adjust the visibility of the floating image in space 3.

[0116] In addition, an illuminance sensor may be provided on the back side (opposite side of the user 230) of the space floating image display device 1000, such as near the back window, to measure the brightness of the space beyond the back window. In this case, the control unit 1110 in Fig. 3 may control the transmittance of the electronically controlled transmittance variable device 1620 according to the detection result of the illuminance sensor. In this way, even if the user 230 does not perform an operation input via the operation input unit 1107 in Fig. 3, the transmittance of the electronically controlled transmittance variable device 1620 can be adjusted according to the brightness of the space beyond the back window, so that the visibility of the space floating image 3 can be more suitably maintained.

[0117] In the above example, a liquid crystal shutter has been described as an example of the electronically controlled transmittance variable device 1620. However, electronic paper may be used as another example of the electronically controlled transmittance variable device 1620. The same effect as described above can be obtained when electronic paper is used. Furthermore, electronic paper consumes very little power to maintain a halftone state. Therefore, a space floating image display device with low power consumption can be realized compared to the case where a liquid crystal shutter is used.

[0118] Fig. 4K is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 of Fig. 4K is different from the space-floating image display device of Fig. 4G in that it has a transmissive self-luminous image display device 1650 instead of the transparent member 100. The other configurations are the same as those of the space-floating image display device of Fig. 4G, so repeated explanations will be omitted.

[0119] In the space-floating image display device 1000 of FIG. 4K, after the image light flux passes through the display surface of the transmissive self-luminous image display device 1650, the space-floating image 3 is formed outside the space-floating image display device 1000. That is, when an image is displayed on the transmissive self-luminous image display device 1650, which is a two-dimensional flat display, the space-floating image 3 can be displayed as a pop-out image further in front of the image of the transmissive self-luminous image display device 1650. At this time, the user 230 can simultaneously view two images at different depth positions. The transmissive self-luminous image display device 1650 may be configured using existing technology such as a transmissive organic EL panel disclosed in, for example, JP 2014-216761 A. Note that the transmissive self-luminous image display device 1650 is not shown in FIG. 3, but may be configured to be connected to other processing units such as the control unit 1110 as one component of the space-floating image display device 1000 of FIG. 3.

[0120] Here, if both the background and an object such as a character are displayed on the transmissive self-luminous image display device 1650, and then only the object such as the character moves to the foreground floating image 3, a more effective surprise video experience can be provided to the user 230.

[0121] Also, if the inside of the space-floating image display device 1000 is kept in a light-shielding state, the background of the transparent self-luminous image display device 1650 becomes sufficiently dark. Therefore, when no image is displayed on the display device 1, or the light source of the display device 1 is turned off, and an image is displayed only on the transparent self-luminous image display device 1650, the transparent self-luminous image display device 1650 appears to the user 230 as a normal two-dimensional flat display, not a transparent display (since the space-floating image 3 in the embodiment of the present invention is displayed as a real optical image in a space without a screen, if the light source of the display device 1 is turned off, the intended display position of the space-floating image 3 becomes an empty space). Therefore, when the transparent self-luminous image display device 1650 is used to display an image as if it were a general two-dimensional flat display, characters, objects, etc. can be suddenly displayed in the air as the space-floating image 3, providing the user 230 with a more effective video experience with a surprise production.

[0122] In addition, the darker the inside of the space-floating image display device 1000, the more the transmissive self-luminous image display device 1650 looks like a two-dimensional flat display. Therefore, an absorptive polarizing plate (not shown) that transmits the polarized wave of the image light reflected by the polarization separation member 101B and absorbs the polarized wave that is 90 degrees out of phase with the polarized wave may be provided on the inner surface of the transmissive self-luminous image display device 1650 (the incident surface of the image light reflected by the polarization separation member 101B to the transmissive self-luminous image display device 1650, i.e., the surface of the transmissive self-luminous image display device 1650 opposite to the space-floating image 3). In this way, the effect on the image light that forms the space-floating image 3 is not so large, but the light that enters the inside of the space-floating image display device 1000 from the outside through the transmissive self-luminous image display device 1650 can be significantly reduced, and the inside of the space-floating image display device 1000 can be made darker, which is preferable.

[0123] FIG. 4L is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 of FIG. 4L is a modified example of the space-floating image display device of FIG. 4K. The orientation of the components in the space-floating image display device 1000 is different from that of the space-floating image display device of FIG. 4K, and is closer to the space-floating image display device of FIG. 4F. The functions and operations of each component are the same as those of the space-floating image display device of FIG. 4K, so repeated explanations will be omitted.

[0124] In the space-floating image display device of FIG. 4L as well, after a luminous flux of image light passes through the transmissive self-luminous image display device 1650, a space-floating image 3 is formed on the user 230 side of the transmissive self-luminous image display device 1650.

[0125] In both the example of the space-floating image display device in FIG. 4K and the example of the space-floating image display device in FIG. 4L, the space-floating image 3 is displayed superimposed on the image of the transmissive self-luminous image display device 1650 as seen by the user 230. Here, the position of the space-floating image 3 and the position of the image of the transmissive self-luminous image display device 1650 are configured to have a difference in the depth direction. Therefore, when the user moves his / her head (position of viewpoint), the user can recognize the depth of the two images due to parallax. Therefore, by displaying two images with different depth positions, a three-dimensional image experience can be more suitably provided to the user with the naked eye without the need for stereoscopic glasses or the like.

[0126] Fig. 4M is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 of Fig. 4M is provided with a second display device 1680 on the rear side of the polarization separation member 101B of the space-floating image display device of Fig. 4G as seen from the user. The other configurations are the same as those of the space-floating image display device of Fig. 4G, so repeated explanations will be omitted.

[0127] In the configuration example shown in FIG. 4M, the second display device 1680 is provided behind the display position of the space-floating image 3, and the image display surface faces the space-floating image 3. With this configuration, the image of the second display device 1680 and the space-floating image 3, which are displayed at two different depth positions, can be viewed as overlapping images from the user 230's perspective. In other words, the second display device 1680 is arranged in a direction to display an image toward the user 230 who views the space-floating image 3. Although the second display device 1680 is not shown in FIG. 3, it may be configured to be connected to other processing units such as the control unit 1110 as one component of the space-floating image display device 1000 of FIG. 3.

[0128] The image light of the second display device 1680 of the space floating image display device 1000 of FIG. 4M is visually recognized by the user 230 after passing through the polarization separation member 101B. Therefore, in order for the image light of the second display device 1680 to pass through the polarization separation member 101B more preferably, it is desirable that the image light output from the second display device 1680 is polarized in a vibration direction that the polarization separation member 101B more preferably transmits. That is, it is desirable that the image light is polarized in the same vibration direction as the polarization of the image light output from the display device 1. For example, when the image light output from the display device 1 is S-polarized light, it is desirable that the image light output from the second display device 1680 is also S-polarized light. Furthermore, when the image light output from the display device 1 is P-polarized light, it is desirable that the image light output from the second display device 1680 is also P-polarized light.

[0129] The example of the space-floating image display device of FIG. 4M also has the same effect as the example of the space-floating image display device of FIG. 4K and the example of the space-floating image display device of FIG. 4L in that the second image is displayed behind the space-floating image 3. However, unlike the example of the space-floating image display device of FIG. 4K and the example of the space-floating image display device of FIG. 4L, in the example of the space-floating image display device of FIG. 4M, the luminous flux of the image light for forming the space-floating image 3 does not pass through the second display device 1680. Therefore, the second display device 1680 does not need to be a transmissive self-luminous image display device, and may be a liquid crystal display that is a two-dimensional flat display. The second display device 1680 may be an organic EL display. Therefore, in the example of the space-floating image display device of FIG. 4M, it is possible to realize the space-floating image display device 1000 at a lower cost than the example of the space-floating image display device of FIG. 4K and the example of the space-floating image display device of FIG. 4L.

[0130] Here, depending on the polarization distribution of the image light output from the display device 1 and the performance of the polarization separation member 101B, a part of the image light output from the display device 1 may be reflected by the polarization separation member 101B and travel toward the second display device 1680. This light (a part of the image light) may be reflected again by the surface of the second display device 1680 and may be visually recognized by the user as stray light.

[0131] Therefore, in order to prevent the stray light, an absorptive polarizing plate may be provided on the surface of the second display device 1680. In this case, the absorptive polarizing plate may be an absorptive polarizing plate that transmits the polarized wave of the image light output from the second display device 1680 and absorbs the polarized wave that is 90° out of phase with the polarized wave of the image light output from the second display device 1680. If the second display device 1680 is a liquid crystal display, an absorptive polarizing plate is also present on the image output side inside the liquid crystal display. However, if there is a cover glass (cover glass on the image display surface side) on the output surface of the absorptive polarizing plate on the image output side inside the liquid crystal display, it is not possible to prevent stray light caused by reflection of the cover glass due to light from outside the liquid crystal display. Therefore, it is necessary to separately provide the above-mentioned absorptive polarizing plate on the surface of the cover glass.

[0132] When an image is displayed on the second display device 1680, which is a two-dimensional flat display, the floating-in-space image 3 can be displayed as an image in front of the image on the second display device 1680. In this case, the user 230 can simultaneously view two images with different depth positions. By displaying a character on the floating-in-space image 3 and displaying a background on the second display device 1680, it is possible to provide an effect in which the user 230 is stereoscopically viewing the space in which the character exists.

[0133] Furthermore, if both the background and an object such as a character are displayed on the second display device 1680, and then only the object such as the character moves to the foreground floating image 3, it is possible to provide the user 230 with a more effective surprise visual experience.

[0134] Next, Fig. 4N is a diagram showing an example of the configuration of a space-floating image display device. The space-floating image display device 1000 in Fig. 4N is a space-floating image display device that employs the optical system in Fig. 2D. As in the example of the space-floating image display device that employs the optical system in Figs. 2A to 2C, an image is formed in the air as a space-floating image 3 by image light that has passed through a transparent member 100. In addition, the operation of the space-floating image 3 by the user's finger 9004 can be detected using the sensing light of the mid-air operation detection sensor 1351 arranged on the back side of the transparent member 100 as seen from the user.

[0135] In both the example of the space-floating image display device employing the optical system of Figures 2A to 2C and the example of the space-floating image display device employing the optical system of Figure 2D, the space-floating image 3 is imaged in front of the transparent member 100, and the operation of the space-floating image 3 by the user's finger can be detected using the sensing light of the aerial operation detection sensor 1351 arranged on the back side of the transparent member 100 as seen from the user. Therefore, the space-floating image display device employing the optical system of Figure 2D has a different optical system from the space-floating image display device in which the optical system of Figures 2A to 2C is arranged on the back side of the transparent member 100 as seen from the user.

[0136] However, from the user's perspective, the usability of the space-floating image display device employing the optical system of FIG. 2D is almost the same as that of the space-floating image display device employing the optical system of FIGS. 2A to 2C.

[0137] Next, Fig. 4O is a diagram showing an example of the configuration of a space-floating image display device. Fig. 4O is a diagram showing the configuration of the internal optical system in the space-floating image display device 1000 of Fig. 4N. The space-floating image display device 1000 shown in Fig. 4O is equipped with an optical system corresponding to the optical system of Fig. 2D. The space-floating image display device 1000 shown in Fig. 4O is installed horizontally so that the surface on which the space-floating image 3 is formed faces upward.

[0138] That is, in Fig. 4O, the space-floating image display device 1000 has a transparent member 100 installed on the top surface of the device. The space-floating image 3 is formed above the surface of the transparent member 100 of the space-floating image display device 1000. The light of the space-floating image 3 travels diagonally upward. When the mid-air operation detection sensor 1351 is provided as shown in the figure, it can detect the operation of the space-floating image 3 by the finger of the user 230.

[0139] Here, the configuration of Fig. 4O is compared with the configuration of Fig. 4A to confirm the differences. In Fig. 4A, the display device 1 and the space-floating image 3 are in a plane-symmetrical relationship with respect to the plane of the polarization separation member 101. In contrast, in Fig. 4O, the display device 1 and the space-floating image 3 are in a plane-symmetrical relationship with respect to the plane of the retroreflector 5. Also, the configuration of Fig. 4A includes the retroreflector 2 and the λ / 4 plate 21, but these do not exist in Fig. 4O. Also, while it would be more preferable to include the absorbing polarizer 12 in Fig. 4A, the absorbing polarizer 12 is not particularly necessary in Fig. 4O.

[0140] That is, in order to replace the optical system of FIG. 2A in the configuration of FIG. 4A with the optical system of FIG. 2D and replace it with the configuration of FIG. 4O, the following can be done. That is, the polarization separation member 101 in the configuration of FIG. 4A can be replaced with the retroreflector 5, and the retroreflector 2 and the λ / 4 plate 21 can be removed from the configuration of FIG. 4A. The absorptive polarizer 12 can be omitted. If a replacement is made based on this idea, the optical system of FIG. 2A to FIG. 2C mounted on the configuration of the space floating image display device of FIG. 4A to FIG. 4G can be replaced with the optical system of FIG. 2D, and the space floating image display device mounted with the optical system of FIG. 2D can be replaced. At this time, the polarization separation member 101 can be replaced with the retroreflector 5 in FIG. 4A and FIG. 4B, and the polarization separation member 101B can be replaced with the retroreflector 5 in FIG. 4C to FIG. 4G.

[0141] In this way, a space-floating image display device can be realized in which the optical system in the configuration of the space-floating image display device in Figures 4A to 4G is replaced with the optical system in Figure 2D. Even in the space-floating image display device in which the optical system in Figure 2D is replaced, a space-floating image display device with almost the same usability as the space-floating image display device in Figures 4A to 4G can be realized.

[0142] <Display device> Next, the display device 1 of this embodiment will be described with reference to the drawings. The display device 1 of this embodiment includes an image display element 11 (liquid crystal display panel) and a light source device 13 that constitutes the light source thereof, and FIG. 5 shows the light source device 13 together with the liquid crystal display panel as an exploded perspective view.

[0143] As shown by the arrow 30 in Fig. 5, this liquid crystal display panel (image display element 11) receives an illumination light beam from a light source device 13, which is a backlight device, that has narrow-angle diffusion characteristics, i.e., has strong directivity (straightness) and characteristics similar to laser light with a polarization plane aligned in one direction. The liquid crystal display panel (image display element 11) modulates the received illumination light beam in accordance with an input video signal. The modulated image light is reflected by the retroreflector 2 and passes through a transparent member 100 to form a real image, which is a floating image in space (see Fig. 1).

[0144] In addition, in FIG. 5, the display device 1 is configured to include a liquid crystal display panel 11, a light direction conversion panel 54 that controls the directional characteristics of the light beam emitted from the light source device 13, and a narrow-angle diffusion plate (not shown) as necessary. That is, polarizing plates are provided on both sides of the liquid crystal display panel 11, and image light of a specific polarized wave is modulated in intensity by a video signal and emitted (see arrow 30 in FIG. 5). As a result, a desired image is projected as light of a specific polarized wave with high directivity (linearity) through the light direction conversion panel 54 toward the retroreflector 2, and after reflection by the retroreflector 2, it is transmitted toward the eyes of a monitor outside the store (space) to form a space-floating image 3. A protective cover 50 (see FIGS. 6 and 7) may be provided on the surface of the light direction conversion panel 54 described above.

[0145] <Display device example 1> FIG. 6 shows an example of a specific configuration of the display device 1. In FIG. 6, a liquid crystal display panel 11 and a light direction conversion panel 54 are arranged on the light source device 13 of FIG. 5. The light source device 13 is formed, for example, of plastic on the case shown in FIG. 5, and is configured by storing an LED element 201 and a light guide 203 inside. As shown in FIG. 5 and other figures, the end surface of the light guide 203 has a shape in which the cross-sectional area gradually increases toward the opposite side to the light receiving part in order to convert the divergent light from each LED element 201 into a substantially parallel light beam, and is provided with a lens shape that has an effect of gradually decreasing the divergence angle by multiple total reflections during propagation inside. The liquid crystal display panel 11 constituting the display device 1 is attached to the upper surface of the display device 1. In addition, an LED (Light Emitting Diode) element 201, which is a semiconductor light source, and an LED board 202 on which a control circuit for the LED element 201 is mounted are attached to one side surface of the case of the light source device 13 (the left end surface in this example). A heat sink, which is a member for cooling the heat generated by the LED elements and the control circuit, may be attached to the outer surface of the LED substrate 202.

[0146] In addition, the liquid crystal display panel frame (not shown) attached to the upper surface of the case of the light source device 13 is configured by attaching the liquid crystal display panel 11 attached to the frame, and further by attaching an FPC (Flexible Printed Circuits) (not shown) electrically connected to the liquid crystal display panel 11. That is, the liquid crystal display panel 11, which is an image display element, generates a display image by modulating the intensity of transmitted light based on a control signal from a control circuit (image control unit 1160 in FIG. 3) constituting an electronic device together with the LED element 201, which is a solid light source. At this time, the generated image light has a narrow diffusion angle and contains only specific polarization components, so that a new image display device that is similar to a surface-emitting laser image source driven by an image signal can be obtained. Note that, at present, it is technically and safety impossible to obtain a laser light beam of the same size as the image obtained by the above-mentioned display device 1 using a laser device. Therefore, in this embodiment, light similar to the above-mentioned surface-emitting laser image light is obtained from a light beam from a general light source equipped with an LED element, for example.

[0147] Next, the configuration of the optical system housed in the case of light source device 13 will be described in detail with reference to FIG. 7 together with FIG.

[0148] 6 and 7 are cross-sectional views, and only one of the LED elements 201 constituting the light source is shown, and this is converted into approximately collimated light by the shape of the light-receiving end surface 203a of the light guide 203. For this reason, the light-receiving part of the end surface of the light guide and the LED element are attached while maintaining a predetermined positional relationship.

[0149] Each of the light guides 203 is formed of a light-transmitting resin such as acrylic. The LED light receiving surface at the end of the light guide 203 has a cone-shaped outer circumferential surface obtained by rotating a parabolic cross section, and at the top of the light guide 203, a concave portion having a convex portion (i.e., a convex lens surface) formed in the center is formed, and at the center of the flat portion, a convex lens surface protruding outward (or a concave lens surface recessed inward) is formed (not shown). The outer shape of the light receiving portion of the light guide to which the LED element 201 is attached is a parabolic shape forming a cone-shaped outer circumferential surface, and is set within an angle range in which the light emitted from the LED element in the peripheral direction can be totally reflected inside the parabolic shape, or a reflective surface is formed.

[0150] On the other hand, the LED elements 201 are arranged at predetermined positions on the surface of the circuit board, that is, the LED substrate 202. The LED substrate 202 is arranged and fixed such that the LED elements 201 on the surface are positioned in the center of the recessed portion described above with respect to the LED collimator (light-receiving end surface 203a).

[0151] According to this configuration, the shape of light-receiving end surface 203a of light guide 203 makes it possible to extract the light emitted from LED element 201 as substantially parallel light, thereby improving the efficiency of use of the generated light.

[0152] As described above, the light source device 13 is configured by mounting a light source unit in which a plurality of LED elements 201 serving as light sources are arranged on the light receiving end surface 203a serving as a light receiving section provided on the end surface of the light guide 203, and the divergent light beam from the LED elements 201 is converted into substantially parallel light by the lens shape of the light receiving end surface 203a of the light guide end surface, and the light is guided inside the light guide 203 (in a direction parallel to the drawing) as shown by the arrow, and is emitted by the light beam direction conversion means 204 toward the liquid crystal display panel 11 arranged substantially parallel to the light guide 203 (in a direction perpendicular to the front side of the drawing). The uniformity of the light beam incident on the liquid crystal display panel 11 can be controlled by optimizing the distribution (density) of the light beam direction conversion means 204 depending on the shape of the inside or surface of the light guide.

[0153] The light beam direction conversion means 204 described above emits the light beam propagated inside the light guide toward the liquid crystal display panel 11 arranged substantially parallel to the light guide 203 (in a direction perpendicular to the front of the drawing) by changing the shape of the light guide surface or by providing, for example, a portion with a different refractive index inside the light guide. At this time, when the brightness of the screen center and the screen periphery are compared while facing the liquid crystal display panel 11 directly at the center of the screen and placing the viewpoint at the same position as the diagonal dimension of the screen, if the relative brightness ratio is 20% or more, there is no practical problem, and if it exceeds 30%, it is an even better characteristic.

[0154] 6 is a cross-sectional layout diagram for explaining the configuration and operation of a light source of this embodiment that performs polarization conversion in light source device 13 including the above-mentioned light guide 203 and LED element 201. In Fig. 6, light source device 13 is composed of light guide 203 formed of, for example, plastic or the like and provided with light beam direction conversion means 204 on its surface or inside, LED element 201 as a light source, reflective sheet 205, retardation plate 206, lenticular lens, etc., and on the upper surface thereof is attached liquid crystal display panel 11 equipped with polarizing plates on the light source light entrance surface and image light exit surface.

[0155] A film or sheet-like reflective polarizing plate 49 is provided on the light source light incidence surface (lower surface in the figure) of the liquid crystal display panel 11 corresponding to the light source device 13, and selectively reflects one side of the polarized wave (e.g. P wave) 212 of the natural light beam 210 emitted from the LED element 201. The reflected light is reflected again by a reflecting sheet 205 provided on one surface (lower surface in the figure) of the light guide 203, and directed toward the liquid crystal display panel 11. Therefore, a retardation plate (λ / 4 plate) is provided between the reflecting sheet 205 and the light guide 203 or between the light guide 203 and the reflective polarizing plate 49, and the reflected light beam is reflected by the reflecting sheet 205 and passes through twice to convert the reflected light beam from P polarized light to S polarized light, improving the utilization efficiency of the light source light as image light. The image light beam, the light intensity of which is modulated by the image signal in the liquid crystal display panel 11 (arrow 213 in FIG. 6), enters the retroreflector 2. After reflection by the retroreflector 2, a real image, a floating image in space, can be obtained.

[0156] Fig. 7 is a cross-sectional layout diagram for explaining the configuration and action of a light source of this embodiment that performs polarization conversion in light source device 13 including light guide 203 and LED element 201, similar to Fig. 6. Light source device 13 is also similarly composed of light guide 203 formed of, for example, plastic, on the surface or inside of which light flux direction conversion means 204 is provided, LED element 201 as a light source, reflection sheet 205, retardation plate 206, lenticular lens, etc. On the upper surface of light source device 13, liquid crystal display panel 11 having polarizing plates on the light source light entrance surface and the image light exit surface is attached as an image display element.

[0157] A film or sheet-like reflective polarizing plate 49 is provided on the light source light incidence surface (lower surface in the figure) of the liquid crystal display panel 11 corresponding to the light source device 13, and selectively reflects one side of the polarized wave (e.g., S wave) 211 of the natural light beam 210 emitted from the LED element 201. That is, in the example of FIG. 7, the selective reflection characteristic of the reflective polarizing plate 49 is different from that of FIG. 7. The reflected light is reflected by the reflective sheet 205 provided on one surface (lower surface in the figure) of the light guide 203, and again heads toward the liquid crystal display panel 11. A retardation plate (λ / 4 plate) is provided between the reflective sheet 205 and the light guide 203 or between the light guide 203 and the reflective polarizing plate 49, and the reflected light beam is reflected by the reflective sheet 205 and passes through it twice, thereby converting the reflected light beam from S polarized light to P polarized light, and improving the utilization efficiency of the light source light as image light. The image light beam intensity-modulated by the image signal in the liquid crystal display panel 11 (arrow 214 in FIG. 7) enters the retroreflector 2. After reflection by the retroreflector 2, a real image, a floating image in space, can be obtained.

[0158] In the light source devices shown in Figures 6 and 7, in addition to the action of the polarizing plate provided on the light incidence surface of the corresponding liquid crystal display panel 11, the polarized component on one side is reflected by the reflective polarizing plate, so that the theoretically obtainable contrast ratio is the reciprocal of the cross transmittance of the reflective polarizing plate multiplied by the reciprocal of the cross transmittance obtained by the two polarizing plates attached to the liquid crystal display panel. This results in high contrast performance. In fact, it was confirmed by experiments that the contrast performance of the displayed image was improved by more than 10 times. As a result, a high-quality image comparable to that of a self-luminous organic EL was obtained.

[0159] <Display device example 2> 8 shows another example of a specific configuration of the display device 1. This light source device 13 is configured by housing LEDs, a collimator, a composite diffusion block, a light guide, etc., in a case made of, for example, plastic, and has a liquid crystal display panel 11 attached to its upper surface. LED (Light Emitting Diode) elements 14a and 14b, which are semiconductor light sources, and an LED board mounting a control circuit for the LED elements are attached to one side of the case of the light source device 13, and a heat sink 103, which is a member for cooling heat generated by the LED elements and the control circuit, is attached to the outer side of the LED board.

[0160] The liquid crystal display panel frame attached to the top surface of the case is configured to have the liquid crystal display panel 11 attached to the frame, and further, an FPC (Flexible Printed Circuits) 403 electrically connected to the liquid crystal display panel 11, etc. attached to it. That is, the liquid crystal display panel 11, which is a liquid crystal display element, generates a display image by modulating the intensity of transmitted light together with the LED elements 14a and 14b, which are solid-state light sources, based on a control signal from a control circuit (not shown here) that constitutes the electronic device.

[0161] <Display device example 3> Next, another example of the specific configuration of the display device 1 (Example 3 of the display device) will be described with reference to Fig. 9. The light source device of this display device 1 converts the divergent light flux of the light (a mixture of P-polarized light and S-polarized light) from the LED into a substantially parallel light flux by the collimator 18, and reflects the light toward the liquid crystal display panel 11 by the reflecting surface of the reflective light guide 304. The reflected light is incident on the reflective polarizing plate 49 disposed between the liquid crystal display panel 11 and the reflective light guide 304. The reflective polarizing plate 49 transmits light of a specific polarized wave (e.g., P-polarized light) and causes the transmitted polarized light to be incident on the liquid crystal display panel 11. Here, polarized waves other than the specific polarized wave (e.g., S-polarized light) are reflected by the reflective polarizing plate 49 and head toward the reflective light guide 304 again.

[0162] The reflective polarizing plate 49 is disposed at an angle with respect to the liquid crystal display panel 11 so as not to be perpendicular to the principal ray of the light from the reflecting surface of the reflective light guide 304. The principal ray of the light reflected by the reflective polarizing plate 49 is incident on the transmitting surface of the reflective light guide 304. The light incident on the transmitting surface of the reflective light guide 304 is transmitted through the rear surface of the reflective light guide 304, transmitted through the λ / 4 plate 270 which is a retardation plate, and reflected by the reflecting plate 271. The light reflected by the reflecting plate 271 is transmitted through the λ / 4 plate 270 again, and transmitted through the transmitting surface of the reflective light guide 304. The light transmitted through the transmitting surface of the reflective light guide 304 is incident on the reflective polarizing plate 49 again.

[0163] At this time, the light re-entering the reflective polarizing plate 49 has passed through the λ / 4 plate 270 twice, and therefore its polarization has been converted to a polarized wave (for example, P-polarized light) that is transmitted through the reflective polarizing plate 49. Therefore, the light whose polarization has been converted is transmitted through the reflective polarizing plate 49 and enters the liquid crystal display panel 11. Note that, with regard to the polarization design related to the polarization conversion, the polarization may be configured inversely from the above explanation (S-polarized light and P-polarized light may be reversed).

[0164] As a result, the light from the LED is aligned to a specific polarization (e.g., P polarization), enters the liquid crystal display panel 11, and is brightness-modulated according to the video signal to display an image on the panel surface. As in the above example, multiple LEDs that make up the light source are shown (however, because this is a vertical cross section, only one is shown in FIG. 9), and these are attached at predetermined positions relative to the collimator 18.

[0165] The collimators 18 are each formed of, for example, a light-transmitting resin such as acrylic or glass. The collimators 18 may have a cone-shaped outer peripheral surface obtained by rotating a parabolic cross section. The collimators 18 may have a concave portion with a convex portion (i.e., a convex lens surface) formed in the center of the apex (the side facing the LED substrate 102). The collimators 18 have a convex lens surface protruding outward (or a concave lens surface recessed inward) in the center of the flat surface (the side opposite to the apex). The parabolic surface forming the cone-shaped outer peripheral surface of the collimators 18 is set within an angle range that allows the light emitted from the LED in the peripheral direction to be totally reflected therein, or a reflective surface is formed.

[0166] The LEDs are arranged at predetermined positions on the surface of the circuit board, that is, the LED board 102. The LED board 102 is arranged and fixed to the collimator 18 so that the LEDs on the surface are located at the center of the apex of the convex cone shape (or in the concave portion if the apex has a concave portion).

[0167] According to this configuration, among the light emitted from the LED by the collimator 18, the light emitted from the central part is condensed into parallel light by the convex lens surface forming the outer shape of the collimator 18. The light emitted from the other parts toward the periphery is reflected by the parabolic surface forming the outer peripheral surface of the cone shape of the collimator 18, and is condensed into parallel light in the same manner. In other words, according to the collimator 18 having a convex lens in its center and a parabolic surface formed on its periphery, it is possible to extract almost all of the light generated by the LED as parallel light, and it is possible to improve the utilization efficiency of the generated light.

[0168] Furthermore, the light converted into approximately parallel light by the collimator 18 shown in FIG. 9 is reflected by the reflective light guide 304. The light of a specific polarized wave is transmitted through the reflective polarizing plate 49 by the action of the reflective polarizing plate 49, and the light of the other polarized wave reflected by the action of the reflective polarizing plate 49 is transmitted through the light guide 304 again. The light is reflected by the reflector 271 located opposite the liquid crystal display panel 11 with respect to the reflective light guide 304. At this time, the light is polarized and converted by passing twice through the λ / 4 plate 270, which is a retardation plate. The light reflected by the reflector 271 is transmitted through the light guide 304 again and enters the reflective polarizing plate 49 provided on the opposite surface. Since the incident light has been polarized and converted, it is transmitted through the reflective polarizing plate 49 and enters the liquid crystal display panel 11 with the same polarization direction. As a result, all the light from the light source can be used, and the geometrical optical utilization efficiency of light is doubled. In addition, since the degree of polarization (extinction ratio) of the reflective polarizer is also included in the extinction ratio of the entire system, the use of the light source device of this embodiment significantly improves the contrast ratio of the entire display device. By adjusting the surface roughness of the reflective surface of the reflective light guide 304 and the surface roughness of the reflector 271, the reflection diffusion angle of light at each reflective surface can be adjusted. The surface roughness of the reflective surface of the reflective light guide 304 and the surface roughness of the reflector 271 can be adjusted for each design so that the uniformity of the light incident on the liquid crystal display panel 11 is more suitable.

[0169] It should be noted that the λ / 4 plate 270, which is the retardation plate in Fig. 9, does not necessarily have to have a phase difference of λ / 4 with respect to polarized light that is perpendicularly incident on the λ / 4 plate 270. In the configuration of Fig. 9, any retardation plate may be used as long as the phase changes by 90° (λ / 2) when polarized light passes through it twice. The thickness of the retardation plate may be adjusted according to the incidence angle distribution of the polarized light.

[0170] <Display device example 4> Furthermore, another example (display example 4) of the configuration of the optical system such as the light source device of the display device will be described with reference to Fig. 10. This is a configuration example in which a diffusion sheet is used instead of the reflective light guide 304 in the light source device of display example 3. Specifically, two optical sheets (optical sheet 207A and optical sheet 207B) that convert the diffusion characteristics in the vertical and horizontal directions (front and back directions not shown in the figure) of the drawing are used on the light emission side of the collimator 18, and the light from the collimator 18 is made to enter between the two optical sheets (diffusion sheets).

[0171] The optical sheet may be one sheet instead of two sheets. In the case of one sheet, the vertical and horizontal diffusion characteristics are adjusted by the fine shape of the front and back surfaces of the single optical sheet. In addition, a plurality of diffusion sheets may be used to share the functions. Here, in the example of FIG. 10, the reflection diffusion characteristics due to the front and back shapes of the optical sheets 207A and 207B may be optimally designed with the number of LEDs, the divergence angle from the LED substrate (optical element) 102, and the optical specifications of the collimator 18 as design parameters so that the surface density of the light beam emitted from the liquid crystal display panel 11 is uniform. In other words, the diffusion characteristics are adjusted by the surface shapes of a plurality of diffusion sheets instead of the light guide.

[0172] In the example of FIG. 10, the polarization conversion is performed in the same manner as in the display device example 3 described above. That is, in the example of FIG. 10, the reflective polarizing plate 49 may be configured to have a property of reflecting S-polarized light (transmitting P-polarized light). In this case, the reflective polarizing plate 49 transmits P-polarized light out of the light emitted from the LED light source, and the transmitted light enters the liquid crystal display panel 11. The reflective polarizing plate 49 reflects S-polarized light out of the light emitted from the LED light source, and the reflected light passes through the retardation plate 270 shown in FIG. 10. The light that passes through the retardation plate 270 is reflected by the reflector 271. The light reflected by the reflector 271 passes through the retardation plate 270 again and is converted to P-polarized light. The polarization-converted light passes through the reflective polarizing plate 49 and enters the liquid crystal display panel 11.

[0173] It should be noted that the λ / 4 plate 270, which is the retardation plate in Fig. 10, does not necessarily have to have a phase difference of λ / 4 with respect to polarized light perpendicularly incident on the λ / 4 plate 270. In the configuration of Fig. 10, any retardation plate may be used in which the phase changes by 90° (λ / 2) when polarized light passes through it twice. The thickness of the retardation plate may be adjusted according to the distribution of the incident angles of the polarized light. It should be noted that, in Fig. 10 as well, the polarization design related to the polarization conversion may be configured in reverse (reversing the S-polarized light and the P-polarized light) based on the above explanation.

[0174] In a device for general TV use, the light emitted from the liquid crystal display panel 11 has similar diffusion characteristics in both the horizontal direction of the screen (shown by the X-axis in FIG. 12(a)) and the vertical direction of the screen (shown by the Y-axis in FIG. 12(b)). In contrast, the diffusion characteristics of the light flux emitted from the liquid crystal display panel of this embodiment are 1 / 5 of the 62 degrees of a device for general TV use, when the viewing angle at which the luminance is 50% of that when viewed from the front (angle 0 degrees) is set to 13 degrees, as shown in Example 1 of FIG. 12. Similarly, the vertical viewing angle is optimized by optimizing the reflection angle of the reflective light guide and the area of ​​the reflection surface so that the viewing angle on the upper side is unequal between the top and bottom and is kept to about 1 / 3 of the viewing angle on the lower side. As a result, the amount of image light heading in the monitoring direction is significantly improved compared to conventional liquid crystal TVs, and the luminance is 50 times or more higher.

[0175] Furthermore, assuming the viewing angle characteristics shown in Example 2 in Figure 12, the viewing angle at which the brightness is 50% of that when viewed from the front (angle 0 degrees) is set to 5 degrees, which is 1 / 12 of the 62 degrees of devices used for general TV applications. Similarly, the vertical viewing angle is optimized by optimizing the reflection angle of the reflective light guide and the area of ​​the reflective surface so that the viewing angle is approximately 1 / 12 of that of devices used for general TV applications, with equal viewing angles both above and below. As a result, the amount of image light heading in the monitoring direction is significantly improved compared to conventional LCD TVs, and the brightness is more than 100 times higher.

[0176] As described above, by setting the viewing angle to a narrow angle, the amount of luminous flux heading in the monitoring direction can be concentrated, greatly improving the efficiency of light utilization. As a result, even if a liquid crystal display panel for general TV applications is used, by controlling the light diffusion characteristics of the light source device, it is possible to achieve a significant improvement in brightness with similar power consumption, making it possible to create an image display device that is compatible with information display systems facing bright outdoors.

[0177] When using a large LCD panel, the overall brightness of the screen can be improved by directing the light around the screen inward so that it is directed toward the observer when the observer faces the center of the screen. Figure 11 shows the convergence angle of the long and short sides of the panel when the observer's distance from the panel L and the panel size (screen ratio 16:10) are used as parameters. When monitoring with the screen vertically long, the convergence angle can be set according to the short side. For example, when using a 22-inch panel vertically and the monitoring distance is 0.8 m, a convergence angle of 10 degrees will allow the image light from the four corners of the screen to be effectively directed toward the observer.

[0178] Similarly, when monitoring with a 15-inch panel in portrait orientation and a monitoring distance of 0.8 m, a convergence angle of 7 degrees will allow the image light from the four corners of the screen to be effectively directed toward the observer. As described above, depending on the size of the LCD panel and whether it is used portrait or landscape, the overall brightness of the screen can be improved by directing the image light from the periphery of the screen toward the observer who is in the optimal position to monitor the center of the screen.

[0179] The basic configuration, as shown in FIG. 9, is that a light beam with a narrow-angle directional characteristic is incident on a liquid crystal display panel 11 from a light source device, and the brightness is modulated according to a video signal, so that the video information displayed on the screen of the liquid crystal display panel 11 is reflected by a retroreflector, and the resulting floating-in-space image is displayed indoors or outdoors via a transparent member 100.

[0180] By using the display device and light source device according to one embodiment of the present invention described above, it is possible to realize a space floating image display device with higher light utilization efficiency.

[0181] <Example of image display processing in a space floating image display device> Next, an example of a problem solved by the image processing of this embodiment will be described with reference to Fig. 13A. In the space-floating image display device 1000, when the back side of the space-floating image 3 from the user's perspective is inside the housing of the space-floating image display device 1000 and is sufficiently dark, the user visually recognizes that the background of the space-floating image 3 is black.

[0182] Here, an example of displaying a character "panda" 1525 in the space floating image 3 will be described with reference to Fig. 13A. First, the image control unit 1160 in Fig. 3 distinguishes and recognizes the pixel area in which the image of the character "panda" 1525 is drawn from the transparent information area 1520 which is the background image, for an image including the pixel area in which the image of the character "panda" 1525 is drawn and the transparent information area 1520 which is the background image, as shown in Fig. 13A(1).

[0183] A method for distinguishing and recognizing a character image from a background image may, for example, be configured so that the image processing of the video control unit 1160 can process the background image layer and the layer of a character image in front of the background image layer as separate layers, and the character image and background image can be distinguished and recognized based on the overlay relationship when these layers are combined.

[0184] Here, the image control unit 1160 recognizes black pixels that draw objects such as character images and transparent information pixels as different information. However, it is assumed that the brightness of both the black pixels that draw objects and the transparent information pixels is 0. In this case, when the space floating image 3 is displayed, there is no difference in brightness between the pixels that draw black in the image of the character "panda" 1525 and the pixels of the transparent information area 1520, which is the background image. Therefore, in the space floating image 3, as shown in FIG. 13A(2), there is no brightness in either the pixels that draw black in the image of the character "panda" 1525 and the pixels of the transparent information area 1520, and they are visually recognized by the user as optically the same black space. In other words, the part that draws black in the image of the character "panda" 1525, which is an object, blends into the background, and only the non-black part of the character "panda" 1525 is recognized as an image floating in the display area of ​​the space floating image 3.

[0185] An example of image processing of this embodiment will be described with reference to FIG. 13B. FIG. 13B is a diagram for explaining an example of image processing that more suitably solves the problem that the black image area of ​​the object blends into the background, as described in FIG. 13A. In FIG. 13B(1) and (2), the upper side shows the display state of the floating in space image 3, and the lower side shows the input / output characteristics of the image processing of the image of the object. Note that the image of the object (character "panda" 1525) and the corresponding data may be read from the storage unit 1170 or memory 1109 in FIG. 3. Alternatively, they may be input from the image signal input unit 1131. Alternatively, they may be acquired via the communication unit 1132.

[0186] Here, in the state of Fig. 13B(1), the input / output characteristics of the image processing of the image of the object are in a linear state with no particular adjustment. In this case, the display state is the same as that of Fig. 13A(2), and the black image area of ​​the object blends into the background. In contrast, in Fig. 13B(2), the video control unit 1160 of this embodiment adjusts the input / output characteristics of the image processing of the image of the object (character "panda" 1525) to the input / output characteristics shown in the lower part.

[0187] That is, the video control unit 1160 performs image processing of input / output characteristics on the image of the object (character "panda" 1525) that has a characteristic of converting the pixels of the input image into output pixels with increased luminance values ​​of pixels in low luminance areas. After the image of the object (character "panda" 1525) is subjected to the image processing of the input / output characteristics, a video including the image of the object (character "panda" 1525) is input to the display device 1 and displayed. Then, as shown in the upper part of FIG. 13B(2), the display state of the floating in space video 3 is such that the luminance of pixel areas that draw black in the image of the character "panda" 1525 increases. As a result, the user can recognize the area that draws black among the areas that draw the image of the character "panda" 1525 as distinct from the black of the background without blending in, and the object can be displayed more suitably.

[0188] That is, by using the image processing of Fig. 13B(2), the area displaying the image of the character "panda" 1525, which is an object, can be distinguished from the black background inside the housing of the space-floating image display device 1000 through the window, improving the visibility of the object. Therefore, for example, even if the pixels constituting the object include pixels with a brightness value of 0 before the image processing (i.e., the time when the image of the object and the corresponding data are read from the storage unit 1170 or memory 1109 in Fig. 3, the time when the image of the object is input from the video signal input unit 1131, or the time when the data of the object is obtained via the communication unit 1132, etc.), the image is converted into an object with a high brightness value of the pixels in the low brightness area by the image processing of the input / output characteristics by the video control unit 1160, and then displayed on the display device 1, and is converted into the space-floating image 3 by the optical system of the space-floating image display device 1000.

[0189] In other words, the pixels that make up the object after image processing of the input / output characteristics are converted to a state in which they do not include pixels with a brightness value of 0, and then the object is displayed on the display device 1 and converted into a floating-in-space image 3 by the optical system of the floating-in-space image display device 1000.

[0190] In the image processing of FIG. 13B(2), a method for applying image processing with the input / output characteristics of FIG. 13B(2) only to the image area of ​​the object (character “panda” 1525) is, for example, to configure the image processing of the video control unit 1160 so that the background image layer and the layer of the character image in front of the background image layer can be processed as separate layers, and the image processing with the input / output characteristics of FIG. 13B(2) is applied to the layer of the character image while not applying the image processing to the background image layer.

[0191] Then, by compositing these layers, image processing with a characteristic of raising the low brightness area of ​​the input image is performed only on the character image, as shown in Fig. 13B(2). Alternatively, after the character image layer and the background image layer are composited, the image processing with the input / output characteristic of Fig. 13B(2) may be performed only on the character image area.

[0192] In addition, the input / output image characteristics used in the image processing for boosting the low luminance region of the input / output characteristics for the input image are not limited to the example of FIG. 13B(2). Any image processing for boosting low luminance may be used, including so-called brightness adjustment. Alternatively, image processing for improving visibility may be performed by controlling the gain that changes the weighting of the Retinex processing, as disclosed in International Publication WO 2014 / 162533.

[0193] According to the image processing of FIG. 13B(2) described above, it is possible to allow the user to recognize areas in which black is drawn among areas in which images of characters, objects, etc. are drawn without blending into the black background, thereby making it possible to realize a more suitable display.

[0194] In the example of Figures 13A and 13B, the problem and more suitable image processing are explained using a space-floating image display device in which the background appears black (for example, the space-floating image display device 1000 in Figures 4A to 4G, or the space-floating image display device 1000 in the state in which the rear window is blocked in Figures 4I and 4J). However, the image processing is also effective in devices other than these space-floating image display devices.

[0195] Specifically, in the space-floating image display device 1000 in Fig. 4H, or in Fig. 4I and Fig. 4J where the rear window is not shaded, the background of the space-floating image 3 is not black, but the view behind the space-floating image display device 1000 through the window. In this case, the problems described in Fig. 13A and Fig. 13B also exist.

[0196] That is, the part of the image of the character "panda" 1525, which is an object, that is drawn in black will blend into the scenery behind the space-floating image display device 1000 through the window. In this case, by using the image processing of Fig. 13B(2), the part of the image of the character "panda" 1525, which is an object, that is drawn in black will be distinguished from the scenery behind the space-floating image display device 1000 through the window, improving the visibility of the object.

[0197] In other words, by using the image processing of FIG. 13B(2), the area displaying the image of the object character “panda” 1525 can be recognized as distinct from the scenery behind the space floating image display device 1000 through the window, and it can be more clearly recognized that the object character “panda” 1525 is in front of the scenery, improving the visibility of the object.

[0198] In addition, in the space-floating image display device 1000 of Figures 4K, 4L, and 4M, as described above, when another image (such as an image of the transmissive self-luminous image display device 1650 or an image of the second display device 1680) is displayed at a position different in depth from the space-floating image 3, the background of the space-floating image 3 is not black, but the other image. In this case, the problem described in Figures 13A and 13B also exists.

[0199] That is, the part of the image of the character "panda" 1525, which is an object, that is drawn in black will blend into the other image that is displayed at a different depth from the floating in space image 3. In this case as well, by using the image processing of Fig. 13B(2), the part of the image of the character "panda" 1525, which is an object, that is drawn in black can be recognized as being distinct from the other image, improving the visibility of the object.

[0200] In other words, by using the image processing of Figure 13B (2), the area displaying the image of the object character "panda" 1525 can be recognized as distinct from the other image, and it can be more easily recognized that the object character "panda" 1525 is in front of the other image, improving the visibility of the object.

[0201] An example of the image display process of this embodiment will be described with reference to Fig. 13C. Fig. 13C shows an example of the image display of this embodiment in which the floating-in-space image 3 and a second image 2050, which is another image, are displayed simultaneously. The second image 2050 may correspond to the display image of the transmissive self-luminous image display device 1650 of Fig. 4K or Fig. 4L. The second image 2050 may also correspond to the display image of the second display device 1680 of Fig. 4M.

[0202] That is, the example of the image display in Fig. 13C shows an example of a specific example of the image display example of the space-floating image display device 1000 in Fig. 4K, Fig. 4L, and Fig. 4M. In the example of this figure, a bear character is displayed in the space-floating image 3. The area other than the bear character in the space-floating image 3 is displayed in black, and becomes transparent as a space-floating image. Also, the second image 2050 is a background image in which a plain, a mountain, and a sun are drawn.

[0203] Here, in Fig. 13C, the floating-in-space image 3 and the second image 2050 are displayed at different depth positions. When the user 230 views the two images, the floating-in-space image 3 and the second image 2050, in the line of sight of the arrow 2040, the user 230 can view the images in a state where the two images are superimposed. Specifically, the bear character of the floating-in-space image 3 appears superimposed in front of the background of the plains, mountains, and sun depicted in the second image 2050.

[0204] Here, since the floating-in-space image 3 is formed as a real image in the air, when the user 230 moves his / her viewpoint slightly, the user 230 can recognize the depth of the floating-in-space image 3 and the second image 2050 due to parallax. Therefore, the user 230 can get a stronger sense of floating in space from the floating-in-space image 3 while viewing the two images in an overlapping state.

[0205] An example of the image display process of this embodiment will be described with reference to Fig. 13D. Fig. 13D(1) is a diagram showing the floating in space image 3 from the line of sight of the user 230, among the image display examples of this embodiment of Fig. 13C. Here, a bear character is displayed in the floating in space image 3. The area other than the bear character in the floating in space image 3 is displayed in black, and becomes transparent as a floating in space image.

[0206] Fig. 13D(2) is a diagram showing the second image 2050 in the example of the image display of this embodiment in Fig. 13C as viewed from the line of sight of the user 230. In the example of this figure, the second image 2050 is a background image in which a plain, a mountain, and the sun are drawn.

[0207] Fig. 13D(3) is a diagram showing a state in which the second image 2050 and the floating in space image 3 are seen superimposed in the line of sight of the user 230, among the example of image display of this embodiment in Fig. 13C. Specifically, the bear character of the floating in space image 3 is seen superimposed in front of the background of the plains, mountains, and sun depicted in the second image 2050.

[0208] Here, when the space-floating image 3 and the second image 2050 are displayed simultaneously, it is desirable to pay attention to the balance of brightness between the two images in order to more suitably ensure the visibility of the space-floating image 3. If the second image 2050 is too bright compared to the brightness of the space-floating image 3, the display image of the space-floating image 3 will be transparent, and the second image 2050, which is the background, will be strongly visible through the transmitted image.

[0209] Therefore, the light source output of the spatially floating image 3 and the display image luminance of the display device 1, and the light source output of the display device displaying the second image 2050 and the display image luminance of the display device should be set so that at least the brightness per unit area of ​​the spatially floating image 3 at the display position of the spatially floating image 3 is greater than the brightness per unit area of ​​the image light reaching the display position of the spatially floating image 3 from the second image 2050.

[0210] In addition, since this condition only needs to be satisfied when the space-floating image 3 and the second image 2050 are displayed simultaneously, when switching from the first display mode in which the space-floating image 3 is not displayed and only the second image 2050 is displayed to the second display mode in which the space-floating image 3 and the second image 2050 are displayed simultaneously, control may be performed to reduce the brightness of the second image 2050 by lowering the output of the light source of the display device that displays the second image 2050 and / or the display image luminance of the display device. These controls may be realized by the control unit 1110 in Fig. 3 controlling the display device 1 and the display device that displays the second image 2050 (the transmissive self-luminous image display device 1650 in Fig. 4K or Fig. 4L or the second display device 1680 in Fig. 4M).

[0211] In addition, when controlling to reduce the brightness of the second image 2050 in switching from the above-mentioned first display mode to the above-mentioned second display mode, the brightness may be reduced uniformly across the entire screen of the second image 2050. Alternatively, instead of reducing the brightness uniformly across the entire screen of the second image 2050, the brightness reduction effect may be maximized in the portion where the object is displayed in the floating-in-space image 3, and the brightness reduction effect may be gradually relaxed around the portion. In other words, if the brightness reduction of the second image 2050 is realized only in the portion where the floating-in-space image 3 is superimposed on the second image 2050 and viewed, the visibility of the floating-in-space image 3 is sufficiently ensured.

[0212] Here, since the floating-in-space image 3 and the second image 2050 are displayed at positions with different depths, when the user 230 slightly changes his / her viewpoint, the superimposed position of the floating-in-space image 3 on the second image 2050 changes due to parallax. Therefore, when reducing the brightness unevenly across the entire screen of the second image 2050 in switching from the first display mode to the second display mode, it is not desirable to reduce the brightness sharply based on the contour of the object displayed in the floating-in-space image 3, but it is desirable to perform a gradation process of the brightness reduction effect, which changes the brightness reduction effect stepwise depending on the position as described above.

[0213] In addition, in the space-floating image display device 1000 where the position of the object displayed in the space-floating image 3 is approximately at the center of the space-floating image 3, the position where the brightness reduction effect of the gradation processing of the brightness reduction effect is the highest can be set to the center position of the space-floating image 3.

[0214] According to the image display process of this embodiment described above, the user 230 can visually recognize the space floating image 3 and the second image 2050 more favorably.

[0215] Note that when displaying the space-floating image 3, control may be performed so as not to display the second image 2050. Since the visibility of the space-floating image 3 is improved when the second image 2050 is not displayed, this is suitable for the space-floating image display device 1000 and the like in which the user must be able to reliably view the space-floating image 3 when the space-floating image 3 is displayed.

[0216] <Example 2> As the second embodiment of the present invention, an example of another configuration example of the space-floating image display device will be described. Note that the space-floating image display device according to this embodiment is obtained by changing the optical system stored in the space-floating image display device described in the first embodiment to the optical system shown in FIG. 14(1) or FIG. 14(2). In this embodiment, differences from the first embodiment will be described, and repeated explanations of the same configuration as the first embodiment will be omitted. Note that in the following description of this embodiment, the predetermined polarized light and the other polarized light are polarized waves whose phases differ from each other by 90°.

[0217] Fig. 14(1) is an example of an optical system and an optical path according to this embodiment. The optical system shown in Fig. 14(1) is configured to be more compact as a whole optical system by moving the display device 1 closer to the polarization separation member 101B in the optical system of Fig. 2C. In Fig. 14(1), the configurations with the same reference numerals as Fig. 2C are omitted from the repeated detailed description.

[0218] 14(1), similar to Fig. 2C, image light of a predetermined polarized light (P polarized light in the figure) emitted from display device 1 travels in a direction perpendicular to the image display surface of display device 1. Here, similar to Fig. 2C, polarization separation member 101B selectively transmits the predetermined polarized light (P polarized light in the figure) emitted from display device 1 and reflects the other polarized light (S polarized light in the figure).

[0219] Therefore, the image light of a predetermined polarization (P-polarized light in the figure) traveling in the vertical direction from the image display surface of the display device 1 passes through the polarization separation member 101B and reaches the retroreflector 2 to which the λ / 4 plate 21 is attached. The image light that is retroreflected by the retroreflector 2 and travels again toward the polarization separation member 101B is converted from the predetermined polarization (P-polarized light in the figure) at the time of emission from the display device 1 to the other polarization (S-polarized light in the figure) by passing through the λ / 4 plate 21 twice. The image light that travels again toward the polarization separation member 101B is the other polarization (S-polarized light in the figure), and is therefore reflected by the polarization separation member 101B toward the position where the user should be. The traveling direction of the image reflected by the polarization separation member 101B is determined based on the angle at which the polarization separation member 101B is arranged.

[0220] In the example of FIG. 14(1), the image light traveling toward the polarization separation member 101B is reflected at a right angle by the polarization separation member 101B and travels as shown in the figure. The image light reflected by the polarization separation member 101B forms a space-floating image 3A. The space-floating image 3A can be visually recognized by the user from the direction of the arrow A.

[0221] Here, due to the characteristics of retroreflection by the retroreflector 2, the optical path length of the image light emitted from the display device 1 until it reaches the retroreflector 2 is equal to the optical path length of the image light emitted from the retroreflector 2 until it reaches the formation position of the space floating image 3A. This relationship determines the formation position of the space floating image 3A in the traveling direction of the image light reflected by the polarization separation member 101B.

[0222] In the example of FIG. 14(1), the display device 1, the polarization separation member 101B, and the retroreflector 2 are arranged closer than in the example of FIG. 2C. This allows the entire optical system to be configured more compactly. However, the amount of the space-floating image 3A projecting from the optical system of FIG. 14(1) is not very large. For example, as an index of the amount of the space-floating image 3A projecting from the optical system, the distance from the position where the central light beam of the image light is reflected by the polarization separation member 101B to the position where the image light forms the space-floating image 3A is shown in the figure (L1 in the example of FIG. 14(1)).

[0223] In addition, in the polarization design of the optical system in Fig. 14(1), the characteristics of P polarization and S polarization may be interchanged. Specifically, a predetermined polarization of the image light emitted from the display device 1 may be S polarization, and the characteristics of P polarization and S polarization may be interchanged in the reflection characteristics of the polarization separation member 101B. In this case, the illustrated P polarization and S polarization are both reversed, but the optical design such as the optical path can be realized in exactly the same way.

[0224] Next, Fig. 14(2) shows another example of the optical system and the optical path according to this embodiment. The optical system in Fig. 14(2) is a modified version of the optical system in Fig. 14(1) in order to increase the amount of the floating image projected from the optical system while realizing the same compactness as the optical system in Fig. 14(1). In Fig. 14(2), the detailed description of the components with the same reference numerals as those in Fig. 14(1) will be omitted.

[0225] 14(2), similarly to FIG. 14(1), image light of a predetermined polarized light (P polarized light in the figure) emitted from display device 1 travels in a vertical direction from the image display surface of display device 1. Here, the polarization characteristics of polarization separation member 101B are arranged 90 degrees differently from FIG. 14(1). Image light of a predetermined polarized light (P polarized light in the figure) traveling in a vertical direction from the image display surface of display device 1 passes through polarization separation member 101B.

[0226] 14(1), a specular reflector 4 to which a λ / 4 plate 21B is attached is disposed after the image light passes through the polarization separation member 101B, rather than a retroreflector 2 to which a λ / 4 plate 21 is attached. Here, the reflection at the specular reflector 4 is specular reflection (also called regular reflection), not retroreflection.

[0227] Therefore, the image light that has passed through the polarization separation member 101B is specularly reflected by the specular reflector 4 to which the λ / 4 plate 21B is attached. The image light that has been specularly reflected by the specular reflector 4 and travels again toward the polarization separation member 101B has been converted from the specified polarization (P-polarized in the figure) at the time of emission from the display device 1 to the other polarization (S-polarized in the figure) by having passed twice through the λ / 4 plate 21. The image light that has traveled again toward the polarization separation member 101B is the other polarization (S-polarized in the figure), and is therefore reflected by the polarization separation member 101B.

[0228] Here, since the orientation of the polarization separation member 101B in FIG. 14(2) is different from that in FIG. 14(1), the image light reflected by the polarization separation member 101B travels in the opposite direction to the position where the user should be. A retroreflector 2 with a λ / 4 plate 21C attached is disposed at the destination of the image light reflected by the polarization separation member 101B. The image light is retroreflected by the retroreflector 2. The image light that is retroreflected by the retroreflector 2 and travels again toward the polarization separation member 101B has been converted from the other polarized light (S polarized light in the figure) to the specified polarized light (P polarized light in the figure) again by transmitting twice through the λ / 4 plate 21C.

[0229] The image light that travels back toward the polarization separation member 101B is a predetermined polarization (P polarization in the figure), so it passes through the polarization separation member 101B and travels directly toward the position where the user should be. The image light that passes through the polarization separation member 101B forms the space floating image 3B. The space floating image 3B can be visually recognized by the user from the direction of the arrow A.

[0230] 14(2), as in FIG. 14(1), due to the characteristics of retroreflection by the retroreflector 2, the optical path length of the image light emitted from the display device 1 to reach the retroreflector 2 is equal to the optical path length of the image light emitted from the retroreflector 2 to reach the formation position of the space floating image 3B. This relationship determines the formation position of the space floating image 3B in the traveling direction of the image light transmitted through the polarization separation member 101B.

[0231] 14(2), the optical path length of the image light emitted from the display device 1 to reach the retroreflector 2 is longer than the optical path length of the image light emitted from the display device 1 to reach the retroreflector 2 in FIG. 14(1). This is because in the optical system of FIG. 14(2), an optical path going back and forth between the polarization separation member 101B and the specular reflector 4, which does not exist in the optical system of FIG. 14(1), is added to the optical path length of the image light emitted from the display device 1 to reach the retroreflector 2.

[0232] As a result, in the optical system of Figure 14(2), the distance from the position where the central light beam of the image light passes through the polarization separation member 101B to the position where the image light forms the space-floating image 3B (L2 in the example of Figure 14(2)) is significantly longer than the distance from the position where the central light beam of the image light is reflected by the polarization separation member 101B to the position where the image light forms the space-floating image 3A (L1 in the example of Figure 14(1)) in the optical system of Figure 14(1).

[0233] In addition, in the polarization design of the optical system in Fig. 14(2), the characteristics of P polarization and S polarization may be interchanged. Specifically, a predetermined polarization of the image light emitted from the display device 1 may be S polarization, and the characteristics of P polarization and S polarization may be interchanged in the reflection characteristics of the polarization separation member 101B. In this case, the illustrated P polarization and S polarization are both reversed, but the optical design such as the optical path can be realized in exactly the same way.

[0234] According to the optical system of Fig. 14(1) and Fig. 14(2) in the embodiment 2 of the present invention described above, a more compact optical system can be realized. In particular, according to the optical system of Fig. 14(2), it is possible to increase the amount of the floating image projecting from the optical system, while being a more compact optical system.

[0235] In addition, when the optical system of Fig. 14(1) or Fig. 14(2) is incorporated into a space-floating image display device, it can be realized by replacing the optical system in the space-floating image display device described in the first embodiment with the optical system of Fig. 14(1) or Fig. 14(2). Specifically, the optical system of Fig. 14(1) may be replaced with the optical system of the space-floating image display device of Fig. 4E, Fig. 4F, Fig. 4G, Fig. 4H, Fig. 4I, Fig. 4J, Fig. 4K, Fig. 4L, or Fig. 4M. In this case, since the optical system becomes compact, it is possible to make the housing of the space-floating image display device of each figure smaller.

[0236] Specifically, the optical system of FIG. 14(2) may be replaced with the optical system of the space-floating image display device of FIG. 4E, FIG. 4F, FIG. 4G, FIG. 4K, or FIG. 4L. In this case, it is possible to increase the amount of the space-floating image projected from the optical system. Also, since the optical system becomes compact, it is possible to make the housing of the space-floating image display device of each figure smaller.

[0237] <Example 3> As a third embodiment of the present invention, a space-floating image display device provided in a space-floating image display system will be described. Specifically, a space-floating image display device provided in a drive-through system will be described. A drive-through system provided with a space-floating image display device is an example of a space-floating image display system.

[0238] 15A and 15B are diagrams showing a space floating image display device according to Example 3. In the description of Example 3, the front-rear direction (traveling direction) of the vehicle is defined as the y' direction, the height direction (vertical direction) of the vehicle is defined as the z' direction, and the left-right direction of the vehicle, that is, the direction perpendicular to the y' direction and the z' direction, is defined as the x' direction. In the following, differences from Examples 1 and 2 are mainly described, and descriptions of the same configurations as Examples 1 and 2 are omitted.

[0239] The drive-through system, which is a space-floating image display system, is equipped with a space-floating image display device, and allows passengers of a vehicle (mainly a passenger car) to order and pay for products by operating the space-floating image formed by the space-floating image display device, and to receive products while remaining in the vehicle. The drive-through system of this example is equipped with a service facility 3000 including a space-floating image display device 1000, as shown in Figures 15A and 15B.

[0240] The service facility 3000 is a facility having equipment for accepting product orders from occupants (users) 230 of a vehicle Ve, which is a passenger car, and equipment for settlement, and can also be called an order terminal. The service facility 3000 is installed on the side of a road surface RS on which the vehicle Ve runs and stops, together with a product menu signboard 3100. As an example, the service facility 3000 is installed close to the road surface RS in the x' direction, which is the left-right direction of the vehicle Ve, and is disposed adjacent to the menu signboard 3100 in the y' direction, which is the front-rear direction of the vehicle Ve.

[0241] The space-floating image display device 1000 forms a space-floating image (also called a floating image) 3 from the side of the vehicle Ve parked at a position corresponding to the service facility 3000 toward the user 230, who is a passenger (e.g., the driver) of the vehicle Ve. As will be explained in detail below, the space-floating image display device 1000 forms the space-floating image 3 in the y' direction, which is the traveling direction of the vehicle Ve, near the position for placing an order with the service facility 3000.

[0242] In other words, the floating-in-space image display device 1000 forms the floating-in-space image 3 in the vicinity of the order window 3001 of the service facility 3000 in the traveling direction of the vehicle Ve, specifically, in the vicinity of the display board 3002 on which the words "order window" are displayed. This display board 3002 is provided on the upper front surface of the housing 3003 of the service facility 3000, that is, on the upper surface on the vehicle Ve side. In this example, the position overlapping with the display board 3002 in the z' direction corresponds to the position for placing an order to the service facility 3000 (the position corresponding to the order window 3001). It can also be said that the position for placing an order to the service facility 3000 is the position on which there is a display indicating that this is the position for placing an order to the service facility 3000.

[0243] Here, the road surface RS on which the vehicle Ve travels and stops is provided with a stop position indication for stopping the vehicle Ve at a position corresponding to the service facility 3000. In this embodiment, a stop line 3200 is indicated on the road surface RS as an example of the stop position indication. By stopping the vehicle Ve at the stop line 3200, the position of the window (which can also be called a side glass or a side window) of the vehicle Ve is generally positioned opposite the service facility 3000.

[0244] This stop line 3200 is shown ahead of the service facility 3000 in the y' direction, which is the travel direction of the vehicle Ve. Conversely, the service facility 3000 is installed behind this stop line 3200 in the y' direction. The space-floating image 3 is then formed on the service facility 3000 side of the stop line 3200. In other words, the space-floating image display device 1000 is configured so that the space-floating image 3 is formed on the service facility 3000 side of the stop line 3200. As a result, when the vehicle Ve is stopped in line with the stop line 3200, the space-floating image 3 is formed near the window of the vehicle Ve in the y' direction.

[0245] The space-floating image display device 1000 of the third embodiment is equipped with the optical system described in the first and second embodiments, and the space-floating image 3 is formed at a position for placing an order to the service facility 3000 as described above, that is, at a position corresponding to the order window 3001.

[0246] As an example, the space-floating image display device 1000 is provided in a service facility 3000. More specifically, the display device (display unit) 1 and the optical system constituting the space-floating image display device 1000 are arranged in a housing 3003 of the service facility 3000. Therefore, it can be said that the housing 3003 of the service facility 3000 in this example also serves as the housing 1190 of the space-floating image display device 1000.

[0247] 3, and includes, for example, a camera 1180 as an imaging unit, a microphone 1139 that collects the voices of the passengers 230 of the vehicle Ve, and a speaker 1140 as an audio output unit. The microphone 1139 and the speaker 1140 do not necessarily have to be included in the space-floating image display device 1000, and may be included in the service facility 3000.

[0248] The display device 1 is installed in the housing 3003 facing upward in the z' direction, which is the vertical direction. The optical system of the space floating image display device 1000 of the third embodiment corresponds to, for example, the optical system of FIG. 2A, and the retroreflector 2 with the λ / 4 plate 21 on its surface is arranged in the housing 3003 along the vertical direction, and the polarization separation member 101 provided on the transparent member 100 is arranged in the housing 3003 at an angle of approximately 45° with respect to the vertical direction. The display device 1 and the optical system are also arranged in the housing 3003 so that at least a part of the space floating image 3 is displayed at a position overlapping the display board 3002 in the z' direction.

[0249] As described above, display board 3002 is provided on housing 3003 of service facility 3000, and a first opening 3004 and a second opening 3005 are provided below display board 3002. First opening 3004 is an opening for video, and is formed in a substantially rectangular shape.

[0250] The polarization separation member 101 and the retroreflector 2 constituting the optical system of the space-floating image display device 1000 are disposed facing the first opening 3004 in the x' direction. The space-floating image display device 1000 forms a space-floating image 3 outside the service facility 3000 through this first opening 3004. In this embodiment, the space-floating image display device 1000 is basically configured so that the space-floating image 3 is formed outside the window W1 of the vehicle Ve, that is, on the service facility 3000 side. In other words, in the third embodiment, the display position of the space-floating image 3 in the x' direction is set to a first position x11 outside the vehicle Ve.

[0251] As described above, the optical path length of the image light emitted from the display device 1 to reach the retroreflector 2 is equal to the optical path length of the image light emitted from the retroreflector 2 to reach the formation position of the floating image 3. Therefore, by adjusting the relative positions of the display device 1 and the retroreflector 2, the display position of the floating image 3 can be set to a desired position, for example, the first position x11.

[0252] The second opening 3005 is a substantially circular opening for audio, and is provided below the first opening 3004 of the housing 3003. The microphone 1139 and the speaker 1140 are provided near the second opening 3005. That is, the microphone 1139 and the speaker 1140 are provided at a position where the occupant 230 places an order with the service facility 3000. Therefore, the position where an order is placed with the service facility 3000 can be said to be a position where the microphone 1139 and the speaker 1140 that collect the voice of the occupant 230 of the vehicle Ve are provided.

[0253] Furthermore, the airborne image display device 1000 includes an airborne operation detection unit 1350 and an airborne operation detection sensor 1351 that detect the operation of the occupant 230 on the airborne image 3 (see FIG. 3). In this embodiment, the camera 1180 also functions as the airborne operation detection sensor 1351, and the airborne operation detection unit 1350 detects the touch operation of the airborne image 3 by the occupant 230 based on the captured image of the camera 1180. The camera 1180 is provided, for example, on the top surface of the housing 3003 so as to capture an image of the vehicle Ve and the occupant 230. The airborne operation detection unit 1350 calculates the presence or absence of contact of the finger of the occupant 230 with an object on the airborne image 3 and the position (contact position) where the finger of the occupant 230 and the object contact based on the image captured by the camera 1180.

[0254] The camera 1180 functioning as the aerial operation detection sensor 1351 may be any camera capable of capturing images or pictures that can detect touch operations of the passenger 230 on the floating image 3, but is preferably a multi-lens camera such as a stereo camera having multiple lenses. The floating image display device 1000 may also be equipped with multiple cameras 1180. This can improve the detection accuracy of the touch position by the passenger 230.

[0255] The space-floating image display device 1000 configured as described above forms a space-floating image 3, which is an image for inputting information to the service facility 3000, for the occupant 230 of the vehicle Ve. The occupant 230 of the vehicle Ve operates the space-floating image 3 with the window of the vehicle Ve, for example, the driver's seat window W1, open, as shown in Fig. 16. As an example, the space-floating image display device 1000 forms an image for ordering a product as the space-floating image 3, as shown in Figs. 17A and 17B.

[0256] In the example shown in Fig. 17A, the floating image 3 includes a menu image 3301 which is an image of a product menu, a cart image 3302 which is an image of product information registered in the cart, and a payment image 3303 which is an image showing the reading range for reading a two-dimensional code for electronic payment. In the case of the floating image 3 shown in Fig. 17A, the passenger 230 orders a product, for example, in the following procedure.

[0257] First, the user changes to menu image 3301 of the item they wish to purchase by touching and sliding menu image 3301 left or right, or by touching movement button image 3304. Then, while menu image 3301 of the item they wish to purchase is displayed, they touch cart button image ("add to cart" button image) 3305. This adds the item they wish to purchase to their cart. If they wish to purchase multiple items, they repeat the same operation. Thereafter, they present, for example, a two-dimensional code for electronic payment displayed on a mobile terminal, toward the reading range of payment image 3303. This executes the electronic payment, and the item ordering operation is completed.

[0258] The two-dimensional code presented by the passenger 230 toward the payment image 3303 is read, for example, by the camera 1180. Of course, the method for reading the two-dimensional code is not particularly limited.

[0259] The example shown in FIG. 17B is an example in which input image 3311 for inputting a product menu number is included in space floating image 3 instead of product menu image 3301, and other than that, it is the same as the example shown in FIG. 17A.

[0260] In the case of the floating image 3 shown in FIG. 17B, the passenger 230 checks the number of the product he or she wishes to purchase on, for example, the menu sign 3100 (see FIG. 15B) and inputs the number of the product he or she wishes to purchase by touching the numeric keypad image 3312, which is an image of a keypad for inputting numbers. In the example of FIG. 17B, "12" is input as the product number. Then, with the number of the product he or she wishes to purchase inputted, he or she touches an image of, for example, a confirmation button, and the product with that number is registered in the cart. After that, the passenger orders the product in the same procedure as in the example shown in FIG. 17A.

[0261] As described above, according to the space floating image display device 1000 of this embodiment, the passenger 230 of the vehicle Ve orders products by operating the space floating image 3, so that the operation of ordering products becomes easier.

[0262] In a conventional drive-through system, for example, a passenger orders products by touching a touch panel display provided in a service facility. Therefore, in order for a passenger to place an order from inside the vehicle, the vehicle must be stopped in a state where it is sufficiently close to the service facility. As a result, there is a risk that the vehicle will come too close to the service facility and come into contact with it. On the other hand, there may be a situation where the vehicle cannot be brought close enough to the service facility, and the passenger cannot place an order from inside the vehicle.

[0263] In contrast, in this embodiment, when the vehicle Ve stops at the order window 3001 of the service facility 3000, the space-floating image display device 1000 forms the space-floating image 3 for the order operation outside the service facility 3000. In other words, the space-floating image 3 for the order operation is formed on the vehicle Ve side rather than the front of the housing 3003 of the service facility 3000. In other words, the space-floating image 3 is formed at a position closer to the vehicle Ve than the front of the housing 3003.

[0264] Therefore, even if the vehicle Ve is stopped at a position slightly away from the service facility 3000, the occupant 230 can perform an ordering operation on the space-floating image 3. In addition, since it is no longer necessary to stop the vehicle Ve close enough to the service facility 3000, contact between the vehicle Ve and the service facility 3000 can be reduced. Furthermore, by forming the image for the ordering operation as the space-floating image 3, the occupant 230 can easily visually recognize the image for the ordering operation, which has the effect of reducing erroneous operations.

[0265] In this embodiment, the configuration in which the space-floating image display device 1000 is arranged inside the housing 3003 of the service facility 3000 has been described, but the space-floating image display device 1000 is not limited to this configuration. The space-floating image display device 1000 does not necessarily have to be arranged inside the service facility 3000 as long as it can form the space-floating image 3 near the order window 3001. For example, the housing 1190 of the space-floating image display device 1000 may be arranged independently of the housing 3003 of the service facility 3000.

[0266] Furthermore, in this embodiment, an example has been described in which an image for performing a product ordering operation is displayed as the floating image 3, but the content of the image displayed as the floating image 3 in the air is not particularly limited.

[0267] Furthermore, in this embodiment, a drive-through system is exemplified as a space-floating image display system equipped with the space-floating image display device 1000, but the space-floating image display system is not limited to a drive-through system. For example, the space-floating image display system may be a parking fee settlement system equipped with service equipment (also called a settlement terminal) including equipment for settling parking fees. In other words, the space-floating image display device 1000 can be applied to other space-floating image display systems such as parking fee settlement systems.

[0268] <Modification 1 of Example 3> 18A and 18B are diagrams showing a space-floating image display device according to Modification 1. The space-floating image display device 1000 shown in Fig. 18A and 18B has the same configuration as the space-floating image display device shown in Fig. 4M, and is characterized in that it includes a second display device 1680.

[0269] 18A and 18B, in the space floating image display device 1000 of the first modification, the display device 1 is also installed in the housing 3003 facing upward in the z' direction, which is the vertical direction, and the polarization separation member 101 provided on the transparent member 100 is disposed in the housing 3003 at an angle of approximately 45° with respect to the vertical direction. In contrast, the retroreflector 2, which has a λ / 4 plate 21 provided on its surface, is disposed so as to face the display device 1 with the polarization separation member 101 in between. The retroreflector 2 is disposed so that its surface is parallel to the image display surface of the display device 1.

[0270] A second display device (second display unit) 1680 is provided on the rear side of the polarization separation member 101 as viewed from the passenger 230. The second display device 1680 is provided at a position farther away from the vehicle Ve in the x' direction than the polarization separation member 101, and its image display surface faces the air-floating image 3. In other words, the second display device 1680 can be said to be provided on the rear side of the air-floating image 3 as viewed from the passenger 230 of the vehicle Ve. This second display device 1680 can display an image different from the air-floating image 3. In addition, in this configuration, the passenger 230 can also visually recognize the image of the second display device 1680 and the air-floating image 3, which are displayed at two positions with different depths, superimposed on each other.

[0271] By combining the space-floating image 3 and the image of the second display device 1680, for example, the menu image 3301 of the product can be expressed more three-dimensionally. This is expected to have the effect of increasing the user's desire to purchase. In addition, the image of the second display device 1680 has a wider visible range than the space-floating image 3. For this reason, even if the vehicle Ve is stopped at a position slightly shifted from the stop line 3200 and the passenger 230 has difficulty viewing the space-floating image 3, the passenger 230 may be able to view the image of the second display device 1680 well. In such a case, an image different from the space-floating image 3, for example, an image that guides the vehicle Ve to an appropriate stopping position, can be displayed on the second display device 1680.

[0272] <Modification 2 of Example 3> FIG. 19 is a diagram showing a space-floating image display device according to the second modification, and FIG. 20 is a diagram showing an example of a space-floating image viewed from inside a car.

[0273] The space-floating image display device 1000 according to the first modification basically generates a space-floating image 3 outside the vehicle Ve, whereas the space-floating image display device 1000 according to the second modification generates a space-floating image 3 inside the vehicle Ve (inside the vehicle cabin) as shown in Figures 19 and 20. That is, in the space-floating image display device 1000 according to the second modification, the display position of the space-floating image 3 in the x' direction is set to a second position x12 inside the vehicle Ve.

[0274] As shown in Fig. 19, in the space floating image display device 1000 according to the second modification, the display device 1 is also installed in the housing 3003 facing upward in the z' direction, which is the vertical direction. The optical system of the space floating image display device 1000 according to the second modification corresponds to the optical system of Fig. 2D, for example, and the retroreflector 5 is arranged in the housing 3003 at an angle of approximately 45° with respect to the vertical direction.

[0275] It should be noted that the optical system shown in Fig. 19 is merely an example. The optical system of the space floating image display device 1000 according to the second modification is not particularly limited, and may be, for example, the same optical system as that in Fig. 15A.

[0276] 19 and 20, the space-floating image display device 1000 according to the second modification is configured so that the space-floating image 3 is formed inside the window W1 of the vehicle Ve (inside the vehicle cabin). In other words, in the space-floating image display device 1000 according to the second modification, the display position of the space-floating image 3 in the x' direction is set to a second position x12 inside the vehicle Ve.

[0277] As described above, the optical path length of the image light emitted from the display device 1 to reach the retroreflector 5 is equal to the optical path length of the image light emitted from the retroreflector 5 to reach the display position of the space floating image 3. Therefore, by adjusting the relative position between the display device 1 and the retroreflector 5, the display position where the space floating image 3 is displayed can be set to a desired position, for example, the second position x12.

[0278] By forming the floating image 3 inside the vehicle Ve in this way, the passenger 230 of the vehicle Ve can operate the floating image 3 without opening the window W1. Therefore, even in bad weather such as rain, the passenger 230 can comfortably operate the floating image 3 to order a product.

[0279] When detecting the operation of the floating image 3 by the occupant 230 based on the image of the camera 1180, it is preferable to provide a polarizing plate on the camera 1180. For example, the camera 1180 is provided with a polarizing plate that cuts S-polarized light, and images are captured with P-polarized light. This reduces the reflected light from the windows of the vehicle Ve, and allows the operation of the floating image 3 by the occupant 230 to be detected more accurately.

[0280] <Modification 3 of Example 3> 21 to 23 are diagrams showing a space-floating image display device 1000 according to Modification 3. In the following figures, the microphone 1139, the speaker 1140, the display board 3002 provided on the housing 3003 of the service facility 3000, the first opening 3004, the second opening 3005, and the like provided on the space-floating image display device 1000 are omitted.

[0281] As described above, the space-floating image display device 1000 according to the third embodiment forms the space-floating image 3 at a specific position. In contrast, the space-floating image display device 1000 according to the third modification is configured to be able to adjust the display position of the space-floating image 3 at least along the height direction of the vehicle Ve. In other words, the space-floating image display device 1000 according to the third modification is configured to be able to adjust the display position of the space-floating image 3 at least in the z' direction. The configurations of the display device 1, the retroreflector 2, and the polarization separation member 101 that constitute the space-floating image display device 1000 according to the third modification are the same as those of the example shown in FIG. 15A.

[0282] Moreover, the space-floating image display device 1000 according to the third modification includes an occupant detection unit that detects an occupant 230 in the vehicle Ve. The occupant detection unit detects the position of the occupant 230 relative to the space-floating image display device 1000, for example, the height in the z' direction, based on, for example, an image of the camera 1180. In this example, the control unit 1110 functions as the occupant detection unit (see FIG. 3). The space-floating image display device 1000 according to the third modification is configured to be able to adjust the display position of the space-floating image 3 in the z' direction according to the position of the occupant in the vehicle Ve.

[0283] 21 is an example in which the display position of the space-floating image 3 can be adjusted by displaying an image on a part of the display device 1 to generate the space-floating image 3. For example, the space-floating image display device 1000 according to the third modification is configured to form the space-floating image 3 near the face of the occupant 230 (230A, 230B) of the vehicle Ve (Ve1, Ve2) according to the position of the occupant 230 based on the image of the camera 1180.

[0284] In detail, the space-floating image display device 1000 according to the third modification generates the space-floating image 3 by displaying an image in a part of the display area of ​​the display device 1 in the x' direction as shown in Fig. 21. Then, by appropriately switching the display area in which the image of the display device 1 is displayed, the display position of the space-floating image 3 in the z' direction is adjusted. In other words, the display device 1 has multiple display areas in which images can be displayed individually, and the space-floating image display device 1000 according to the third modification displays the image in a part of these multiple display areas, and adjusts the display position of the floating image 3 by changing the display area in which the image is displayed.

[0285] For example, when an occupant 230A of the vehicle Ve1 is detected based on the image of the camera 1180, the image is displayed in the first area Sa on the vehicle Ve side of the display device 1 in the x' direction. As a result, the display position of the space floating image 3 in the z' direction becomes the first height z11. That is, the space floating image 3 is formed near the face of the occupant 230A of the vehicle Ve1. Also, when an occupant 230B of the vehicle Ve2 is detected based on the image of the camera 1180, the image is displayed in the second area Sb on the retroreflector 2 side of the display device 1 in the x' direction. As a result, the display position of the space floating image 3 in the z' direction becomes the second height z12. That is, the space floating image 3 is formed near the face of the occupant 230B of the vehicle Ve2.

[0286] In this way, by appropriately switching the display area of ​​the display device 1 in the x' direction between the first area Sa and the second area Sb, the display position of the floating image 3 in the z' direction can be adjusted within the range of the first height z11 to the second height z12. Also, by appropriately adjusting the display position of the floating image 3 according to the height of the face of the occupant 230 (230A, 230B), the occupant 230 can more easily view the floating image 3.

[0287] As described above, the optical path length of the image light emitted from the display device 1 to reach the retroreflector 2 is equal to the optical path length of the image light emitted from the retroreflector 2 to reach the display position of the floating image 3. Therefore, the display position of the floating image 3 in the x' direction is always the same.

[0288] The space-floating image display device 1000 shown in Fig. 22 is an example in which the display device 1 itself is movable in a plane perpendicular to the optical axis direction of the display device 1. Specifically, it is an example in which the display device 1 itself is movable in the x' direction, and the other configurations are the same as those of the space-floating image display device 1000 shown in Fig. 21.

[0289] In this example, the display device 1 is configured to be movable in the x' direction by a movement mechanism (not shown) within a range facing the polarization separation member 101. The display device 1 has a display area with a size corresponding to the first area Sa and the second area Sb shown in Fig. 21, for example, and is configured to be movable in the x' direction within the range from the first area Sa to the second area Sb.

[0290] Even with this configuration, the display position (display height) of the space floating image 3 can be adjusted appropriately according to the height of the face of the occupant 230 (230A, 230B), making it easier for the occupant 230 to visually recognize the space floating image 3.

[0291] 23 is an example in which a position adjustment mechanism 1191 is provided to support a housing 1190 housing the display device 1 and the optical system so as to be movable in the z' direction, and other configurations are the same as those of the space-floating image display device 1000 of the third embodiment. In other words, this is an example in which the display position of the space-floating image 3 in the z' direction is adjusted within a range from a first height z11 to a second height z12 by moving the housing 1190 itself in the z' direction by the position adjustment mechanism 1191. The configuration of the position adjustment mechanism 1191 is not particularly limited, and an existing configuration may be adopted.

[0292] Even with this configuration, the display position of the floating image 3 in space can be adjusted appropriately according to the height of the face of the passenger 230, making it easier for the passenger 230 to visually recognize the floating image 3 in space.

[0293] <Modification 4 of Example 3> FIG. 24 is a diagram showing a modified example of the space floating image display device according to the fourth modification.

[0294] The space-floating image display device 1000 according to the third modification is configured to adjust the display position of the space-floating image 3 in the height direction of the vehicle Ve. In contrast, the space-floating image display device 1000 according to the fourth modification is configured to be able to adjust the position of the floating image 3 along a direction intersecting the traveling direction of the vehicle Ve (the left-right direction of the vehicle Ve) as shown in Fig. 24. In other words, the space-floating image display device 1000 according to the fourth modification is configured to be able to adjust the display position of the space-floating image 3 in the x' direction.

[0295] Specifically, the display device 1 is disposed below the retroreflector 2, on the rear side (opposite side from the vehicle Ve) of the housing 3003 along the vertical direction, similar to the retroreflector 2. The display device 1 and the retroreflector 2 are disposed so as to face the x' direction, which is the left-right direction of the vehicle Ve.

[0296] The optical system of the space floating image display device 1000 according to the fourth modification is basically the same as the optical system of FIG. 2A, but is different in that it includes a mirror member 1980 provided on the optical path of the image light emitted from the display device 1. That is, the mirror member 1980 is provided on the optical path between the display device 1 and the polarization separation member 101. In this example, the mirror member 1980 is arranged on the front side (vehicle Ve side) of the housing 3003 so that the image light emitted from the display device 1 is reflected toward the polarization separation member 101. In other words, it is arranged at an angle of approximately 45° with respect to the vertical direction so that the image light emitted from the display device 1 in the x' direction is reflected toward the z' direction.

[0297] The display device 1 is configured to be movable along the optical axis direction of the image, that is, the x' direction, for example, by a moving mechanism (not shown). In this example, the position of the occupant 230 relative to the space floating image display device 1000 is detected based on the image of the camera 1180, and the display position of the space floating image 3 in the x' direction is adjusted according to the detected position of the occupant 230. The moving mechanism for moving the display device 1 is not particularly limited, and an existing moving mechanism can be adopted.

[0298] As described above, the optical path length of the image light emitted from the display device 1 until it reaches the retroreflector 2 is equal to the optical path length of the image light emitted from the retroreflector 2 until it reaches the display position (forming position) of the floating image 3. Therefore, by moving the display device 1 along the x' direction, the display position of the floating image 3 can be adjusted to a desired position along the x' direction.

[0299] As an example, when the display device 1 is moved along the x' direction to a third position x13 on the rear side of the housing 3003, the optical path length is the longest, and the floating image 3 is formed near the center of the vehicle interior in the x' direction. On the other hand, when the display device 1 is moved along the x' direction to a fourth position x14 on the front side of the housing 3003, the optical path length is the shortest, and the floating image 3 is formed near the window of the right seat in the vehicle.

[0300] In this way, by moving the display device 1 along the x' direction, the display position of the floating image 3 in the x' direction can be adjusted. Therefore, by adjusting the display position of the floating image 3 in the x' direction according to the position of the passenger 230, the floating image 3 in the x' direction can always be formed close to the passenger 230. This makes it easier for the passenger 230 to view the floating image 3 and to perform ordering operations.

[0301] <Modification 5 of Example 3> Fig. 25 is a diagram showing a modified example of the space-floating image display device according to Modification 5. As shown in Fig. 25, the space-floating image display device 1000 according to Modification 5 forms a floating image 3 from the front of the vehicle Ve parked at a position corresponding to the service facility 3000 toward the passenger 230 of the vehicle Ve.

[0302] Furthermore, in the space floating image display device 1000 of variant example 5, light for forming the floating image 3 is emitted from the exit surface of the optical system (e.g., the surface of the transparent member 100), and the floating image 3 is formed inside the vehicle Ve further from the windshield (which can also be called the front glass or front window) WS of the vehicle Ve, and the exit surface of the optical system is arranged at an angle that is inclined along the inclination direction of the surface of the windshield WS.

[0303] The space floating image display device 1000 of variant example 5 is provided independently of the service facility 3000, and as shown in FIG. 25, the housing 1190 housing the display device 1 and the optical system is supported in a suspended state from a position higher than the vehicle Ve by a position adjustment mechanism 1192.

[0304] The position adjustment mechanism 1192 supports the housing 1190 so that it can move and swing within a predetermined angle range within the y'-z' plane. When the vehicle Ve stops at a position corresponding to the service facility 3000, the position adjustment mechanism 1192 moves the housing 1190 in the y' direction to a position facing the windshield WS of the vehicle Ve. The position of the vehicle Ve is detected based on the image of a camera 1180 attached to the housing 1190.

[0305] In addition, when the vehicle Ve is not stopped at a position corresponding to the service facility 3000, the position adjustment mechanism 1192 positions the housing 1190 at a position sufficiently above the vehicle Ve so as not to interfere with the travel of the vehicle Ve.

[0306] The display device 1 and the optical system provided in the housing 1190 are basically configured similarly to those in the fourth modification, but the arrangement of each component is different. Specifically, the display device 1 is disposed above the retroreflector 2. The display device 1 and the retroreflector 2 are disposed on the rear side (opposite side from the vehicle Ve) in the housing 1190 so as to face the vehicle Ve side along the y' direction which is the front-rear direction of the vehicle Ve.

[0307] Moreover, the polarization separation member 101 provided on the transparent member 100 is disposed on the front side (vehicle Ve side) of the housing 1190 so as to face upward at an angle of approximately 45° with respect to the vertical direction. The mirror member 1980 is disposed so as to reflect the image light emitted from the display device 1 toward the polarization separation member 101. In other words, the mirror member 1980 is disposed so as to face downward at an angle of approximately 45° with respect to the vertical direction so that the image light emitted from the display device 1 in the x' direction is reflected toward the z' direction. Moreover, a lower portion 11901 of the front surface of the housing 1190 is formed along the surface of the polarization separation member 101. Furthermore, in this example, an upper portion 11902 of the housing 1190 is formed along the surface of the mirror member 1980.

[0308] In this way, in the space floating image display device 1000 according to the fifth modification, the polarization separation member 101 and the lower part 11901 of the front surface of the housing 1190 on which the polarization separation member 101 is provided are inclined along the inclined surface of the windshield WS of the vehicle Ve. This makes it easier to position the housing 1190 close to the windshield WS when the housing 1190 is moved in the y' direction to a position facing the windshield WS of the vehicle Ve. Accordingly, it becomes easier to form the space floating image 3 from the front of the vehicle Ve through the windshield WS inside the vehicle Ve.

[0309] In addition, in the fifth modification, similar to the fourth modification, the position of the occupant 230 is detected based on the image of the camera 1180, and the display position of the floating image 3 in space is adjustable according to the detected position of the occupant 230. Specifically, the display device 1 is configured to be movable along the y' direction, which is the optical axis direction of the image.

[0310] <Modification 6 of Example 3> FIG. 26 is a diagram showing a modified example of the space floating image display device according to the sixth modification.

[0311] The space-floating image display device 1000 according to the modified example 5 forms the space-floating image 3 toward the passenger 230 in the vehicle with the housing 1190 disposed near the windshield WS of the vehicle Ve. In contrast, the space-floating image display device 1000 according to the modified example 6 forms the space-floating image 3 toward the passenger 230 in the vehicle from a position a predetermined distance away from the vehicle Ve, for example, about 10 m, as shown in FIG. The space-floating image display device 1000 according to the modified example 6 displays, for example, travel direction guidance, no-entry warnings, and other traffic information toward the passenger 230 of the vehicle Ve. However, the use of the space-floating image display device according to the modified example 6 is not particularly limited. Of course, the space-floating image display device according to the modified example 6 can also be used as a drive-through system.

[0312] 26, the space floating image display device 1000 of the sixth modification includes an optical system including a plurality of mirror members (reflecting members) 1980 that reflect the image displayed on the display device 1. Then, after the image displayed on the display device 1 is reflected three or more times by these plurality of mirror members 1980, a space floating image 3 is formed toward the occupant 230 of the vehicle Ve.

[0313] As an example, the optical system has three mirror elements 1980, and the image displayed on the display device 1 is reflected three times by these three mirror elements 1980, in other words, folded three times, and then a floating image 3 is formed toward the occupant 230 of the vehicle Ve.

[0314] The display device 1 and the optical system provided in the housing 1190 are basically configured similarly to those in the fourth modification, but the number of mirror members 1980 and the arrangement of each member are different. Specifically, the display device 1 is arranged vertically below the center of the housing 1190. The display device 1 emits image light toward the opposite side to the vehicle Ve along the y' direction, which is the traveling direction of the vehicle Ve.

[0315] The retroreflector 2 is disposed closer to the front surface of the housing 1190 (closer to the vehicle Ve) than the display device 1. The polarization separation member 101 is disposed near a corner closer to the front surface of the housing 1190 than the retroreflector 2, facing upward at an angle of approximately 45° with respect to the vertical direction. In other words, the polarization separation member 101 is disposed so that the image light incident along the z' direction is incident on the retroreflector 2.

[0316] 26, the three mirror members 1980 are arranged near three corners of the housing 1190 where the polarization separation member 101 is not arranged, facing the center of the housing 1190. That is, the three mirror members 1980 are arranged at an angle of approximately 45° with respect to the z' direction, which is the vertical direction, so that the image light emitted from the display device 1 is reflected and ultimately directed toward the polarization separation member 101.

[0317] As described above, the optical path length of the image light emitted from the display device 1 until it reaches the retroreflector 2 is equal to the optical path length of the image light emitted from the retroreflector 2 until it reaches the display position (forming position) of the space-floating image 3. Therefore, by arranging a plurality of mirror members 1980 on the optical path between the display device 1 and the retroreflector 2 and extending the optical path length until it reaches the retroreflector 2, it is possible to display the space-floating image near a vehicle stopped at a position a predetermined distance away from the space-floating image display device 1000.

[0318] According to the space floating image display device 1000 of the sixth modification, it is possible to form the guidance of the traveling direction, warning information, etc., from a relatively distant position toward the occupant 230 as the space floating image 3. This allows the occupant 230 to be alerted early.

[0319] In addition, in the sixth modification, as in the fourth modification, the position of the occupant 230 may be detected based on the image of the camera 1180, and the display position of the floating image 3 in space may be adjusted according to the detected position of the occupant 230.

[0320] <Modification 7 of Example 3> FIG. 27 is a diagram showing a space floating image display device according to the seventh modification.

[0321] 27, the space floating image display device 1000 according to the seventh modification forms a space floating image 3 inside a vehicle Ve3 through a window W2 of the vehicle Ve3 that passengers can board while standing. Examples of the vehicle Ve3 that passengers can board while standing include public vehicles such as trains and buses.

[0322] As an example, the floating-in-space image display device 1000 shown in FIG. 27 is installed on the wall of a subway station platform, etc., and when a vehicle (train) Ve3 stops at the station platform, a floating-in-space image 3, for example an advertising image, is generated inside the vehicle Ve3 through a window W2 of the vehicle Ve3.

[0323] The configuration of the space floating image display device 1000 according to the seventh modification is the same as that of the second modification, so a description thereof will be omitted here.

[0324] In this way, by displaying advertising images as floating images 3 inside the vehicle Ve3 through the window W2 of the vehicle Ve3 where passengers can stand, it is expected that the images will attract attention more easily and be more effective as advertising than, for example, displaying the images on the walls of a station platform or on a display inside the vehicle.

[0325] <Modification 8 of Example 3> FIG. 28 is a diagram showing a space floating image display device according to the eighth modification.

[0326] 28, the space-floating image display device 1000 according to the eighth modification is an example in which the area in which the image of the display device 1 is displayed is divided into a plurality of display areas, and the space-floating image 3 includes a plurality of image areas aligned in the height direction of the vehicle Ve3. More specifically, the space-floating image display device 1000 according to the eighth modification is configured such that the area in which the image of the display device 1 is displayed is divided into five display areas Da-De in the x' direction, and the space-floating image 3 includes five image areas Ia-Ie aligned in the z' direction.

[0327] Moreover, the space floating image display device 1000 according to the eighth modification includes a window detection unit that detects the position and size of the window W2 of the vehicle Ve3. Then, based on the detection result of the window detection unit, only the image area located within the window W2 in the height direction of the vehicle Ve3 among the multiple image areas Ia to Ie is displayed as a floating-in-the-air image. As an example, the window detection unit detects the position of the window W2 based on the image of the camera 1180. In this example, the control unit 1110 also functions as the window detection unit (see FIG. 3).

[0328] 28, of the multiple image areas Ia to Ie of the space-floating image 3, the image areas Ib to Id are located inside the window W2. Therefore, the space-floating image display device 1000 displays images in the display areas Db to Dd of the multiple display areas Da to De of the display device 1, so that the image areas Ib to Id are formed as the space-floating image 3.

[0329] In this case, the display contents of each image area Ib-Id may be the same content, or may be different content. For example, the lower image area Id may display content for children, and the upper image area Ib may display content for adults. In this example, the image area formed as the floating in space image 3 is switched according to the size and position of the window W2, but for example, the position of the face of the passenger 230 of the vehicle Ve3 may be detected based on the image of the camera 1180, and the image area formed as the floating in space image 3 may be switched based on the detection result.

[0330] In this configuration, the floating image 3 can be displayed for many passengers of different heights, i.e., different eye levels. In addition, there is no need to adjust the display height of the floating image 3 to suit passengers of different heights, which allows for simplification of the device.

[0331] <Modification 9 of Example 3> Fig. 29 is a diagram showing the configuration of a space-floating image display device according to Modification 9. As shown in Fig. 29, the space-floating image display device 1000 according to Modification 9 is installed on the ceiling of a vehicle Ve3 on which passengers 230 can stand and ride, and forms a floating image 3 toward the passengers 230 of the vehicle Ve3.

[0332] Specifically, the space-floating image display device 1000 according to the modification 9 is fixed to the ceiling of a vehicle Ve3 such as a train so that the surface on which the space-floating image 3 is formed faces downward. That is, the display device 1 and the optical system are disposed in a housing 1190 fixed to the ceiling of the vehicle Ve3 so that the surface on which the space-floating image 3 is formed faces downward.

[0333] Specifically, the display device 1 is disposed so as to face obliquely upward at an angle of approximately 45° with respect to the z' direction, which is the vertical direction. The optical system of the space floating image display device 1000 according to the ninth modification is basically the same as the optical system of FIG. 2A, but differs in that it includes a mirror member 1980 provided on the optical path of the image light emitted from the display device 1. The mirror member 1980 is provided on the optical path between the display device 1 and the polarization separation member 101.

[0334] In this example, the polarization separation member 101 and the mirror member 1980 provided on the transparent member 100 are disposed along the ceiling surface of the vehicle Ve3. The polarization separation member 101 is disposed adjacent to the lower surface of the housing 1190, and the mirror member 1980 is disposed adjacent to the upper surface of the housing 1190.

[0335] With this configuration, the floating image 3 is formed in the z' direction, which is the height direction of the vehicle Ve3, near the hanging strap St provided on the vehicle Ve3. That is, the floating image display device 1000 according to the 9th modification is configured so that the floating image 3 is formed in the z' direction near the hanging strap St. In other words, in the floating image display device 1000 according to the 9th modification, the floating image 3 is formed at a height that can be reached by the passenger 230 standing on the vehicle Ve3.

[0336] In this example, similar to the fourth modification, the position of the passenger 230 is detected based on the image of the camera 1180, and the display position of the floating image 3 in space is adjustable according to the detected position of the passenger 230. Specifically, the display device 1 is configured to be movable along the optical axis direction of the image.

[0337] In this way, by forming the floating image 3 near the strap St in the z' direction, it becomes easier to attract the attention of passengers (especially standing passengers) 230. In addition, it becomes easier for standing passengers 230 to view and operate the floating image 3. For example, by allowing passengers 230 to operate the floating image 3 to selectively display their preferred advertisements, it is expected that the effectiveness of advertisements will be improved. In addition, for example, by displaying a quiz-style advertisement and allowing passengers 230 to select the answer, it is expected that the effectiveness of advertisements will be improved, thereby increasing the entertainment value.

[0338] According to the above-described space floating image display device according to the third embodiment of the present invention, it is possible to provide a more comfortable space floating image display technology for crew members or passengers of various vehicles.

[0339] The technology according to this embodiment displays high-resolution, high-brightness image information in a state of floating in space, which allows users to operate the system without worrying about contact infection. If the technology according to this embodiment is used in a system used by an unspecified number of users, it is possible to provide a contactless user interface that can be used without worry, reducing the risk of contact infection. This contributes to the achievement of "Good health and well-being for all," one of the Sustainable Development Goals (SDGs) advocated by the United Nations.

[0340] In addition, the technology according to this embodiment makes it possible to efficiently reflect only the normal reflected light from the retroreflector by reducing the divergence angle of the emitted image light and aligning it to a specific polarization, which makes it possible to obtain a bright and clear floating image with high light utilization efficiency. The technology according to this embodiment makes it possible to provide a highly usable non-contact user interface that can significantly reduce power consumption. This contributes to the achievement of the Sustainable Development Goals (SDGs) proposed by the United Nations, "9 Build resilient infrastructure, promote inclusive and sustainable industrialization, and promote technological innovation" and "11 Make cities and towns sustainable and livable."

[0341] Although various embodiments have been described above in detail, the present invention is not limited to the above-described embodiments, and various modified examples are included. For example, the above-described embodiments are detailed descriptions of the entire system in order to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration. [Explanation of symbols]

[0342] 1...display device, 2, 5...retroreflector (retroreflector), 3...spatial image (space-floating image), 105...window glass, 100...transparent member, 101...polarized light separation member, 101B...polarized light separation member, 12...absorptive polarizer, 13...light source device, 54...light direction conversion panel, 151...retroreflector, 102, 202...LED substrate, 203...light guide, 205...reflective sheet, 206, 270...phase difference plate, 271...reflector, 230...user , 1000... Space floating image display device, 1110... Control unit, 1160... Image control unit, 1180,... Imaging unit, 1102... Image display unit, 1350... Air operation detection unit, 1351... Air operation detection sensor, 1980... Mirror member, 3000... Service equipment, 3001... Ordering window, 3002... Display board, 3003... Housing, 3004... First opening, 3005... Second opening, 3100... Menu signboard, 3200... Stop line (stop position display)

Claims

1. A floating-in-the-air image display device provided in a floating-in-the-air image display system, An image processing section; a display unit that displays the image that has been processed by the image processing unit; an optical system for generating a floating image based on the image displayed by the display unit; having forming the floating image toward the occupants of a vehicle parked at a position corresponding to a service facility equipped with the floating image display system from the side of the vehicle; The floating image is formed in the vicinity of a position for placing an order or a position for making a payment at the service facility in the traveling direction of the vehicle. A floating image display device.

2. 2. The airborne image display device according to claim 1, the location for placing an order with the service facility is a location having a sign indicating that it is a location for placing an order with the service facility; A floating image display device.

3. 2. The airborne image display device according to claim 1, The location for making a payment to the service facility is a location having a sign indicating that it is a location for making a payment to the service facility. A floating image display device.

4. 2. The airborne image display device according to claim 1, The position for placing an order with the service facility or the position for making a payment is a position where a microphone for collecting the voices of the occupants of the vehicle is installed. A floating image display device.

5. 2. The airborne image display device according to claim 1, The service facility is provided on the side of a road surface on which the vehicle runs and stops, a stop position indication for stopping the vehicle at a position corresponding to the service facility is provided on a road surface on which the vehicle runs and stops; The floating image is formed on the service facility side of the stop position display in the traveling direction of the vehicle. A floating image display device.

6. 2. The airborne image display device according to claim 1, a second display unit that is provided on the rear side of the display position of the floating-in-the-air image as seen by an occupant of the vehicle and displays an image different from the floating-in-the-air image; A floating image display device.

7. 2. The airborne image display device according to claim 1, an operation detection unit that detects an operation of the occupant with respect to the floating image; The floating image is an image for inputting information to the service equipment. A floating image display device.

8. The air-floating image display device according to claim 7, The floating image includes an image showing a reading range for reading a two-dimensional code for electronic payment. A floating image display device.

9. 2. The airborne image display device according to claim 1, The floating image is formed inside the window of the vehicle. A floating image display device.

10. 2. The airborne image display device according to claim 1, The position of the floating image is adjustable at least along the height direction of the vehicle. A floating image display device.

11. The air-floating image display device according to claim 10, an occupant detection unit for detecting an occupant in the vehicle; adjusting a position of the floating-in-the-air image based on a detection result of the occupant detection unit so that the floating-in-the-air image is displayed at a height of the occupant's face; A floating image display device.

12. The air-floating image display device according to claim 10, the display unit includes a plurality of display areas capable of individually displaying the images; displaying the image in a part of the plurality of display areas, and adjusting a position of the floating image by changing the display area in which the image is displayed; A floating image display device.

13. The air-floating image display device according to claim 10, The display unit is configured to be movable within a plane perpendicular to an optical axis of the display unit, adjusting a position of the floating-in-the-air image by moving the display unit in an in-plane direction of the display unit; A floating image display device.

14. The air-floating image display device according to claim 10, a housing in which the display unit and the optical system are housed; a position adjustment mechanism that supports the housing and is capable of moving the housing; adjusting a position of the floating image by moving the housing using the position adjustment mechanism; A floating image display device.

15. 2. The airborne image display device according to claim 1, The position of the floating image can be changed in a direction intersecting the traveling direction of the vehicle. A floating image display device.

16. 16. The airborne image display device according to claim 15, The display unit is configured to be movable along an optical axis direction of the image, Adjusting the position of the floating image by moving the display unit; A floating image display device.

17. A floating-in-the-air image display device provided in a floating-in-the-air image display system, An image processing section; a display unit that displays the image that has been processed by the image processing unit; an optical system for generating a floating image based on the image displayed by the display unit; having forming the floating image from the front of a vehicle parked at a position corresponding to a service facility equipped with the floating image display system toward an occupant of the vehicle; The light for forming the floating image is emitted from an exit surface of the optical system, and the floating image is formed on an inside of a windshield of the vehicle; the exit surface of the optical system is arranged in a tilted direction along the tilt direction of the surface of the windshield; A floating image display device.

18. A floating-in-the-air image display device, An image processing section; a display unit that displays the image that has been processed by the image processing unit; an optical system for generating a floating image based on the image displayed by the display unit; Equipped with forming the floating image toward the vehicle occupant; the optical system includes a plurality of reflective members that reflect the image displayed on the display unit, the floating image is formed toward an occupant of the vehicle after the image is reflected three or more times by the plurality of reflecting members; A floating image display device.

19. A floating-in-the-air image display device, An image processing section; a display unit that displays the image that has been processed by the image processing unit; an optical system for generating a floating image based on the image displayed by the display unit; Equipped with The floating image is formed inside a vehicle through a window of the vehicle in which passengers can stand. A floating image display device.

20. 20. The airborne image display device according to claim 19, A window detection unit is provided to detect the size of a window of the vehicle, The floating image includes a plurality of image areas aligned in a height direction of the vehicle, based on a detection result of the window detection unit, only an image area located within the window in a height direction of the vehicle among the plurality of image areas is displayed as the floating image. A floating image display device.

21. A floating-in-the-air image display device, An image processing section; a display unit that displays the image that has been processed by the image processing unit; an optical system for generating a floating image based on the image displayed by the display unit; Equipped with a vehicle that is installed on the ceiling of the vehicle in which passengers can stand and form the floating image toward the passengers of the vehicle; The floating image is formed in the vehicle height direction near a strap provided on the vehicle. A floating image display device.

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