Air floating image display apparatus

Abstract

To provide a technique that can display an air floating image more suitably, and contributes to "3 Good Health and Well-Being", "9 Industry, Innovation and Infrastructure" and "11 Sustainable Cities and Communities" of the Sustainable Development Goals.SOLUTION: An air floating image display apparatus includes: a display panel which displays an image; a polarization separation member which reflects a portion of image light emitted from the display panel; and a retroreflective member which is disposed so as to be opposite to the display panel, and retroreflects the reflected light from the polarization separation member. The reflected light retroreflected by the retroreflective member forms an air floating image via the polarization separation member. By forming the polarization separation member in a non-planar shape, the air floating image is formed in a non-planar shape.SELECTED DRAWING: Figure 15A

Description

[Technical field]

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

[0002] As an example of a space-floating image display device, an image display device and a display method that directly displays an image as a spatial image toward the outside are already known. In addition, a detection system that reduces false detections of operations on the operation surface of the displayed spatial image is also described in, for example, JP 2019-128722 A (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 space floating image display device of Patent Document 1 does not fully consider the technology for more suitably displaying the space floating image under various usage conditions.

[0005] An object of the present invention is to provide a technique for more suitably displaying a floating-in-space image. [Means for solving the problem]

[0006] In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above problems, and as an example, a floating image display device for displaying a floating image includes a display panel for displaying an image, a polarized light separating member for reflecting a portion of the image light emitted from the display panel, and a retroreflective member arranged opposite the display panel for retroreflecting the reflected light from the polarized light separating member, and the reflected light retroreflected by the retroreflective member forms a floating image via the polarized light separating member, and the polarized light separating member is made non-planar to form the floating image in a non-planar shape. Effect of the Invention

[0007] According to the representative embodiment of the present invention, a more suitable floating-in-the-air image display device can be realized. The above-mentioned problems and other problems, as well as the configurations for solving these problems and the effects thereof, will be made clear from the following description of the embodiment. [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; [Diagram 2] FIG. 1 is a diagram showing a V-shaped configuration as an example of a main part configuration of a space floating image display device according to an embodiment. [Diagram 3] FIG. 1 is a diagram showing a Z-shaped configuration as an example of a main part configuration of a space floating image display device according to an embodiment. [Figure 4] 4A to 4C are diagrams illustrating an example of a detailed structure of a retroreflective member. [Diagram 5] 1 is a characteristic diagram showing the relationship between the surface roughness of a retroreflective member and the amount of blurring of a retroreflected image (a spatially floating image). [Figure 6] 1 is a diagram showing an example of the configuration of a video display device according to an embodiment; [Figure 7] FIG. 1 is a diagram showing an example of a V-type configuration of a space floating image display device according to an embodiment (first embodiment). [Figure 8]FIG. 13 is a diagram showing another example of a V-type configuration of the space floating image display device according to an embodiment (second embodiment). [Figure 9] FIG. 13 is a diagram showing another example of a V-type configuration of the space floating image display device according to an embodiment (third embodiment). [Figure 10] FIG. 13 is a block diagram showing an example of an internal configuration of a space floating image display device according to an embodiment (fourth embodiment). [Figure 11] FIG. 13 is a diagram showing an example of a Z-type configuration of a space floating image display device according to an embodiment (fifth embodiment). [Figure 12] FIG. 13 is a diagram showing another example of a Z-type configuration of the space floating image display device according to an embodiment (sixth embodiment). [Figure 13] FIG. 13 is a diagram showing another example of a Z-type configuration of the space floating image display device according to one embodiment (seventh embodiment). [Figure 14] FIG. 13 is a diagram showing an example of the shape of a polarization separation member in a space floating image display device according to an embodiment (eighth embodiment). [Figure 15A] FIG. 13 is a diagram showing another example of a Z-type configuration of the space floating image display device according to an embodiment (eighth embodiment). [Figure 15B] FIG. 13 is a diagram showing another example of a Z-type configuration of the space floating image display device according to an embodiment (eighth embodiment). [Figure 15C] FIG. 13 is a diagram showing another example of a Z-type configuration of the space floating image display device according to an embodiment (eighth embodiment). [Figure 15D] FIG. 13 is a diagram showing another example of a Z-type configuration of the space floating image display device according to an embodiment (eighth embodiment). [Figure 15E] FIG. 13 is a diagram showing another example of a Z-type configuration of the space floating image display device according to an embodiment (eighth embodiment). [Figure 15F] FIG. 13 is a diagram showing another example of a Z-type configuration of the space floating image display device according to an embodiment (eighth embodiment). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same parts are generally given the same reference numerals, and repeated explanations are omitted. In the drawings, the representation of each component may not show the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. For the purpose of explanation, when describing processing by a program, the program, functions, processing units, etc. may be described as the main body, but the main body as hardware for them is a processor, or a controller, device, computer, system, etc., configured with the processor, etc. The computer executes processing according to the program read onto the memory while appropriately using resources such as memory and communication interfaces by the processor. This realizes a predetermined function, processing unit, etc. The processor is configured with semiconductor devices such as CPU / MPU and GPU, for example. The processor is configured with devices and circuits capable of performing a predetermined calculation. The processing is not limited to software program processing, and can also be implemented by a dedicated circuit. The dedicated circuit can be an FPGA, an ASIC, a CPLD, etc. The program may be installed in the target computer as data in advance, or may be distributed as data from the program source to the target computer and installed. The program source may be a program distribution server on a communication network, or a non-transitory computer-readable storage medium, such as a memory card or a disk. The program may be composed of multiple modules. The computer system may be composed of multiple devices. The computer system may be composed of a client-server system, a cloud computing system, or the like. The various data and information are composed of structures such as, for example, tables and lists, but are not limited to these. Expressions such as identification information, identifiers, IDs, names, and numbers are interchangeable.

[0010] <Embodiment> The space-floating image display device of the embodiment is configured to include an image display device, a beam splitter which is a polarization separation member, and a retroreflective member having a λ / 4 plate (phase difference plate, quarter-wave plate) on the retroreflective surface. The image display device is configured to include a light source device, and a display panel or liquid crystal display panel which emits image light of a specific polarization (e.g., P-polarized light) as an image source (image display element). The light source device generates and supplies light as a backlight to the liquid crystal display panel. A polarization separation member is disposed in a space connecting the liquid crystal display panel of the image display device and the retroreflective member. The polarization separation member has a property of transmitting the image light of a specific polarization from the liquid crystal display panel toward the retroreflective member, and reflecting the image light of the other polarization (e.g., S-polarized light) after polarization conversion by the retroreflective member and the λ / 4 plate. The image light of the other polarization after reflection generates and displays a space-floating image which is a real image at a predetermined position in a direction different from the image display device.

[0011] In order to improve the contrast performance of the spatial floating image, the image display device may be provided with a polarization conversion section that aligns the light source light from the light source device to a polarization direction in a specific direction. For example, the light source device includes a point-like or planar light source, an optical element section that reduces the divergence angle of the light from the light source, a polarization conversion section (such as a polarization conversion element) that aligns the light from the light source to a polarization direction in a specific direction, and a light guide having a reflective surface that propagates the light from the light source to the liquid crystal display panel, and controls the image luminous flux of the image light from the liquid crystal display panel by the shape and surface roughness of the reflective surface of the light guide.

[0012] The space-floating image display device of the embodiment is configured with an image display device unit having a housing that can be placed on a desk, and a space-floating image display unit having a frame structure, taking into consideration use particularly indoors, although this is not limited thereto.

[0013] The image display device mainly comprises a liquid crystal display panel and a light source (backlight).

[0014] The space floating image display unit is configured to have an optical system made up of a polarized light separation member and a retroreflective member, etc. The optical system of this embodiment has a structure supported by a frame made up of a groove, metal, resin, etc.

[0015] [Space-floating image display device] The following embodiment relates to a space-floating image display device that can display an image generated by image light from a large-area image emission source as a space-floating image inside or outside the space of a store by transmitting the image generated by image light from a large-area image emission source through a transparent member that divides the space, such as the glass of a display window. In addition to the above embodiment, the present invention relates to a space-floating image display device that is mainly used for displaying space-floating images indoors, using an optical system composed of a polarization separation member (in other words, a polarization beam splitter, or simply a beam splitter) and a retroreflector, and transmitting the image generated by image light from a smaller-area image emission source (for example, about 2 to 5 inches).

[0016] In the following description of the embodiments, an image floating in space is expressed by the term "space-floating image". Instead of this term, it may be expressed as "aerial image", "space-floating image", "space-floating optical image of displayed image", "space-floating optical image of displayed image", etc. The term "space-floating image" used in the description of the embodiments is used as a representative example of these terms.

[0017] According to the following embodiment, for example, it is possible to display high-resolution image information in a floating state on the glass surface of a shop window or a light-transmitting plate. Furthermore, the floating image display device of the embodiment can be installed in a relatively small space such as on a desk in a study, on a table in a living room, or on a kitchen counter.

[0018] In the conventional floating image display device, an organic EL panel or a liquid crystal display panel is used as a high-resolution color display image source in combination with a retroreflective material. In the conventional floating image display device, the image light is diffused at a wide angle, which causes the following problems.

[0019] As shown in Fig. 4, in the retroreflective member 2, since the retroreflective member 2a is a hexahedron, in addition to the normally reflected light, ghost images are generated by the image light that is obliquely incident on the retroreflective member 2, which causes a problem of impairing the image quality of the spatial floating image. The retroreflective member 2 is also called a retroreflective plate or a retroreflective sheet.

[0020] Furthermore, as shown in FIG. 5, the floating image obtained by reflecting the image light from the image display device, which is the image source, using the retroreflective member 2 has the problem that in addition to the ghost image mentioned above, blurring occurs in each pixel of the liquid crystal display panel.

[0021] FIG. 1 shows an example of a usage form and a configuration example of a space-floating image display device according to an embodiment. FIG. 1(A) shows the overall configuration of the space-floating image display device according to this embodiment. For example, in a store or the like, a show window (window glass) 105, which is a light-transmitting member (also described as a transparent member) such as glass, divides the space. According to the space-floating information display device of this embodiment, the space-floating image 3 can be displayed in one direction to the outside of the store space through the transparent member 100. Specifically, light with a narrow-angle directional characteristic and specific polarization is emitted as an image light beam from the image display device 1 in the space-floating information display device, once enters the retroreflective member 2, is retroreflected, and passes through the window glass 105 to form the space-floating image 3, which is a real image, outside the store space. FIG. 1(A) shows a case where the back side of the window glass 105 in the depth direction is the store space, and the front side is the outside store space (for example, a sidewalk). On the other hand, by providing the window glass 105 with a means for reflecting a specific polarized wave (such as an optical member), it is possible to reflect the image light beam and form the floating image 3 in a desired position within the store.

[0022] FIG. 1B shows a block diagram of the image display device 1 described above. The image display device 1 includes an image display unit 1a that displays an original image of the floating image 3, an image control unit 1b that converts the input image to match the resolution of the panel of the image display unit 1a, an image signal receiving unit 1c that receives an image signal, and a receiving antenna 1d. The image signal receiving unit 1c supports wired input signals such as USB (Universal Serial Bus: registered trademark) input and HDMI (High-Definition Multimedia Interface: registered trademark) input, and supports wireless input signals such as Wi-Fi (Wireless Fidelity: registered trademark). The image display device 1 functions independently as an image receiving and display device, and can also display image information from an external PC, tablet, smartphone, etc. Furthermore, the image display device 1 can be provided with capabilities such as calculation processing and image analysis processing by connecting a stick PC, etc.

[0023] [V-type space floating image display device] FIG. 2 shows an example of the configuration of the main part of a space floating image display device according to an embodiment. The embodiment of FIG. 2 shows a configuration in which an image display device 1 and a retroreflection member (in other words, a retroreflection plate) 2 are arranged in a substantially V-shape (hereinafter, referred to as a V-shape). As shown in FIG. 2, in the V-shape configuration, an image display device 1 that generates image light of a specific polarization is provided in an oblique direction (a direction corresponding to an optical axis A1) relative to a transparent member 100 such as flat glass (arranged horizontally in this example). In addition, a retroreflection member 2 is provided in another oblique direction (a direction corresponding to an optical axis A2) relative to the transparent member 100 such as flat glass. The image display device 1 is composed of a light source device 13, a liquid crystal display panel 11 which is a liquid crystal display element, an absorptive polarizing plate 12, and the like.

[0024] 2, image light of a specific polarization emitted from a liquid crystal display panel 11 of an image display device 1 travels in the direction of an optical axis A1, is reflected by a beam splitter 101 (polarization separation member) having a film that selectively reflects image light of a specific polarization provided on a transparent member 100, travels in the direction of an optical axis A2, and enters a retroreflective member 2. In this example, the beam splitter 101 is formed in a sheet shape and adhered to the lower surface of the transparent member 100 such as a flat glass. Alternatively, the beam splitter 101 may be formed by directly evaporating an optical thin film onto the flat glass.

[0025] A λ / 4 plate 21 is provided on the image light incident surface (in other words, the retroreflective surface) of the retroreflective member 2. In other words, the λ / 4 plate 21 is a polarization conversion element, a phase difference plate, and a quarter-wave plate.

[0026] The image light on the optical axis A2 from the beam splitter 101 is made to pass through the λ / 4 plate 21 twice in total, once when it enters the retroreflective member 2 and once when it leaves the retroreflective member 2, and is polarized and converted from a specific polarized wave (one polarized wave) to the other polarized wave. Here, the beam splitter 101, which selectively reflects the image light of a specific polarized wave, has the property of transmitting the image light of the other polarized wave after the polarization conversion. Therefore, the image light of the other polarized wave after the polarization conversion passes through the beam splitter 101. The image light transmitted through the beam splitter 101 forms and displays a real image, a floating-in-space image 3, at a predetermined position outside the transparent member 100 in the direction of the optical axis A3 corresponding to the optical axis A2.

[0027] The light forming the floating image 3 is a collection of light rays that converge from the retroreflective member 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, in the configuration of FIG. 2, when a user views the floating image 3 from the direction A indicated by the arrow corresponding to the optical axis A3, the floating image 3 is seen as a bright image. However, when another person views the floating image 3 from the direction B indicated by the arrow, for example, the floating image 3 cannot be seen as an image at all. Such characteristics are very 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.

[0028] Depending on the performance of the retroreflective member 2, the polarization axis of the reflected image light may become misaligned. In this case, a part of the image light with the misaligned polarization axis is reflected by the beam splitter 101 and returns to the image display device 1. This returned light may be re-reflected on the image display surface of the liquid crystal display panel 11 constituting the image display device 1, generating a ghost image and possibly degrading the image quality of the floating image 3. Therefore, in this embodiment, an absorbing polarizing plate 12 is provided on the image display surface of the image display device 1. The image light emitted from the image display device 1 is transmitted through the absorbing polarizing plate 12, and the reflected light returning from the beam splitter 101 is absorbed by the absorbing polarizing plate 12. This makes it possible to suppress the re-reflection and prevent degradation of the image quality of the floating image 3 due to the ghost image.

[0029] The above-mentioned beam splitter (polarized light separating member) 101 is formed of, for example, a reflective polarizing plate, a metal multilayer film that reflects a specific polarized wave, etc. More specifically, the beam splitter 101 can be formed by evaporating an optical thin film onto a flat glass (for example, quartz glass).

[0030] [Z-type space floating image display device] Fig. 3 shows an example of the configuration of the main parts of a space floating image display device according to an embodiment, which is different from the embodiment in Fig. 2. The embodiment in Fig. 3 shows a configuration in which an image display device 1 and a retroreflective member 2 (retroreflective plate) are arranged facing each other, and a beam splitter 101 is arranged in the space connecting them at an angle of about 45 degrees to the image display device 1 and the retroreflective member 2, roughly in a Z shape (or an inverted Z shape) (hereinafter referred to as Z shape).

[0031] The Z-shaped configuration shown in Fig. 3 includes a transparent member 100 such as a glass plate and an absorptive polarizer 112 for the purpose of reducing the effect of external light incident from a direction C on the retroreflective member 2 and the image display device 1. As shown in Fig. 3, the image display device 1 and the retroreflective member 2 are disposed at an angle of about 90 degrees with the transparent member 100 and the absorptive polarizer 112, and at an angle of about 45 degrees with the beam splitter 101. In this embodiment, the beam splitter 101 is disposed in the horizontal direction, and the position of the image displayed on the image display device 1, more specifically the liquid crystal display panel 11, and the position where the floating image 3 is formed are in a plane-symmetrical relationship with the beam splitter 101.

[0032] [Retroreflective material] 4 shows an example of the surface shape of a retroreflector as a representative retroreflective member 2. Light rays incident on the interior of regularly arranged triangular pyramid prisms are reflected by the three walls and the bottom of the triangular pyramid 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.

[0033] The resolution of the floating image 3 in space depends largely on the outer diameter D and pitch P of the retroreflective area 2a (area surrounded by a hexagon) of the retroreflective member 2 shown in FIG. 4, in addition to the resolution of the liquid crystal display panel 11. For example, when a 7-inch WUXGA (1920×1200 pixels) liquid crystal display panel 11 is used, even if one pixel (one triplet) is about 80 μm, if the diameter D of the retroreflective area 2a is 240 μm and the pitch P is 300 μm, one pixel of the floating image 3 in space is equivalent to 300 μm. Therefore, the effective resolution of the floating image 3 in space is reduced to about 1 / 3. Therefore, in order to make the resolution of the floating image 3 equivalent to the resolution of the image display device 1, it is desirable to make the diameter D and pitch P of the retroreflective area 2a close to one pixel of the liquid crystal display panel 11. On the other hand, in order to suppress the occurrence of moire caused by the retroreflective member 2 and the pixels of the liquid crystal display panel 11, it is preferable to design the pitch ratio of each to be a different integer multiple of one pixel. Also, it is preferable to arrange the retroreflective area 2a in a shape such that none of its sides overlaps any of the sides of one pixel of the liquid crystal display panel 11.

[0034] 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.

[0035] The present inventor has experimentally determined the relationship between the amount of blur l (small L) and the pixel size L (large L) of the image of the floating image 3 that can be tolerated to improve visibility by creating an image display device 1 that combines a liquid crystal display panel 11 with a pixel pitch of 40 μm and a light source device 13 with a narrow divergence angle (divergence angle of 15°) of this embodiment. FIG. 5 shows the experimental results. It was found that the amount of blur l that deteriorates visibility is preferably 40% or less of the pixel size, and is barely noticeable if it is 15% or less. It was found that the surface roughness of the reflective surface at which the amount of blur l is tolerable is an average roughness of 160 nm or less within a measurement distance of 40 μm, and that to make the amount of blur l less noticeable, the surface roughness of the reflective surface is preferably 120 nm or less. For this reason, it is desirable to reduce the surface roughness of the retroreflective member 2 described above, and to make the surface roughness of the reflective film and its protective film that form the reflective surface less than the above-mentioned value.

[0036] On the other hand, in order to manufacture the retroreflective member 2 at a low cost, it is preferable to use a roll press method. Specifically, this is a method in which the retroreflective members 2a are aligned and shaped on a film. In this method, the inverse shape of the shape to be shaped is formed on the roll surface, an ultraviolet curable resin is applied onto a base material for fixing, and the required shape is shaped by passing it between the rolls, and the desired shape is obtained by irradiating ultraviolet rays to harden it.

[0037] The image display device 1 of this embodiment, by using the liquid crystal display panel 11 and the light source device 13 (see FIG. 6 for details) as a light source that generates light of a specific polarization, reduces the possibility that image light will be obliquely incident on the retroreflective member 2. As a result, the occurrence of ghost images is suppressed, and even if a ghost image occurs, the brightness of the ghost image is low, resulting in a structurally excellent system.

[0038] 3, the image display device 1, which is configured with a liquid crystal display panel 11, an absorptive polarizer 12, and a light source device 13, is disposed at a predetermined angle (for example, an angle of about 45 degrees with respect to the beam splitter 101 on the horizontal plane). The image light from the image display device 1 passes through the beam splitter 101 in the direction of the optical axis B1 (diagonal direction with respect to the beam splitter 101) and proceeds toward the retroreflective member 2 in the direction of the optical axis B2 (corresponding to the direction D) corresponding to the optical axis B1.

[0039] Here, the image light from the image display device 1 is image light having characteristics of, for example, P-polarized (parallel polarization) as light of a specific polarization. The beam splitter 101 is a polarization separation member such as a reflective polarizing plate, and has the property of transmitting the P-polarized image light from the image display device 1 but reflecting the S-polarized (vertical polarization) image light. The beam splitter 101 is formed of a reflective polarizing plate or a metal multilayer film that reflects a specific polarization. The beam splitter 101 can generally be formed by evaporating an optical thin film on a flat glass substrate. Therefore, the refractive index of the beam splitter 101 is substantially the same as the refractive index n (n≈1.5) of flat glass.

[0040] Meanwhile, a λ / 4 plate 21 is provided on the light incidence surface (retroreflective surface) of the retroreflective member 2. The P-polarized image light transmitted through the beam splitter 101 from the image display device 1 is polarized and converted from P-polarized light to S-polarized light by passing through the λ / 4 plate 21 twice in total, when it enters the retroreflective member 2 and when it leaves the retroreflective member 2. As a result, the S-polarized image light after the polarization conversion from the retroreflective member 2 is reflected by the beam splitter 101 and travels toward the transparent member 100 and the like. The S-polarized image light that travels in a direction corresponding to the optical axis B3 after reflection (a diagonal direction with respect to the beam splitter 101) passes through the transparent member 100 made of a glass plate or the like and the absorptive polarizing plate 112, and generates and displays the space floating image 3, which is a real image, at a predetermined position outside the transparent member 100 and the like.

[0041] Here, in order to reduce degradation of image quality caused by sunlight or illumination light entering an optical system composed of optical components such as the image display device 1, the retroreflective member 2, and the beam splitter 101, it is advisable to provide an absorptive polarizing plate 112 on the outer surface of the transparent member 100. Since the polarization axis may become uneven due to the retroreflective member 2 reflecting light, some of the image light may be reflected by the beam splitter 101 and returned to the image display device 1. This returned light is reflected again by the image display surface of the liquid crystal display panel 11 constituting the image display device 1, generating a ghost image and significantly degrading the image quality of the floating image 3 in space.

[0042] 2 and 3, an absorptive polarizing plate 12 is provided on the image display surface of the image display device 1. Alternatively, an anti-reflection film (not shown) may be provided on the image output side of the absorptive polarizing plate 12 provided on the surface of the image display device 1. In this way, the light that causes the ghost image to be generated is absorbed by the absorptive polarizing plate 12, thereby preventing degradation of image quality due to the ghost image of the spatial floating image 3.

[0043] Furthermore, in the Z-shaped configuration of FIG. 3, when external light is directly incident on the retroreflective member 2, a strong ghost image is generated. Therefore, in order to suppress and prevent the generation of this ghost image, in this embodiment, the retroreflective member 2 is tilted downward with respect to the incident direction of the external light to prevent the incidence of the external light. Specifically, the main incident direction of the external light is set to a direction (diagonal direction like the optical axis B3) corresponding to the direction C indicated by the arrow (the direction in which the user views the floating image 3 from the front). In this case, the retroreflective member 2 is arranged so that the optical axis B2 is, for example, at about 90 degrees relative to the direction C (optical axis B3). In other words, the main surface of the retroreflective member 2 is arranged so that the main surface of the transparent member 100 or the like is, for example, at about 90 degrees. As a result, the external light incident in the direction C does not directly enter the main surface (retroreflective surface) of the retroreflective member 2, thereby preventing the generation of a ghost image.

[0044] Moreover, the image display device 1 is also disposed in a direction different from the incident direction of the external light (direction C). Specifically, the main surface (image light exit surface) of the image display device 1 is disposed in the same direction (in other words, parallel) as the main surface of the retroreflective member 2, and the optical axis B1 of the image display device 1 is disposed at an angle of about 90 degrees with respect to the optical axis B3 corresponding to the incident direction of the external light (direction C). Moreover, when considering the range of the light flux when external light is incident on the main surface of the transparent member 100 functioning as an opening in direction C, the image display device 1 is disposed at a position slightly outside that range. As a result, the occurrence of ghost images caused by re-reflection at the image display device 1 is reduced.

[0045] [Video display device] Fig. 6 shows a configuration example of an image display device 1 applicable to the embodiments of Fig. 2 and Fig. 3. This image display device 1 is configured to include a light source device 13, a liquid crystal display panel 11, a light direction conversion panel 54, etc. The image output surface side of the liquid crystal display panel 11 may be provided with the above-mentioned absorptive polarizer 12. The light source device 13 is configured to include a plurality of LED elements 201 (LEDs: Light Emitting Diodes) which are semiconductor light sources (solid light sources) constituting the light source, a light guide 203, etc. Fig. 6 shows a developed perspective view of the liquid crystal display panel 11 and the light direction conversion panel 54 arranged on the light output side of the light source device 13.

[0046] Light source device 13 is formed of, for example, a plastic case (not shown) and is configured to house LED elements 201 and light guide 203 inside. A light receiving end surface 203a is provided on the light incident side of light guide 203 to convert divergent light from each LED element 201 into a substantially parallel light beam. Light receiving end surface 203a has a shape in which the cross-sectional area gradually increases toward the opposite side to the light receiving portion, and is provided with a lens shape that has the effect of gradually decreasing the divergence angle by multiple total reflections during propagation inside.

[0047] Furthermore, the liquid crystal display panel 11 arranged approximately parallel to the light guide 203 is attached to the upper surface of the light guide 203. The upper surface of the light guide 203 serves as an emission surface that emits light reflected by the light guide 203. Furthermore, a plurality of LED elements 201 are attached to one side surface (the lower side surface in FIG. 6) of the case of the light source device 13. The light from the plurality of LED elements 201 is converted into approximately collimated light (approximately parallel light) by the shape of the light receiving end surface 203a of the light guide 203. For this reason, the light receiving portion of the light receiving end surface 203a and the LED elements 201 are attached while maintaining a predetermined positional relationship.

[0048] The light source device 13 is configured by attaching a light source unit in which a plurality of LED elements 201 serving as light sources are arranged to a light receiving end surface 203a serving as a light receiving section provided on the light incident side of the light guide 203. The divergent light beam from the LED elements 201 is made into a substantially collimated light by the lens shape of the light receiving end surface 203a of the light guide 203. This substantially collimated light is guided inside the light guide 203 in a direction A indicated by an arrow. The direction A is a direction substantially parallel to the liquid crystal display panel 11 (a direction from bottom to top in the drawing). The light guided in the direction A has its light beam direction converted by a light beam direction conversion section 204 provided in the light guide 203, and is emitted in a direction B indicated by an arrow toward the liquid crystal display panel 11 that is substantially parallel to the light guide 203. The direction B is a direction substantially perpendicular to the display surface of the liquid crystal display panel 11.

[0049] The light guide 203 has a configuration in which the distribution (in other words, density) of the light beam direction conversion parts 204 is optimized by the shape inside or on the surface of the light guide 203. This makes it possible to control the uniformity of light, which is the light beam emitted from the light source device 13 shown in the direction B and incident on the liquid crystal display panel 11.

[0050] Furthermore, in the image display device 1 including the light source device 13 and the liquid crystal display panel 11, in order to improve the utilization efficiency of the light flux emitted from the light source device 13 shown in the direction B and to significantly reduce power consumption, the directivity of the light from the light source device 13 in the direction B can also be controlled. More specifically, a light source having a narrow divergence angle can be configured as the light source device 13. As a result, the image light from the image display device 1 can efficiently reach the observer with high directivity (in other words, linearity) like laser light, and a high-quality floating-in-space image can be displayed with high resolution. At the same time, the power consumption by the image display device 1 including the LED elements 201 of the light source device 13 can be significantly reduced.

[0051] The liquid crystal display panel 11 is attached to a frame (not shown) of the liquid crystal display panel 11, which is attached to the upper surface of a case (not shown) of the light source device 13, and is configured by attaching the liquid crystal display panel 11 attached to the frame, and a flexible printed circuit (FPC: Flexible Printed Circuits) (not shown) electrically connected to the liquid crystal display panel 11, etc. 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 201 based on a control signal from a control circuit (not shown) constituting the electronic device.

[0052] Next, a desk-mounted type space-floating image display device according to one embodiment will be described with reference to Fig. 7 and subsequent drawings. The space-floating image display device of each embodiment shown in Fig. 7 to Fig. 9 corresponds to the V-shaped configuration shown in Fig. 2 as a basic configuration.

[0053] [First Example] FIG. 7 shows a configuration example of the main part of a space floating image display device 400 suitable for installation on a desk, according to one embodiment (hereinafter referred to as a first embodiment).

[0054] 7 shows a cross-sectional view of the space-floating image display device 400 as seen from the side. The front of the device here corresponds to the direction in which the space-floating images 3 (3A, 3B) formed by the space-floating image display device 400 can be viewed by the user (230A, 230B) from the front.

[0055] Directions AA and AB are directions in which the user views the floating-in-space image 3 (3A, 3B) from the front, and correspond to the negative direction in the Y direction.

[0056] For the purpose of explanation, a coordinate system and directions such as (X, Y, Z) shown in the figure may be used. In this figure, the Z direction is the vertical direction, the up-down direction, the X direction and the Y direction are two horizontal directions that are perpendicular to each other, the X direction is the depth direction, the front-back direction (the front-back horizontal direction within the screen of the floating image 3), and the Y direction is the left-right direction (the left-right horizontal direction within the screen of the floating image 3).

[0057] The basic configuration of the V-shaped configuration in Fig. 7 is similar to that of the V-shaped configuration in Fig. 2 in terms of the positional relationship of the components (image display device 1, beam splitter 101A and transparent member 100A, and retroreflective member 2, etc.). In addition, the image display device 1 includes a liquid crystal display panel 11 and a light source device 13.

[0058] In the following description, the beam splitter 101A and the transparent member 100A will be treated as an integrated unit, and the transparent member will be abbreviated. Other similar components will also be abbreviated in the same manner.

[0059] In order to form the space-floating image 3A, the components of the space-floating image display device 400 (image display device 1, beam splitter 101A, retroreflective member 2, etc.) are mutually arranged with a predetermined positional relationship. That is, the image display device 1, beam splitter 101A, retroreflective member 2, etc. in Fig. 7 are arranged with a predetermined positional relationship so as to form a V-shape, similar to the configuration in Fig. 2. The formed space-floating image 3A can be viewed from the front by the user 230A from the direction AA.

[0060] The floating-in-air image display device 400 of the first embodiment shown in Fig. 7 is provided with a hinge mechanism 330 serving as a rotation fulcrum at one end of the beam splitter 101A. The hinge mechanism 330 is a mechanism that does not move up, down, left, or right, but is free to rotate, and is provided in the X direction at the left end of the beam splitter 101A, and the beam splitter 101A is structured to be rotatable up and down around the hinge mechanism 330 as a rotation fulcrum. In other words, the floating-in-air image display device shown in Fig. 7 is provided with a display panel that displays an image, a polarized light separating member that reflects a portion of the image light emitted from the display panel, and a retroreflective member that retroreflects the reflected light from the polarized light separating member, and the reflected light retroreflected by the retroreflective member passes through the polarized light separating member to form a floating-in-air image, and the angle of the polarized light separating member with respect to the display panel and the retroreflective member is variable.

[0061] That is, the beam splitter 101A and the transparent member 100A can be arranged at different angles with respect to the fixed arrangement of the image display device 1 and the retroreflective member 2. Alternatively, the beam splitter 101A and the transparent member 100A can be rotated around the hinge mechanism 330 as a rotation fulcrum, thereby changing the distance between the beam splitter 101A and the image display device 1, and between the beam splitter 101A and the retroreflective member 2. Even if the arrangement angle of the beam splitter 101A and the transparent member 100A is different, they are arranged with a positional relationship to form a V shape, similar to the configuration of FIG.

[0062] 7, the beam splitter 101A and the transparent member 100A are rotated upward by an angle γ with respect to the horizontal position (XY plane) around the hinge mechanism 330 as a rotation fulcrum, and placed at the position of the beam splitter 101B and the transparent member 100B. In this arrangement, the image light from the image display device 1 passes through an optical axis AB1, which is longer than the optical axis A1, is reflected by the beam splitter 101B, passes through the λ / 4 plate 21 along the optical axis AB2, and enters the retroreflective member 2.

[0063] The image light retroreflected by the retroreflective member 2 passes through the λ / 4 plate 21 again, where it is converted to the other polarized wave, and passes through the beam splitter 101B. The image light transmitted through the beam splitter 101B forms and displays a real image, a floating-in-space image 3B, at a predetermined position outside the transparent member 100B, in the direction of the optical axis AB3 corresponding to the optical axis AB2. The formed floating-in-space image 3B can be viewed as a bright image by the user 230B in a frontal position from the direction AB indicated by the arrow corresponding to the optical axis AB3.

[0064] Since the beam splitter 101B is positioned above the beam splitter 101A by an angle γ, the length of the optical axis AB1 from the image display device 1 to the beam splitter 101B is longer than the optical axis A1 from the image display device 1 to the beam splitter 101A, and the floating image 3B is formed at a higher position than the floating image 3A. Therefore, when the height of the viewpoint position differs due to the height difference of the users, it is possible to form the floating image 3 at a position that is easy to view by changing the tilt angle of the beam splitter 101.

[0065] In the embodiment of FIG. 7, beam splitter 101A in a horizontal position forms a floating image 3A that is optimal for user 230A, whereas beam splitter 101B with an upward angle of γ with respect to the horizontal position (XY plane) forms a floating image 3B that is suitable for user 230B, who is taller than user 230A.

[0066] [Second Example] FIG. 8 shows a configuration example of a space floating image display device 400 suitable for installation on a desk, according to one embodiment (hereinafter referred to as a second embodiment).

[0067] FIG. 8 shows a cross-sectional view of the space floating image display device 400 as seen from the side.

[0068] In this embodiment, the space floating image display device 400 of the first embodiment in Fig. 7 is placed in a housing 4001, and the housing 4001 has an opening (opening hole) 4002 in the horizontal direction (parallel to the XY plane). The hinge mechanism 330 is provided at one end of the opening 4002, and rotatably holds the beam splitter 101A at one side of the beam splitter 101A opposite to the user 230, and serves as a rotation fulcrum for the beam splitter 101A.

[0069] The space floating image display device 400 also includes a control unit 500 having functions such as control, an imaging unit 510, and a piston mechanism 310 that moves a piston up and down or expands and contracts.

[0070] In Fig. 8, the positional relationship of the components (image display device 1, beam splitter 101A and transparent member 100A, retroreflective member 2, etc.) is the same as that of the V-shaped configuration in Fig. 7. Note that, hereinafter, the beam splitter 101A and transparent member 100A may be treated as one unit, and the transparent member may be abbreviated. Other similar components may also be abbreviated in the same manner.

[0071] In order to form the space-floating image 3A, the components of the space-floating image display device 400 (image display device 1, beam splitter 101A, retroreflective member 2, etc.) are mutually arranged with a predetermined positional relationship. That is, the image display device 1, beam splitter 101A, retroreflective member 2, etc. in Fig. 8 are arranged with a predetermined positional relationship so as to form a V-shape, similar to the configuration in Fig. 7. The formed space-floating image 3A can be viewed from the front by the user 230A from the direction AA.

[0072] This is an example of a structure in which the beam splitter 101A rotates or moves up and down around the hinge mechanism 330. That is, this structure allows the beam splitter 101A and the transparent member 100A to be arranged at different angles, while the image display device 1 and the retroreflective member 2 are fixedly arranged. Alternatively, this structure allows the beam splitter 101A and the transparent member 100A to be rotated around the hinge mechanism 330, thereby changing the distance between the beam splitter 101A and the image display device 1, and the distance between the beam splitter 101A and the retroreflective member 2. In other words, the floating-in-the-air image display device shown in Figure 8 comprises a display panel that displays an image, a polarizing separation member that reflects a portion of the image light emitted from the display panel, and a retroreflective member that retroreflects the light reflected from the polarizing separation member, and the light reflected by the retroreflective member passes through the polarizing separation member to form a floating-in-the-air image, and the angle of the polarizing separation member relative to the display panel and the retroreflective member is variable.

[0073] The piston mechanism 310 is disposed on the side of the beam splitter 101A and the transparent member 100A that faces the hinge mechanism 330. In the initial state, the piston of the piston mechanism 310 is in contact with one side of the beam splitter 101A and the transparent member 100A with the length of the piston 310A, and holds the beam splitter 101A and the transparent member 100A horizontally (parallel to the XY plane). When the piston 310A of the piston mechanism 310 extends and is in the state of piston 310B, the beam splitter 101A and the transparent member 100A rotate upward by angle γ with respect to the horizontal position (XY plane) with the hinge mechanism 330 as the rotation fulcrum, and move to the position of the beam splitter 101B and the transparent member 100B. That is, the piston mechanism 310 rotates the beam splitter 101A around the hinge mechanism 330 of the rotation axis as a rotation fulcrum, and the angle with respect to the image display device 1 and the retroreflective member 2 can be changed.

[0074] At the position of the beam splitter 101B and the transparent member 100B, the image light from the image display device 1 passes through an optical axis AB1, which is longer than the optical axis A1, is reflected by the beam splitter 101B, passes through the λ / 4 plate 21 along the optical axis AB2, and enters the retroreflective member 2. The image light retroreflected by the retroreflective member 2 passes through the λ / 4 plate 21 again, is converted into the other polarized wave, and transmits the beam splitter 101B. The image light transmitted through the beam splitter 101B forms and displays a real image, a floating-in-space image 3B, at a predetermined position outside the transparent member 100B, in the direction of an optical axis AB3 corresponding to the optical axis AB2. The formed floating-in-space image 3B can be viewed as a bright image by the user 230B in a front position from the direction AB indicated by the arrow corresponding to the optical axis AB3.

[0075] The arrangement of the piston mechanism 310 is not limited to this embodiment, and the same effect can be obtained by arranging it on other sides of the beam splitter 101A and the transparent member 100A or in a plurality of positions. Also, the method of rotating or vertically driving the beam splitter 101A with the hinge mechanism 330 as a rotation fulcrum is not limited to the piston mechanism 310.

[0076] (Regarding the imaging unit, control unit, etc.) The imaging unit 510 captures images of the height, face, and facial components such as the eyes and mouth of the user 230, and information such as the height and face of the user 230 is input to the control unit 500. The imaging unit 510 detects, for example, the position of the eyes of the user 230 from the input information of the user 230, and obtains information on the height of the eyes of the user 230.

[0077] If the obtained eye height information of the user 230 differs from the previously assumed viewing height, the control unit 500 can drive the piston mechanism 310 to change the angle of the beam splitter 101A to a position optimal for viewing by the user 230.

[0078] For example, if user 230A is at a predetermined viewing height, image capturing unit 510 and control unit 500 control piston mechanism 310 so that beam splitter 101A holds the horizontal position. In the case of user 230B who is taller than user 230A, image capturing unit 510 and control unit 500 extend piston 310A of piston mechanism 310 to piston 310B, and change the position of beam splitter 101A to that of beam splitter 101B tilted by angle γ, so that user 230B can view a bright image from a frontal position.

[0079] [Third Example] FIG. 9 shows a configuration example of a space floating image display device suitable for installation on a desk, according to one embodiment (hereinafter referred to as a third embodiment).

[0080] 9 shows a cross-sectional view of the space-floating image display device as seen from the side. In this embodiment, a space-floating image display device 400 is disposed in a housing 4001.

[0081] In Fig. 9, the positional relationship of the components (image display device 1, beam splitter 101A and transparent member 100A, retroreflective member 2, etc.) is the same as that of the V-shaped configuration in Fig. 2. Note that, hereinafter, the beam splitter 101A and transparent member 100A may be treated as one unit, and the transparent member may be abbreviated. Other similar components may also be abbreviated in the same manner.

[0082] In order to form the space-floating image 3A, the components of the space-floating image display device (image display device 1, beam splitter 101A, retroreflective member 2, etc.) are mutually arranged with a predetermined positional relationship. That is, the image display device 1, beam splitter 101A, retroreflective member 2, etc. in Fig. 9 are arranged with a predetermined positional relationship so as to form a V-shape, similar to the configuration in Fig. 2. The formed space-floating image 3A can be viewed from the front by the user 230A from the direction AA.

[0083] 9, the hinge mechanism 331 is provided near the center of the opening 4002, and rotatably holds both ends of the beam splitter 101A at or near the center line of the beam splitter 101A that is parallel to one side of the beam splitter 101A facing the user 230, and serves as a rotation fulcrum for the beam splitter 101A. The hinge mechanism 331 does not move up, down, left, or right, but is free to rotate, and the beam splitter 101A rotates up and down with the hinge mechanism 331 as the rotation fulcrum. In other words, the floating-in-the-air image display device shown in Figure 9 comprises a display panel that displays an image, a polarizing separation member that reflects a portion of the image light emitted from the display panel, and a retroreflective member that retroreflects the light reflected from the polarizing separation member, and the light reflected by the retroreflective member passes through the polarizing separation member to form a floating-in-the-air image, and the angle of the polarizing separation member relative to the display panel and the retroreflective member is variable.

[0084] That is, the beam splitter 101A and the transparent member 100A can be arranged at different angles with respect to the fixed arrangement of the image display device 1 and the retroreflective member 2. Alternatively, the beam splitter 101A and the transparent member 100A can be rotated around the hinge mechanism 331 as a rotation fulcrum, thereby changing the distance between the beam splitter 101A and the image display device 1, and between the beam splitter 101A and the retroreflective member 2. Even if the arrangement angle of the beam splitter 101A and the transparent member 100A is different, they are arranged with a positional relationship to form a V shape, similar to the configuration of FIG.

[0085] The piston mechanism 310 is disposed on the side of the beam splitter 101A and the transparent member 100A facing the user 230. In the initial state, the piston of the piston mechanism 310 is in contact with one side of the beam splitter 101A and the transparent member 100A at the length of the piston 310A, and holds the beam splitter 101A and the transparent member 100A horizontally (parallel to the XY plane). When the piston 310A of the piston mechanism 310 extends and is in the state of piston 310C, the beam splitter 101A and the transparent member 100A rotate upward by an angle γ with respect to the horizontal position (XY plane) around the hinge mechanism 331 as the rotation fulcrum, and move to the position of the beam splitter 101C and the transparent member 100C. That is, the piston mechanism 310 rotates the beam splitter 101A around the hinge mechanism 331 of the rotation axis as the rotation fulcrum, and the angle with respect to the image display device 1 and the retroreflective member 2 can be changed.

[0086] In this arrangement, the image light from the center position of the image display device 1 is reflected or passes along the rotation fulcrum axis (X-axis direction) of the hinge mechanism 331 of the beam splitter 101A along the optical axes A1, A2, and A3. Even when the beam splitter 101A and the transparent member 100A rotate by an angle and the image light comes to the position of the beam splitter 101C and the transparent member 100C, the path and length of the optical path of the image light from the center position of the image display device 1 remains almost unchanged, so the image light is reflected by the beam splitters 101A and 101C, passes through the λ / 4 plate 21 along the optical axis A2, and enters the retroreflective member 2.

[0087] The image light retroreflected by the retroreflective member 2 passes through the λ / 4 plate 21 again and is converted to the other polarized wave, and then passes through the beam splitters 101A and 101C. The image light transmitted through the beam splitters 101A and 101C generates a real image, a floating image in space, at a predetermined position outside the transparent members 100A and 100C in the direction of the optical axis A3 corresponding to the optical axis A2, and the floating images in space are generated at approximately the same position, so that the floating images in space 3A and 3C are approximately overlapped.

[0088] In this arrangement, consider image light from a position away from the center of the image display device 1. When image light with optical axis A11 at the bottom end (left end in FIG. 9) of the image display device 1 is reflected by the beam splitter 101A, it passes through the λ / 4 plate 21 along the optical axis A12 and enters the retroreflective member 2. The image light retroreflected by the retroreflective member 2 passes through the λ / 4 plate 21 again, is converted into the other polarized wave, and transmits through the beam splitter 101A. The image light transmitted through the beam splitter 101A generates a real image, a floating-in-space image 3A, at a predetermined position outside the transparent member 100A in the direction of the optical axis A13 corresponding to the optical axis A12.

[0089] Next, when the beam splitter 101A and the transparent member 100A rotate by an angle γ and come to the position of the beam splitter 101C and the transparent member 100C, the image light of the optical axis A11 at the lower end of the image display device 1 is reflected by the beam splitter 101C, passes through the λ / 4 plate 21 along the optical axis C12, and enters the retroreflective member 2. The image light retroreflected by the retroreflective member 2 passes through the λ / 4 plate 21 again, is converted into the other polarized wave, and transmits through the beam splitter 101C. The image light transmitted through the beam splitter 101C generates a real image, a floating-in-space image 3C, at a predetermined position outside the transparent member 100C in the direction of the optical axis C13 corresponding to the optical axis C12.

[0090] The distance between the lower end of the image display device 1 and the beam splitter 101C becomes shorter than the distance between the image display device 1 and the beam splitter 101A due to the rotation of the angle γ, in other words, the optical path distance becomes shorter, so that the position of the upper end (left end in FIG. 9) of the generated floating-in-space image 3C becomes lower than the position of the upper end of the floating-in-space image 3A. When the image light of the optical axis A21 of the upper end (right end in FIG. 9) of the image display device 1 is reflected by the beam splitter 101A, it passes through the λ / 4 plate 21 along the optical axis A22 and enters the retroreflective member 2. The image light retroreflected by the retroreflective member 2 passes through the λ / 4 plate 21 again, is converted into the other polarized wave, and transmits through the beam splitter 101A. The image light transmitted through the beam splitter 101A generates a real image, a floating-in-space image 3A, at a predetermined position outside the transparent member 100A in the direction of an optical axis A23 corresponding to the optical axis A22.

[0091] Next, when the beam splitter 101A and the transparent member 100A rotate by an angle γ and come to the position of the beam splitter 101C and the transparent member 100C, the image light of the optical axis A21 at the upper end of the image display device 1 is reflected by the beam splitter 101C, passes through the λ / 4 plate 21 along the optical axis C22, and enters the retroreflective member 2. The image light retroreflected by the retroreflective member 2 passes through the λ / 4 plate 21 again, is converted into the other polarized wave, and transmits through the beam splitter 101C. The image light transmitted through the beam splitter 101C generates a real image, a floating-in-space image 3C, at a predetermined position outside the transparent member 100C in the direction of the optical axis C23 corresponding to the optical axis C22.

[0092] Because the distance between the upper end of the image display device 1 and the beam splitter 101C becomes longer than the distance between the image display device 1 and the beam splitter 101A due to the rotation of the angle γ, in other words, the optical path distance becomes longer, so that the position of the lower end (the left end in FIG. 9) of the generated floating-in-space image 3C becomes higher than the position of the upper end of the floating-in-space image 3A.

[0093] In other words, the floating image 3C is tilted counterclockwise more than the floating image 3A, or the tilt angle of the floating image 3C is shallower and closer to the horizontal plane than the floating image 3A. The floating image 3C can be seen as a bright floating image in the front position in the direction AC indicated by the arrow by user 230C who is taller or has a higher viewpoint than user 230A.

[0094] [Fourth Example] Next, a block diagram of the internal configuration of the space floating image display device 400 will be described.

[0095] 10 is a block diagram showing an example of the internal configuration of the space-floating image display device 400. The space-floating image display device 400 includes a retroreflective member 2, a liquid crystal display panel 11, a light guide 203, a light source device 13, 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, a video 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, an image control unit 1160, a storage unit 1170, an imaging unit 510, a beam splitter 101, a beam splitter angle adjustment unit 1010, and the like.

[0096] Here, the beam splitter angle adjustment unit 1010 includes the piston mechanism 310 shown in FIG. 8 and FIG.

[0097] It should be noted that a removable media interface 1134, an attitude sensor 1113, a transmissive self-luminous image display device (not shown), a second display device (not shown), a secondary battery 1112, or the like may also be provided.

[0098] Each component of the space floating image display device 400 is disposed in a housing 4001. Note that the imaging unit 510 and the mid-air operation detection sensor 1351 may be provided outside the housing 4001.

[0099] The retroreflective member 2 retroreflects the light modulated by the liquid crystal display panel 11. Of the light reflected by the retroreflective member 2, the light outputted to the outside of the space floating image display device 400 forms the space floating image 3.

[0100] The liquid crystal display panel 11 is a display unit that generates an image by modulating transmitted light based on an input video signal under the control of a video control unit 1160 described later. For example, a transmissive liquid crystal panel is used as the liquid crystal display panel 11. 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 liquid crystal display panel 11.

[0101] The light source device 13 supplies light to the liquid crystal display panel 11, 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 device 13. The power source 1106 also supplies the necessary DC current to each part in the space floating image display device 400.

[0102] The secondary battery 1112 stores the power supplied from the power source 1106. Furthermore, the secondary battery 1112 supplies power to the light source device 13 and other components that require power when power is not supplied from the outside via the external power input interface 1111. In other words, when the space-floating image display device 400 includes the secondary battery 1112, the user can use the space-floating image display device 400 even when power is not supplied from the outside.

[0103] The light guide 203 guides the light generated by the light source device 13 and irradiates the liquid crystal display panel 11. A combination of the light guide 203 and the light source device 13 can be called a backlight for the liquid crystal display panel 11. The light guide 203 may be mainly made of glass. The light guide 203 may be mainly made of plastic. The light guide 203 may be made of a mirror. There are various possible combinations of the light guide 203 and the light source device 13.

[0104] The aerial operation detection sensor 1351 is a sensor that detects an operation on the floating in space image 3 by a finger of the user 230. The aerial operation detection sensor 1351 senses, for example, the entire display range of the floating in space image 3 and the range that overlaps with it.

[0105] The aerial operation detection sensor 1351 may sense only a range that overlaps with at least a part of the display range of the floating in space image 3. Specific examples of the aerial operation detection sensor 1351 include a distance sensor that uses invisible light such as infrared rays, invisible light laser, ultrasonic waves, etc. The aerial operation detection sensor 1351 may also be configured to detect coordinates on a two-dimensional plane by combining multiple sensors. The aerial operation detection sensor 1351 may also be configured with a ToF (Time of Flight) LiDAR (Light Detection and Ranging) or an image sensor.

[0106] 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.

[0107] 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.

[0108] 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 400, or may be provided externally as a separate entity from the space-floating image display device 400. When provided as a separate entity from the space-floating image display device 400, 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 400 via a wired or wireless communication connection path or image signal transmission path.

[0109] In addition, 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 400 without an aerial operation detection function is used as the main body, and only the aerial operation detection function can be added as an option.

[0110] Also, the aerial operation detection sensor 1351 alone may be a separate component, and the aerial operation detection unit 1350 may be built into the space-floating image display device 400. In cases where it is desired to more freely arrange the aerial operation detection sensor 1351 relative to the installation position of the space-floating image display device 400, etc., a configuration in which only the aerial operation detection sensor 1351 is a separate component is advantageous.

[0111] The imaging unit 510 is a camera having an image sensor, and captures images of the face, eyes, arms, fingers, and / or the space near the floating in space image 3 of the user 230, and the like.

[0112] For example, the information on the face and eyes of the user 230 captured by the imaging unit 510 is used to detect the positions of the face and eyes of the user 230 by the beam splitter angle adjustment unit 1010 to obtain height information. If the obtained height information differs from a pre-assumed viewing height, the beam splitter angle adjustment unit 1010 can drive the piston mechanism 310 to change the angle of the beam splitter 101 to a position optimal for viewing by the user 230.

[0113] A plurality of imaging units 510 may be provided. By using a plurality of imaging units 510 or an imaging unit with a depth sensor, the mid-air operation detection unit 1350 can be assisted in detecting the touch operation of the user 230 on the floating-in-space image 3. The imaging unit 510 may be provided separately from the floating-in-space image display device 400. When the imaging unit 510 is provided separately from the floating-in-space image display device 400, it is sufficient to configure the imaging unit 510 so that an imaging signal can be transmitted to the floating-in-space image display device 400 via a wired or wireless communication connection path or the like.

[0114] 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 that has not intruded into the intrusion detection plane (e.g., a user's finger) is from the intrusion detection plane, or how close the object is to the intrusion detection plane.

[0115] 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 510 and object depth information by a 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. Also, without using the mid-air operation detection sensor 1351, the mid-air operation detection unit 1350 may detect a touch operation on the floating-in-space image 3 by the user 230 based on the captured images of the imaging unit 510.

[0116] Also, the imaging unit 510 may capture an image of the face of the user 230 operating the space-floating image 3, and the control unit 1110 may perform an identification process for the user 230. Also, in order to determine whether or not a third person is standing around or behind the user 230 operating the space-floating image 3 and peeking at the operation of the user 230 on the space-floating image 3, the imaging unit 510 may capture an image of a range including the user 230 operating the space-floating image 3 and the surrounding area of ​​the user 230.

[0117] 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 400.

[0118] The video signal input unit 1131 is connected to an external video output device and inputs video data. The video signal input unit 1131 may be implemented using various digital video input interfaces. For example, the video signal input unit 1131 may be implemented using 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. Alternatively, an analog video input interface such as analog RGB or composite video may be provided.

[0119] An external audio output device is connected to the audio signal input unit 1133 to input audio data. 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.

[0120] 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.

[0121] The audio output unit 1140 can output audio based on audio data input to the audio signal input unit 1133. The audio output unit 1140 may be configured with a speaker. The audio output unit 1140 may also output built-in operation sounds and error warning sounds. Alternatively, the audio output unit 1140 may be configured to output a digital signal to an external device, like an Audio Return Channel function defined in the HDMI standard.

[0122] The non-volatile memory 1108 stores various data used by the space-floating image display device 400. 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 the user, layout information, etc. The memory 1109 stores image data to be displayed as the space-floating image 3, data for controlling the device, etc.

[0123] The control unit 1110 controls the operation of each unit connected to it. In addition, the control unit 1110 may cooperate with a program stored in the memory 1109 to perform calculation processing based on information acquired from each unit in the space floating image display device 400.

[0124] 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.

[0125] The removable media interface 1134 is an interface for connecting a removable recording medium. The removable recording medium may be a semiconductor device 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 including 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 liquid crystal display panel 11 and the retroreflective member 2.

[0126] 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.

[0127] The video data, image data, etc. recorded in the storage unit 1170 are output as a space floating image 3 via the liquid crystal display panel 11 and the retroreflective member 2. Video data, image data, etc. of 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.

[0128] 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.

[0129] The video control unit 1160 performs various controls related to the video signal input to the liquid crystal display panel 11. 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 be called a video processing unit or an image processing unit. The video control unit 1160 performs control of video switching, such as which video signal is input to the liquid crystal display panel 11 out of the video signal stored in the memory 1109 and the video signal (video data) input to the video signal input unit 1131. The video control unit 1160 may also perform control to form a composite video as the floating-in-space video 3 by generating a superimposed video signal by superimposing the video signal stored in the memory 1109 and the video signal input from the video signal input unit 1131, and inputting the superimposed video signal to the liquid crystal display panel 11.

[0130] The video control unit 1160 may also control image processing of the video signal input from the video signal input unit 1131 and the video signal to be stored in the memory 1109. Examples of image processing include scaling processing for enlarging, reducing, transforming, and the like an image, brightness adjustment processing for changing the luminance, contrast adjustment processing for changing the contrast curve of an image, and Retinex processing for decomposing an image into light components and changing the weighting of each component. The video control unit 1160 may also perform special effect video processing and the like for assisting the aerial operation (touch operation) of the user 230 on the video signal input to the liquid crystal display panel 11. 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 and the captured image of the user 230 by the imaging unit 510.

[0131] The attitude sensor 1113 is a sensor consisting 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 400 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 is detected as the user's usage state, the control unit 1110 may perform control to stop displaying the image displayed on the liquid crystal display panel 11 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 400 has changed, the control unit 1110 may perform control to rotate the display direction of the image displayed on the liquid crystal display panel 11.

[0132] As explained above, various functions are installed in the space floating image display device 400. However, the space floating image display device 400 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.

[0133] [Fifth Example] The space floating image display devices of the respective embodiments shown in FIGS. 11 to 13 correspond to the Z-type configuration shown in FIG. 3 as a basic configuration.

[0134] FIG. 11 shows a configuration example of a space floating image display device suitable for installation on a desk, according to one embodiment (hereinafter referred to as a fifth embodiment).

[0135] FIG. 11 shows a cross-sectional view (A) of the space-floating image display device as viewed from the side, and a top view (B) of the device as viewed from the front. The front of the device here is the surface corresponding to the direction in which the user can view the space-floating image 3D formed by the space-floating image display device 400 from the front. Direction D is the direction in which the user views the space-floating image 3D from the front, and corresponds to the negative direction in the Z direction. For the sake of explanation, a coordinate system or direction such as the illustrated (X, Y, Z) may be used. The Z direction is the vertical direction, the up-down direction, the X direction and the Y direction are two horizontal directions that are orthogonal to each other, the X direction is the depth direction, the front-back direction (the front-back horizontal direction in the screen of the space-floating image 3D), and the Y direction is the left-right direction (the left-right horizontal direction in the screen of the space-floating image 3D).

[0136] The Z-shaped configuration of Fig. 11 has the same positional relationship of the components (image display device 1, beam splitter 101D, retroreflective member 2A, etc.) as the Z-shaped configuration of Fig. 3. In order to form the space-floating image 3D, the components of the space-floating image display device (image display device 1, beam splitter 101D, retroreflective member 2, etc.) are mutually arranged with a predetermined positional relationship. That is, the image display device 1, beam splitter 101D, retroreflective member 2A, etc. of the image display device unit 300 of Fig. 11 are arranged with a predetermined positional relationship so as to form a Z shape, similar to the configuration of Fig. 3.

[0137] The space-floating image display device of the fifth embodiment shown in FIG. 11 is roughly composed of an image display device unit 300, a housing 106 corresponding to the image display device unit 300, a space-floating image display device 400, a housing 4001 having an opening 4002 corresponding to the space-floating image display device 400, and a hinge mechanism 332 serving as a rotation fulcrum at one end of the beam splitter 101D.

[0138] Hinge mechanism 332 is provided in housing 4001, rotatably holds beam splitter 101D at one side of beam splitter 101D opposite user 230, and serves as a rotation fulcrum for beam splitter 101D.

[0139] The image display device 1 is mounted and stored in a storage section of a housing 106. In Fig. 11, if the illustrated XY plane is a desk surface (a horizontal plane in this example), the housing 106 is disposed along an XZ plane perpendicular to the desk surface.

[0140] The housing 106 is generally rectangular and flat with a predetermined height (predetermined thickness in the Y direction). The image display device 1 is arranged along the XZ plane on the desk surface inside the housing 106. The space floating image display device 400 is arranged facing the housing 106 in the Y direction.

[0141] The space-floating image display device 400 is mounted and housed in a housing 4001. The space-floating image display device 400 is composed of a retroreflection member 2A, a λ / 4 plate 21A, a beam splitter 101D, and the like.

[0142] In this embodiment, a transparent member 100 such as a glass plate and an absorptive polarizing plate 112 are provided for the purpose of reducing the effect of external light incident from the opening 4002 on the retroreflective member 2A and the image display device 1. The direction D is a direction from top to bottom in the Z direction, which is a vertical direction in this embodiment, and is a direction perpendicular to the opening 4002.

[0143] In this embodiment, the beam splitter 101D is disposed at an angle to the desk surface inside the housing 4001. The angle corresponds to the angle that the direction of one side of the main surface of the beam splitter 101D makes with the Y direction of the desk surface (XY plane), and for example, in FIG. 11, the angle α, which is the angle of the angle, is about 45 degrees (≈45°).

[0144] The retroreflective member 2A and the λ / 4 plate 21A are arranged on the opposite side in the Y direction across the beam splitter 101D from the image display device 1 (FIG. 11). The λ / 4 plate 21A is arranged on the side where the beam splitter 101D is arranged with respect to the main surface of the retroreflective member 2A. In other words, the λ / 4 plate 21A is arranged on the light incident side of the retroreflective member 2A. The space floating image 3D (shown in a dashed frame) is arranged in the horizontal direction (XY plane) between the housing 106 and the retroreflective member 2A, protruding from the beam splitter 101D to the upper side in the Z direction. The space floating image 3D is an aerial image formed corresponding to the beam splitter 101D.

[0145] In this embodiment, the components of the image display device 1, ie, the light source device 13, the liquid crystal display panel 11, the absorptive polarizer 12, etc., are housed and fixed in a housing .

[0146] An opening 1061 is provided on the left surface of the housing 106 in the Y direction and on the right surface of the housing 4001 in the Y direction. The opening 1061 is a portion through which the image light from the image display device 1 passes or is transmitted. A transparent member or the like may be provided in the opening 1061. The image light corresponding to the image displayed on the image display device 1, more specifically, on the liquid crystal display panel 11, passes through the opening 1061 and travels toward the beam splitter 101D located in the left direction (negative direction) in the Y direction.

[0147] As with the configuration described above (Fig. 3), the beam splitter 101D has the property of transmitting P-polarized light and reflecting S-polarized light, and can be formed, for example, by evaporating an optical thin film onto a flat glass substrate. At this time, the incident angle of the polarized light to the beam splitter 101D is about 45 degrees ±15 degrees, and a 3D floating image is generated that is positioned in the horizontal direction (XY plane).

[0148] In FIG. 11, the image light emitted from the image display device 1 through the opening 1061 in the negative direction in the Y direction on the optical axis D1 is indicated by a dashed arrow. This is shown as a representative example of four dashed arrows for the beam splitter 101D. The image light emitted from the liquid crystal display panel 11 is light having a predetermined polarization characteristic, for example, P polarization (parallel polarization: P stands for Parallel). This P-polarized image light passes through the beam splitter 101D on the optical axis D1 in the negative direction (left) in the Y direction as it is, and proceeds toward the retroreflective member 2A on the optical axis D2 corresponding to the optical axis D1. The beam splitter 101D has a property of passing P-polarized light and reflecting S-polarized light (vertical polarization: S stands for Senkrecht). The beam splitter 101D is disposed so as to form an angle of, for example, about 45 degrees with this P-polarized image light (optical axis D2, Y direction). In other words, the beam splitter 101D is disposed so that its principal surface forms an angle of approximately 45 degrees with respect to the Z direction which forms the principal surfaces of the liquid crystal display panel 11 and the retroreflective member 2A.

[0149] A λ / 4 plate 21A is provided on the light incidence surface of the retroreflective member 2A. The P-polarized image light with optical axis D1 emitted from the image display device 1 and transmitted through the beam splitter 101D passes through the λ / 4 plate 21A twice in total, once before being reflected by the retroreflective member 2A and once after being reflected, and is polarized and converted from P-polarized light to S-polarized light. As a result, the S-polarized image light traveling on the optical axis D2 after being reflected by the retroreflective member 2A is reflected by the beam splitter 101D and travels on the optical axis D3 in the Z direction. As shown in the figure, the S-polarized image light generates and displays a real image, a floating-in-space image 3D, at a predetermined position in the Z direction after transmitting outside the opening 4002, the transparent member 100, and the absorptive polarizing plate 112.

[0150] The predetermined position where the floating image 3D is formed is determined according to the optical distance of the optical path of the optical system including the image display device 1, the beam splitter 101D, and the retroreflective member 2A. The distance between the floating image 3D and the beam splitter 101D is approximately equal to the distance between the image display device 1 and the beam splitter 101D.

[0151] The hinge mechanism 332 shown in Fig. 11 is a mechanism that does not move up, down, left, or right, but is free to rotate, and is provided in the X direction at the left end of the beam splitter 101D, and the beam splitter 101D rotates up and down around the hinge mechanism 332 as a rotation fulcrum. That is, the beam splitter 101D can be arranged at a different angle with respect to the fixed arrangement of the image display device 1 and the retroreflective member 2. Alternatively, the beam splitter 101D can be rotated around the hinge mechanism 330 as a rotation fulcrum to change the separation distance between the beam splitter 101D and the image display device 1, and between the beam splitter 101D and the retroreflective member 2A. Even if the arrangement angle of the beam splitter 101D is different, it is arranged with a positional relationship to form a Z-shape similar to the configuration of Fig. 3.

[0152] In the space floating image display device of the fifth embodiment shown in FIG. 11, a case is considered in which the beam splitter 101D is rotated upward by an angle γ with respect to the horizontal position (XY plane) with the hinge mechanism 332 as a rotation fulcrum, and moved to the position of the beam splitter 101E. In this arrangement, the P-polarized image light from the image display device 1 travels along the optical axis D1, passes through the beam splitter 101E, and passes through the λ / 4 plate 21A twice in total, before and after being reflected by the retroreflection member 2A, thereby being polarized and converted from P-polarized light to S-polarized light. As a result, the S-polarized image light that traveled along the optical axis D2 after being reflected by the retroreflection member 2 is reflected by the beam splitter 101E and travels along the optical axis E3 in the Z direction. As shown in the figure, the S-polarized image light generates and displays a space floating image 3E, which is a real image, at a predetermined position in the Z direction after passing through the outside of the opening 4002, the transparent member 100, and the absorbing polarizing plate 112.

[0153] The predetermined position where the floating image 3E is formed is determined according to the optical path length of the optical system including the image display device 1, the beam splitter 101E, and the retroreflective member 2A. The distance between the floating image 3E and the beam splitter 101E is approximately equal to the distance between the image display device 1 and the beam splitter 101E.

[0154] By rotating the beam splitter 101E upward by an angle γ with respect to the horizontal position (XY plane) with the hinge mechanism 332 as the rotation fulcrum, the distance between the image display device 1 and the beam splitter 101E becomes farther on the surface of the beam splitter 101E away from the hinge mechanism 332 than on the surface of the beam splitter 101D. Therefore, the floating-in-space image 3E of the beam splitter 101E is generated and displayed at a position rotated upward by an angle γ with respect to the floating-in-space image 3D of the beam splitter 101D, which is in a nearly horizontal position. The formed floating-in-space image 3E can be viewed as a bright image by the user 230E in a front position from the direction E indicated by the arrow. In other words, by changing the tilt angle γ of the beam splitter 101D with the hinge mechanism 332 as the rotation fulcrum, the floating-in-space image 3D can be generated and displayed at a position tilted from the horizontal position.

[0155] The imaging unit 510 is a camera having an image sensor, and images the faces, eyes, arms, and fingers of the users 230D and 230E, and / or the space of the floating in space image 3D and the floating in space image 3E, etc. For example, the beam splitter angle adjustment unit 1010 (FIG. 10) detects the positions of the faces and eyes of the users 230D and 230E from the information of the faces and eyes of the users 230D and 230E captured by the imaging unit 510, and drives the hinge mechanism 332 to adjust the angle of the beam splitter 101D from the angle optimal for the visibility of the user 230D to the angle optimal for the visibility of the user 230E.

[0156] [Sixth Example] FIG. 12 shows a configuration example of a space floating image display device suitable for installation on a desk, according to one embodiment (hereinafter referred to as a sixth embodiment).

[0157] The embodiment of FIG. 12 is an arrangement in which the space-floating image display device of the embodiment of FIG. 11 is rotated 90° to the left around the X axis. In this embodiment, the coordinate system has a Y direction that is the vertical direction, the up-down direction, a Z direction and a Y direction that are two horizontal directions that are perpendicular to each other, a X direction that is the depth direction, the front-back direction, and a Z direction that is the left-right direction. In other words, the coordinate relationship seen from the space-floating image display device is the same in the embodiment of FIG. 11 and the embodiment of FIG. 12. The front of the device here is a plane (YX plane) that corresponds to the direction in which the user can view the space-floating image 3D formed by the space-floating image display device 400 from the front. The direction D is the direction in which the user views the space-floating image 3D from the front, and corresponds to the negative direction in the Z direction.

[0158] In the embodiment of FIG. 12, the space-floating image display device 400 has the same components as the embodiment of FIG. 11, and the same reference numerals are used. The space-floating image 3D and the space-floating image 3E are generated and displayed by the same means. The viewpoint positions of the user 230D and the user 230E in the embodiment of FIG. 12 are in the same positional relationship as the embodiment of FIG. 11, but the user 230D is shown assuming that he is taller than the user 230E. The space-floating image 3D in the front direction is optimal for the user 230D. Since the user 230E is shorter than the user 230D, he will look up slightly at the space-floating image display device 400, and the space-floating image 3E will be in the front direction, which is the optimal viewing position.

[0159] The imaging unit 510 is a camera having an image sensor, and images the height, face, eyes, and / or the space around the floating image 3D and the floating image 3E of the users 230D and 230E. For example, for the user 230D, the beam splitter angle adjustment unit 1010 (FIG. 10) detects the position of the eyes of the user 230D from the height, face, and eye position information of the user 230D captured by the imaging unit 510, and adjusts and places the angle of the beam splitter 101 to the position of the beam splitter 101D by the hinge mechanism 332. This allows the user 230D to view the floating image 3D in the optimal position in the front direction.

[0160] For a short user 230E, the beam splitter angle adjustment unit 1010 (FIG. 10) detects the eye position of the user 230E from the height of the user 230E captured by the imaging unit 510 and the position information of the face and eyes, and adjusts and places the angle of the beam splitter 101D at the position of the beam splitter 101E by rotating the angle γ clockwise by the hinge mechanism 332. This allows the user 230E to view the floating image 3E in the space at the optimal position in the front direction, looking up slightly.

[0161] This embodiment is effective not only for users shorter than the user 230D, but also for users taller than the user 230D. By adjusting the angle of the beam splitter 101D in a clockwise rotational direction based on, for example, eye position information of a user taller than the user 230D captured by the imaging unit 510, the tilt angle of the generated floating-in-space image can be adjusted so that it is optimally visible to a user taller than the user 230D. This improves the visibility of the user (observer), and is suitable for improving operability.

[0162] [Seventh Example] FIG. 13 shows a configuration example of a space floating image display device suitable for installation on a desk, according to one embodiment (hereinafter referred to as a seventh embodiment).

[0163] 13(A) is a cross-sectional view of the appearance of the space-floating image display device according to an embodiment (seventh embodiment) when viewed from the side, and FIG. 13(B) is a cross-sectional view of the appearance of the space-floating image display device according to an embodiment (seventh embodiment) when viewed from above. In FIG. 13(B), the retroreflective member 2B is arranged to face the liquid crystal display panel 11 at a predetermined angle. The front of the device here is the surface corresponding to the direction in which the user can view the space-floating image 3F formed by the space-floating image display device 400 from the front. The direction F is the direction in which the user 230F views the space-floating image 3F from the front, and corresponds to the negative direction in the Z direction.

[0164] The Z-shaped configuration in FIG. 13 is similar to the Z-shaped configuration in FIG. 3 in terms of the relative positions of the components (image display device 1, beam splitter 101F, retroreflective member 2B, etc.).

[0165] In order to form the space-floating image 3F, the components of the space-floating image display device (image display device 1, beam splitter 101F, retroreflective member 2B, etc.) are mutually arranged with a predetermined positional relationship. That is, the image display device 1, beam splitter 101F, retroreflective member 2B, etc. of the image display device unit 300 in Fig. 13 are arranged with a predetermined positional relationship so as to form a Z-shape, similar to the configuration in Fig. 3.

[0166] The seventh embodiment of the floating-in-space image display device shown in FIG. 13 is roughly comprised of an image display device unit 300, a housing 106 corresponding to the image display device unit 300, a floating-in-space image display device 400, a housing 4001 having an opening 4002 corresponding to the floating-in-space image display device 400, and a hinge mechanism 333 for rotatably holding a beam splitter 101F.

[0167] The hinge mechanism 333 rotatably holds both ends of the beam splitter 101F at or near the center line of the beam splitter 101F, which is parallel to one side of the beam splitter 101F facing the user 230, and serves as a rotation fulcrum for the beam splitter 101F. The hinge mechanism 333 is a mechanism that does not move up, down, left, or right, but is free to rotate, and the beam splitter 101F is structured to rotate up and down around the hinge mechanism 333 as a rotation fulcrum. In other words, the beam splitter 101F is structured to be able to be positioned at a different angle with respect to the fixed position of the image display device 1 and the retroreflective member 2B. Alternatively, the beam splitter 101F is structured to be rotated around the hinge mechanism 333 as a rotation fulcrum, and the separation distance between the beam splitter 101F and the image display device 1, and between the beam splitter 101F and the retroreflective member 2B, can be changed. Even if the arrangement angle of the beam splitter 101F is different, the beam splitters are arranged with a positional relationship so as to form a Z shape similar to the configuration in FIG.

[0168] The P-polarized image light emitted from the image display device 1 passes through the beam splitter 101F and reaches the λ / 4 plate 21B. By passing through the λ / 4 plate 21B, the image light is reflected by the retroreflective member 2B and passes through the λ / 4 plate 21B a total of two times, and is polarized and converted from P-polarized light to S-polarized light. The image light is reflected by the beam splitter 101F and generates a space-floating image 3F in the Z-axis direction, i.e., the vertical direction.

[0169] In this embodiment, unwanted light 600 is shown diagrammatically by a white arrow in Fig. 13(B). Of the P-polarized image light that becomes unwanted light 600, a portion of the P-polarized image light that reaches λ / 4 plate 21B is specularly reflected by the surface of λ / 4 plate 21B and proceeds to beam splitter 101F as P-polarized light. Furthermore, a portion of the P-polarized image light is also specularly reflected by the surface of beam splitter 101F.

[0170] In this embodiment, the retroreflective member 2B and the λ / 4 plate 21B are arranged at an angle on the XY plane, not parallel to the XZ plane. Therefore, the P-polarized image light, which becomes the unnecessary light 600, is mirror-reflected on the surface of the λ / 4 plate 21B in parallel with the incident light on the YZ plane, but since the λ / 4 plate 21B has an angle with respect to the XY plane, it is mirror-reflected at an angle corresponding to the incident angle and is incident on the surface of the beam splitter 101F at an angle on the XY plane. Therefore, the unnecessary light 600 is mirror-reflected on the surface of the beam splitter 101F at an angle corresponding to the incident angle, but deviates from the Z direction in the upward direction and proceeds in a direction outside the screen of the space-floating image 3F. As a result, when a user looks at the space-floating image 3F from the direction F, the unnecessary light 600 is outside the screen of the space-floating image 3F and is not visible, so that it is possible to avoid the unnecessary light 600 interfering with the visibility of the space-floating image.

[0171] In the first embodiment of the floating-in-space image display device shown in FIG. 13, the beam splitter 101F is rotated counterclockwise or upward by an angle γ with respect to the horizontal position (XY plane) using a hinge mechanism 333 provided at or near the center line of the beam splitter 101F as a rotation fulcrum, and positioned at the position of the beam splitter 101J.

[0172] In this arrangement, consider image light from a position away from the center of the image display device 1. When image light with optical axis F1 at the lower end of the image display device 1 is transmitted by the beam splitter 101F, it passes through the λ / 4 plate 21B along the optical axis F1 and enters the retroreflective member 2B. The image light retroreflected by the retroreflective member 2 passes through the λ / 4 plate 21B again and is converted into the other polarized wave, and the image light reflected by the beam splitter 101F generates a real image, a floating-in-space image 3F, at a predetermined position outside the transparent member 100 in the direction of the optical axis F3 corresponding to the optical axis F2.

[0173] Next, when the beam splitter 101F rotates by angle γ and reaches the position of the beam splitter 101J, the image light of the optical axis F1 of the image display device 1 passes through the beam splitter 101J, passes through the λ / 4 plate 21B along the optical axis F2, and enters the retroreflective member 2B. The image light retroreflected by the retroreflective member 2B passes through the λ / 4 plate 21B again and is converted into the other polarized wave, and is reflected by the beam splitter 101J, generating a real image, a floating-in-space image 3J, at a predetermined position outside the transparent member 100 in the direction of the optical axis J3.

[0174] Due to the rotation of angle γ, the distance between the bottom end of image display device 1 and beam splitter 101J becomes shorter than that of beam splitter 101F; in other words, the optical path distance becomes shorter, so that the left end position of the generated floating-in-space image 3J becomes lower than the left end position of the floating-in-space image 3F.

[0175] Conversely, the distance between the top of the image display device 1 and the beam splitter 10J becomes farther than that of the beam splitter 101F due to the rotation of the angle γ, in other words, the optical path distance becomes longer, so that the right end position of the generated floating-in-space image 3J becomes higher than the right end position of the floating-in-space image 3F. In other words, the floating-in-space image 3J is tilted counterclockwise more than the floating-in-space image 3F. In other words, by changing the tilt angle γ of the beam splitter 101F with the hinge mechanism 333 as the rotation fulcrum, the floating-in-space image 3F can be generated and displayed at a position tilted from the horizontal position.

[0176] The imaging unit 510 is a camera having an image sensor, and images the faces, eyes, arms, and fingers of the users 230F and 230J, and / or the space of the floating in space image 3F and the floating in space image 3J, etc. For example, the information on the faces and eyes of the users 230F and 230J captured by the imaging unit 510 can be detected by the beam splitter angle adjustment unit 1010 (FIG. 10) to detect the positions of the faces and eyes of the users 230F and 230J, and the hinge mechanism 333 can be driven to adjust the angle of the beam splitter 101F from, for example, the optimal viewing position of the user 230F to the angle of the beam splitter 101J suitable for viewing by the user 230J.

[0177] As described above, the air-floating image display device shown in Figures 7 to 9 comprises a display panel that displays an image, a polarizing separation member that reflects a portion of the image light emitted from the display panel, and a retroreflective member that retroreflects the light reflected from the polarizing separation member, and the light reflected by the retroreflective member passes through the polarizing separation member to form a air-floating image, and the angle of the polarizing separation member relative to the display panel and the retroreflective member is variable.

[0178] As described above, the air-floating image display device shown in Figures 11 to 13 also comprises a display panel that displays an image, a polarization separation member that transmits a portion of the image light emitted from the display panel, and a retroreflective member that retroreflects the light that has transmitted through the polarization separation member, and the reflected light retroreflected by the retroreflective member is reflected back onto the polarization separation member to form a air-floating image, and the angle of the polarization separation member relative to the display panel and the retroreflective member is variable.

[0179] As described above, the space-floating image display device of each embodiment and modification can display a space-floating image with high visibility that is suitable for use mainly indoors. In addition, the space-floating image display device of this embodiment is configured to display the spatial image at different heights and inclinations to improve visibility and operability. More specifically, a function is provided to adjust the angle of the beam splitter relative to the bottom surface, etc., and the space-floating image is displayed at different heights and inclinations from each beam splitter.

[0180] This has the effect of improving the visibility and operability of the floating image for users with different viewing positions and heights. When the generated floating image is used as a non-contact user interface, it provides better usability for users, higher visibility and operability, and prevents or reduces operational errors and input errors.

[0181] This embodiment may be installed on a desk, for example. The λ / 4 plate 21B may be located at any position between the beam splitter 101 and the opening 4002, as long as it is located before the image of the floating image is formed. The retroreflective member 2 may be located so as to face the liquid crystal display panel 11 at a predetermined angle.

[0182] As a result of the above effects, the space-floating image display device of each embodiment and modified example can display bright, space-floating images with excellent visibility, even when used in a relatively small room, without emitting image light that is unnecessary for people other than the user, and because it is small and lightweight, it is ideal for easy installation on a desk, table, shelf, etc. indoors.

[0183] Although the embodiments of the present disclosure have been specifically described above, they are not limited to the above-described embodiments and can be modified in various ways without departing from the scope of the present disclosure. Unless otherwise specified, each component may be singular or plural. The components of each embodiment can be added, deleted, or replaced, except for essential components. Also, a form in which each embodiment is combined is possible.

[0184] For example, the beam splitter may be curved rather than flat. In the above embodiment, the user mainly sees the floating image in the vertical direction, but the present invention is not limited to this. If the arrangement of the floating image display device in each embodiment is rotated as a whole, the floating image in the space can be displayed in a direction different from the above embodiment. The image display device 1 may be called a display panel, a liquid crystal display panel, a liquid crystal panel, or the like.

[0185] [Eighth Example] The space floating image display devices of the respective embodiments shown in FIG. 14 and FIG. 15A to FIG. 15F correspond to the Z-type configuration shown in FIG. 3 as a basic configuration.

[0186] Fig. 14 is a perspective view showing an example of the shape of a beam splitter (polarized light separating member) that transmits a part of the image light emitted from a display panel of a floating-in-air image display device suitable for installation on a desk, according to one embodiment (referred to as an eighth embodiment). (A) is a flat beam splitter, which corresponds to 101D, 101J, etc. of the floating-in-air image display device shown in Figs. 11 to 13. In contrast, (B), (C), and (D) show examples of beam splitter shapes that are curved rather than flat, and the height of the inside of the beam splitter differs from the surrounding sides of the beam splitter. The beam splitter 101K in (B) is a semi-cylindrical plate material, and is surrounded by a pair of straight sides A1, A1' and a pair of curved sides B1, B1'. Beam splitter 101L in (C) is a semi-cylindrical plate material obtained by rotating beam splitter 101K in (B) by 90 degrees, and is surrounded by a pair of straight sides A2, A2' and a pair of curved sides B2, B2'. Note that curved sides B1, B1', B2, B2' of beam splitters 101K and 101L are not limited to being parts of a circle or ellipse, and may be approximated curves of curves or polygons having any curvature. Beam splitter 101P in (D) is a cone-shaped or lens-shaped plate material, and the peripheral part B3 on the bottom side is surrounded by a circle or curve, and the side faces rise obliquely toward the apex of the plate material. The peripheral part B3 on the bottom side is not limited to being parts of a circle or ellipse, and may be approximated curves of curves or polygons having any curvature.

[0187] FIG. 15A shows a configuration example of a space-floating image display device suitable for installation on a desk according to one embodiment (referred to as an eighth embodiment). FIG. 15A shows a YZ cross section (A) of the space-floating image display device when viewed from the side, an XY top view (B) and an XZ cross section (C) when viewed from the front of the device. The front of the device here is the surface corresponding to the direction in which the user can view the space-floating image 3K formed by the space-floating image display device 400 from the front. The direction K is the direction in which the user 230K views the space-floating image 3K from the front, and corresponds to the negative direction in the Z direction. For the sake of explanation, a coordinate system or direction such as (X, Y, Z) shown in the figure may be used. The Z direction is the vertical direction, the up-down direction, the X direction and the Y direction are two horizontal directions that intersect at right angles, the X direction is the depth direction, the front-to-back direction (the front-to-back horizontal direction within the screen of the floating-in-space image K), and the Y direction is the left-to-right direction (the left-to-right horizontal direction within the screen of the floating-in-space image 3K).

[0188] The Z-shaped configuration of Fig. 15A has the same positional relationship of the components (image display device 1, beam splitter 101K, retroreflective member 2A, etc.) as the Z-shaped configuration of Fig. 3. In order to form the space-floating image 3K, the components of the space-floating image display device 400 (image display device 1, beam splitter 101K, retroreflective member 2A, etc.) are mutually arranged with a predetermined positional relationship. That is, the image display device 1, beam splitter 101K, retroreflective member 2A, etc. of the image display device unit 300 of Fig. 15A are arranged with a predetermined positional relationship so as to form a Z shape, similar to the configuration of Fig. 3.

[0189] The space-floating image display device 400 is mounted and housed in a housing 4001. The space-floating image display device 400 is composed of a retroreflection member 2A, a λ / 4 plate 21A, a beam splitter 101K, and the like.

[0190] In this embodiment, a transparent member 100 such as a glass plate and an absorptive polarizing plate 112 are provided for the purpose of reducing the effect of external light incident from the opening 4002 on the retroreflective member 2A and the image display device 1. The direction K is a direction from top to bottom in the Z direction, which is a vertical direction in this embodiment, and is perpendicular to the opening 4002.

[0191] In this embodiment, the beam splitter 101K is a semi-cylindrical plate material as shown in FIG. 14B, and is surrounded by a pair of straight sides and a pair of curved sides. In the housing 4001, the beam splitter 101K is disposed at an angle to the desk surface. The oblique angle means that one straight side (e.g., A1) of the beam splitter 101K is disposed near the image display device 1, and the other straight side (e.g., A1') of the beam splitter 101K is disposed near the retroreflective member 2A. The angle formed by the direction of the line segment connecting both ends of the arc of the curved side surface of the beam splitter 101K corresponds to the Y direction of the desk surface (XY plane), and for example, in FIG. 15A, the angle α, which is the oblique angle, is about 45 degrees (≒45°).

[0192] The retroreflective member 2A and the λ / 4 plate 21A are disposed on the opposite side of the image display device 1 in the Y direction across the beam splitter 101K. The λ / 4 plate 21A is disposed on the side where the beam splitter 101K is disposed with respect to the main surface of the retroreflective member 2A. In other words, the λ / 4 plate 21A is disposed on the light incident side of the retroreflective member 2A. The space-floating image 3K (shown in a dashed frame) is disposed between the housing 106 and the retroreflective member 2A, protruding upward from the beam splitter 101K in the Z direction, and disposed in the horizontal direction (XY plane). The space-floating image 3K is an aerial image formed in correspondence with the beam splitter 101K. The space-floating image 3K is also an aerial image having a curved surface in correspondence with the shape of the beam splitter 101K.

[0193] An opening 1061 is provided on the left surface of the housing 106 in the Y direction and on the right surface of the housing 4001 in the Y direction. The opening 1061 is a portion through which the image light from the image display device 1 passes or is transmitted. A transparent member or the like may be provided in the opening 1061. The image light corresponding to the image displayed on the image display device 1, more specifically, on the liquid crystal display panel 11, passes through this opening 1061 and travels toward the beam splitter 101K located in the left direction (negative direction) in the Y direction.

[0194] As with the configuration described above (Figure 3), beam splitter 101K has the property of transmitting P-polarized light and reflecting S-polarized light. For example, it can be formed by evaporating an optical thin film onto a curved glass substrate or resin substrate. In this case, the angle of incidence of the polarized light on beam splitter 101K changes depending on the angle of the curved surface, centered around approximately 45 degrees, and a floating image 3K is generated that is positioned almost horizontally (XY plane).

[0195] In FIG. 15A, an example of image light emitted from the image display device 1 through the opening 1061 in the negative direction in the Y direction is shown by a dashed arrow, and will be described with the dashed arrow of the optical axis K1 as a representative example. The image light emitted from the liquid crystal display panel 11 is light having a predetermined polarization characteristic, for example, P-polarized light (parallel polarization: P is an abbreviation for Parallel). This P-polarized image light passes through the beam splitter 101K on the optical axis K1 in the negative direction (left) in the Y direction as it is, and proceeds toward the retroreflective member 2A on the optical axis K2 corresponding to the optical axis K1. The beam splitter 101K has a property of passing P-polarized light and reflecting S-polarized light (vertical polarization: S is an abbreviation for Senkrecht). The curved surface of the beam splitter 101K that transmits the P-polarized light on this optical axis K1 forms an angle greater than the previously mentioned angle α ≒ approximately 45 degrees as shown in the figure.

[0196] A λ / 4 plate 21A is provided on the light incidence surface of the retroreflective member 2A. The P-polarized image light with optical axis K1 emitted from the image display device 1 and transmitted through the beam splitter 101K passes through the λ / 4 plate 21A twice in total, once before being reflected by the retroreflective member 2A and once after being reflected, and is thereby converted from P-polarized light to S-polarized light. As a result, the S-polarized image light that has traveled along the optical axis K2 after being reflected by the retroreflective member 2A is reflected by the beam splitter 101K and travels along the optical axis K3 in the Z direction. Since the angle of incidence of optical axis K2 with respect to the curved reflecting surface of beam splitter 101K is smaller than the aforementioned angle of approximately 45 degrees, this S-polarized image light travels in a direction slightly tilted toward the -Y direction from the Z direction straight up (approximately 90 degrees) as shown in the figure, passes through the outside of opening 4002, transparent member 100, and absorptive polarizing plate 112, and generates and displays space-floating image 3K, which is a real image, at a predetermined position in the Z direction. The other image light indicated by the dashed arrows that is emitted in the negative direction in the Y direction also behaves in the same way as the aforementioned optical axes K1 and K2, but the angle of incidence of the S-polarized image light reflection corresponding to optical axis K2 with respect to the curved reflecting surface of beam splitter 101K differs depending on the reflection position on the surface of beam splitter 101K. For this reason, the reflected S-polarized image light travels in the Z direction, but as in the example shown in Figure 15A(A), depending on the reflection position on the surface of the beam splitter 101K, it travels in a direction tilted from the -Y direction to +Y rather than the Z direction straight up (approximately 90 degrees), generating and displaying a real image, a floating-in-space image 3K, at a specified position in the Z direction.

[0197] The predetermined position where the floating image 3K is formed is determined according to the optical distance of the optical path of the optical system including the image display device 1, the beam splitter 101K, and the retroreflective member 2A. The distance between the floating image 3K and the beam splitter 101K is approximately equal to the distance between the image display device 1 and the beam splitter 101K. Since the beam splitter 101K has a semi-cylindrical shape as described above in FIG. 14(B), the floating image 3K also has an approximately semi-cylindrical shape. In other words, the shape is an extension of the circular curve of the YZ cross section in the -X direction. Therefore, when viewed from the direction K, the user 230K can visually recognize the floating image 3K whose center part along the X axis rises convexly in the traveling direction of the light forming the floating image.

[0198] Fig. 15B is a diagram showing an example of the configuration of a space-floating image display device suitable for installation on a desk according to one embodiment (eighth embodiment). Fig. 15B is configured by replacing the beam splitter 101K in the space-floating image display device 400 of the embodiment of Fig. 15A with a beam splitter 101M. Fig. 15B(A) shows a YZ cross-sectional view, and Fig. 15B(B) shows the configuration of the beam splitter 101M. In this embodiment, differences from the embodiment of Fig. 15A are explained, and repeated explanations of the same configuration as Fig. 15A are omitted.

[0199] 14B, the beam splitter 101M is configured by the pair of straight sides A1, A1' and a pair of curved sides B1, B1', and the curved sides B1, B1' are configured by polygonal approximate curves BM1 and BM1'. In this embodiment, a plurality of rectangular beam splitter pieces are arranged in a staircase pattern to configure the staircase approximate curves BM1 and BM1' parallel to the bottom surface of the beam splitter 101M and the corresponding approximate curved surfaces.

[0200] In this embodiment, the beam splitter 101M is disposed in the housing 4001 at an angle to the desk surface. One straight side (e.g., A1) of the beam splitter 101M is disposed near the image display device 1, and the other straight side (e.g., A1') of the beam splitter 101M is disposed near the retroreflective member 2A. The angle formed by the direction of the line segment connecting both ends of the arc of the approximate curved side surface of the beam splitter 101M corresponds to the Y direction of the desk surface (XY plane), and for example, in FIG. 15B, the angle α, which is the oblique angle, is about 45 degrees (≒45°). Since the stepped beam splitter pieces of this embodiment are disposed parallel to the bottom surface of the beam splitter 101M, the angle of each beam splitter piece is the same as the angle α, which is about 45 degrees (≒45°).

[0201] In FIG. 15B(A), an example of image light emitted from the image display device 1 in the negative direction in the Y direction is shown by a dashed arrow, and will be described with the dashed arrow of the optical axis M1 as a representative example. The image light emitted from the liquid crystal display panel 11 is light having a predetermined polarization characteristic, for example, P polarization. This P-polarized image light passes through the beam splitter 101M on the optical axis M1 in the negative direction (left) in the Y direction as it is, and proceeds toward the retroreflective member 2A on the optical axis M2 corresponding to the optical axis M1. The beam splitter 101M has the property of passing P-polarized light and reflecting S-polarized light. The rectangular beam splitter piece of the beam splitter 101M that transmits P-polarized light on this optical axis M1 has the above-mentioned angle α ≒ approximately 45 degrees.

[0202] The P-polarized image light of optical axis M1 that has been transmitted through beam splitter 101M passes through retroreflective member 2A and λ / 4 plate 21A, and is converted from P-polarized light to S-polarized light. As a result, the S-polarized image light that has traveled along optical axis M2 after being reflected by retroreflective member 2 is reflected by beam splitter 101M and travels along optical axis M3 in the Z direction. Since the angle of incidence of optical axis M2 with respect to the reflecting surface of beam splitter 101M is approximately 45 degrees as described above, this S-polarized image light travels in the Z direction directly above (approximately 90 degrees) as shown in the figure, and transmits through the outside of opening 4002, transparent member 100, and absorptive polarizing plate 112 to generate and display space-floating image 3M, which is a real image, at a predetermined position in the Z direction. The S-polarized reflected image light from the other image light indicated by the dashed arrows emitted in the negative direction in the Y direction also travels in the Z direction, and a real image, a floating in space image 3M, is generated and displayed at a specified position in the Z direction, as in the example shown in Figure 15B(A).

[0203] The predetermined position where the floating image 3M is formed is determined according to the optical distance of the optical path of the optical system including the image display device 1, the beam splitter 101M, and the retroreflective member 2A. The distance between the floating image 3M and the beam splitter 101M is approximately equal to the distance between the image display device 1 and the beam splitter 101M. Since the beam splitter 101M has an approximate shape of a semi-cylinder as described above in FIG. 15B(B), the shape of the floating image 3M is also approximately similar to a semi-cylinder. In other words, it is a shape that is an extension of a stepped circular curve in the YZ cross section in the -X direction. Therefore, when viewed from the direction M, the user 230M can visually recognize the floating image 3M with a convex central part along the X-axis in the traveling direction of the light that forms the floating image.

[0204] FIG. 15C is a diagram showing an example of the configuration of a space-floating image display device suitable for installation on a desk according to an embodiment (eighth embodiment). FIG. 15C is configured by replacing the beam splitter 101K in the space-floating image display device 400 of the embodiment of FIG. 15A with a beam splitter 101L. FIG. 15C(A) shows a YZ cross-sectional view, FIG. 15C(B) shows an XY top view, and FIG. 15C(C) shows an XZ cross-sectional view. As described above in FIG. 14(C), the beam splitter 101L is a semi-cylindrical plate material obtained by rotating the beam splitter 101K of FIG. 14(B) by 90 degrees, and is surrounded by a pair of straight sides A2, A2' and a pair of curved sides B2, B2'. In this embodiment, differences from the embodiment of FIG. 15A are described, and repeated description of the same configuration as in FIG. 15A is omitted.

[0205] In this embodiment, the beam splitter 101L is a semi-cylindrical plate material as shown in FIG. 14C, and is surrounded by a pair of straight sides and a pair of curved sides. In the housing 4001, the beam splitter 101L is disposed at an angle to the desk surface. The angle means that one curved side (e.g., B2) of the beam splitter 101L is disposed near the image display device 1, and the other curved side (e.g., B2') of the beam splitter 101L is disposed near the retroreflective member 2A. The angle formed by the straight sides A2 and A2' of the beam splitter 101L corresponds to the Y direction of the desk surface (XY plane), and for example, in FIG. 15C, the angle α, which is the angle of the angle, is about 45 degrees (≒45°). In this embodiment, the cylindrical surface sandwiched between the pair of curved sides B2 and B2' is parallel to the straight sides A2 and A2', and therefore the oblique angle is also about 45 degrees (≈45°).

[0206] The P-polarized image light on optical axis L1 that was transmitted through beam splitter 101L is converted from P-polarized light to S-polarized light by passing through retroreflective member 2A and λ / 4 plate 21A. As a result, the S-polarized image light that traveled on optical axis L2 after being reflected by retroreflective member 2 is reflected by beam splitter 101L and travels on optical axis L3 in the Z direction.

[0207] Since the angle of incidence of optical axis L2 with respect to the reflecting surface of beam splitter 101L is approximately 45 degrees as described above, this S-polarized image light travels in the Z direction directly upward (approximately 90 degrees) as shown, passes through the outside of opening 4002, transparent member 100, and absorptive polarizing plate 112, and generates and displays space-floating image 3L, which is a real image, at a predetermined position in the Z direction. The other S-polarized reflected image light from the image light indicated by the dashed arrows emitted in the negative direction in the Y direction also travels in the Z direction, and generates and displays space-floating image 3L, which is a real image, at a predetermined position in the Z direction, as in the example shown in FIG. 15C(A).

[0208] The predetermined position where the floating image 3L is formed is determined according to the optical distance of the optical path of the optical system including the image display device 1, the beam splitter 101L, and the retroreflective member 2A. The distance between the floating image 3L and the beam splitter 101L is approximately equal to the distance between the image display device 1 and the beam splitter 101L. Since the beam splitter 101L has a semi-cylindrical shape as described above in FIG. 14(C), the shape of the floating image 3L is also approximately semi-cylindrical. In other words, it is a shape in which the circular curve of the XZ cross section is extended in the Y direction. Therefore, when viewed from the direction L, the user 230L can visually recognize the floating image 3L whose center part along the Y axis rises convexly in the traveling direction of the light forming the floating image.

[0209] FIG. 15D is a diagram showing an example of the configuration of a space-floating image display device suitable for installation on a desk according to an embodiment (eighth embodiment). FIG. 15D is configured by replacing the beam splitter 101K in the space-floating image display device 400 of the embodiment of FIG. 15A with a beam splitter 101N. The beam splitter 101N is arranged so that one straight side of the beam splitter 101N is near the display panel 11 and the other straight side of the beam splitter 101N is near the retroreflective member 2A. FIG. 15D(A) shows a YZ cross-sectional view, FIG. 15D(B) shows an XY top view, FIG. 15D(C) shows an XZ cross-sectional view, and FIG. 15D(E) shows the configuration of the beam splitter 101N. In this embodiment, differences from the embodiment of FIG. 15A are described, and repeated description of the same configuration as FIG. 15A is omitted.

[0210] The beam splitter 101N is a semi-cylindrical plate material with a reduced distance between the straight sides A1 and A1' of the beam splitter 101K in FIG. 14(B) and a larger curvature, and is surrounded by a pair of straight sides AN1, AN1' and a pair of curved sides BN1, BN1'. In the housing 4001, the beam splitter 101N is disposed obliquely with respect to the desk surface. The oblique position means that one straight side (e.g., AN1) of the beam splitter 101N is disposed near the image display device 1, and the other straight side (e.g., AN1') of the beam splitter 101N is disposed near the retroreflective member 2A. The angle formed by the direction of the line segment connecting both ends of the arc of the curved side surface of the beam splitter 101N corresponds to the Y direction of the desk surface (XY plane), and for example, in FIG. 15D, the oblique angle α is about 45 degrees (≒45°).

[0211] As with the configuration described above (Figure 3), the beam splitter 101N has the property of transmitting P-polarized light and reflecting S-polarized light. For example, it can be formed by evaporating an optical thin film onto a curved glass substrate or resin substrate. In this case, the angle of incidence of the polarized light on the beam splitter 101N changes depending on the angle of the curved surface, centered around 45 degrees, and a floating image 3N in space is generated, which is positioned almost horizontally (XY plane).

[0212] The P-polarized image light on optical axis N1 that was transmitted through beam splitter 101N is converted from P-polarized light to S-polarized light by passing through retroreflective member 2A and λ / 4 plate 21A. As a result, the S-polarized image light that traveled on optical axis N2 after being reflected by retroreflective member 2 is reflected by beam splitter 101N and travels on optical axis N3 in the Z direction.

[0213] When the incident angle of optical axis N2 with respect to the reflective curved surface of beam splitter 101N is approximately 45 degrees as mentioned above, this S-polarized image light travels in the Z direction directly upward (approximately 90 degrees) as shown in the figure, passes through the outside of opening 4002, transparent member 100 and absorptive polarizing plate 112, and generates and displays a real image, a floating-in-space image 3N, at a predetermined position in the Z direction.

[0214] The other image lights N12 and N13 indicated by dashed arrows that are emitted in the negative direction in the Y direction also behave in a similar manner to the optical axes N1 and N2 described above, but the reflection of the S-polarized image light corresponding to optical axis N2 on the reflective curved surface of beam splitter 101N has a different angle of incidence depending on the reflection position on the surface of beam splitter 101N.

[0215] For this reason, the reflected image light of S-polarized light travels in the Z direction, but as shown in the example in Fig. 15D(A), the reflection angle of the S-polarized light differs depending on the reflection position on the surface of the beam splitter 101N. Since the incident angle of N22 on the bottom side of the optical axis N2 is smaller than 45 degrees, it travels to N32 tilted in the -Y direction from the Z direction directly above (approximately 90 degrees), and since the incident angle of N23 on the top side of the optical axis N2 is larger than 45 degrees, it travels to N33 tilted in the +Y direction from the Z direction directly above (approximately 90 degrees), and a real image floating in space 3N is generated and displayed at a specified position in the Z direction.

[0216] The predetermined position where the floating image 3N is formed is determined according to the optical distance of the optical path of the optical system including the image display device 1, the beam splitter 101N, and the retroreflective member 2A. The distance between the floating image 3N and the beam splitter 101N is approximately equal to the distance between the image display device 1 and the beam splitter 101N. Since the beam splitter 101N has a semi-cylindrical shape as shown in FIG. 15D(E), the shape of the floating image in space is also approximately semi-cylindrical, but since the curvature is larger than that of the beam splitter 101K in FIG. 15A described above, the floating image in space is greatly tilted in the +Y direction and the -Y direction, that is, the floating image in space 3N is obtained which is more enlarged than the shape of the beam splitter 101N. Therefore, when viewed from the direction N, the user 230N can see the floating image 3N which is enlarged more than the display image of the image display device 1, with the center part along the X-axis rising in a convex shape.

[0217] FIG. 15E is a diagram showing an example of the configuration of a space-floating image display device suitable for installation on a desk according to an embodiment (eighth embodiment). FIG. 15E is configured by replacing the beam splitter 101N in the space-floating image display device 400 of the embodiment of FIG. 15D with a beam splitter 101P. FIG. 15E(A) shows the configuration of a YZ cross section, FIG. 15E(B) shows the configuration of an XY top view, and FIG. 15E(C) shows the configuration of an XZ cross section. The beam splitter 101P is a cone-shaped or lens-shaped plate material of FIG. 14(D), and the peripheral part B3 on the bottom side is surrounded by a circle or a curve, and the side surface rises obliquely toward the apex of the plate material. In addition, the beam splitter 101P is disposed at a predetermined angle so that the bottom surface of the beam splitter 101P faces the direction of the display panel 11, and the apex of the beam splitter 101P faces the direction of the retroreflective member 2A. In this embodiment, differences from the embodiment in FIG. 15D will be described, and repeated description of the same configuration as in FIG. 15D will be omitted.

[0218] The beam splitter 101P is disposed obliquely with respect to the desk surface within the housing 4001. Obliquely means that one curved side AA of the beam splitter 101P is disposed near the image display device 1, and the other curved side BB opposite to the curved side is disposed near the retroreflective member 2A. The angle formed by the direction of the line segment connecting one curved side AA and the other curved side BB of the beam splitter 101P described above corresponds to the Y direction of the desk surface (XY plane), and for example, in FIG. 14, the oblique angle α is about 45 degrees (≒45°).

[0219] As with the configuration described above (FIG. 15D), beam splitter 101P has the property of transmitting P-polarized light and reflecting S-polarized light. For example, it can be formed by evaporating an optical thin film onto a curved glass substrate or resin substrate. At this time, unlike the cylindrical shape of beam splitter 101N described above, beam splitter 101P has a curved surface surrounded by curves in the shape of a lens, so that S-polarized light is reflected not only in the ±Z directions but also in the ±X directions with respect to beam splitter 101P, generating a space-floating image 3P that is positioned approximately on the XY plane.

[0220] The P-polarized image light with optical axis P1 that was transmitted through beam splitter 101P is converted from P-polarized light to S-polarized light by passing through retroreflective member 2A and λ / 4 plate 21A. As a result, the S-polarized image light that has traveled along optical axis P2 after being reflected by retroreflective member 2 is reflected by beam splitter 101P and travels along optical axis P3 in the Z direction.

[0221] When the incident angle of optical axis P2 with respect to the reflective curved surface of beam splitter 101P is approximately 45 degrees as mentioned above, this S-polarized image light travels in the Z direction directly upward (approximately 90 degrees) as shown in the figure, passes through the outside of opening 4002, transparent member 100 and absorptive polarizing plate 112, and generates and displays a real image, a floating-in-space image 3P, at a predetermined position in the Z direction.

[0222] The other image lights P12 and P13 indicated by dashed arrows emitted in the negative Y direction behave in the same manner as in Fig. 15D, generating the space floating images PA and PB. Also, the image lights P14 and P15 are reflected in the ±X directions to generate the space floating images PC and PD.

[0223] The predetermined position where the floating image 3P is formed is determined according to the optical distance of the optical path of the optical system including the image display device 1, the beam splitter 101P, and the retroreflective member 2A. The distance between the floating image 3P and the beam splitter 101P is approximately equal to the distance between the image display device 1 and the beam splitter 101P. Since the beam splitter 101P has a curved surface surrounded by the curved lens shape described in Fig. 14(D), the shape of the floating image in space is similar to a circle, and since the curvature in the ±X direction is larger than that of the beam splitter 101N in Fig. 15D described above, the floating image in space is greatly inclined in the +Y direction and the -Y direction, and the +X direction and the -X direction, that is, the floating image in space 3P is obtained which is greatly enlarged compared to the shape of the beam splitter 101P. Therefore, when viewed from direction P, user 230P can see a floating-in-the-air image 3P, which has a convex central portion on the XY plane in the direction of travel of the light that forms the floating-in-the-air image, and which is enlarged compared to the display image of the image display device 1.

[0224] Fig. 15F is a diagram showing an example of the configuration of a space-floating image display device suitable for installation on a desk according to one embodiment (eighth embodiment). Fig. 15F has the same optical configuration as the embodiment of Fig. 15A in which a beam splitter 101K is arranged in the space-floating image display device 400, but has a function of correcting image distortion of the floating image generated by the reflected light retroreflected by the retroreflecting member through the curved surface of the beam splitter 101K. In this embodiment, differences from the embodiment of Fig. 15A are described, and repeated description of the same configuration as Fig. 15A is omitted.

[0225] FIG. 15F(1) shows in more detail the behavior of the image light in the optical configuration having the curved beam splitter 101K of FIG. 15A described above. As shown in the YZ cross-sectional view (A) of FIG. 15F(1), the display device 1 displays the P-polarized image light P1 to P7 traveling in the -Y direction arranged at equal intervals. When an observer (not shown) looks at the space-floating image 3K from the front of the device, the S-polarized image light that generates and displays the space-floating image 3K has a wide interval between the image light S3 and the image light S4 near the central convex part as shown in the top view (B) of FIG. 15F(1), and the interval becomes narrower as it approaches both ends (the display device 1 side or the retroreflective member 2A side), such as between the image light S1 and the image light S2, or between the image light S6 and the image light S7, etc. In other words, it is visually recognized as a space-floating image 3K with image distortion.

[0226] This phenomenon occurs because the beam splitter 101K has a curved surface, and the angle of incidence varies depending on the reflection position of the S-polarized image light on the surface of the beam splitter 101K. Therefore, although the reflected S-polarized image light travels in the Z direction, depending on the reflection position on the surface of the beam splitter 101K, it travels in a direction tilted towards -Y or +Y from the Z direction straight up (approximately 90 degrees), and a real image floating in space 3K is generated and displayed at a specified position in the Z direction.

[0227] If such a floating-in-space image effect is not desired, for example, image light in which image distortion of the floating-in-the-air image has been corrected may be displayed from the display device 1. For image distortion correction of the floating-in-the-air image, the image control unit 1160 in Fig. 10 described above controls image processing of the image signal input from the image signal input unit 1131 and the image signal to be stored in the memory 1109. The image processing is, for example, a scaling process that enlarges, reduces, transforms, etc. the image.

[0228] Fig. 15F(2) shows an embodiment for correcting image distortion of a floating image. As shown in the (A) YZ cross-sectional view of Fig. 15F(2), image processing is performed by the image control unit 1160 from the display device 1, and P-polarized image light that has been corrected so that the closer to the center, the narrower the interval is, like the interval between image light P3' and image light P4', and the closer to both ends (the Z direction side of the display device 1 and the -Z direction side of the display device 1), the wider the interval is, like the interval between image light P1' and image light P2', or between image light P6' and image light P7', etc., travels in the -Y direction. When an observer (not shown) views the generated and displayed floating-in-space image 3K' from the front of the device, as shown in the top view of Figure 15F(2)(B), the image light S3' and image light S4' near the central convexity, the image light S1' and image light S2' at both ends, and the image light S6' and image light S7' are all equally spaced apart, and are visually recognized as a floating-in-space image 3K' without image distortion.

[0229] This correction is realized by correcting the interval of the image light on the display device 1 side in advance so that even if there is a difference in the angle of incidence due to the reflection position of the S-polarized image light on the curved surface of the beam splitter 101K, the image will be equally spaced on the space floating image 3K'. Therefore, the reflected image light of S-polarized light travels in a direction tilted in the -Y direction or +Y direction from the Z direction directly above (about 90 degrees) depending on the reflection position on the surface of the beam splitter 101K, but the space floating image 3K', which is a real image with equal intervals at a predetermined position in the Z direction, is generated and displayed, and the observer can view it as the space floating image 3K' without image distortion. This correction is not limited to the embodiment of FIG. 15A, and it is possible to generate and display a distortion-free space floating image for the embodiments of FIG. 15B to FIG. 15E.

[0230] As described above, according to the space floating image display device of each embodiment and modification, it is possible to display a space floating image with high visibility, which is suitable for use indoors, for example. In addition, the space floating image display device of this embodiment is configured so that the spatial image displayed is displayed in a curved shape, improving impressive display and operability. More specifically, the beam splitter is configured to have a curved surface, and a space floating image with a curved shape is displayed. In this way, by making the polarization separation member non-planar, it is possible to form a floating image in a non-planar shape.

[0231] This has the effect of improving the visibility and operability of the floating-in-space image for users. When the generated floating-in-space image is used as a non-contact user interface, it has the effect of preventing or reducing operational errors and input errors, while providing a more impressive visibility and operability for users.

[0232] In the technology of this embodiment, the floating image is displayed as high-resolution, high-brightness image information floating in space, and this floating image can be used as a contactless user interface, allowing users to operate it without worrying about contact infection. This contributes to the "3 Health and Well-being for All" of the Sustainable Development Goals (SDGs) advocated by the United Nations.

[0233] In addition, the technology according to this embodiment makes it possible to efficiently reflect only the normal reflected light from the retroreflective material 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 "9th Sustainable Development Goal (SDGs)" advocated by the United Nations, "Build resilience, promote inclusive and sustainable development."

[0234] Furthermore, the technology according to the embodiment enables the formation of a floating image by imaging light with high directionality (linearity). The technology according to the present embodiment makes it possible to provide a non-contact user interface with low risk of people other than the user looking at the floating image by displaying highly directional imaging light, even when displaying images that require high security such as images displayed on so-called kiosk terminals, or highly confidential images that should be concealed from people directly facing the user. By providing the above-mentioned technology, the present invention contributes to "Sustainable cities and towns" of the Sustainable Development Goals (SDGs) proposed by the United Nations. [Explanation of symbols]

[0235] 1: image display device, 2, 2A, 2B: retroreflective member, 3, 3A, 3B, 3C, 3D, 3E, 3F, 3J: spatial floating image, 11: liquid crystal display panel, 12, 112: absorption type polarizing plate, 13: light source device, 21, 21A, 21B: λ / 4 plate, 203: light guide, 100, 100A, 100B, 100C: transparent member, 101, 101A, 101B, 101C, 101D, 101E, 101F, 101J, 101G, 101K, 101L, 101M, 101N, 101P: beam splitter (polarized light separation member), 1010: beam splitter angle adjustment unit, 106: image display Housing of device unit, 300: image display unit, 400: space floating image display unit, 1061: opening, 4001: housing, 4002: opening, 230A, 230B, 230C, 230D, 230E, 230F, 230J, 230K, 230M, 230L, 230N, 230P: user, 310: piston mechanism, 310A, 310B, 310C: piston, 330, 331, 332, 333: hinge mechanism, 500: control unit, etc., 510: imaging unit, 600: unwanted light, 1110: control unit, 1160: image control unit, 1350: mid-air operation detection unit, 1351: mid-air operation detection sensor

Claims

1. A floating-in-the-air image display device, A display panel for displaying an image; a polarization separation member that reflects a portion of the image light emitted from the display panel; a retroreflective member disposed opposite the display panel and configured to retroreflect light reflected by the polarization separating member, The light reflected by the retroreflective member forms a floating image through the polarization separation member, The polarization separation member is made to have a non-planar shape, thereby forming the floating image in a non-planar shape. A floating image display device.

2. 2. The airborne image display device according to claim 1, The non-planar shape is a curved shape. A floating image display device.

3. 2. The airborne image display device according to claim 1, The non-planar shape is a semi-cylindrical shape and is bounded by a pair of straight sides and a pair of curved sides. A floating image display device.

4. 2. The airborne image display device according to claim 1, The non-planar shape is a cone shape or a lens shape. A floating image display device.

5. 2. The airborne image display device according to claim 1, The non-planar shape is stepped. A floating image display device.

6. 4. The airborne image display device according to claim 3, The polarization separation member is disposed such that one straight side of the polarization separation member is adjacent to the display panel and the other straight side of the polarization separation member is adjacent to the retroreflective member. A floating image display device.

7. 4. The airborne image display device according to claim 3, In the traveling direction of the light forming the floating-in-the-air image, the center of the floating-in-the-air image is higher than the vicinity of the display panel of the floating-in-the-air image and the vicinity of the retroreflective member of the floating-in-the-air image; A floating image display device.

8. 4. The airborne image display device according to claim 3, The floating image is larger than the size of the polarization separation member. A floating image display device.

9. 4. The airborne image display device according to claim 3, The polarization separation member is disposed such that one curved side of the polarization separation member is adjacent to the display panel and the other curved side of the polarization separation member is adjacent to the retroreflective member. A floating image display device.

10. 4. The airborne image display device according to claim 3, In the traveling direction of the light forming the floating-in-the-air image, the curved side of the polarization separation member near the display panel and the curved side of the polarization separation member near the retroreflective member have high central portions; A floating image display device.

11. 5. The airborne image display device according to claim 4, The bottom surface of the polarization separation member faces the display panel, and the apex of the polarization separation member faces the retroreflective member at a predetermined angle. A floating image display device.

12. 5. The airborne image display device according to claim 4, The floating image is larger than the size of the polarization separation member. A floating image display device.

13. 2. The airborne image display device according to claim 1, A function of correcting image distortion of the floating image, A floating image display device.

14. The air-floating image display device according to claim 13, The image distortion correction of the floating-in-the-air image is performed by displaying an image on the display panel that cancels out the distortion of the non-planar floating-in-the-air image. A floating image display device.

Images