Optical image display device

Abstract

To provide a more suitable aerial floating image display device. According to the present invention, it will contribute to Sustainable Development Goals (SDGs) "3 Good Health and Well-being," "9 Industry, Innovation and Infrastructure," and "11 Sustainable Cities and Communities." [Solution] An optical image display device that generates an optical image for a worker performing manual work, comprising a display device that displays an image processed by an image processing unit, and an optical element that generates an optical image based on the image light emitted from the display device, wherein the display device and the optical element are positioned outside the workspace where the manual work is performed, and the optical image is generated so as to be seen by the worker that it overlaps with the workspace.

Description

Technical Field

[0001] The present invention relates to an optical image display device including an airborne floating image display device and a virtual image display device.

Background Art

[0002] Regarding airborne floating information display technology, for example, it is disclosed in Patent Document 1.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the disclosure of Patent Document 1, the consideration regarding the configuration for obtaining practical brightness and quality of the airborne floating image, the configuration for the user to view the airborne floating image more enjoyably, etc. was not sufficient.

[0005] An object of the present invention is to provide a more suitable optical image display device.

Means for Solving the Problems

[0006] In order to solve the above problems, for example, the configuration described in the claims is adopted. This application includes a plurality of means for solving the above problems. If an example is given, it may be configured as follows. An optical image display device that generates an optical image for an operator performing manual work, including a display device that displays an image obtained by the video processing unit performing video processing, and an optical member that generates an optical image based on the video light emitted from the display device, wherein the display device and the optical member are arranged outside the work space where manual work is performed, and the optical image is generated so as to overlap the work space as viewed by the operator.

Effects of the Invention

[0007] According to the present invention, a more suitable optical image display device can be realized. Other problems, configurations, and effects will be clarified in the following description of embodiments. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an example of how to use a spatially floating image display device according to one embodiment of the present invention. [Figure 2A] This figure shows an example of the main component configuration and retroreflective component configuration of a spatial floating image display device according to one embodiment of the present invention. [Figure 2B] This figure shows an example of the main component configuration and retroreflective component configuration of a spatial floating image display device according to one embodiment of the present invention. [Figure 2C] This figure shows an example of the main component configuration and retroreflective component configuration of a spatial floating image display device according to one embodiment of the present invention. [Figure 2D] This figure shows an example of the main components and retroreflective components of an aerial levitation image display device according to one embodiment of the present invention. [Figure 2E] This is a projection view of a retroreflective plate that constitutes an aerial levitation image display device according to one embodiment of the present invention. [Figure 2F] This is a top view of a retroreflective plate that constitutes an aerial levitation image display device according to one embodiment of the present invention. [Figure 2G] This is a perspective view showing a corner reflector that constitutes a retroreflective plate, which is part of an aerial floating image display device according to one embodiment of the present invention. [Figure 2H] This is a top view showing a corner reflector, which constitutes a retroreflective plate, as part of an aerial floating image display device according to one embodiment of the present invention. [Figure 2I] This is a side view showing a corner reflector, which constitutes a retroreflective plate, as part of an aerial floating image display device according to one embodiment of the present invention. [Figure 3] This figure shows an example of the configuration of a spatially floating image display device according to one embodiment of the present invention. [Figure 4A]It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4B] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4C] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4D] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4E] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4F] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4G] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4H] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4I] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4J] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4K] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4L] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4M] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4N] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4O] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 4P] It is a diagram showing an example of the configuration of a spatial floating image display device according to an embodiment of the present invention. [Figure 5]This cross-sectional view shows a specific example of the configuration of a light source device according to one embodiment of the present invention. [Figure 6] This cross-sectional view shows a specific example of the configuration of a light source device according to one embodiment of the present invention. [Figure 7] This cross-sectional view shows a specific example of the configuration of a light source device according to one embodiment of the present invention. [Figure 8] This is a layout diagram showing the main parts of a spatial floating image display device according to one embodiment of the present invention. [Figure 9] This is a cross-sectional view showing the configuration of a display device according to one embodiment of the present invention. [Figure 10] This is a cross-sectional view showing the configuration of a display device according to one embodiment of the present invention. [Figure 11] This is an explanatory diagram illustrating the light source diffusion characteristics of an image display device according to one embodiment of the present invention. [Figure 12] This is an explanatory diagram illustrating the diffusion characteristics of an image display device according to one embodiment of the present invention. [Figure 13A] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 13B] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 14] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 15] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 16] This figure illustrates an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 17] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 18] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 19] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 20] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 21] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 22] This figure illustrates an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 23] This figure shows an example of an optical image according to one embodiment of the present invention. [Figure 24] This figure shows an example of an optical image according to one embodiment of the present invention. [Figure 25] This figure shows an example of an optical image according to one embodiment of the present invention. [Figure 26] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 27] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 28] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 29A] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 29B] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 30] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 31] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 32] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 33] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 34] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 35] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 36A] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 36B]This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 37A] This figure shows an example of an optical image according to one embodiment of the present invention. [Figure 37B] This figure shows an example of an optical image according to one embodiment of the present invention. [Figure 38] This figure shows an example of the configuration of an optical image display device according to one embodiment of the present invention. [Figure 39] This figure shows an example of an optical image according to one embodiment of the present invention. [Figure 40] This figure illustrates an example of an airborne operation detection sensor according to one embodiment of the present invention. [Figure 41] This figure illustrates the procedure for manipulating an optical image according to one embodiment of the present invention. [Figure 42A] This figure shows an example of an optical image according to one embodiment of the present invention. [Figure 42B] This figure illustrates an example of an airborne operation detection sensor according to one embodiment of the present invention. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the examples described herein, and various modifications and alterations are possible by those skilled in the art within the scope of the technical ideas disclosed herein. Furthermore, in all the figures used to illustrate the present invention, components having the same function are given the same reference numerals, and repeated descriptions may be omitted.

[0010] The following embodiments relate to an image display device capable of transmitting an image generated by image light from an image light source through a transparent component that partitions a space, such as glass, and displaying it as a floating image in space outside the transparent component. In the following description of embodiments, the image floating in space is referred to as a "floating image in space." Instead of this term, other terms such as "aerial image," "spatial image," "floating image in space," "floating optical image of a displayed image," or "floating optical image of a displayed image in space" may be used. The term "floating image in space," which is mainly used in the description of embodiments, is used as a representative example of these terms.

[0011] According to the following embodiment, a suitable video display device can be realized for applications such as bank ATMs, train station ticket machines, and digital signage. For example, currently, bank ATMs and train station ticket machines typically use touch panels, but by using a transparent glass surface or a light-transmitting plate material, high-resolution video information can be displayed on this glass surface or light-transmitting plate material in a state of floating in space. At this time, by making the divergence angle of the emitted video light small, i.e., acute, and further aligning it to a specific polarization, only the normal reflected light is efficiently reflected by the retroreflector, resulting in high light utilization efficiency. This suppresses ghost images that occur in addition to the main floating image, which was a problem in conventional retroreflection methods, and allows for the acquisition of a clear floating image. Furthermore, the device including the light source of this embodiment can provide a novel and highly usable floating image display device (floating image display system) that can significantly reduce power consumption. In addition, for example, a floating image display device for vehicles can be provided that enables so-called unidirectional floating image display, which is visible inside and / or outside a vehicle.

[0012] <Example 1> Below, an example configuration of a spatially floating image display device will be described as Embodiment 1 of the present invention.

[0013] <An example of how a spatially floating image display device can be used> Figure 1 is a diagram showing an example of how to use a spatially floating image display device according to one embodiment of the present invention, and is a diagram showing the overall configuration of the spatially floating image display device according to this embodiment. The specific configuration of the spatially floating image display device will be described in detail using Figure 2, etc., but light with narrow-angle directivity and specific polarization is emitted from the image display device 1 as an image light beam, and after reflection in the optical system inside the spatially floating image display device, it enters the retroreflector plate 2, is retroreflected and passes through a transparent member 100 (glass, etc.), and forms an aerial image (spatially floating image 3), which is a real image, on the outside of the glass surface. In the following embodiments, the retroreflector plate 2 (retroreflective plate) will be used as an example of a retroreflective member. However, the retroreflector plate 2 of the present invention is not limited to a planar plate, but is used as an example of a concept that includes a sheet-like retroreflector attached to a planar or non-planar member, or the entire assembly in which a sheet-like retroreflector is attached to a planar or non-planar member. Furthermore, since the light rays reflected by the retroreflector 2 have imaging optical properties, the retroreflector 2 may also be described as an imaging optical member or imaging optical plate.

[0014] Furthermore, in stores and other similar establishments, the space is partitioned by a translucent material such as glass, called a "show window" (also known as "window glass") 105. According to the spatial floating image display device of this embodiment, it is possible to transmit such a transparent material and display the floating image in one direction to the outside and / or inside of the store (space).

[0015] In Figure 1, the inside of the window glass 105 (inside the store) is shown in the depth direction, and the outside (for example, the sidewalk) is shown in the foreground. Alternatively, by providing the window glass 105 with means for reflecting specific polarizations, it is also possible to reflect the light and form an aerial image at a desired location inside the store.

[0016] <Example of optical system configuration for a floating image display device> Figure 2A is a diagram showing an example of the configuration of the optical system of a spatially floating image display device according to one embodiment of the present invention. The configuration of the spatially floating image display device will be explained in more detail using Figure 2A. As shown in Figure 2A(1), a display device 1 is provided that emits image light of a specific polarization at a narrow angle in the oblique direction of a transparent member 100 such as glass. The display device 1 comprises a liquid crystal display panel 11 and a light source device 13 that generates light of a specific polarization having narrow-angle diffusion characteristics.

[0017] The image light of a specific polarization from the display device 1 is reflected by a polarization separation member 101 (in the figure, the polarization separation member 101 is formed in a sheet shape and adhered to the transparent member 100) which has a film that selectively reflects the image light of the specific polarization, and is incident on the retroreflector 2. A λ / 4 plate 21 is provided on the image light incident surface of the retroreflector 2. The image light is polarized from the specific polarization to the other polarization by passing through the λ / 4 plate 21 twice, once when it is incident on the retroreflector 2 and once when it is emitted. Here, the polarization separation member 101, which selectively reflects the image light of the specific polarization, has the property of transmitting the polarization of the other polarization after polarization conversion, so the image light of the specific polarization after polarization conversion is transmitted through the polarization separation member 101. The image light that has been transmitted through the polarization separation member 101 forms a spatially floating image 3, which is a real image, on the outside of the transparent member 100. Note that in Figure 2A, the principal ray of the image light incident on the retroreflector 2 is shown as being incident at a 90° angle to the retroreflector 2. However, the incident angle of the principal ray of the image light on the retroreflector 2 is not limited to 90°; for example, 90°±15° can also be used.

[0018] Here, we will describe a first example of polarization design in the optical system shown in Figure 2A. For example, the display device 1 may be configured to emit S-polarized (S stands for senkrecht; polarization in which the electric field oscillates perpendicular to the incident plane) image light to the polarization separation member 101, and the polarization separation member 101 may be configured to reflect S-polarized light and transmit P-polarized (P stands for parallel; polarization in which the electric field oscillates within the incident plane) light. In this case, the S-polarized image light that reaches the polarization separation member 101 from the display device 1 is reflected by the polarization separation member 101 and heads towards the retroreflector 2. When the image light is reflected by the retroreflector 2, it passes through the λ / 4 plate 21 provided on the incident surface of the retroreflector 2 twice, so the image light is converted from S-polarized to P-polarized. The image light converted to P-polarized light heads towards the polarization separation member 101 again. Here, since the polarization separation member 101 has the characteristic of reflecting S-polarized light and transmitting P-polarized light, the P-polarized image light passes through the polarization separation member 101 and then through the transparent member 100. Since the image light that has passed through the transparent member 100 is light generated by the retroreflector 2, a floating image 3, which is the optical image of the display image of the display device 1, is formed at a position that is mirror-image to the display image of the display device 1 with respect to the polarization separation member 101. With such a polarization design, the floating image 3 can be suitably formed.

[0019] Next, a second example of polarization design in the optical system shown in Figure 2A will be described. For example, the display device 1 may emit P-polarized image light to the polarization separation member 101, and the polarization separation member 101 may be configured to reflect P-polarized light and transmit S-polarized light. In this case, the P-polarized image light that reaches the polarization separation member 101 from the display device 1 is reflected by the polarization separation member 101 and heads towards the retroreflector 2. When the image light is reflected by the retroreflector 2, it passes through the λ / 4 plate 21 provided on the incident surface of the retroreflector 2 twice, so the image light is converted from P-polarized to S-polarized light. The image light converted to S-polarized light heads towards the polarization separation member 101 again. Here, since the polarization separation member 101 has the characteristic of reflecting P-polarized light and transmitting S-polarized light, the S-polarized image light passes through the polarization separation member 101 and then through the transparent member 100. Since the image light transmitted through the transparent member 100 is light generated by the retroreflector 2, a floating image 3, which is an optical image of the display image of the display device 1, is formed at a position that is mirror-like to the display image of the display device 1 with respect to the polarization separation member 101. With such a polarization design, a floating image 3 can be suitably formed.

[0020] The light that forms the floating image 3 is a collection of light rays converging from the retroreflector 2 to the optical image of the floating image 3, and these light rays continue to travel in a straight line even after passing through the optical image of the floating image 3. Therefore, unlike the diffused image light formed on a screen by a typical projector, the floating image 3 is an image with high directivity. Thus, in the configuration of Figure 2A, when a user views from the direction of arrow A, the floating image 3 is visible as a bright image. However, when another person views from the direction of arrow B, the floating image 3 cannot be seen as an image at all. This characteristic is very suitable for use in systems that display images requiring high security or highly confidential images that should be hidden from people directly facing the user.

[0021] Furthermore, depending on the performance of the retroreflector 2, the polarization axis of the reflected image light may become uneven. The reflection angle may also become uneven. Such uneven light may not maintain the polarization state and propagation angle assumed in the design. For example, light with such an unintended polarization state and propagation angle may re-enter the image display side of the liquid crystal display panel 11 directly from the position of the retroreflector 2 without passing through the polarization separation member. Light with such an unintended polarization state and propagation angle may also be reflected by components within the floating image display device and then re-enter the image display side of the liquid crystal display panel 11. This re-entered light on the image display side of the liquid crystal display panel 11 may be re-reflected by the image display surface of the liquid crystal display panel 11 that constitutes the display device 1, potentially generating ghost images and degrading the image quality of the floating image. Therefore, in this embodiment, an absorbing polarizer 12 may be provided on the image display surface of the display device 1. The image light emitted from the display device 1 is transmitted through the absorbing polarizer 12, and the reflected light returning from the polarization separation member 101 is absorbed by the absorbing polarizer 12, thereby suppressing the above-mentioned re-reflection. This prevents image quality degradation due to ghost images of floating images in space. Specifically, if the display device 1 emits S-polarized image light to the polarization separation member 101, the absorbing polarizer 12 should be a polarizer that absorbs P-polarized light. Alternatively, if the display device 1 emits P-polarized image light to the polarization separation member 101, the absorbing polarizer 12 should be a polarizer that absorbs S-polarized light.

[0022] The polarization separation member 101 described above may be formed, for example, from a reflective polarizer or a multilayer metal film that reflects specific polarizations.

[0023] Next, Figure 2A(2) shows an example of the surface shape of a typical retroreflector 2. The retroreflector 2 has a prism body in which regularly arranged triangular pyramidal recesses serve as reflective surfaces. Light rays incident on the arranged triangular pyramidal recesses are reflected by multiple reflective surfaces of the triangular pyramidal recesses and emitted as retroreflected light in the direction corresponding to the incident light, and a floating image, which is a real image, is displayed on the display device 1.

[0024] The surface shape of the retroreflector in this embodiment is not limited to the examples described above. It may have various surface shapes that realize retroreflection. Specifically, retroreflective elements formed by periodically arranging triangular pyramidal prisms, hexagonal pyramidal prisms, other polygonal prisms, multi-vertex prisms, or combinations thereof may be provided on the surface of the retroreflector in this embodiment. Alternatively, retroreflective elements forming cube corners by periodically arranging these prisms may be provided on the surface of the retroreflector in this embodiment. These can also be expressed as corner reflector arrays or polyhedron reflector arrays. Alternatively, capsule lens type retroreflective elements formed by periodically arranging glass beads may be provided on the surface of the retroreflector in this embodiment. Since the detailed configuration of these retroreflective elements can be described using existing technology, a detailed explanation is omitted. Specifically, the technology disclosed in Japanese Patent Publication No. 2001-33609, Japanese Patent Publication No. 2001-264525, Japanese Patent Publication No. 2005-181555, Japanese Patent Publication No. 2008-70898, Japanese Patent Publication No. 2009-229942, etc., can be used.

[0025] <Another example of the optical system configuration for a spatially floating image display device 1> Another example of the optical system configuration for the floating image display device will be explained using Figure 2B. In Figure 2B, components with the same reference numerals as those in Figure 2A have the same function and configuration as those in Figure 2A. For simplicity, repeated explanations of such components will be omitted.

[0026] In the optical system shown in Figure 2B, as in Figure 2A, image light with a specific polarization is output from the display device 1. The image light with a specific polarization output from the display device 1 is input to the polarization separation member 101B. The polarization separation member 101B is a member that selectively transmits image light with a specific polarization. Unlike the polarization separation member 101 in Figure 2A, the polarization separation member 101B is not integrated with the transparent member 100, but has an independent plate-like shape. Therefore, the polarization separation member 101B may also be described as a polarization separation plate. The polarization separation member 101B may be configured as a reflective polarizer, for example, by attaching a polarization separation sheet to a transparent member. Alternatively, it may be formed by a metal multilayer film that selectively transmits the specific polarization and reflects the polarization of other specific polarizations to the transparent member. In Figure 2B, the polarization separation member 101B is configured to transmit image light with a specific polarization output from the display device 1.

[0027] The image light that has passed through the polarization separation member 101B is incident on the retroreflector 2. A λ / 4 plate 21 is provided on the image light incident surface of the retroreflector. The image light is polarized from one polarization to the other by passing through the λ / 4 plate 21 twice, once when it is incident on the retroreflector and once when it is emitted. Here, the polarization separation member 101B has the property of reflecting the polarization of the other polarization that has been polarized by the λ / 4 plate 21, so the image light after polarization conversion is reflected by the polarization separation member 101B. The image light reflected by the polarization separation member 101B passes through the transparent member 100, forming a spatially floating image 3, which is a real image, on the outside of the transparent member 100.

[0028] Here, we will describe a first example of polarization design in the optical system shown in Figure 2B. For example, the display device 1 may emit P-polarized video light to the polarization separation member 101B, and the polarization separation member 101B may have the characteristic of reflecting S-polarized light and transmitting P-polarized light. In this case, the P-polarized video light that reaches the polarization separation member 101B from the display device 1 passes through the polarization separation member 101B and heads towards the retroreflector 2. When the video light is reflected by the retroreflector 2, it passes through the λ / 4 plate 21 provided on the incident surface of the retroreflector 2 twice, so the video light is converted from P-polarized to S-polarized light. The video light converted to S-polarized light heads towards the polarization separation member 101B again. Here, since the polarization separation member 101B has the characteristic of reflecting S-polarized light and transmitting P-polarized light, the S-polarized video light is reflected by the polarization separation member 101 and transmitted through the transparent member 100. Since the image light transmitted through the transparent member 100 is light generated by the retroreflector 2, a floating image 3, which is an optical image of the display image of the display device 1, is formed at a position that is mirror-like to the display image of the display device 1 with respect to the polarization separation member 101B. With such a polarization design, a floating image 3 can be suitably formed.

[0029] Next, a second example of polarization design in the optical system shown in Figure 2B will be described. For example, the display device 1 may be configured to emit S-polarized video light to the polarization separation member 101B, and the polarization separation member 101B may be configured to reflect P-polarized light and transmit S-polarized light. In this case, the S-polarized video light that reaches the polarization separation member 101B from the display device 1 passes through the polarization separation member 101B and heads towards the retroreflector 2. When the video light is reflected by the retroreflector 2, it passes through the λ / 4 plate 21 provided on the incident surface of the retroreflector 2 twice, so the video light is converted from S-polarized to P-polarized light. The video light converted to P-polarized light heads towards the polarization separation member 101B again. Here, since the polarization separation member 101B has the characteristic of reflecting P-polarized light and transmitting S-polarized light, the P-polarized video light is reflected by the polarization separation member 101 and transmitted through the transparent member 100. Since the image light transmitted through the transparent member 100 is light generated by the retroreflector 2, a floating image 3, which is an optical image of the display image of the display device 1, is formed at a position that is mirror-like to the display image of the display device 1 with respect to the polarization separation member 101B. With such a polarization design, the floating image 3 can be suitably formed.

[0030] In Figure 2B, the image display surface of the display device 1 and the surface of the retroreflector 2 are arranged parallel to each other. The polarization separation member 101B is positioned at an angle α (e.g., 30°) relative to the image display surface of the display device 1 and the surface of the retroreflector 2. As a result, in the reflection by the polarization separation member 101B, the direction of propagation of the image light reflected by the polarization separation member 101B (the direction of the principal ray of the image light) differs from the direction of propagation of the image light incident from the retroreflector 2 (the direction of the principal ray of the image light) by an angle β (e.g., 60°). With this configuration, in the optical system of Figure 2B, image light is output at a predetermined angle shown toward the outside of the transparent member 100, forming a real image of a floating image in space 3. In the configuration of Figure 2B, when a user views from the direction of arrow A, the floating image in space 3 is visible as a bright image. However, when another person views from the direction of arrow B, the floating image in space 3 cannot be seen as an image at all. This characteristic makes it ideal for systems that display video requiring high security, or highly confidential video that should be kept hidden from the user.

[0031] As explained above, the optical system in Figure 2B, although having a different configuration from the optical system in Figure 2A, can form suitable floating images in space, just like the optical system in Figure 2A.

[0032] Alternatively, an absorbing polarizer may be provided on the side of the transparent member 100 facing the polarization separation member 101B. This absorbing polarizer should transmit the polarization of the image light from the polarization separation member 101B and absorb the polarization that is 90° out of phase with the polarization of the image light from the polarization separation member 101B. In this way, the image light for forming the floating image 3 can be sufficiently transmitted, while the ambient light incident on the floating image 3 side of the transparent member 100 can be reduced by approximately 50%. This reduces stray light in the optical system shown in Figure 2B, which is caused by ambient light incident on the floating image 3 side of the transparent member 100.

[0033] <Another example of the optical system configuration for a floating image display device (2)> Another example of the optical system configuration for the floating image display device will be explained using Figure 2C. In Figure 2C, components with the same reference numerals as those in Figure 2B have the same function and configuration as those in Figure 2B. Such configurations will not be repeated in order to simplify the explanation.

[0034] The only difference between the optical system in Figure 2C and the optical system in Figure 2B is the positioning angle of the polarization separation member 101B with respect to the image display surface of the display device 1 and the surface of the retroreflector 2. All other configurations are the same as those of the optical system in Figure 2B, so repeated explanations are omitted. The polarization design of the optical system in Figure 2C is also the same as that of the optical system in Figure 2B, so repeated explanations are omitted.

[0035] In the optical system shown in Figure 2C, the polarization separation member 101B is positioned at an angle α with respect to the image display surface of the display device 1 and the surface of the retroreflector 2. In Figure 2C, this angle α is 45°. With this configuration, in the reflection by the polarization separation member 101B, the angle β between the direction of propagation of the image light reflected by the polarization separation member 101B (the direction of the principal ray of the image light) and the direction of propagation of the image light incident from the retroreflector 2 (the direction of the principal ray of the image light) is 90°. With this configuration, the image display surface of the display device 1 and the surface of the retroreflector 2 are perpendicular to the direction of propagation of the image light reflected by the polarization separation member 101B, thus simplifying the angular relationships of the surfaces constituting the optical system. If the surface of the transparent member 100 is positioned perpendicular to the direction of propagation of the image light reflected by the polarization separation member 101B, the angular relationships of the surfaces constituting the optical system can be further simplified. In the configuration shown in Figure 2C, when a user views the image from the direction of arrow A, the floating image 3 is visible as a bright image. However, when another person views the image from the direction of arrow B, the floating image 3 is not visible at all. This characteristic makes it ideal for systems that display highly secure images or highly confidential images that should be concealed from people directly facing the user.

[0036] As explained above, the optical system in Figure 2C, while having a different configuration from the optical systems in Figures 2A and 2B, can form suitable floating images in space, just like the optical systems in Figures 2A and 2B. Furthermore, the angles of the surfaces constituting the optical system can be made simpler.

[0037] Alternatively, an absorbing polarizer may be provided on the side of the transparent member 100 facing the polarization separation member 101B. This absorbing polarizer should transmit the polarization of the image light from the polarization separation member 101B and absorb the polarization that is 90° out of phase with the polarization of the image light from the polarization separation member 101B. In this way, the image light for forming the floating image 3 can be sufficiently transmitted, while the ambient light incident on the floating image 3 side of the transparent member 100 can be reduced by approximately 50%. This reduces stray light in the optical system of Figure 2C caused by ambient light incident on the floating image 3 side of the transparent member 100.

[0038] <Another example of the optical system configuration for a floating image display device 3> Another example of the optical system configuration for the floating image display device will be explained using Figure 2D. The optical system in Figure 2D is an optical system that uses a retroreflector 5, which is different from the retroreflector 2 used in Figures 2A to 2C. Below, another example of the optical system configuration 3 will be explained in more detail using Figures 2D to 2I. In Figure 2D, components that are denoted by the same reference numerals as in Figures 2A to 2C have the same function and configuration as those in Figures 2A to 2C. Such components will not be explained again in order to simplify the explanation.

[0039] Figure 2D shows an example of the main components and retroreflective components of a spatially floating image display device according to one embodiment of the present invention. A display device 1 that emits image light is provided obliquely to a transparent member 100 such as glass. The display device 1 comprises a liquid crystal display panel 11 and a light source device 13 that generates light.

[0040] The principal ray 9020, which represents the light beam emitted from the display device 1, travels toward the retroreflector 5 and is incident on the retroreflector 5 at an incident angle α. The incident angle α can be, for example, 45°. However, the incident angle α is not limited to 45°; for example, 45°±15° can also be used.

[0041] The retroreflector 5 is an optical component having optical properties that retroreflect light rays in at least some directions. Furthermore, since the reflected light rays have optical properties that form an image, the retroreflector 5 may also be described as an imaging optical component or imaging optical plate.

[0042] The specific configuration of the retroreflector 5 will be described in detail using Figures 2E and 2F, but the retroreflector 5 causes the principal ray 9020 to propagate in the z direction while being retroreflected in the x and y directions. As a result, the reflected ray 9021 travels away from the retroreflector 5 in an optical path that is mirror-symmetric with respect to the principal ray 9020 with respect to the retroreflector 5, passes through the transparent member 100, and forms a floating image 3 as a real image at the imaging plane.

[0043] The light beam forming the floating image 3 is a collection of light rays converging from the retroreflector 5 to the optical image of the floating image 3, and these light rays continue to travel in a straight line even after passing through the optical image of the floating image 3. Therefore, unlike diffuse images formed on a screen by general projectors, the floating image 3 is an image with high directivity. Thus, in the configuration of Figure 2, when a user views from the direction of arrow A, the floating image 3 is perceived as a bright image. However, when another person views from the direction of arrow B, the floating image 3 cannot be seen as an image at all. This characteristic is suitable for use in systems that display images requiring high security or highly confidential images that should be hidden from people directly facing the user.

[0044] An example of the configuration of the retroreflector 5 will be explained using Figures 2E and 2F. The retroreflector 5 has a configuration in which multiple corner reflectors 9040 are arranged in an array on the surface of a transparent material. This may also be called a corner reflector array or a polyhedron reflector array. The specific configuration of the corner reflectors 9040 will be described in detail using Figures 2G, 2H, and 2I, but the light rays 9111, 9112, 9113, and 9114 emitted from the light source 9110 are reflected twice by the two mirror surfaces 9041 and 9042 of the corner reflectors 9040, becoming reflected light rays 9121, 9122, 9123, and 9124. This double reflection is retroreflection in the x and y directions, where the light is reflected back in the same direction as the incident direction (moving in a direction rotated 180°), and in the z direction, it is specular reflection in which the angle of incidence and the angle of reflection coincide due to total internal reflection.

[0045] In other words, the light rays 9111 to 9114 produce reflected light rays 9121 to 9124 on a straight line symmetrical in the z direction with respect to the corner reflector 9040, forming the aerial real image 9120. The light rays 9111 to 9114 emitted from the light source 9110 are four representative rays of diffused light from the light source 9110, and depending on the diffusion characteristics of the light source 9110, the light rays incident on the retroreflector 5 are not limited to these, but any incident light ray will cause similar reflection and form the aerial real image 9120. For the sake of clarity in the diagram, the position of the light source 9110 and the position of the aerial real image 9120 in the x direction are shown offset, but in reality, the position of the light source 9110 and the position of the aerial real image 9120 in the x direction are at the same position, and when viewed from the z direction, they are in overlapping positions.

[0046] Next, the configuration and effects of the corner reflectors 9040 that constitute the retroreflector 5 will be explained in Figures 2G, 2H, and 2I. The corner reflector 9040 is a rectangular parallelepiped in which only two specific faces, 9041 and 9042, are mirrored surfaces, while the other four faces are made of a transparent material. The retroreflector 5 has a configuration in which these corner reflectors 9040 are arranged in an array such that their corresponding mirrored surfaces face the same direction.

[0047] When viewed from above (+z direction), the light ray 9111 emitted from the light source 9110 is incident on the mirror surface 9041 (or mirror surface 9042) at a specific angle of incidence, undergoes total internal reflection at the reflection point 9130, and then undergoes total internal reflection again at the reflection point 9132 on the mirror surface 9042 (or mirror surface 9041).

[0048] If the angle of incidence of ray 9111 to mirror surface 9041 (or mirror surface 9042) is θ, then the angle of incidence of the first reflected ray 9131, reflected by mirror surface 9041 (or mirror surface 9042), to mirror surface 9042 (or mirror surface 9041) can be expressed as 90°-θ. Therefore, with respect to ray 9111, the second reflected ray 9121 gains a rotation of 2θ from the first reflection and 2×(90°-θ) from the second reflection, resulting in a total reversed optical path of 180°. On the other hand, when viewed from the side (the direction midway between -x and -y), total internal reflection in the z direction occurs only once. Therefore, if the angle of incidence to mirror surface 9041 or mirror surface 9042 is φ, then with respect to ray 9111, the reflected ray 9121 gains a rotation of 2×φ from one reflection.

[0049] From the above, the light rays incident on the corner reflector 9040 undergo retroreflection with reversed optical paths in the x and y directions, and specular reflection due to total internal reflection in the z direction. Considering the retroreflector 5, similar reflections occur in each optical path, so in the x and y directions, the image is formed at a point symmetrical with respect to the z axis due to the reversing optical path with convergence properties.

[0050] In the optical system shown in Figures 2A to 2C, the retroreflector 2 has retroreflective properties in three axes. As a result, when a diffusive incident light beam is incident on the retroreflector 2, a convergent reflected light beam travels toward the side of the incident light beam where the light source is located. This convergent reflected light beam forms an image in the air, creating a floating image 3. The direction of propagation of the principal ray of the convergent reflected light beam reflected from the retroreflector 2 is opposite to the direction of propagation of the principal ray of the diffusive incident light beam incident on the retroreflector 2.

[0051] In contrast, in the optical system shown in Figure 2D, the retroreflector 5 has retroreflective properties in two axes and specular reflection in the other axis. As a result, when a diffuse incident light beam is incident on the retroreflector 5, the convergent reflected light beam reflected by the corner reflector array travels toward the retroreflector 5 toward the side of the incident light beam away from the light source. This convergent reflected light beam forms an image in the air, creating a floating image 3.

[0052] The direction of propagation of the principal ray of the convergent reflected light beam reflected by the corner reflector array of the retroreflector 5 is not in the opposite direction to the direction of propagation of the principal ray of the diffuse incident light beam incident on the retroreflector 5. The component of the direction of propagation of the principal ray of the diffuse incident light beam incident on the retroreflector 5 in the direction of the plate-shaped surface of the retroreflector 5, and the component of the direction of propagation of the principal ray after it has been reflected by the retroreflector 5 and become a convergent reflected light beam, remain in a straight line before and after reflection by the corner reflector array.

[0053] In other words, the diffusive incident light beam is converted into a convergent reflected light beam by reflection at the retroreflector 5, but in the direction normal to the plate-shaped surface of the retroreflector 5, the light beam will travel through the retroreflector 5. Here, the diffusive incident light beam that enters the retroreflector 5 and the convergent reflected light beam that exits the retroreflector 5 are geometrically symmetrical with respect to the plate-shaped surface of the retroreflector 5.

[0054] The resolution of the floating image formed by light rays from the display device 1 depends not only on the resolution of the liquid crystal display panel 11, but also largely on the diameter D and pitch P (not shown) of the retroreflective portion of the retroreflective plate 5, as shown in Figures 2E and 2F. For example, when using a 7-inch WUXGA (1920 x 1200 pixels) liquid crystal display panel, even if one pixel (one triplet) is approximately 80 μm, if the diameter D of the retroreflective portion is 240 μm and the pitch P is 300 μm, then one pixel of the floating image will be equivalent to 300 μm. As a result, the effective resolution of the floating image is reduced to about one-third.

[0055] Therefore, in order to make the resolution of the floating image in space equivalent to the resolution of the display device 1, it is desirable to bring the diameter D and pitch P of the retroreflective portion close to that of one pixel of the liquid crystal display panel. On the other hand, in order to suppress the occurrence of moiré patterns caused by the retroreflective plate and the pixels of the liquid crystal display panel, it is advisable to design the respective pitch ratios to be outside of integer multiples of one pixel. Furthermore, the shape should be arranged so that none of the sides of the retroreflective portion overlap with any of the sides of one pixel of the liquid crystal display panel.

[0056] The shape of the retroreflector (imaging optical plate) in this embodiment is not limited to the example described above. It may have various shapes that realize retroreflection. Specifically, it may be various cubic corner bodies, corner reflector arrays, slit mirror arrays, two-sided corner reflector arrays, multi-sided reflector arrays, or a shape in which combinations of their reflective surfaces are arranged periodically. Alternatively, a capsule lens type retroreflector element with glass beads arranged periodically may be provided on the surface of the retroreflector in this embodiment. The detailed configuration of these retroreflector elements can be described using existing technology, so a detailed explanation is omitted. Specifically, the technology disclosed in Japanese Patent Publication No. 2017-33005, Japanese Patent Publication No. 2019-133110, Japanese Patent Publication No. 2017-67933, WO2009 / 131128, etc., can be used.

[0057] In the optical system shown in Figure 2D, the image light emitted from the display device 1 can be in any polarization state. Both S-polarization and P-polarization are acceptable.

[0058] As explained above, the optical system in Figure 2D, while using a different retroreflector than the optical systems in Figures 2A to 2C, can form a more suitable floating image in space, similar to the optical systems in Figures 2A to 2C.

[0059] As described above, the optical systems shown in Figures 2A, 2B, 2C, and 2D can provide brighter, higher-quality floating images in space.

[0060] <<Block diagram of the internal structure of the floating image display device>> Next, a block diagram of the internal configuration of the floating image display device 1000 will be described. Figure 3 is a block diagram showing an example of the internal configuration of the floating image display device 1000.

[0061] The floating video display device 1000 includes a retroreflective section 1101, a video display section 1102, a light guide 1104, a light source 1105, a power supply 1106, an external power input interface 1111, an operation input section 1107, a non-volatile memory 1108, a memory 1109, a control section 1110, a video signal input section 1131, an audio signal input section 1133, a communication section 1132, an aerial operation detection sensor 1351, an aerial operation detection section 1350, an audio output section 1140, a microphone 1139, a video control section 1160, a storage section 1170, an imaging section 1180, and the like. It may also include a removable media interface 1134, an attitude sensor 1113, a transmissive self-emissive video display device 1650, a second display device 1680, or a secondary battery 1112.

[0062] Each component of the floating video display device 1000 is arranged in the housing 1190. Note that the imaging unit 1180 and the aerial operation detection sensor 1351 shown in Figure 3 may be provided on the outside of the housing 1190.

[0063] The retroreflective section 1101 in Figure 3 corresponds to the retroreflective plate 2 in Figures 2A, 2B, and 2C. The retroreflective section 1101 retroreflectively reflects light modulated by the image display section 1102. The floating image 3 is formed by the light from the reflected light from the retroreflective section 1101 that is output to the outside of the floating image display device 1000. When the optical system in Figure 2D is applied, the retroreflective section 1101 corresponds to the retroreflective plate 5 in Figure 2D.

[0064] The image display unit 1102 in Figure 3 corresponds to the liquid crystal display panel 11 in Figures 2A, 2B, and 2C. The light source 1105 in Figure 3 corresponds to the light source device 13 in Figures 2A, 2B, and 2C. The image display unit 1102, light guide 1104, and light source 1105 in Figure 3 correspond to the display device 1 in Figures 2A, 2B, and 2C.

[0065] The video display unit 1102 is a display unit that generates an image by modulating transmitted light based on a video signal input under control by the video control unit 1160, which will be described later. For example, a transmissive liquid crystal panel is used as the video display unit 1102 (the liquid crystal display panel 11 described above), but it is not limited to this. Alternatively, for example, a reflective liquid crystal panel that modulates reflected light or a DMD (Digital Micromirror Device: registered trademark) panel may be used as the video display unit 1102.

[0066] The light source 1105 generates light for the image display unit 1102 and is a solid-state light source such as an LED (Light Emitting Diode) or a laser light source. The power supply 1106 converts the AC current input from an external source via the external power input interface 1111 into DC current and supplies power to the light source 1105. The power supply 1106 also supplies the necessary DC current to each part of the floating image display device 1000. The secondary battery 1112 stores the power supplied from the power supply 1106. The secondary battery 1112 also supplies power to the light source 1105 and other components that require power via the external power input interface 1111 when power is not supplied from an external source. In other words, if the floating image display device 1000 is equipped with a secondary battery 1112, the user can use the floating image display device 1000 even when power is not supplied from an external source.

[0067] The light guide 1104 guides the light generated by the light source 1105 and illuminates the image display unit 1102. The combination of the light guide 1104 and the light source 1105 can also be called the backlight of the image display unit 1102. The light guide 1104 may be mainly made of glass. The light guide 1104 may be mainly made of plastic. The light guide 1104 may be made of mirrors. Various combinations of the light guide 1104 and the light source 1105 are possible. Specific examples of combinations of the light guide 1104 and the light source 1105 will be explained in detail later.

[0068] The aerial operation detection sensor 1351 is a sensor that detects manipulation of the floating image 3 by an object such as a user's finger. The aerial operation detection sensor 1351 senses, for example, the area that overlaps with the entire display range of the floating image 3. Alternatively, the aerial operation detection sensor 1351 may sense only the area that overlaps with at least a portion of the display range of the floating image 3.

[0069] Specific examples of the aerial operation detection sensor 1351 include distance sensors using invisible light such as infrared, invisible light lasers, and ultrasonic waves. The aerial operation detection sensor 1351 may also be configured by combining multiple sensors to detect coordinates on a two-dimensional plane. Furthermore, the aerial operation detection sensor 1351 may consist of a Time of Flight (ToF) LiDAR (Light Detection and Ranging) or an image sensor.

[0070] The aerial operation detection sensor 1351 only needs to be capable of sensing touch operations by a user's finger on an object displayed as a floating spatial image 3. Such sensing can be performed using existing technologies.

[0071] The aerial operation detection unit 1350 acquires a sensing signal from the aerial operation detection sensor 1351 and, based on the sensing signal, calculates whether or not the user's finger has made contact with an object in the floating spatial image 3, and the position where the user's finger and the object made contact (contact position). The aerial operation detection unit 1350 is composed of circuits such as an FPGA (Field Programmable Gate Array). In addition, some functions of the aerial operation detection unit 1350 may be implemented in software, for example, by a spatial operation detection program executed in the control unit 1110 or the video control unit 1160. The aerial operation detection sensor 1351 and the aerial operation detection unit 1350 may be configured as an integrated unit. The aerial operation detection unit 1350 and the control unit 1110 or the video control unit 1160 may be configured as an integrated unit.

[0072] The aerial operation detection sensor 1351 and the aerial operation detection unit 1350 may be built into the floating video display device 1000, or they may be provided separately from the floating video display device 1000. When provided separately from the floating video display device 1000, the aerial operation detection sensor 1351 and the aerial operation detection unit 1350 are configured to transmit information and signals to the floating video display device 1000 via wired or wireless communication lines or video signal transmission lines. This makes it possible to construct a system in which the floating video display device 1000 without the aerial operation detection function is used as the main unit, and only the aerial operation detection function can be added as an option.

[0073] Alternatively, the aerial operation detection sensor 1351 may be a separate unit, with the aerial operation detection unit 1350 built into the floating image display device 1000. A separate unit configuration offers advantages, such as when it is desirable to have more freedom in positioning the aerial operation detection sensor 1351 relative to the installation location of the floating image display device 1000.

[0074] The imaging unit 1180 is a camera with an image sensor that captures images of the space near the floating image 3 and / or the user's face, arms, fingers, etc. Multiple imaging units 1180 may be provided. For example, the imaging units 1180 may be provided as a stereo camera. By using multiple imaging units 1180, or by using an imaging unit with a depth sensor, the aerial operation detection unit 1350 can be assisted when detecting touch operations on the floating image 3 by the user 230. The imaging unit 1180 may be provided separately from the floating image display device 1000. If the imaging unit 1180 is provided separately from the floating image display device 1000, it should be configured to transmit imaging signals to the floating image display device 1000 via a wired or wireless communication connection path.

[0075] For example, if the aerial operation detection sensor 1351 is configured as an object intrusion sensor that detects whether or not an object has entered a plane (intrusion detection plane) that includes the display surface (display range) of the floating spatial image 3, the aerial operation detection sensor 1351 may not be able to detect information such as how far away an object that has not entered the intrusion detection plane (for example, a user's finger) is from the intrusion detection plane, or how close an object is to the intrusion detection plane.

[0076] In such cases, the distance between the object and the intrusion detection plane (floating spatial image 3) can be calculated by using information such as depth calculation information based on images captured by multiple imaging units 1180 and depth information of the object from a depth sensor. This various information, including depth calculation information, depth information, and the distance between the object and the intrusion detection plane, is then used for various display controls on the floating spatial image 3.

[0077] Alternatively, instead of using the aerial operation detection sensor 1351, the aerial operation detection unit 1350 may detect touch operations on the floating video 3 by the user 230 based on the image captured by the imaging unit 1180. In this case, the imaging unit 1180 may be referred to as the aerial operation detection sensor.

[0078] Alternatively, the imaging unit 1180 may capture an image of the user operating the floating video 3, and the control unit 1110 or the like may perform user identification processing. Furthermore, in order to determine whether other people are standing around or behind the user operating the floating video 3 and whether they are peeking at the user's operation of the floating video 3, the imaging unit 1180 may capture an area that includes the user operating the floating video 3 and the area surrounding the user.

[0079] 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 signals for operations other than aerial operations (touch operations) performed by the user. Separately from the aforementioned user who touches the floating spatial image 3, the operation input unit 1107 may also be used, for example, by an administrator to operate the floating spatial image display device 1000.

[0080] The video signal input unit 1131 receives video data (video signals) by connecting an external video output device. Various digital video input interfaces can be considered for the video signal input unit 1131. For example, it can be configured with a video input interface conforming to the HDMI (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.

[0081] The audio signal input unit 1133 receives audio data (audio signals) by connecting an external audio output device. The audio signal input unit 1133 can be configured as an HDMI standard audio input interface, an optical digital terminal interface, or a coaxial digital terminal interface, etc. In the case of an HDMI standard interface, the video signal input unit 1131 and the audio signal input unit 1133 may be configured as an interface with integrated terminals and cables.

[0082] The audio output unit 1140 is capable of outputting audio based on audio data input to the audio signal input unit 1133. The audio output unit 1140 may be configured as a speaker 1140. The audio output unit 1140 may also include a section for audio synthesis processing, etc. The audio output unit 1140 may also output built-in operation sounds or error warning sounds. Alternatively, the audio output unit 1140 may be configured to output as a digital signal to an external device, such as the Audio Return Channel function specified in the HDMI standard.

[0083] The audio input unit 1139 may be composed of a microphone 1139. The microphone 1139 is a microphone that picks up sounds from the vicinity of the floating image display device 1000, converts them into signals, and generates an audio signal. The microphone may record a person's voice, such as the user's voice, and the control unit 1110 or the like may perform speech recognition processing on the generated audio signal to obtain text information from the audio signal. The audio input unit 1139 may also be equipped with a part that performs speech recognition processing, etc. Note that the audio output unit 1140 and the audio input unit 1139, etc. may be connected as external devices to the floating image display device 1000.

[0084] The non-volatile memory 1108 stores various data used by the floating image display device 1000. The data stored in the non-volatile memory 1108 includes, for example, data for various operations displayed on the floating image 3, display icons, data and layout information for objects that the user can operate. Memory 1109 stores video data to be displayed as the floating image 3, control data for the device, and the like.

[0085] The control unit 1110 includes a processor and controls the operation of each connected part. The control unit 1110 may also work in cooperation with a program stored in the memory 1109 to perform calculation processing based on information acquired from each part of the floating image display device 1000.

[0086] The communication unit 1132 communicates with external devices, external servers, etc., via a wired or wireless communication interface. If the communication unit 1132 has a wired communication interface, the wired communication interface may be configured as, for example, an Ethernet standard LAN interface. If the communication unit 1132 has a wireless communication interface, it may be configured as, for example, a Wi-Fi communication interface, a Bluetooth communication interface, or a mobile communication interface such as 4G or 5G. Various types of data, such as video data, image data, and audio data, are transmitted and received through communication via the communication unit 1132.

[0087] Furthermore, the removable media interface 1134 is an interface for connecting removable recording media. Removable recording media may consist of semiconductor memory such as solid-state drives (SSDs), magnetic recording media recording devices such as hard disk drives (HDDs), or optical recording media such as optical discs. The removable media interface 1134 can read various types of information, such as video data, image data, and audio data, recorded on the removable recording media. Video data, image data, etc., recorded on the removable recording media are output as floating-in-space images 3 via the video display unit 1102 and the retroreflective unit 1101.

[0088] The storage unit 1170 is a storage device that records various types of information, such as video data, image data, and audio data. The storage unit 1170 may be composed of a magnetic recording medium such as a hard disk drive (HDD) or a semiconductor memory such as a solid-state drive (SSD). The storage unit 1170 may have various types of information, such as video data, image data, and audio data, pre-recorded in it at the time of product shipment. The storage unit 1170 may also record various types of information, such as video data, image data, and audio data, acquired from external devices or external servers via the communication unit 1132.

[0089] The video data, image data, etc., recorded in the storage unit 1170 are output as floating-in-space video 3 via the video display unit 1102 and the retroreflection unit 1101, based on processing by the video control unit 1160. The video data, image data, etc., of display icons and user-operable objects, etc., that are displayed as floating-in-space video 3 are also recorded in the storage unit 1170. Layout information of display icons and objects, etc., that are displayed as floating-in-space video 3, as well as various metadata information related to the objects, etc., are also recorded in the storage unit 1170.

[0090] The audio data recorded in the storage unit 1170 is output as audio from, for example, the audio output unit 1140.

[0091] The video control unit 1160 performs various controls related to the video signal input to the video display unit 1102. Based on the video signal (video data), the video control unit 1160 creates a video signal (display data) for displaying an image on the video display unit 1102 (for example, the liquid crystal display panel 11 of the aforementioned display device 1) and supplies it to the video display unit 1102. The video control unit 1160 may also be called a video processing circuit and may be composed of hardware such as an ASIC, FPGA, or video processor. The video control unit 1160 may also be called a video processing unit or image processing unit. For example, the video control unit 1160 performs video switching control, such as determining which video signal to input to the video display unit 1102 from among the video signals to be stored in the memory 1109 and the video signals (video data) input to the video signal input unit 1131.

[0092] Furthermore, the control unit 1110 may perform the same processing as the video control unit 1160, in which case the control unit 1110 may be referred to as the video processing unit, etc. At least one of the control unit 1110, the video control unit 1160, the aerial operation detection unit 1360, etc. may perform specific control processing, in which case the control unit 1110, the video control unit 1160, the aerial operation detection unit 1360, etc. may be referred to as the video processing unit.

[0093] Alternatively, the video control unit 1160 may generate a superimposed video signal by superimposing the video signal to be stored in the memory 1109 and the video signal input from the video signal input unit 1131, and then input the superimposed video signal to the video display unit 1102 to form the composite image as a floating image 3.

[0094] Furthermore, the video control unit 1160 may perform image processing on video signals input from the video signal input unit 1131 and video signals stored in the memory 1109. Examples of image processing include scaling, which enlarges, reduces, and transforms images; brightness adjustment, which changes the brightness; contrast adjustment, which changes the contrast curve of an image; and retinex processing, which decomposes an image into its light components and changes the weighting of each component.

[0095] Furthermore, the video control unit 1160 may perform special effects video processing on the video signal input to the video display unit 1102 to assist the user's aerial operation (touch operation). Special effects video processing is performed, for example, based on the detection result of the user's touch operation by the aerial operation detection unit 1350 or the user's image captured by the imaging unit 1180. The video control unit 1160 may also perform audio control processing when audio is output from the audio output unit 1140 simultaneously with the floating video 3. An audio control unit for this audio control processing may be provided separately from the video control unit 1160.

[0096] The attitude sensor 1113 is a sensor composed of a gravity sensor, an acceleration sensor, or a combination thereof, and can detect the orientation in which the floating video display device 1000 is installed. Based on the attitude detection result of the attitude sensor 1113, the control unit 1110 may control the operation of each connected part. For example, if an undesirable orientation for the user is detected, the control unit 1110 may stop displaying the video that the video display unit 1102 was showing and display an error message to the user. Alternatively, if the attitude sensor 1113 detects that the installation orientation of the floating video display device 1000 has changed, the control unit 1110 may rotate the orientation of the video that the video display unit 1102 was showing.

[0097] As explained above, the floating image display device 1000 is equipped with various functions. However, the floating image display device 1000 does not need to have all of these functions; any configuration is acceptable as long as it has the function of forming the floating image 3.

[0098] <Example configuration of a floating image display device> Next, we will describe an example configuration of the floating image display device. The layout of the components of the floating image display device according to this embodiment can vary depending on the usage. Below, we will describe each of the layouts shown in Figures 4A to 4P. In all of the examples in Figures 4A to 4P, the thick lines surrounding the components of the floating image display device 1000 (display device 1, etc.) indicate an example of the housing structure of the floating image display device 1000 (housing 1190 in Figure 3).

[0099] Figure 4A shows an example of the configuration of a floating image display device. The floating image display device 1000 shown in Figure 4A is equipped with an optical system corresponding to the optical system in Figure 2A. In the floating image display device 1000 shown in Figure 4A, it is installed horizontally so that the side on which the floating image 3 is formed faces upward. That is, in Figure 4A, the floating image display device 1000 has a transparent member 100 installed on the top surface of the device. The floating image 3 is formed above the surface of the transparent member 100 of the floating image display device 1000. The light of the floating image 3 travels diagonally upward. If the air operation detection sensor 1351 is installed as shown in the figure, it is possible to detect operation of the floating image 3 by the user 230's finger. Note that the x direction is the left-right direction from the user's perspective, the y direction is the front-back direction (depth direction) from the user's perspective, and the z direction is the up-down direction (vertical direction). In the following diagrams in Figure 4, the definitions of the x, y, and z directions are the same, so repeated explanations will be omitted.

[0100] Figure 4B shows an example of the configuration of a floating image display device. The floating image display device 1000 shown in Figure 4B is equipped with an optical system corresponding to the optical system in Figure 2A. The floating image display device 1000 shown in Figure 4B is installed vertically so that the side on which the floating image 3 is formed faces the front of the floating image display device 1000 (towards the user 230). That is, in Figure 4B, the floating image display device has a transparent member 100 installed on the front of the device (towards the user 230). The floating image 3 is formed on the user 230 side relative to the surface of the transparent member 100 of the floating image display device 1000. The light of the floating image 3 travels diagonally upward. If the aerial operation detection sensor 1351 is provided as shown in the figure, it is possible to detect operation of the floating image 3 by the user 230's finger. As shown in Figure 4B, the airborne operation detection sensor 1351 senses the user's finger from above, allowing it to utilize the reflection of sensing light from the user's fingernail for touch detection. Generally, fingernails have a higher reflectivity than the pads of the fingers, so this configuration can improve the accuracy of touch detection.

[0101] Figure 4C shows an example of the configuration of a floating image display device. The floating image display device 1000 shown in Figure 4C is equipped with an optical system corresponding to the optical system in Figure 2B. In the floating image display device 1000 shown in Figure 4C, it is installed horizontally so that the side on which the floating image 3 is formed faces upward. That is, in Figure 4C, the floating image display device 1000 has a transparent member 100 installed on the top surface of the device. The floating image 3 is formed above the surface of the transparent member 100 of the floating image display device 1000. The light of the floating image 3 travels diagonally upward. If the aerial operation detection sensor 1351 is provided as shown in the figure, it is possible to detect operation of the floating image 3 by the user 230's finger.

[0102] Figure 4D shows an example of the configuration of a floating image display device. The floating image display device 1000 shown in Figure 4D is equipped with an optical system corresponding to the optical system in Figure 2B. The floating image display device 1000 shown in Figure 4D is installed vertically so that the side on which the floating image 3 is formed faces the front of the floating image display device 1000 (towards the user 230). That is, in Figure 4D, the floating image display device 1000 has a transparent member 100 installed on the front of the device (towards the user 230). The floating image 3 is formed on the user 230 side of the transparent member 100 of the floating image display device 1000. The light of the floating image 3 travels diagonally upward. If the aerial operation detection sensor 1351 is provided as shown in the figure, it is possible to detect operation of the floating image 3 by the user 230's finger. Here, as shown in Figure 4D, the airborne operation detection sensor 1351 senses the user's finger from above, and the reflection of the sensing light from the user's fingernail can be used for touch detection. Generally, fingernails have a higher reflectivity than the pads of the fingers, so this configuration can improve the accuracy of touch detection.

[0103] Figure 4E shows an example of the configuration of a floating image display device. The floating image display device 1000 shown in Figure 4E is equipped with an optical system corresponding to the optical system in Figure 2C. In the floating image display device 1000 shown in Figure 4E, it is installed horizontally so that the side on which the floating image 3 is formed faces upward. That is, in Figure 4E, the floating image display device 1000 has a transparent member 100 installed on the top surface of the device. The floating image 3 is formed above the surface of the transparent member 100 of the floating image display device 1000. The light of the floating image 3 travels in a direction directly upward. If the air operation detection sensor 1351 is provided as shown in the figure, it is possible to detect operation of the floating image 3 by the user 230's finger.

[0104] Figure 4F shows an example of the configuration of a floating image display device. The floating image display device 1000 shown in Figure 4F is equipped with an optical system corresponding to the optical system in Figure 2C. The floating image display device 1000 shown in Figure 4F is installed vertically so that the side on which the floating image 3 is formed faces the front of the floating image display device 1000 (towards the user 230). That is, in Figure 4F, the floating image display device 1000 has a transparent member 100 installed on the front of the device (towards the user 230). The floating image 3 is formed on the user 230 side relative to the surface of the transparent member 100 of the floating image display device 1000. The light of the floating image 3 travels in the direction toward the user. If the aerial operation detection sensor 1351 is provided as shown in the figure, it is possible to detect operation of the floating image 3 by the user 230's finger.

[0105] Figure 4G shows an example of the configuration of a floating image display device. The floating image display device 1000 shown in Figure 4G is equipped with an optical system corresponding to the optical system in Figure 2C. In the optical systems of the floating image display devices shown in Figures 4A to 4F, the optical path of the center of the image light emitted from the display device 1 was on the yz plane. That is, within the optical systems of the floating image display devices shown in Figures 4A to 4F, the image light traveled in the front-to-back and up-and-down directions as viewed from the user. In contrast, in the optical system of the floating image display device shown in Figure 4G, the optical path of the center of the image light emitted from the display device 1 is on the xy plane. That is, within the optical system of the floating image display device shown in Figure 4G, the image light travels in the left-to-right and front-to-back directions as viewed from the user. In the floating image display device 1000 shown in Figure 4G, the side on which the floating image 3 is formed is installed so that it faces the front of the device (towards the user 230). In other words, in Figure 4G, the floating image display device 1000 has a transparent member 100 installed on the front of the device (towards the user 230). The floating image 3 is formed on the user side relative to the surface of the transparent member 100 of the floating image display device 1000. The light of the floating image 3 travels toward the user. If the aerial operation detection sensor 1351 is provided as shown in the figure, it is possible to detect operation of the floating image 3 by the user 230's finger.

[0106] Figure 4H shows an example of the configuration of a floating image display device. The floating image display device 1000 in Figure 4H differs from the floating image display device in Figure 4G in that it has a window with a transparent plate 100B made of glass or plastic on the back of the device (opposite the position from which the user 230 views the floating image 3, i.e., opposite the direction of propagation of the image light of the floating image 3 directed toward the user 230). The other configurations are the same as those of the floating image display device in Figure 4G, so repeated explanations are omitted. The floating image display device 1000 in Figure 4H has a window with a transparent plate 100B at a position opposite to the direction of propagation of the image light of the floating image 3. Therefore, when the user 230 views the floating image 3, they can recognize the scenery behind the floating image display device 1000 as the background of the floating image 3. Therefore, the user 230 can perceive the floating image 3 as floating in the air in front of the scenery behind the floating image display device 1000. This further enhances the sense of floating in the air of the floating image 3.

[0107] Depending on the polarization distribution of the video light output from the display device 1 and the performance of the polarization separation member 101B, some of the video light output from the display device 1 may be reflected by the polarization separation member 101B and directed toward the transparent plate 100B. Depending on the coating performance of the surface of the transparent plate 100B, this light may be reflected again by the surface of the transparent plate 100B and seen by the user 230 as stray light. Therefore, in order to prevent such stray light, the transparent plate 100B may not be provided in the window on the back of the floating video display device 1000.

[0108] Figure 4I shows an example of the configuration of a floating image display device. The floating image display device 1000 in Figure 4I differs from the floating image display device in Figure 4H in that it has an opening / closing door 1410 for light shielding on the window of the transparent plate 100B located on the back of the device (opposite the position from which the user 230 views the floating image 3). The other configurations are the same as those of the floating image display device in Figure 4H, so repeated explanations are omitted.

[0109] The opening and closing door 1410 of the floating spatial image display device 1000 in Figure 4I has, for example, a light-shielding plate and is equipped with a mechanism for moving (sliding), rotating, or attaching / detaching the light-shielding plate, thereby enabling switching between an open state and a light-shielding state for the window (rear window) of the transparent plate 100B located at the back of the floating spatial image display device 1000. The movement (sliding) and rotation of the light-shielding plate by the opening and closing door 1410 may be electrically driven by a motor (not shown). This motor may be controlled by the control unit 1110 in Figure 3. Note that in the example in Figure 4I, an example is disclosed in which the opening and closing door 1410 has two light-shielding plates. However, the opening and closing door 1410 may have only one light-shielding plate.

[0110] For example, if the view beyond the window of the transparent panel 100B of the floating image display device 1000 is outdoors, the brightness of sunlight will vary depending on the weather. If the sunlight outdoors is strong, the background of the floating image 3 may become too bright, reducing the visibility of the floating image 3 for the user 230. In such cases, by moving (sliding), rotating, or attaching the light-shielding plate of the opening / closing door 1410 to block the light on the rear window, the background of the floating image 3 will become darker, thereby relatively improving the visibility of the floating image 3. This shielding operation by the light-shielding plate of the opening / closing door 1410 may be performed directly by the force of the user 230's hand. Alternatively, the control unit 1110 may control a motor (not shown) in response to an operation input via the operation input unit 1107 in Figure 3 to perform the shielding operation by the light-shielding plate of the opening / closing door 1410.

[0111] Furthermore, an illuminance sensor may be installed on the rear side of the floating spatial image display device 1000 (opposite side of the user 230), such as near the rear window, to measure the brightness of the space beyond the rear window. In this case, the control unit 1110 in Figure 3 may control a motor (not shown) to open and close the light-shielding plate of the opening / closing door 1410 according to the detection result of the illuminance sensor. By controlling the opening and closing operation of the light-shielding plate of the opening / closing door 1410 in this way, the visibility of the floating spatial image 3 can be more favorably maintained without the user 230 having to manually open or close the light-shielding plate of the opening / closing door 1410.

[0112] Furthermore, the light-shielding plate provided by the opening / closing door 1410 may be manually detachable. Depending on the intended use and installation environment of the spatial floating image display device 1000, the user can choose whether to leave the rear window open or detached. If the rear window is to be used in a detached state for a long period of time, the detachable light-shielding plate can be fixed in the detached state. If the rear window is to be used in an open state for a long period of time, the detachable light-shielding plate can be removed. The light-shielding plate may be attached and detached using screws, a hook structure, or a snap-in structure.

[0113] In the example of the floating video display device 1000 shown in Figure 4I, depending on the polarization distribution of the video light output from the display device 1 and the performance of the polarization separation member 101B, some of the video light output from the display device 1 may be reflected by the polarization separation member 101B and directed toward the transparent plate 100B. Depending on the coating performance of the surface of the transparent plate 100B, this light may be reflected again by the surface of the transparent plate 100B and seen by the user 230 as stray light. Therefore, in order to prevent such stray light, the window on the back of the floating video display device 1000 may be configured without the transparent plate 100B. The window without the transparent plate 100B may be provided with the above-mentioned opening and closing door 1410. In order to prevent such stray light, it is desirable that the inner surface of the housing of the light-shielding plate of the above-mentioned opening and closing door 1410 has a coating or material with low light reflectivity.

[0114] Figure 4J shows an example of the configuration of a floating image display device. The floating image display device 1000 in Figure 4J differs from the floating image display device 1000 in Figure 4H in that instead of placing a transparent plate 100B made of glass or plastic in the rear window, an electronically controlled variable transmittance device 1620 is placed therein. The other configurations are the same as those of the floating image display device in Figure 4H, so repeated explanations are omitted. An example of the electronically controlled variable transmittance device 1620 is a liquid crystal shutter. Although the electronically controlled variable transmittance device 1620 is not shown in Figure 3, if it is to be provided, it should be configured as a component of the floating image display device 1000 in Figure 3 and connected to other processing units such as the control unit 1110.

[0115] A liquid crystal shutter can control the light transmittance by controlling the voltage of a liquid crystal element sandwiched between two polarizing plates. Therefore, by controlling the liquid crystal shutter to increase the transmittance, the background of the floating image 3 will be the scenery visible through the rear window. Conversely, by controlling the liquid crystal shutter to decrease the transmittance, the scenery visible through the rear window will not be visible as the background of the floating image 3.

[0116] Furthermore, since the liquid crystal shutter allows for control of intermediate tones, it can be set to a state such as 50% transmittance. For example, the control unit 1110 can control the transmittance of the electronically controlled variable transmittance device 1620 in response to an operation input via the operation input unit 1107 in Figure 3. With this configuration, if the view through the rear window is desired as the background for the floating image 3, but the view through the rear window is too bright, reducing the visibility of the floating image 3, the visibility of the floating image 3 can be adjusted by adjusting the transmittance of the electronically controlled variable transmittance device 1620.

[0117] Alternatively, an illuminance sensor may be installed on the rear side of the floating image display device 1000 (opposite the user 230), such as near the rear window, to measure the brightness of the space beyond the rear window. In this case, the control unit 1110 in Figure 3 can control the transmittance of the electronically controlled variable transmittance device 1620 according to the detection result of the illuminance sensor. In this way, the transmittance of the electronically controlled variable transmittance device 1620 can be adjusted according to the brightness of the space beyond the rear window without the user 230 having to perform an operation input via the operation input unit 1107 in Figure 3, thereby making it possible to maintain the visibility of the floating image 3 more favorably.

[0118] Furthermore, in the above example, a liquid crystal shutter was described as an example of the electronically controlled variable transmittance device 1620. In contrast, electronic paper may be used as another example of the electronically controlled variable transmittance device 1620. The same effects as described above can be obtained even when electronic paper is used. Moreover, electronic paper consumes very little power to maintain the halftone state. Therefore, a spatial levitation image display device with lower power consumption can be realized compared to the case in which a liquid crystal shutter is used.

[0119] Figure 4K shows an example of the configuration of a floating image display device. The floating image display device 1000 in Figure 4K differs from the floating image display device in Figure 4G in that it has a transmissive self-emissive image display device 1650 instead of a transparent member 100. The other configurations are the same as those of the floating image display device in Figure 4G, so repeated explanations are omitted.

[0120] In the spatial levitation image display device 1000 shown in Figure 4K, the spatial levitation image 3 is formed outside the spatial levitation image display device 1000 after the image light beam passes through the display surface of the transmissive self-emissive image display device 1650. That is, when an image is displayed on the transmissive self-emissive image display device 1650, which is a two-dimensional planar display, the spatial levitation image 3 can be displayed as a projecting image further in front of the user than the image on the transmissive self-emissive image display device 1650. At this time, the user 230 can simultaneously view two images at different depth positions. The transmissive self-emissive image display device 1650 can be constructed using existing technologies such as transmissive organic EL panels, as disclosed in, for example, Japanese Patent Application Publication No. 2014-216761. When the transmissive self-emissive image display device 1650 is provided, it can be configured to be connected to other processing units such as the control unit 1110 as one component of the spatial levitation image display device 1000 shown in Figure 3.

[0121] Here, if the transparent self-emissive video display device 1650 displays both the background and objects such as characters, and then displays only the objects such as characters moving to the floating video 3 in the foreground, the user 230 can be provided with a more effective surprise video experience.

[0122] Furthermore, if the inside of the floating image display device 1000 (housing 1190) is kept in a light-shielding state, the background of the transmissive self-emissive image display device 1650 becomes sufficiently dark. Therefore, when no image is displayed on the display device 1, or when the light source of the display device 1 is turned off and an image is displayed only on the transmissive self-emissive image display device 1650, the user 230 will perceive the transmissive self-emissive image display device 1650 as a normal two-dimensional planar display rather than a transmissive display. In this embodiment of the present invention, the floating image 3 is displayed as a real optical image in space without a screen, so if the light source of the display device 1 is turned off, the planned display location for the floating image 3 becomes empty space. Therefore, when the transmissive self-emissive image display device 1650 is being used as if it were a general two-dimensional planar display to show an image, characters or objects can be suddenly displayed in mid-air as the floating image 3, providing the user 230 with a more effective surprise visual experience.

[0123] Furthermore, the darker the interior of the floating image display device 1000 is made, the more the transmissive self-emissive image display device 1650 appears like a two-dimensional planar display. Therefore, an absorbing polarizing plate (not shown) that transmits the polarization of the image light reflected by the polarization separation member 101B and absorbs polarization that is 90° out of phase with that polarization may be provided on the interior side of the transmissive self-emissive image display device 1650 (the incident surface for the image light reflected by the polarization separation member 101B into the transmissive self-emissive image display device 1650, i.e., the side of the transmissive self-emissive image display device 1650 opposite to the floating image 3). In this way, the impact on the image light forming the floating image 3 is not so great, but the amount of light incident on the interior of the floating image display device 1000 from the outside via the transmissive self-emissive image display device 1650 can be significantly reduced, making the interior of the floating image display device 1000 darker, which is preferable.

[0124] Figure 4L shows an example of the configuration of a floating image display device. The floating image display device 1000 in Figure 4L is a modified version of the floating image display device in Figure 4K. The orientation of the components in the floating image display device 1000 differs from that of the floating image display device in Figure 4K, and is closer to that of the floating image display device in Figure 4F. The functions and operations of each component are the same as those of the floating image display device in Figure 4K, so repeated explanations are omitted.

[0125] In the floating image display device shown in Figure 4L, after the light beam of the image passes through the transmissive self-emissive image display device 1650, the floating image 3 is formed on the user 230 side of the transmissive self-emissive image display device 1650.

[0126] In both the example of the floating image display device in Figure 4K and the example of the floating image display device in Figure 4L, the floating image 3 is displayed superimposed in front of the image on the transmissive self-emissive image display device 1650 to the user 230. Here, the position of the floating image 3 and the position of the image on the transmissive self-emissive image display device 1650 are configured to have a difference in the depth direction. Therefore, when the user 230 moves their head (viewpoint position), they can perceive the depth of the two images due to parallax. Thus, by displaying two images with different depth positions, a three-dimensional image experience can be more favorably provided to the user with the naked eye, without the need for stereoscopic glasses or other such devices.

[0127] Figure 4M shows an example of the configuration of a floating image display device. In the floating image display device 1000 of Figure 4M, a second display device 1680 is provided on the rear side (for example, the back panel of the housing 1190) from the user 230's perspective, relative to the polarization separation member 101B of the floating image display device in Figure 4G. The other configurations are the same as those of the floating image display device in Figure 4G, so repeated explanations are omitted.

[0128] In the configuration example shown in Figure 4M, the second display device 1680 is located behind the display position of the floating image 3, with its display surface facing the floating image 3. With this configuration, the user 230 can view the image from the second display device 1680 and the floating image 3, which are displayed at two different depths, superimposed on each other. In other words, the second display device 1680 is positioned to display the image in the direction of the user 230 who is viewing the floating image 3. When providing the second display device 1680, it can be configured as a component of the floating image display device 1000 in Figure 3, and connected to other processing units such as the control unit 1110.

[0129] In Figure 4M, the video light from the second display device 1680 of the floating video display device 1000 is seen by the user 230 after passing through the polarization separation member 101B. Therefore, in order for the video light from the second display device 1680 to pass through the polarization separation member 101B more favorably, it is desirable that the video light output from the second display device 1680 has polarization in the direction of vibration that the polarization separation member 101B passes through more favorably. That is, it is desirable that the polarization is in the same direction of vibration as the video light output from the display device 1. For example, if the video light output from the display device 1 is S-polarized, it is desirable that the video light output from the second display device 1680 is also S-polarized. Also, if the video light output from the display device 1 is P-polarized, it is desirable that the video light output from the second display device 1680 is also P-polarized.

[0130] The example of the floating image display device in Figure 4M has the same effect as the examples of the floating image display devices in Figure 4K and Figure 4L, in that it displays a second image behind the floating image 3. However, unlike the examples of the floating image display devices in Figure 4K and Figure 4L, in the example of the floating image display device in Figure 4M, the light beam of the image light that forms the floating image 3 does not pass through the second display device 1680. Therefore, the second display device 1680 does not need to be a transmissive self-emissive image display device, and can be a liquid crystal display, which is a two-dimensional planar display. The second display device 1680 can also be an organic EL display. Therefore, in the example of the floating image display device in Figure 4M, it is possible to realize the floating image display device 1000 at a lower cost than in the examples of the floating image display devices in Figure 4K and Figure 4L.

[0131] Here, depending on the polarization distribution of the video light output from the display device 1 and the performance of the polarization separation member 101B, a portion of the video light output from the display device 1 may be reflected by the polarization separation member 101B and directed toward the second display device 1680. This light (a portion of the video light) may be reflected again by the surface of the second display device 1680 and may be visible to the user as stray light.

[0132] Therefore, in order to prevent stray light, an absorbing polarizer may be provided on the surface of the second display device 1680. In this case, the absorbing polarizer should be one that transmits the polarization of the image light output from the second display device 1680 and absorbs polarization that is 90° out of phase with the polarization of the image light output from the second display device 1680. If the second display device 1680 is a liquid crystal display, an absorbing polarizer also exists on the image output side inside the liquid crystal display. However, if there is a cover glass (cover glass on the image display surface side) on the output surface of the absorbing polarizer on the image output side inside the liquid crystal display, it is not possible to prevent stray light caused by reflection from the cover glass due to light from outside the liquid crystal display. Therefore, it is necessary to separately provide the above-mentioned absorbing polarizer on the surface of the cover glass.

[0133] Furthermore, when displaying an image on the second display device 1680, which is a two-dimensional planar display, the floating spatial image 3 can be displayed as an image further in front of the user than the image on the second display device 1680. In this case, the user 230 can simultaneously view two images with different depth positions. By displaying a character on the floating spatial image 3 and a background on the second display device 1680, it is possible to provide the user 230 with the effect of viewing the space in which the character exists in three dimensions.

[0134] Furthermore, by displaying both the background and objects such as characters on the second display device 1680, and then displaying the objects such as characters moving to the foreground floating image 3, it is possible to provide the user 230 with a more effective surprise-style video experience.

[0135] Next, Figure 4N shows an example of the configuration of a floating image display device. The floating image display device 1000 in Figure 4N is a floating image display device that employs the optical system shown in Figure 2D. Similar to the examples of floating image display devices employing the optical systems in Figures 2A to 2C, the floating image display device 1000 in Figure 4N projects the image light that has passed through the transparent member 100 into the air as a floating image 3. Furthermore, the sensing light from the air operation detection sensor 1351, which is positioned behind the transparent member 100 as seen from the user's perspective, can be used to detect the user's finger 9004 operating the floating image 3.

[0136] In both the example of a floating image display device employing the optical system shown in Figures 2A to 2C, and the example of a floating image display device employing the optical system shown in Figure 2D, the floating image 3 is projected in front of the transparent member 100, and the user's operation of the floating image 3 by their finger can be detected using the sensing light of the air operation detection sensor 1351, which is positioned behind the transparent member 100 as seen from the user's perspective.

[0137] The floating image display device employing the optical system shown in Figure 2D has a different optical system from the floating image display devices employing the optical systems shown in Figures 2A to 2C, which are located behind the transparent component 100 as seen from the user's perspective. However, the usability of the floating image display device employing the optical system shown in Figure 2D as seen from the user's perspective is almost the same as that of the floating image display devices employing the optical systems shown in Figures 2A to 2C.

[0138] Next, Figure 4O is a diagram showing an example of the configuration of a floating image display device. Figure 4O is a diagram that shows the configuration of the internal optical system in the floating image display device 1000 of Figure 4N. The floating image display device 1000 shown in Figure 4O is equipped with an optical system corresponding to the optical system in Figure 2D. In the floating image display device 1000 shown in Figure 4O, it is installed horizontally so that the side on which the floating image 3 is formed faces upward.

[0139] In other words, in Figure 4O, the floating image display device 1000 has a transparent member 100 installed on its upper surface. The floating image 3 is formed above the surface of the transparent member 100 of the floating image display device 1000. The light of the floating image 3 travels diagonally upward. If the aerial operation detection sensor 1351 is provided as shown in the figure, it is possible to detect operation of the floating image 3 by the user 230's finger.

[0140] Here, we compare the configuration of Figure 4O with the configuration of Figure 4A and confirm the differences. In Figure 4A, the display device 1 and the floating image 3 are symmetrical with respect to the plane of the polarization separation member 101. In contrast, in Figure 4O, the display device 1 and the floating image 3 are symmetrical with respect to the plane of the retroreflector 5. Also, the configuration of Figure 4A includes a retroreflector 2 and a λ / 4 plate 21, but these are not present in Figure 4O. Furthermore, in Figure 4A, it is preferable to have an absorptive polarizer 12, but in Figure 4O, an absorptive polarizer 12 is not particularly necessary.

[0141] To replace the optical system of Figure 2A in the configuration of Figure 4A with the optical system of Figure 2D and to replace it with the configuration of Figure 4O, the following should be done. That is, the polarization separation member 101 in the configuration of Figure 4A should be replaced with the retroreflector 5, and the retroreflector 2 and λ / 4 plate 21 should be removed from the configuration of Figure 4A. The absorbing polarizer 12 may or may not be included. By performing substitutions based on this idea, the optical systems of Figures 2A to 2C mounted on the spatial floating image display device configurations of Figures 4A to 4G can be replaced with the optical system of Figure 2D, and the spatial floating image display device can be replaced with the optical system of Figure 2D. In this case, in Figures 4A and 4B, the polarization separation member 101 should be replaced with the retroreflector 5, and in Figures 4C to 4G, the polarization separation member 101B should be replaced with the retroreflector 5.

[0142] For example, Figure 4P is a diagram showing an example of the configuration of a floating image display device. The floating image display device 1000 shown in Figure 4P is equipped with an optical system corresponding to the optical system in Figure 2D. Figure 4P is a configuration of the floating image display device in Figure 4B in which the optical system in Figure 2A is replaced with the optical system in Figure 2D. The floating image display device 1000 shown in Figure 4P is installed vertically so that the side on which the floating image 3 is formed faces the front of the floating image display device 1000 (towards the user 230). That is, in Figure 4P, the floating image display device has a transparent member 100 installed on the front of the device (towards the user 230). The floating image 3 is formed on the user 230 side relative to the surface of the transparent member 100 of the floating image display device 1000. The light of the floating image 3 travels diagonally upward. If the air operation detection sensor 1351 is provided as shown in the figure, it is possible to detect operation of the floating image 3 by the user 230's finger. As shown in Figure 4P, the airborne operation detection sensor 1351 senses the user's finger from above, allowing it to utilize the reflection of sensing light from the user's fingernail for touch detection. Generally, fingernails have a higher reflectivity than the pads of the fingers, so this configuration can improve the accuracy of touch detection.

[0143] According to the configuration of the floating image display device shown in Figures 4N to 4P, a user-friendly floating image display device can be realized using the optical system shown in Figure 2D.

[0144] <Display device> Next, the display device 1 of this embodiment will be described with reference to the figures. The display device 1 of this embodiment includes a liquid crystal display panel 11, which is an image display element 11, and a light source device 13 that constitutes the light source of the liquid crystal display panel 11. In Figure 5, the light source device 13 is shown together with the liquid crystal display panel 11 in an unfolded perspective view.

[0145] The liquid crystal display panel 11, which is the image display element 11, receives an illumination beam from the light source device 13, which is the backlight device, as shown by the arrow 30 in Figure 5. The illumination beam has narrow-angle diffusion characteristics, that is, it has strong directionality (in other words, straight-line propagation) and characteristics similar to laser light with the polarization plane aligned in one direction. The liquid crystal display panel 11, which is the image display element 11, modulates the received illumination beam according to the input video signal. The modulated video light is reflected by the retroreflector 2 and transmitted through the transparent member 100 to form a floating image in space, which is a real image (see Figure 1).

[0146] Furthermore, in Figure 5, the display device 1 is configured to include a light source device 13 and a liquid crystal display panel 11, as well as an optical direction conversion panel 54 that controls the directional characteristics of the light beam emitted from the light source device 13, and a narrow-angle diffuser (not shown) as needed. That is, polarizing plates are provided on both sides of the liquid crystal display panel 11, and as shown by the arrow 30 in Figure 5, the configuration is such that image light of a specific polarization is emitted after the intensity of the light is modulated by the image signal. As a result, the desired image is projected as light of a specific polarization with high directionality (straight-line propagation) via the optical direction conversion panel 54 toward the retroreflector 2, reflected by the retroreflector 2, and then transmitted toward the eyes of a monitor outside the store (space) in Figure 1 to form a floating image 3 in space. Note that a protective cover 50 (see Figures 6 and 7) may be provided on the surface of the optical direction conversion panel 54 described above.

[0147] <Example of a display device 1> Figure 6 shows an example of the specific configuration of the display device 1. In Figure 6, a liquid crystal display panel 11 and a light direction conversion panel 54 are arranged on top of the light source device 13 shown in Figure 5. This light source device 13 is constructed by housing LED elements 201 and a light guide 203 inside, for example, a plastic case. As shown in Figure 5, the end face of the light guide 203 has a lens shape that gradually increases in cross-sectional area toward the light receiving part, and has the effect of gradually decreasing the divergence angle by undergoing multiple total internal reflections as the light propagates through the interior, in order to convert the divergent light emitted from each LED element 201 into a substantially parallel luminous beam. The liquid crystal display panel 11 that constitutes the display device 1 is mounted on the top surface of the display device 1. In addition, an LED substrate 202 on which semiconductor light sources, namely LED elements 201 and their control circuits are mounted is attached to one side of the light source device 13 (the left end face in this example). A heat sink, which is a component for cooling the heat generated by the LED elements 201 and the control circuits, may be attached to the outer surface of the LED substrate 202.

[0148] Furthermore, the frame (not shown) of the liquid crystal display panel 11, which is mounted on the top surface of the case of the light source device 13, is configured by mounting the liquid crystal display panel 11 attached to the frame, and also by mounting an FPC (Flexible Printed Circuits) (not shown) electrically connected to the liquid crystal display panel 11. In other words, the liquid crystal display panel 11, which is the image display element 11, generates a display image by modulating the intensity of transmitted light based on a control signal from a control circuit (image control unit 1160 in Figure 3) that constitutes the electronic device, together with the LED element 201, which is the solid light source. At this time, the generated image light has a narrow diffusion angle and consists only of specific polarization components, so a new and unprecedented image display device is obtained that is similar to a surface-emitting laser image source driven by an image signal. Currently, it is technically and safely impossible to obtain a laser beam of the same size as the image obtained by the above-described display device 1 using a laser device. Therefore, in this embodiment, for example, light similar to the surface-emitting laser image light described above is obtained from a light beam from a general light source equipped with an LED element.

[0149] Next, the configuration of the optical system housed within the case of the light source device 13 will be described in detail with reference to Figure 6 and Figure 7. Since Figures 6 and 7 are cross-sectional views, only one of the multiple LED elements 201 constituting the light source is shown, and these are converted into approximately parallel light (collimated light) by the shape of the light-receiving end face 203a of the light guide 203. For this reason, the light-receiving portion of the end face of the light guide and the LED element 201 are mounted while maintaining a predetermined positional relationship.

[0150] Each of these light guides 203 is formed from a translucent resin such as acrylic. The LED light-receiving surface at the end of the light guide 203 has, for example, a cone-shaped outer surface obtained by rotating a parabolic cross-section, with a recess at its apex that forms a convex portion (i.e., a convex lens surface) in its center, and a convex lens surface (or a concave lens surface that is recessed inward) in the center of its flat portion (not shown). The outer shape of the light-receiving portion of the light guide to which the LED element 201 is attached is a parabolic shape that forms a cone-shaped outer surface, and is set within an angle range that allows for total internal reflection of light emitted from the LED element in the peripheral direction, or a reflective surface is formed.

[0151] On the other hand, the LED elements 201 are each positioned at predetermined locations on the surface of the LED substrate 202, which is their circuit board. The LED substrate 202 is fixed to the light-receiving end face 203a, which is an LED collimator, with the LED elements 201 on its surface positioned in the center of the aforementioned recesses.

[0152] With this configuration, the shape of the light-receiving end face 203a of the light guide 203 makes it possible to extract the light emitted from the LED element 201 as substantially parallel light, thereby improving the utilization efficiency of the generated light.

[0153] As described above, the light source device 13 is configured by attaching a light source unit, which consists of multiple LED elements 201 arranged in a row, to a light-receiving end surface 203a, which is a light-receiving part provided on the end face of a light guide 203. The divergent light beam from the LED elements 201 is guided through the inside of the light guide 203 as substantially parallel light by the lens shape of the light-receiving end surface 203a of the light guide 203, as indicated by the arrows, and is emitted toward the liquid crystal display panel 11, which is arranged substantially parallel to the light guide 203, by the light beam direction conversion means 204. By optimizing the distribution (in other words, density) of this light beam direction conversion means 204 depending on the shape of the inside or surface of the light guide 203, the uniformity of the light beam incident on the liquid crystal display panel 11 can be controlled.

[0154] The aforementioned light beam direction conversion means 204, by the shape of the surface of the light guide 203, or by providing, for example, a portion with a different refractive index inside the light guide 203, emits the light beam propagating within the light guide 203 toward the liquid crystal display panel 11, which is arranged substantially parallel to the light guide 203. At this time, if the liquid crystal display panel 11 is facing the center of the screen and the viewpoint is placed at the same position as the screen diagonal, and the relative brightness ratio of the screen center and the screen periphery is 20% or more, there is no practical problem, and if it exceeds 30%, it is an even better characteristic.

[0155] Figure 6 is a cross-sectional diagram illustrating the configuration and operation of the light source in this embodiment, which performs polarization conversion in the light source device 13 including the light guide 203 and LED element 201 described above. In Figure 6, the light source device 13 consists of a light guide 203 with a light beam direction conversion means 204 provided on its surface or inside, which is formed of, for example, plastic; an LED element 201 as a light source; a reflective sheet 205; a phase difference plate 206; a lenticular lens, etc. A liquid crystal display panel 11 equipped with polarizing plates on the light source light incident surface and the image light output surface is mounted on the upper surface of the light source device 13.

[0156] Furthermore, a film or sheet-like reflective polarizer 49 is provided on the light source light incident surface (lower surface in the figure) of the liquid crystal display panel 11 corresponding to the light source device 13, selectively reflecting one side of the polarization (e.g., P-wave) 212 of the natural light beam 210 emitted from the LED element 201. The reflected light is reflected again by a reflective sheet 205 provided on one side (lower surface in the figure) of the light guide 203 and directed towards the liquid crystal display panel 11. Therefore, a phase difference plate (λ / 4 plate) is provided between the reflective sheet 205 and the light guide 203 or between the light guide 203 and the reflective polarizer 49. The reflected light (reflected light beam) is reflected by the reflective sheet 205 and passes through the phase difference plate (λ / 4 plate) a total of two times, converting it from P-polarized to S-polarized. This improves the efficiency of utilizing the light source as image light. The image light beam, whose light intensity has been modulated by the video signal on the liquid crystal display panel 11, is emitted as shown by arrow 213 in Figure 6 and incident on the retroreflector 2. After reflection by the retroreflector 2, a real image, a floating image in space, can be obtained.

[0157] Figure 7, similar to Figure 6, is a cross-sectional arrangement diagram illustrating the configuration and operation of the light source in this embodiment, which performs polarization conversion in a light source device 13 including a light guide 203 and an LED element 201. The light source device 13 is similarly composed of a light guide 203 with a light beam direction conversion means 204 provided on its surface or inside, for example, made of plastic, an LED element 201 as a light source, a reflective sheet 205, a phase difference plate 206, a lenticular lens, and the like. A liquid crystal display panel 11, equipped with polarizing plates on the light source light incident surface and the image light output surface, is mounted on the upper surface of the light source device 13.

[0158] Furthermore, a film or sheet-like reflective polarizer 49 is provided on the light source light incident surface (lower surface in the figure) of the liquid crystal display panel 11 corresponding to the light source device 13, selectively reflecting one side of the polarization (e.g., S-wave) 211 of the natural light beam 210 emitted from the LED element 201. That is, in the example of Figure 7, the selective reflection characteristics of the reflective polarizer 49 are different from those in Figure 7. The reflected light is reflected by a reflective sheet 205 provided on one side (lower surface in the figure) of the light guide 203 and returns to the liquid crystal display panel 11. A phase difference plate (λ / 4 plate) is provided between the reflective sheet 205 and the light guide 203 or between the light guide 203 and the reflective polarizer 49. The reflected light (reflected light beam) is reflected by the reflective sheet 205 and passes through the phase difference plate (λ / 4 plate) a total of two times, converting it from S-polarized to P-polarized. This improves the efficiency of utilizing the light source as image light. The image light beam, whose light intensity is modulated by the video signal on the liquid crystal display panel 11, is emitted as shown by arrow 214 in Figure 7 and incident on the retroreflector 2. After reflection by the retroreflector 2, a real image, a floating image in space, can be obtained.

[0159] In the light source device 13 shown in Figures 6 and 7, in addition to the action of the polarizer provided on the light incident surface of the corresponding liquid crystal display panel 11, a reflective polarizer reflects one side of the polarization component. Therefore, the theoretically obtainable contrast ratio is the product of the reciprocal of the cross transmittance of the reflective polarizer and the reciprocal of the cross transmittance obtained by the two polarizers attached to the liquid crystal display panel 11. This results in high contrast performance. In actual experiments, it was confirmed that the contrast performance of the displayed image improved by more than 10 times. As a result, high-quality images comparable to those of self-emissive organic EL displays were obtained.

[0160] <Example of display device 2> Figure 8 shows another example of the specific configuration of the display device 1. The light source device 13 of this display device 1 is constructed by housing LEDs, collimators, composite diffusion blocks, light guides, etc., in a case made of, for example, plastic, and a liquid crystal display panel 11 is mounted on the top surface of the light source device 13. In addition, an LED substrate 202 on which semiconductor light sources, namely LED elements 201 and the control circuit for the LED elements 201 are mounted is attached to one side of the case of the light source device 13, and a heat sink 103, which is a component for cooling the heat generated by the LED elements 201 and the control circuit, is attached to the outer surface of the LED substrate 202.

[0161] Furthermore, the liquid crystal display panel frame attached to the top surface of the case of the light source device 13 is configured with a liquid crystal display panel 11 attached to the frame, and an FPC 403 electrically connected to the liquid crystal display panel 11. In other words, the liquid crystal display panel 11, which is the image display element 11, generates a display image by modulating the intensity of transmitted light based on control signals from a control circuit (not shown) that constitutes the electronic device, together with the LED element 201, which is the solid light source.

[0162] <Example of a display device 3> Next, using Figure 9, another example of the specific configuration of the display device 1 (Example 3 of the display device) will be explained. In this display device 1, the light source device converts the divergent luminous flux of light (a mixture of P-polarized and S-polarized light) from the LED 201 into a nearly parallel luminous flux by a collimator (LED collimator) 18, and reflects it toward the liquid crystal display panel 11 by the reflective surface of the reflective light guide 304. The reflected light is incident on a reflective polarizer 49 placed between the liquid crystal display panel 11 and the reflective light guide 304. The reflective polarizer 49 transmits light of a specific polarization (e.g., P-polarized light) and causes the transmitted polarized light to be incident on the liquid crystal display panel 11. Here, other polarizations other than the specific polarization (e.g., S-polarized light) are reflected by the reflective polarizer 49 and return to the reflective light guide 304.

[0163] The reflective polarizer 49 is installed at an angle to the liquid crystal display panel 11 so as not to be perpendicular to the principal ray of light from the reflective surface of the reflective light guide 304. The principal ray of light reflected by the reflective polarizer 49 is incident on the transmissive surface of the reflective light guide 304. The light incident on the transmissive surface of the reflective light guide 304 passes through the back of the reflective light guide 304, passes through the λ / 4 plate 270 which is a phase difference plate, and is reflected by the reflector 271. The light reflected by the reflector 271 passes through the λ / 4 plate 270 again and passes through the transmissive surface of the reflective light guide 304. The light that has passed through the transmissive surface of the reflective light guide 304 is incident on the reflective polarizer 49 again.

[0164] At this time, the light that again enters the reflective polarizer 49 has passed through the λ / 4 plate 270 twice, so its polarization has been converted to a polarization that can be transmitted through the reflective polarizer 49 (for example, P-polarization). Therefore, the light whose polarization has been converted passes through the reflective polarizer 49 and enters the liquid crystal display panel 11. Regarding the polarization design related to polarization conversion, it is also acceptable to configure the polarization in reverse from the above explanation (reversing S-polarization and P-polarization).

[0165] As a result, the light from LED201 is aligned to a specific polarization (e.g., P-polarization), incident on the liquid crystal display panel 11, and is luminance-modulated in accordance with the video signal to display an image on the panel surface. Similar to the example described above, there are multiple LED201 that constitute the light source, and these are mounted at predetermined positions for each corresponding collimator 18 of the multiple collimators 18. However, in Figure 9, only one LED201 and one collimator 18 are shown because it is a vertical cross-section.

[0166] Each collimator 18 is formed from a translucent resin such as acrylic or glass. The collimator 18 may have a cone-shaped outer surface obtained by rotating a parabolic cross-section. The collimator 18 may also have a recess with a convex portion (i.e., a convex lens surface) in the center of the top portion (the side facing the LED substrate 202). Furthermore, the central part of the planar portion of the collimator 18 (the side opposite to the top portion) has a convex lens surface that protrudes outward (or a concave lens surface that is recessed inward). The parabolic surface forming the cone-shaped outer surface of the collimator 18 is set within an angle range that allows for total internal reflection of light emitted from the LED 201 in the peripheral direction, or a reflective surface is formed thereon.

[0167] The LEDs 201 are each positioned at predetermined locations on the surface of the LED board 202, which is the circuit board for the LEDs. The LED board 202 is fixed to the collimator 18 such that the LEDs 201 on its surface are each positioned at the center of the apex of the cone-shaped convex form (or in the recess if there is a recess at the apex).

[0168] With this configuration, the collimator 18 focuses the light emitted from the LED 201, particularly the light emitted from its central portion, into parallel light due to the convex lens surface that forms the outer shape of the collimator 18. Similarly, the light emitted from other parts toward the periphery is reflected by the parabolic surface that forms the conical outer surface of the collimator 18, and is also focused into parallel light. In other words, a collimator 18 with a convex lens in its center and a parabolic surface around its periphery makes it possible to extract almost all of the light generated by the LED 201 as parallel light, thereby improving the utilization efficiency of the generated light.

[0169] Furthermore, the light converted to nearly parallel light by the collimator 18 shown in Figure 9 is reflected by the reflective light guide 304. Of this light, light of a specific polarization is transmitted through the reflective polarizer 49 due to the action of the reflective polarizer 49, and the light of the other polarization reflected by the reflective polarizer 49 is transmitted again through the light guide 304. This light is reflected by the reflector 271 located opposite the liquid crystal display panel 11 to the reflective light guide 304. At this time, the light undergoes polarization conversion by passing through the λ / 4 plate 270, which is a phase difference plate, twice. The light reflected by the reflector 271 is transmitted again through the light guide 304 and incident on the reflective polarizer 49 located on the opposite side. Since the polarization conversion has been performed on this incident light, it is transmitted through the reflective polarizer 49, and the polarization direction is aligned before it is incident on the liquid crystal display panel 11. As a result, all of the light from the light source can be utilized, so the geometrical optical utilization efficiency of the light is doubled. Furthermore, since the polarization degree (extinction ratio) of the reflective polarizer 49 is also included in the extinction ratio of the entire system, the contrast ratio of the entire display device is significantly improved by using the light source device of this embodiment. The reflection and diffusion angles of light at each reflective surface can be adjusted by adjusting the surface roughness of the reflective surface of the reflective light guide 304 and the surface roughness of the reflector 271. The surface roughness of the reflective surface of the reflective light guide 304 and the surface roughness of the reflector 271 should be adjusted for each design to further optimize the uniformity of the light incident on the liquid crystal display panel 11.

[0170] Note that the λ / 4 plate 270, which is the phase difference plate in Figure 9, does not necessarily need to have a phase difference of λ / 4 with respect to polarization incident perpendicularly to the λ / 4 plate 270. In the configuration of Figure 9, any phase difference plate that changes its phase by 90° (λ / 2) after the polarization passes through it twice is sufficient. The thickness of the phase difference plate should be adjusted according to the incident angle distribution of the polarization.

[0171] <Example of a display device 4> Furthermore, another example of the optical system configuration of the light source device of the display device 1 (Example 4 of the display device) will be explained using Figure 10. Example 4 of the display device is a configuration example in which a diffusion sheet is used instead of the reflective light guide 304 in the light source device of Example 3 of the display device. Specifically, two optical sheets (in other words, diffusion sheets) that convert the diffusion characteristics in the vertical and horizontal directions (front and back directions not shown in the figure) are used on the light output side of the collimator 18. The two optical sheets are shown as optical sheet 207A and optical sheet 207B. Light from the collimator 18 is incident between the two optical sheets.

[0172] Note that the optical sheet described above may be a single sheet instead of two. If a single sheet is used, the vertical and horizontal diffusion characteristics are adjusted by the fine shape of the front and back surfaces of the single optical sheet. Alternatively, multiple diffusion sheets may be used to share the function. In the example shown in Figure 10, the reflection and diffusion characteristics due to the surface and back surface shapes of optical sheets 207A and 207B should be optimally designed using the number of LEDs 201, the divergence angle from the LED substrate 202, and the optical specifications of the collimator 18 as design parameters so that the surface density of the light beam emitted from the liquid crystal display panel 11 is uniform. In other words, in the example shown in Figure 10, the diffusion characteristics are adjusted by the surface shapes of multiple diffusion sheets instead of a light guide.

[0173] In the example shown in Figure 10, polarization conversion is performed in the same manner as in Example 3 of the display device described above. That is, in the example shown in Figure 10, the reflective polarizer 49 should be configured to have the characteristic of reflecting S-polarized light (and transmitting P-polarized light). In that case, the P-polarized light emitted from the light source LED 201 is transmitted, and the transmitted light is incident on the liquid crystal display panel 11. The S-polarized light emitted from the light source LED 201 is reflected, and the reflected light passes through the phase difference plate 270 shown in Figure 10. The light that has passed through the phase difference plate 270 is reflected by the reflector 271. The light reflected by the reflector 271 is converted to P-polarized light by passing through the phase difference plate 270 again. The polarized light passes through the reflective polarizer 49 and is incident on the liquid crystal display panel 11.

[0174] Note that the λ / 4 plate 270, which is the phase difference plate in Figure 10, does not necessarily need to have a phase difference of λ / 4 with respect to polarization incident perpendicularly to the λ / 4 plate 270. In the configuration of Figure 10, any phase difference plate that changes its phase by 90° (λ / 2) after the polarization passes through it twice is sufficient. The thickness of the phase difference plate should be adjusted according to the incident angle distribution of the polarization. Also, in Figure 10, regarding the polarization design related to polarization conversion, the polarization can be reversed from the explanation above (S-polarization and P-polarization are reversed).

[0175] In typical TV applications, the light emitted from the liquid crystal display panel 11 has similar diffusion characteristics in both the horizontal direction (shown on the X-axis in Figure 12(a)) and the vertical direction (shown on the Y-axis in Figure 12(b)). In contrast, the diffusion characteristics of the light beam emitted from the liquid crystal display panel 11 in this embodiment are such that, for example, as shown in Example 1 in Figure 12, the viewing angle at which the brightness is 50% of that of a front view (0-degree angle) is 13 degrees, which is 1 / 5 of the 62 degrees of a typical TV application. Similarly, the vertical viewing angle is made uneven, with the upper viewing angle being reduced to about 1 / 3 of the lower viewing angle by optimizing the reflection angle of the reflective light guide and the area of ​​the reflective surface. As a result, the amount of image light directed towards the monitoring direction is significantly improved compared to conventional LCD TVs, and the brightness is more than 50 times higher.

[0176] Furthermore, with the viewing angle characteristics shown in Example 2 of Figure 12, the viewing angle at which the brightness is 50% of that of a front view (0-degree angle) is set to 5 degrees, which is 1 / 12 of the 62 degrees of a typical TV device. Similarly, the vertical viewing angle is made uniform both vertically and horizontally, and the reflection angle of the reflective light guide and the area of ​​the reflective surface are optimized to reduce the viewing angle to about 1 / 12 of that of a typical TV device. As a result, the amount of image light directed towards the monitoring direction is significantly improved compared to conventional LCD TVs, and the brightness becomes more than 100 times higher.

[0177] As described above, by narrowing the viewing angle, the amount of light flux directed towards the monitoring direction can be concentrated, significantly improving the efficiency of light utilization. As a result, even when using a liquid crystal display panel for general TV applications, by controlling the light diffusion characteristics of the light source device, a significant increase in brightness can be achieved with similar power consumption, making it possible to create a video display device that is suitable for information display systems for bright outdoor environments.

[0178] When using a large LCD display panel, the overall brightness of the screen can be improved by directing the light from the edges of the screen inward so that it is directed towards the monitor when the monitor is facing the center of the screen. Figure 11 shows the convergence angles of the long and short sides of the panel, with the monitor's distance L from the panel and the panel size (screen aspect ratio 16:10) as parameters. When monitoring with the screen in portrait orientation, the convergence angle should be set to match the short side. For example, with a 22-inch panel used vertically and a monitoring distance of 0.8m, setting the convergence angle to 10 degrees will effectively direct the image light from the four corners of the screen towards the monitor.

[0179] Similarly, when monitoring with a 15-inch panel in portrait orientation, if the monitoring distance is 0.8m, a convergence angle of 7 degrees will effectively direct the image light from the four corners of the screen towards the monitor. As described above, depending on the size of the LCD display panel and whether it is used vertically or horizontally, the overall brightness of the screen can be improved by directing the image light from the periphery of the screen towards the monitor who is in the optimal position to monitor the center of the screen.

[0180] In its basic configuration, as shown in Figure 9, a light source device emits a light beam with narrow-angle directional characteristics onto the liquid crystal display panel 11. By modulating the brightness in accordance with the video signal, the video information displayed on the screen of the liquid crystal display panel 11 is reflected by a retroreflector, and the resulting floating image is displayed outdoors or indoors via a transparent member 100.

[0181] By using the display device and light source device according to one embodiment of the present invention described above, it becomes possible to realize a spatial floating image display device with higher light utilization efficiency.

[0182] Next, as Examples 2 and 3 of the present invention, we will describe examples of optical image display devices that generate optical images for the operator.

[0183] <Example 2> The optical image display device according to Example 2 is a spatial floating image display device that displays a spatial floating image as an optical image to a worker performing manual work, for example, on a workbench or inside a glove box. The basic configuration is similar to that of each figure described in Example 1. In Example 2, the differences from Example 1 will be mainly explained, and the same configuration as in Example 1 will not be repeated.

[0184] When workers perform various tasks at a workbench, they may refer to instruction sheets containing work procedures and instructions. These instruction sheets can be printed on paper or displayed on digital devices such as monitors. With conventional instruction sheets, if the medium displaying the instructions is far from the worker, it becomes difficult to see. On the other hand, if the medium displaying the instructions is too close to the worker, it can create a feeling of pressure, and there is a risk that the worker may physically come into contact with the medium, interfering with their work.

[0185] Furthermore, when workers perform various tasks using a glove box, conventionally, instructions were made visible to the worker by, for example, attaching a paper or other medium with instructions to the surface of the glove box. However, when a worker wants to check the instructions while working inside the glove box, they need to move their face and body away from the glove box, that is, they have to pull their face and body back. This action can be burdensome and may lead to a decrease in work efficiency.

[0186] In the floating image display device according to Embodiment 2, a floating image, which is an optical image, is generated and displayed so that it overlaps with the work space as seen by the worker. In the floating image display device according to Embodiment 2, for example, by displaying an instruction sheet as a floating image, the worker can more easily see the instruction sheet while performing their work. For example, even when working on a workbench or inside a glove box, the worker can see the floating image of the instruction sheet without having to move their gaze significantly. Furthermore, the floating image of the instruction sheet does not physically come into contact with the worker's fingers and interfere with their work, and the feeling of pressure on the worker can be reduced. Therefore, it becomes easier to secure a wider work space than before, and the worker can perform their work in the work space more easily.

[0187] <Example Configuration 1> Figures 13A and 13B show an example of a floating spatial image display device according to the first configuration example of Embodiment 2. In Figures 13A and subsequent figures, the left-right direction is defined as the x1 direction, the front-back direction (depth direction) as the y1 direction, and the height direction (up-down direction) as the z1 direction, relative to a user facing the floating spatial image display device. The floating spatial image display device 1000 according to the first configuration example shown in Figures 13A and 13B is used when a user 230, who is a worker, performs manual work on a workbench 300, and displays an instruction sheet as a floating spatial image 3, and is positioned above the workbench 300. As an example, the floating spatial image display device 1000 is suspended from the ceiling surface 400 inside the building where the workbench 300 is installed and positioned in the space above the workbench 300. Furthermore, the floating spatial image display device 1000 is positioned on the opposite side of the workbench 300 from the user 230's standing position, that is, at the back of the workbench 300 from the user 230's perspective, and forms a floating spatial image 3 toward the user 230.

[0188] The floating image display device 1000 shown in Figure 13A comprises a display device 1 and optical components, such as a polarization separation member 101 and a retroreflector 2, which generate a floating image, an optical image, based on the image light output from the display device 1 (see Figure 2A(1), etc.). The display device 1 and the optical components, the polarization separation member 101 and the retroreflector 2, are housed in a housing 1190. The housing 1190 is also provided with an aerial operation detection sensor 1351 that detects the operation of the floating image 3 by the user 230.

[0189] The display device 1 comprises a liquid crystal display panel 11 and a light source device 13 that generates light, and displays an image processed by an image control unit 1160, etc., which functions as an image processing unit. An absorbing polarizing plate 12 is also provided on the image display surface of the display device 1. In this example, the display device 1 is positioned so that its surface is aligned with the ceiling surface 400 and outputs image light downwards. The polarization separation member 101 is positioned diagonally on the underside of the display device 1 at a predetermined angle to intersect the direction of propagation of the image light. The retroreflector 2 is positioned on the opposite side of the working space A1 from the polarization separation member 101. A λ / 4 plate 21 is provided on the image light incident surface of the retroreflector 2.

[0190] The housing 1190, which houses the display device 1 and the polarization separation member 101 and retroreflector 2 as optical components, is positioned outside the workspace A1 where the user 230 performs manual work. The housing 1190 is positioned relatively far from the user 230, in a position where the user's fingers 231 are unlikely to come into contact with it during work. In this example, the housing 1190, which houses the display device 1 and the polarization separation member 101 and retroreflector 2 as optical components, is positioned above the workspace A1. Therefore, the space below the housing 1190 above the workbench 300 can be called workspace A1. Furthermore, in this example, the housing 1190, which houses the display device 1 and the polarization separation member 101 and retroreflector 2 as optical components, is positioned further back than the workspace A1. Therefore, the space in front of the housing 1190 above the workbench 300 can be called workspace A1.

[0191] As described in Example 1, the image light emitted from the display device 1 is incident on the retroreflector 2 via the polarization separation member 101. The image light retroreflected by the retroreflector 2 passes through the polarization separation member 101 and forms a floating image 3, which is a real image, on the outside of the housing 1190. In other words, the floating image 3 is displayed at a position relatively close to the user 230.

[0192] In the floating image display device 1000 according to Embodiment 2, for example, an image (screen) of an instruction sheet is generated as the floating image 3, and the generated floating image 3 of the instruction sheet is displayed so as to overlap with the work space A1 as seen by the user 230. In the floating image display device 1000 according to the first configuration example, the floating image 3 of the instruction sheet is displayed above the workbench 300 so as to overlap with the work space A1 as seen by the user 230. In this case, it is preferable that the floating image display device 1000 displays the floating image 3 above the workbench 300 at a height approximately the same as the user 230's head.

[0193] This allows user 230 to clearly see the floating image 3 of the instruction sheet. Furthermore, user 230 can also see the workspace A1 beyond the floating image 3 through the floating image 3 of the instruction sheet. Additionally, the floating image 3 of the instruction sheet is formed within the reach of user 230's fingers while working, but does not physically come into contact with the worker's fingers. Therefore, work can be performed even in the area where the floating image 3 of the instruction sheet is displayed, resulting in easier securing of a wider workspace A1 than before.

[0194] In this example, workspace A1 refers to the space on the workbench 300 where user 230 performs their work. Furthermore, when user 230 sees the floating image 3 overlapping workspace A1, it can be said that the floating image 3 is displayed in front of workspace A1, within workspace A1, or behind workspace A1 in the depth direction (y1 direction) of the workbench 300. For example, in the case of the floating image display device 1000 according to the first configuration example, the floating image 3 is formed within workspace A1.

[0195] Incidentally, if the instruction sheet is shown on a medium such as paper, as in the past, that medium will be in physical contact with the user's fingers 231. For this reason, for example, if the instruction sheet is shown on a medium M1 suspended from the ceiling surface 400, as shown by the dashed line in Figure 13A, the workspace A1' will be limited to the space below the medium M1. Therefore, if the instruction sheet is written on the medium M1, the medium M1 on which the instruction sheet is shown will not overlap with the workspace A1' from the user's perspective.

[0196] Here, it is preferable that the floating image display device 1000 is installed at a position slightly lower than the eye level of the user 230 in the vertical direction z1. In other words, it is preferable that the floating image 3 of the instruction sheet is displayed at a position slightly lower than the eye level of the worker 230. In this case, it is preferable that the image light that forms the floating image 3 (image light emitted from the retroreflector 2) is directed upward by a predetermined angle θ1 with respect to the horizontal plane. That is, it is preferable that the display device 1 and the optical components, namely the polarization separation member 101 and the retroreflector 2, are arranged such that the floating image 3 is generated facing upward with respect to the horizontal direction. This makes it even easier for the worker 230 to see the floating image 3 of the instruction sheet, even when their line of sight is focused on their hands while working.

[0197] Furthermore, as described above, the floating image display device 1000 is equipped with an aerial operation detection sensor 1351, which can detect operations on the floating image 3 by the user 230's fingers or other manipulative objects. Therefore, the user 230 can also operate the floating image 3 on the instruction sheet.

[0198] Furthermore, while a spatial floating image display device 1000 comprising a display device 1, a polarization separation member 101, and a retroreflector 2 has been described as a first configuration example, the spatial floating image display device 1000 according to the first configuration example is not limited to this. For example, as shown in Figure 14, the spatial floating image display device 1000 according to the first configuration example can also be configured to include a display device 1 and a retroreflector 5, similar to the case of Embodiment 1. The retroreflector 5 retroreflects the image light emitted from the display device 1 and generates a spatial floating image 3 at a position that is mirror-symmetric with respect to the retroreflector 5, and is positioned diagonally to the direction of propagation of the image light on the lower side of the display device 1.

[0199] <Example Configuration 2> Figure 15 shows an example of a floating image display device according to the second configuration example of Embodiment 2. Figure 16 illustrates an example of a workbench according to the second configuration example of Embodiment 2.

[0200] The floating image display device 1000 according to the second configuration example is also used when the user 230 performs manual work on the workbench 300, and displays the instruction sheet screen (video) as a floating image 3. As shown in Figure 15, the floating image display device 1000 according to the second configuration example is positioned on the back side of the workbench 300 from the user 230's perspective, so that the floating image 3 of the instruction sheet is formed near the surface of the workbench 300. In addition, a part of the floating image display device 1000 in the second configuration example is positioned below the workbench 300, and the floating image 3 is displayed diagonally upward relative to the horizontal plane.

[0201] The floating image display device 1000 shown in Figure 15 comprises a display device 1 and optical components, namely a polarization separation member 101 and a retroreflector 2, similar to the first configuration example. These components are housed within a housing 1190. In this example, the polarization separation member 101 is positioned approximately vertically, and the display device 1 is positioned such that image light is incident on the polarization separation member 101 at a predetermined angle, for example, approximately 45°. That is, the polarization separation member 101 is positioned below the display device 1, obliquely to the direction of propagation of the image light emitted from the display device 1.

[0202] In this example as well, the retroreflector 2 is positioned on the opposite side of the working space A1 from the polarization separation member 101. The image light emitted from the display device 1 is incident on the retroreflector 2 via the polarization separation member 101, and the image light retroreflected by the retroreflector 2 passes through the polarization separation member 101, forming a floating image 3, which is a real image, on the outside of the housing 1190. In the floating image display device 1000 according to the second configuration example, the floating image 3 of the instruction sheet is displayed near the surface of the workbench 300 so that it overlaps with the working space A1 as seen from the user 230.

[0203] Here, as described above, a portion of the floating image display device 1000 is positioned below the workbench 300. In the example shown in Figure 15, approximately half of the housing 1190 on the display device 1 side is positioned above the workbench 300, and approximately half on the retroreflector 2 side is positioned below the workbench 300. Therefore, some of the image light retroreflected by the retroreflector 2 may be blocked by the workbench 300. For this reason, it is preferable that at least a portion of the workbench 300 be a transparent portion 301 made of a transparent material such as glass or resin that can transmit the image light emitted from the retroreflector 2, as shown in Figures 15 and 16. In this example, only a portion of the workbench 300 is a transparent portion 301, but the entire workbench 300 may be a transparent portion 301. This ensures that the floating image 3 is formed well without the image light emitted from the retroreflector 2 being blocked by the workbench 300.

[0204] In the floating image display device 1000 according to this second configuration example, the worker 230 can clearly see the floating image 3 of the instruction sheet, and it becomes easier to secure a wider workspace A1 than in the conventional model.

[0205] As a second example configuration, a spatial levitation image display device 1000 comprising a display device 1, a polarization separation member 101, and a retroreflector 2 has been described. However, the spatial levitation image display device 1000 according to the second example configuration is not limited to this. The spatial levitation image display device 1000 according to the second example configuration can also be configured to include a display device 1 and a retroreflector 5, similar to the first example configuration (see Figure 14).

[0206] <Example 3 configuration> Figure 17 shows an example of a floating image display device according to the third configuration example of Embodiment 2. The floating image display device 1000 according to the third configuration example shown in Figure 17 is used when a user 230 is working in a so-called glove box 310, and displays instruction sheets, etc., as floating images 3. The floating image display device 1000 according to the third configuration example displays floating images 3 of instruction sheets, etc., in the upper part of the glove box 310.

[0207] Here, the glove box 310 is a sealed, transparent container into which only the hands can be placed, allowing work to be performed in an environment isolated from the outside air. It has a space inside that becomes a workspace A1 where the user 230 performs work. Multiple gloves 320 for working in workspace A1 are attached to the glove box 310. The front panel 311 that makes up the front of the glove box 310 is provided with glove attachment holes 312 into which multiple gloves 320 are attached. The user 230 inserts their arm (forearm) into the glove 320 through the glove attachment hole (also called glove insertion opening) 312 and performs work in workspace A1 inside the glove box 310 while wearing the gloves 320.

[0208] The glove box 310 is made of a transparent plate such as glass or resin, and is configured so that the internal workspace A1 can be seen from the outside of the glove box 310. The glove box 310 does not necessarily have to be made entirely of transparent plate; a portion of it may be made of transparent plate as needed. The glove 320 is made of a rubber material, for example, and is attached to the glove box 310 so as to cover the glove mounting hole 312. The glove box 310 with the glove 320 attached is designed to maintain airtightness inside.

[0209] The floating image display device 1000 according to the third configuration example is attached to such a glove box 310 and used when the user 230 is performing work. For example, the floating image display device 1000 according to the third configuration example is suspended from the top panel 313 that constitutes the top surface (sometimes called the upper surface) of the glove box 310 and is positioned in the upper part of the space inside the glove box 310. The floating image display device 1000 is also positioned on the opposite side of the front panel 311 of the glove box 310, that is, near the back panel 314 that constitutes the back of the glove box 310, and forms a floating image 3 toward the user 230 who is located outside the front panel 311 of the glove box 310. In the floating image display device 1000 according to the third configuration example, the floating image 3, such as an instruction sheet, is displayed in the upper part of the glove box 310 so that it overlaps with the work space A1 as seen from the user 230's perspective.

[0210] The third configuration example of the floating image display device 1000 comprises a display device 1 and optical components, namely a polarization separation member 101 and a retroreflector 2, similar to the first configuration example. The housing 1190, which houses the display device 1 and the optical components, namely the polarization separation member 101 and the retroreflector 2, is positioned above the workspace A1 where the user 230 performs their work.

[0211] Furthermore, since the spatial floating image display device 1000 according to the third configuration example is used when working inside the glove box 310, the working space A1 is the range that the user's fingers 231 can reach while wearing the gloves 320, and is determined by the range of motion of the gloves 320. Therefore, in the spatial floating image display device 1000 according to the third configuration example, the working space A1 can be rephrased as the range of motion of the gloves 320 inside the glove box 310. Incidentally, since the gloves 320 are attached to the glove box 310 as described above, the range of motion of the gloves 320 is determined by the length and flexibility of the gloves 320.

[0212] In the spatially floating image display device 1000 according to this third configuration example, the user 230 can clearly see the spatially floating image 3 of the instruction sheet, and it becomes easier to secure a wider workspace A1 than in the conventional model.

[0213] Furthermore, the floating image display device 1000 according to the third configuration example comprises a display device 1 and optical components, namely a polarization separation member 101 and a retroreflector 2, similar to the first configuration example, with the display device 1, the polarization separation member 101 and the retroreflector 2 housed within a housing 1190. The floating image display device 1000 according to the third configuration example can also be configured to include a display device 1 and a retroreflector 5, similar to the first configuration example (see Figure 14).

[0214] In the example shown in Figure 17, the display device 1, polarization separation member 101, and retroreflective member 2 of the spatial floating image display device 1000 are each housed within the housing 1190, and the housing 1190 is located inside the glove box 310. However, the display device 1, polarization separation member 101, and retroreflective member 2 do not necessarily have to be housed within the housing 1190, nor do they have to be located inside the glove box 310. For example, as shown in Figure 18, the display device 1 may not be housed within the housing 1190, but may be located outside the top panel 313 of the glove box 310. By placing the display device 1 outside the glove box 310, the temperature rise inside the glove box 310 due to the heat generated by the display device 1 is suppressed. Therefore, even in work processes where temperature and humidity are important, the work can be carried out smoothly in the work space A1 inside the glove box 310.

[0215] Furthermore, if the display device 1 is placed outside the glove box 310 in this manner, the display position of the floating image 3 and the position of the air operation detection sensor 1351 will change, and consequently, the housing 1190 may become relatively large. Also, there is a risk that the housing 1190 may come too close to the user 230, causing the user 230 to feel cramped. In this case, for example, as shown in Figure 19, the air operation detection sensor 1351 may be fixed to the top panel 313 of the glove box 310, and the front end of the housing 1190 on the user 230 side may be cut out to ensure an appropriate length for the distance D1 between the housing 1190 and the user 230 (the distance between the housing 1190 and the front panel 311 of the glove box 310).

[0216] Furthermore, as shown in Figure 20, the floating image display device 1000 may be located outside the glove box 310. In the example shown in Figure 20, an inclined portion 315 is provided at the corner formed by the top panel 313 and the back panel 314 of the glove box 310, inclining toward the inside of the glove box 310. In other words, the top panel 313 and the back panel 314 are connected via this inclined portion 315. The housing 1190, which houses the display device 1, the polarization separation member 101, and the retroreflective member 2, is located outside this inclined portion 315. In this example, the housing 1190 is mounted to the inclined portion 315. Also, in this example, as in the first configuration example, the image light emitted from the retroreflective plate 2 is directed upward by a predetermined angle θ1 with respect to the horizontal plane. In other words, the inclined portion 315 is positioned at an inclination angle such that the image light emitted from the retroreflective plate 2 is directed upward by a predetermined angle θ1 with respect to the horizontal plane.

[0217] Furthermore, the floating image display device 1000 may be positioned such that the floating image 3 is formed at the bottom of the glove box 310. For example, as shown in Figures 21 and 22, the housing 1190, which contains the display device 1, the polarization separation member 101, and the retroreflective member 2, may be positioned at the back of the glove box 310 from the user 230's perspective, such that the floating image 3 is formed near the surface of the bottom plate 316 inside the glove box 310, or near the boundary between the back plate 314 and the bottom plate 316. In other words, the housing 1190 may be positioned outside the glove box 310. In this example, the housing 1190 is fixed in contact with the back plate 314 of the glove box 310. However, the housing 1190 may be positioned at a distance from the glove box 310. Furthermore, although not shown in the figures, the glove box 310 may be fixed to the outer surface of the bottom plate 316. In this case, the video light emitted from the display device 1 and transmitted through the bottom plate 316 forms a floating image 3 near the surface of the bottom plate 316 inside the glove box 310.

[0218] Incidentally, inside the glove box 310, the user 230, as an operator, may perform tasks such as compounding samples of chemicals. In the sample compounding process, the following steps are performed as an example: First, the sample before compounding is weighed using an instrument placed inside the glove box 310, such as a weighing scale. Next, the weighed sample is compounded. After that, the compounded sample is weighed again using the instrument inside the glove box.

[0219] When a blending operation involving such a process is performed, as shown in Figure 23 as an example, the floating video 3, which serves as an instruction sheet, displays information such as work procedure, work content, equipment / samples, as well as other necessary information such as sample name, lot number, safety information, and handling precautions, as appropriate. Based on this instruction sheet, the user 230 performs each step of the weighing and blending operation while confirming the specific work content, such as how many grams of each sample to mix.

[0220] Furthermore, during the mixing process, user 230 needs to record mixing data, such as how many grams of each sample were mixed. For this reason, in the third configuration example of the floating image display device 1000, instead of the instruction sheet screen (image), a data input sheet screen (image), as shown in Figure 24 as an example, is displayed as the floating image 3, allowing user 230 to input mixing data into the floating image 3 on the data input sheet. The data input sheet shown in Figure 25 is an example in which user 230 inputs weighing data (weighing results) for each sample. As shown in Figure 17, user 230 can input weighing data into the data input sheet by moving their fingers 231 while wearing gloves 320 and touching the floating image 3 to operate it. Similar to Example 1, the floating image display device 1000 is equipped with an air operation detection sensor 1351, which can detect the operation of the floating image 3 by user 230's fingers 231.

[0221] The data entry procedure is not particularly limited, but as an example, data entry is performed in the following procedure. First, with the floating image 3 of the data entry table shown in Figure 24 displayed, the user 230 touches the cell in the data entry table into which they want to enter weighing data. When the air operation detection sensor 1351 detects the user 230 touching the cell, the floating image 3 switches from the data entry table screen to the screen of the input operation means, such as a keyboard or numeric keypad, as shown in Figure 25 as an example. The example shown in Figure 25 shows the state in which the input data "1.459 mg" entered by the user 230 using the keyboard is displayed in the input display field. In this example, the user 230 then touches the "Confirm" key on the keyboard, and the input data displayed in the input display field is entered into the predetermined cell touched by the user 230 in the data entry table shown in Figure 25. Also, when the user 230 touches the "Back" button, the floating image 3 switches from the input operation means screen to the data entry table screen.

[0222] In this example, the data input table screen is displayed separately from the instruction table screen. However, the data input table and instruction table screens may be displayed simultaneously as the floating spatial image 3. Alternatively, for example, the floating spatial image display device 1000 and the in-box instrument may be connected by wire or wireless, and the measurement results of the linked in-box instrument may be displayed on the screen in Figure 25, or displayed on the data input table screen in Figure 24 as entered.

[0223] As described above, with the spatial floating image display device 1000 according to the third configuration example, when performing mixing work etc. in the glove box 310, the user 230 can input mixing data etc. while wearing the gloves 320, thereby improving work efficiency. In this case, it is preferable that the entire spatial floating image 3 is located within the work space A1. In other words, it is preferable that the entire spatial floating image 3 overlaps with the work space A1 from the user 230's perspective. This allows the user 230 to operate the entire spatial floating image 3, making data input easier.

[0224] <Example 3> As Embodiment 3 of the present invention, another example of an optical image display device that generates an optical image for a worker will be described. The optical image display device according to Embodiment 3 is a virtual image display device that displays a virtual image as an optical image for a worker performing manual work, for example, inside a glove box.

[0225] As explained in Example 2, when workers perform various tasks using a glove box, conventionally, instructions were made visible to the worker by attaching a paper or other medium to the surface of the glove box. This often resulted in workers having to move more freely when checking the instructions, potentially leading to a decrease in work efficiency.

[0226] The virtual image display device according to Embodiment 3 generates a virtual image of the image displayed on the display device as an optical image. More specifically, the virtual image display device according to Embodiment 3 generates a virtual image outside the glove box so that it overlaps with the work space as seen from the worker's perspective. This makes it easier for the worker to see instructions, etc., even while working inside the glove box. For example, the worker can see the virtual image of instructions, etc., without having to move their gaze significantly.

[0227] Figure 26 is a diagram illustrating a virtual image display device according to Embodiment 3. As shown in Figure 26, the virtual image display device 2000 according to Embodiment 3 comprises a display device 2001 positioned below the bottom plate 316 of the glove box 310, and an image reflecting unit 2002 as an optical element provided on the back plate 314 of the glove box 310. The image light emitted from the display device 2001 passes through the bottom plate 316 of the glove box 310 and is projected onto the image reflecting unit 2002, generating a virtual image 4 on the outside of the back plate 314 of the glove box 310. In other words, the image displayed on the display device 2001 positioned outside the bottom plate 316 of the glove box 310 is perceived by the user 230 as a virtual image 4 generated on the outside of the back plate 314 of the glove box 310.

[0228] The display device 2001 has the same configuration as the display device 1 of Example 1, and is equipped with a liquid crystal display panel 11 and a light source device 13. However, the configuration of the display device 2001 is not particularly limited. The image reflection section 2002 is the part that reflects the image light emitted from the display device 2001, and is formed, for example, on the back panel 314 of the glove box 310. In this example, the image reflection section 2002 is equipped with an optical film attached to the inner surface of the glove box 310. The optical film referred to here has the characteristic of reflecting image light of a specific polarization emitted from the display device 2001, and examples include a polarizing reflective film that reflects the polarization of the image light with high reflectivity.

[0229] In this way, by forming the image reflective section 2002 with an optical film, the user 230 can clearly see the image displayed on the display device 2001 as a virtual image 4. If the optical film is not attached to the back panel 314, the image displayed on the display device 2001 (image light emitted from the display device 2001) will be reflected by the inner and outer surfaces of the back panel 314 of the glove box 310, and there is a risk that the virtual image 4 will become a so-called double image. By forming the image reflective section 2002 with an optical film, the virtual image 4 becomes less likely to be recognized as a double image, and the user 230 can clearly see the virtual image 4. Of course, if the virtual image 4 does not become a double image, the image reflective section 2002 does not have to be formed with an optical film, and for example, it may be made of the back panel 314 of the glove box 310. Furthermore, the double image can also be reduced by changing the inclination of the inner and outer surfaces of the back panel 314.

[0230] According to the virtual image display device 2000 of this embodiment 3, by displaying an image of an instruction sheet or the like on the display device 2001, the user 230 can clearly see the virtual image 4 of the instruction sheet or the like. For example, even while working inside the glove box 310, the user 230 can see the virtual image 4 of the instruction sheet or the like without having to move their head or body. Therefore, the burden during work can be reduced and work efficiency can be improved.

[0231] Here, the installation position of the display device 2001 is not particularly limited as long as it is in the area facing the bottom plate 316 of the glove box 310. For example, the installation position of the display device 2001 in the x1 direction may be any of the following positions, as shown in Figure 27: the first position P1 in the center of the glove box 310, the second position P2 on the right side, or the third position P3 on the left side. However, it is preferable to appropriately adjust the position of the image reflector 2002 according to the installation position of the display device 2001.

[0232] Specifically, if the display device 2001 is installed in front of the user 230 during work, in this example at the first position P1 in the x1 direction, the position of the image reflector 2002 should also be the first position P1. On the other hand, if it is installed at a position shifted to the left or right from the user 230 during work, for example at the second position P2 in the x1 direction, it is preferable that the position of the image reflector 2002 be the fourth position P4, which is shifted from the second position P2 towards the center of the glove box 310, i.e., an offset position. Similarly, if the display device 2001 is installed at the third position P3 in the x1 direction, it is preferable that the position of the image reflector 2002 be the fifth position P5, which is offset from the third position P3 towards the center of the glove box 310. The amount of offset of the image reflector 2002 is determined by the amount of displacement of the display device 2001 in the x1 direction (the amount of displacement from the center position of the glove box 310), and the larger the amount of displacement of the display device 2001, the larger the offset. In this example, the center of the glove box 310 in the x1 direction can also be described as the midpoint between the pair of glove mounting holes 312.

[0233] By appropriately offsetting the position of the image reflecting section 2002 according to the arrangement of the display device 2001, the user 230 can clearly see the virtual image 4, such as an instruction sheet, even while working inside the glove box 310, regardless of the arrangement of the display device 2001.

[0234] Here, when working inside the glove box 310, the user 230 is considered to be located between the pair of glove mounting holes 312. In other words, the user 230's viewpoint during work is considered to be between the pair of glove mounting holes 312. For this reason, as shown in Figure 28, when the display device 2001 is positioned at the first position P1, which is the center of the glove box 310 in the x1 direction, the image reflector (optical film) 2002 is also provided at the first position P1 in the x1 direction, so that the image reflector 2002 is located on the optical path OP from the user (user's viewpoint) 230 to the virtual image 4. That is, from the user 230's perspective, the entire virtual image 4 is generated behind the image reflector 2002. Therefore, the user 230 can clearly see the entire image displayed on the display device 2001 as the virtual image 4.

[0235] On the other hand, for example, as shown in Figure 29A, if the display device 2001 and the image reflector 2002 are each positioned at a second position P2, which is the right side of the glove box 310 in the x1 direction, then there will be a portion of the optical path OP from the user 230 to the virtual image 4 where the image reflector 2002 does not exist. That is, from the user 230's perspective, a portion of the virtual image 4 will be generated in a part that is outside the image reflector 2002. As a result, the user 230 may not be able to clearly perceive the entire image displayed on the display device 2001 as the virtual image 4.

[0236] Therefore, as shown in Figure 29B, when the display device 2001 is installed at a second position P2 in the x1 direction, it is preferable to install the image reflector 2002 at a fourth position P4, which is offset from the second position P2 towards the center of the glove box 310. In other words, when the display device 2001 is positioned at a location offset in the left-right direction from the user 230 with respect to a reference line CL that passes through the midpoint between a pair of gloves 320 (glove mounting holes 312), it is preferable to position the image light reflector 2002 at a location offset by a predetermined amount from the position of the display device 2001 towards the reference line CL.

[0237] As a result, the image reflection unit 2002 is located on the optical path OP from the user (user's viewpoint) 230 to the virtual image 4, and when viewed from the user 230, the entire virtual image 4 is generated on the back side of the image reflection unit 2002. Therefore, the user 230 can clearly visually recognize the image displayed on the display device 2001 as the virtual image 4. In this example, the case where the position of the image reflection unit 2002 is offset with respect to the position of the display device 2001 has been described. Of course, the position of the display device 2001 may be offset with respect to the position of the image reflection unit 2002.

[0238] Incidentally, in the above-described embodiment, the case where one user 230 uses the glove box 310 has been described. The glove box 310 may be configured such that a plurality of users 230 can work simultaneously. As shown in an example in FIG. 30, the glove box 310 is provided with a pair of glove attachment holes 312 in each of the front panel 311 and the back panel 314, and the first user 230A and the second user 230B facing each other in the y1 direction can work simultaneously inside the glove box 310.

[0239] In the case of the virtual image display device 2000 according to the third embodiment, even when a plurality of users 230 work simultaneously inside the glove box 310, an instruction sheet or the like can be clearly displayed as the virtual image 4 for each user 230.

[0240] Also, in this case, the position of the virtual image 4A displayed for the first user 230A is preferably a position outside the working space A1B of the second user 230B in the x1 direction. In other words, it is preferable that the display device 2001 and the image reflection unit 2002 are arranged such that the optical path OP from the user 230A to the virtual image 4A passes outside the working space A1B. In this example, the display device 2001 and the image reflection unit 2002 are arranged such that the virtual image 4A is displayed at a position outside the left side (upper side in FIG. 30) of the working space A1B of the second user 230B when viewed from the first user 230A.

[0241] Similarly, the position of the virtual image 4B displayed for the second user 230B is preferably a position outside the work space A1A of the first user 230A in the x1 direction. That is, it is preferable that the display device 2001 and the video reflection unit 2002 are arranged so that the optical path OP from the second user 230B to the virtual image 4B passes outside the work space A1A. In this example, as viewed from the second user 230B, the display device 2001 and the video reflection unit 2002 are arranged so that the virtual image 4B is displayed at a position offset to the left side (lower side in FIG. 30) of the work space A1A of the first user 230A. Note that the virtual image 4B may be displayed at a position offset to the right side (upper side in FIG. 30) of the work space A1A of the first user 230A as viewed from the second user 230B. Similarly, the virtual image 4A may be displayed at a position offset to the right side (lower side in FIG. 30) of the work space A1B of the second user 230B as viewed from the first user 230A.

[0242] Furthermore, the glove box 310 may be configured such that a plurality of users 230 arranged in the x1 direction can perform operations simultaneously. As shown in an example in FIG. 31, in addition to the first user 230A and the second user 230B facing each other in the y1 direction, the glove box 310 may be configured such that a third user 230C arranged in the x1 direction parallel to the second user 230B can perform operations simultaneously within the glove box 310. In this case, the virtual image 4A for the first user 230A is preferably displayed in a region between the work space A1B of the second user 230B and the work space A1C of the third user 230C in the x1 direction, particularly at a position outside the work spaces A1B and A1C.

[0243] In other words, it is preferable that the virtual image 4A is displayed in a position that does not overlap with the workspaces A1B and A1C from the perspective of the first user 230A. That is, it is preferable that the image light reflecting unit 2002 is positioned such that the virtual image 4A does not overlap with the workspaces A1B and A1C from the perspective of the first user 230A. For example, even in the z1 direction, which is the height direction of the glove box 310, it is preferable that the virtual image 4A is displayed in a position that does not overlap with the workspaces A1B and A1C from the perspective of the first user 230A. In order to achieve such a position for the virtual image 4A, it is preferable that the image reflecting unit 2002 corresponding to the virtual image 4A is positioned above the upper end position Pt of the workspaces A1B and A1C in the z1 direction, for example, as shown in Figure 32. More specifically, it is preferable that the lower end position Pb of the image reflecting unit 2002 is located above the upper end position Pt of the workspaces A1B and A1C.

[0244] Furthermore, when the glove box 310 is configured to allow simultaneous operation by multiple users 230 (230A, 230B, 230C), it is preferable that the display device 2001 and the image reflective section 2002 are appropriately offset from each other, as described above. This allows each user 230 (230A, 230B, 230C) to clearly see the virtual image 4 (4A, 4B, 4C) of the instruction sheet, etc.

[0245] As mentioned above, when user 230 works inside the glove box 310, each work space A1 (A1A, A1B, A1C) is determined by the range of motion of the glove 320. Therefore, when each work space A1 is viewed in plan view, as shown in Figures 30 to 32, each work space (work range) A1 can be represented as a combination of roughly sector-shaped areas centered on the glove mounting hole 312.

[0246] <Example 4> As Example 4, an example of how the optical image display device is used will be described. Figures 33 and 34 are schematic diagrams illustrating an example of how the optical image display device according to Example 4 is used.

[0247] As shown in Figures 33 and 34, Example 4 is an example in which the spatial levitation image display device 1000 and the virtual image display device 2000, which are optical image display devices, are applied to the glove box 310. In other words, Example 4 is an example in which the spatial levitation image display device 1000 is further applied to the glove box 310 in addition to the virtual image display device 2000 according to Example 3.

[0248] The virtual image display device 2000 has the same configuration as described in Embodiment 3, and comprises a display device 2001 positioned below the bottom plate 316 of the glove box 310, and an image reflecting part 2002 as an optical element provided on the back plate 314 of the glove box 310, forming a virtual image 4 on the outside of the back plate 314. In this example, the virtual image display device 2000 is provided in the center of the glove box 310 in the left-right direction (x1 direction), but of course, it may be provided on the left side or the right side of the glove box 310.

[0249] The floating image display device 1000 is positioned on the outside (lower side in the z1 direction) of the bottom plate 316 of the glove box 310. The configuration of the floating image display device 1000 itself is the same as the configuration described in Embodiment 2, and comprises a display device 1, a polarization separation member 101 and a retroreflector 2 as optical elements, and a housing 1190 that houses the display device 1, the polarization separation member 101 and the retroreflector 2. This housing 1190 is attached to the outer surface of the bottom plate 316 of the glove box 310, and the floating image 3 is formed near the bottom plate 316 inside the glove box 310. That is, the image displayed on the display device 1 is displayed as the floating image 3 near the bottom plate 316 inside the glove box 310. As shown in Figure 34 as an example, the display device 1 is positioned along the y1' direction which is inclined with respect to the y1 direction, and as a result, the floating image 3 is formed along the z1' direction which is inclined with respect to the z1 direction.

[0250] Here, when the user 230 performs work inside the glove box 310, it may be necessary to record various data. For example, as described in Example 2, when performing compounding work, it is necessary to record compounding data, etc. However, the virtual image display device 2000 does not have an input interface such as a detector that detects input operations by the user 230, and it is not possible to input data by manipulating the virtual image 4. Therefore, in Example 4, in addition to the virtual image display device 2000, a floating spatial image display device 1000 is applied to the glove box 310. As a result, while displaying instruction sheets, etc., as virtual images 4 using the virtual image display device 2000, various data can be recorded using the floating spatial image 3 as described in Example 2 using the floating spatial image display device 1000.

[0251] Furthermore, when user 230 operates the floating image 3 to input data, the floating image 3 must be displayed within reach of user 230's fingers 231 while wearing the gloves 320. In other words, the floating image 3 must be displayed within user 230's workspace A1.

[0252] Furthermore, it is preferable that the housing 1190 (floating image display device 1000) containing the display device 1, the polarization separation member 101, and the retroreflector 2 is arranged so that the floating image 3 is displayed toward the user 230. For example, if the floating image display device 1000 is provided in the center of the glove box 310 in the x1 direction, it is sufficient for the display device 1, the polarization separation member 101, and the retroreflector 2 to be arranged along the y1 direction. In contrast, for example, if the floating image display device 1000 is provided on one side of the glove box 310 (the left side in Figure 33), it is preferable that the display device 1, the polarization separation member 101, and the retroreflector 2 be arranged along a direction that intersects diagonally with the y direction. It is particularly preferable that the display device 1, the polarization separation member 101, and the retroreflector 2 be arranged along a straight line connecting the midpoint of the pair of glove mounting holes 312 and the retroreflector 2.

[0253] To achieve this arrangement of the floating image display device 1000, it is preferable that the housing 1190 is rotatable around an axis in the vertical direction z1 along the surface of the bottom plate 316. This allows the housing 1190 to be fixed in a desired orientation, thereby displaying the floating image 3 to the user 230 in an appropriate orientation, and enabling the user 230 to view the floating image 3 more clearly.

[0254] Furthermore, in the example shown in Figure 33, the floating image display device 1000 is located on the outside (bottom) of the bottom plate 316 of the glove box 310, but the placement of the floating image display device 1000 is not limited to this. The floating image display device 1000 may also be located on the outside of the top plate 313 or the back plate 314 of the glove box 310, as described in Embodiment 2.

[0255] However, if the glove box 310 is configured to allow simultaneous operation by multiple users (workers) 230, it is preferable that the floating spatial image display device 1000 is located outside the bottom plate 316 of the glove box 310, as described in Example 4.

[0256] As shown in Figure 35 as an example, the glove box 310 of Embodiment 4 may be configured to allow two users facing each other to work simultaneously. The glove box 310 shown in Figure 35 is provided with a pair of glove mounting holes 312 on each of the front panel 311 and the back panel 314, and is configured so that a first user 230A and a second user 230B facing each other in the y1 direction can work simultaneously inside the glove box 310 (see Figure 30). Inside the glove box 310, two workspaces A1A and A1B corresponding to the first user 230A and the second user 230B are secured so as not to interfere with each other.

[0257] In the case of a glove box 310 that allows multiple users 230 (230A, 230B) to work simultaneously, it is preferable that the floating image display device 1000 be positioned outside the bottom plate 316 of the glove box 310. This makes it easier to position the floating image display device 1000 so as not to obstruct the work of each of the multiple users 230. In this case, it is also preferable that the polarization separation member 101 be positioned outside the workspace of the worker facing the floating image 3. For example, in the case of a floating image display device 1000 that displays the floating image 3 toward the first user 230A, it is preferable that the polarization separation member 101 be positioned outside the workspace A1B of the second user 230B, who is the opposing worker. This allows the floating image 3 to be viewed clearly by the first user 230A without being obstructed by the second user 230B.

[0258] Furthermore, in the case of a glove box 310 where multiple users 230 perform simultaneous work, it is preferable that the virtual image display device 2000 is positioned so that the virtual image 4 is displayed in a location outside the workspace of the opposing worker in the x1 direction. For example, in the case of a virtual image display device 2000 that displays a virtual image 4 to the first user 230A, it is preferable that the virtual image 4 is displayed in a location outside the workspace A1B of the second user 230B in the x1 direction. This prevents the virtual image 4 from being obstructed by the opposing worker, and allows each user 230 to clearly see the virtual image 4, such as the instruction sheet.

[0259] Incidentally, regardless of where the floating image display device 1000 is installed in the glove box 310, it is preferable that the display device 1, the polarization separation member 101, and the retroreflector 2 are arranged so that the floating image 3 is displayed facing the user 230. As shown in Figure 36A, if the floating image display device 1000 is located in the center of the glove box 310 in the x1 direction, for example, between a pair of glove mounting holes 312, then the display device 1, the polarization separation member 101, and the retroreflector 2 should be arranged along the y1 direction. In other words, the display device 1, the polarization separation member 101, and the retroreflector 2 should be arranged so that they face the front panel 311 side of the glove box 310. Figures 36A and 36B schematically show the floating image display device 1000 installed in the glove box 310 as viewed from the z1' direction (see Figure 34).

[0260] In contrast, if the floating image display device 1000 is provided on one side of the glove box 310, it is preferable, as described above, that the display device 1, the polarization separation member 101, and the retroreflector 2 be arranged in a direction that intersects the y1 direction at an angle so that the floating image 3 is displayed toward the user 230. However, depending on the positional relationship of each work space A1, for example, even if the floating image display device 1000 is provided on one side of the glove box 310, the display device 1, the polarization separation member 101, and the retroreflector 2 may be arranged so that they face toward the front panel 311 of the glove box 310, as shown in Figure 36B. For example, the housing 1190 may be arranged so that the surface of the polarization separation member 101 is aligned with the x1 direction.

[0261] Here, as described in Example 1, in the spatial floating image display device 1000, which comprises a display device 1, a polarization separation member 101, and a retroreflector 2, the spatial floating image 3, which is an optical image of the image displayed on the display device 1, is formed at a position that is mirror-image to the image displayed on the display device 1 with respect to the polarization separation member 101. Furthermore, the spatial floating image 3 is an image with high directivity and can be clearly seen when viewed from a specific direction.

[0262] Therefore, as shown in FIG. 36A, when the spatial floating image display device 1000 is disposed at the center in the x1 direction of the glove box 310, for example, between a pair of glove mounting holes 312, the user 230 who is an operator will visually recognize the spatial floating image 3 from the front in the y1' direction (a direction orthogonal to the x1 direction) (see FIG. 34). Therefore, as shown in FIG. 37A, the user 230 can visually recognize the entire spatial floating image 3 well.

[0263] On the other hand, as shown in FIG. 36B, when the spatial floating image display device 1000 is disposed on one side in the x1 direction of the glove box 310, for example, on the left side of a pair of glove mounting holes 312, the user 230 who is an operator will visually recognize the spatial floating image 3 in a direction obliquely intersecting the y1' direction. For this reason, there is a possibility that the user 230 cannot visually recognize the entire spatial floating image 3 well. For example, as shown in FIG. 37B, it is likely to be a situation where only a part of the image displayed on the display device 1 can be visually recognized as the spatial floating image 3 by the user 230. In other words, it is likely to be a situation where the spatial floating image 3 appears to be partially missing from the user 230. In the example of FIG. 36B, since the spatial floating image display device 1000 is disposed on the left side of the glove box 310, it is likely to be a situation where a part on the left side of the image of the display device 1 appears to be missing. In other words, it is likely to be a situation where only a part on the right side of the image of the display device 1 is displayed as the spatial floating image 3.

[0264] Therefore, when the floating image display device 1000 is positioned on one side of the glove box 310 in the x1 direction, it is preferable to offset the position of the display device 1 in the x1 direction toward the center of the glove box 310 compared to the position of the retroreflector 2, as shown in Figure 38. In other words, when the retroreflector (retroreflective member) 2 is positioned at a location shifted in the left-right direction from the perspective of the user 230, with respect to a reference line CL passing through the midpoint C1 between a pair of glove mounting holes 312 (between a pair of gloves 320), it is preferable to position the display device 1 at a location offset by a predetermined amount toward the reference line CL from the position of the retroreflector 2 in the x1 direction. Furthermore, it is also preferable to appropriately offset the position of the polarization separation member 101 according to the positional relationship between the display device 1 and the retroreflector 2.

[0265] As a result, the floating image 3 is formed at a position offset from the position of the retroreflector 2 towards the center of the glove box 310 (towards the reference line CL). Therefore, even if the floating image display device 1000 is located on one side of the glove box 310 in the x1 direction, the user 230 can clearly see the entire floating image 3 (see Figure 37A). In this case, it is preferable to appropriately offset the position of the airborne operation detection sensor 1351 to match the position of the floating image 3.

[0266] <Example 5> Example 5 is an example in which a floating image display device displays operation buttons (display content) operated by the user as floating images, and is characterized by the method of detecting the operation of the operation buttons by the user. The configuration of the floating image display device in Example 5 is the same as that of the floating image display device in Example 4, so the explanation is omitted (see Figure 34, etc.).

[0267] As explained in Example 4, for user 230 to operate the floating image 3 with fingers 231 wearing gloves 320, the floating image 3 must be displayed within the workspace A1. If the floating image 3 is displayed within the workspace A1, user 230 can operate the floating image 3. When user 230 operates the floating image 3, the fingers 231 wearing gloves 320 can be moved smoothly in directions intersecting the length of the gloves 320 (for example, left / right or up / down from the user 230's perspective). However, because the gloves 320 are attached to the glove box 310, it is difficult to smoothly move the fingers 231 wearing gloves 320 in the length direction of the gloves 320 (for example, front / back from the user 230's perspective). In particular, when the floating image 3 is displayed near the surface of the bottom plate 316 of the glove box 310, or when the floating image 3 is displayed relatively far inside the work space A1, it becomes difficult to smoothly move the fingers 231 wearing the glove 320 along the length of the glove 320. As a result, the user 230 may not be able to properly operate the floating image 3. For example, if multiple operation buttons are displayed as the floating image 3, and the user 230 operates these multiple operation buttons, there is a risk that the user 230 may operate an operation button other than the one intended.

[0268] Therefore, in the floating image display device 1000 according to Embodiment 5, a plurality of operation buttons displayed as floating images 3 are arranged in a row, as described below. Furthermore, in a portion of the floating images 3 in a direction perpendicular to the direction in which the operation buttons are arranged, user 230 operations are detected only in the vertical direction. This makes it possible to suppress erroneous operation of the operation buttons by the user 230.

[0269] Figure 39 shows an example of a floating image displayed by the floating image display device according to Embodiment 5. As shown in Figure 39, the floating image display device 1000 according to Embodiment 5 displays multiple keypad images 31 as floating images 3 for inputting numerical values ​​from "0" to "9" as an example of operation buttons. These multiple keypad images 31 are arranged in the height direction of the floating image 3, in this example, along the z1' direction (see Figure 34).

[0270] Furthermore, the floating video display device 1000 according to Embodiment 5 includes an aerial operation detection sensor 1351, as described in the above embodiment. The operation of each keypad image 31 by the user 230 is detected based on the sensing signal from this aerial operation detection sensor 1351.

[0271] In the above-described embodiment, the aerial operation detection sensor 1351 sensed an area that overlapped with the entire display range of the floating spatial image 3. The aerial operation detection sensor 1351 in the above-described embodiment sensed the operation of the floating spatial image 3 by the user 230 in two directions: left-right (x1 direction) and height (z1' direction) within the display range of the floating spatial image 3. The aerial operation detection sensor 1351 in the above-described embodiment was, for example, provided across the display range of the floating spatial image 3 in the left-right direction, and detected the operation position of the floating spatial image 3 in the height direction by the user 230 at multiple locations within the display range.

[0272] In contrast, in Example 5, the operation position of the user 230 in the height direction of the floating spatial image 3 is detected by an aerial operation detection sensor 1351 that is provided only in an area that overlaps with a part of the display range of the floating spatial image 3 in the left-right direction. As shown in Figure 40 as an example, the aerial operation detection sensor 1351 according to Example 5 is provided only in a detection range 3Ra, which is a part of the center of the display range 3R of the floating spatial image 3 in the left-right direction. As shown by the arrow in Figure 40, the aerial operation detection sensor 1351 according to Example 5 detects the operation position of the user 230 in the height direction of the floating spatial image 3 only within the detection range 3Ra. For this reason, it can be said that the multiple keypad images 31, which are the floating spatial image 3, are arranged in a line along the detection direction (identification direction) of the aerial operation detection sensor 1351.

[0273] The detection range 3Ra in which the aerial operation detection sensor 1351 is positioned can be set arbitrarily, but it is preferable that it be narrow enough to appropriately detect the operation of the floating spatial image 3. Furthermore, the position of the detection range 3Ra is not limited to the center of the display range 3R of the floating spatial image 3 in the left-right direction, but can be anywhere within the display range 3R of the floating spatial image 3.

[0274] As described above, in the floating image display device 1000 according to Embodiment 5, multiple keypad images 31 displayed as floating image 3 are arranged in a row, and the user 230's operation position in the height direction of the floating image 3 is detected only in a detection range 3Ra that is part of the display range 3R of the floating image 3. As a result, the user 230 can appropriately operate the desired keypad image 31 with their fingers 231 without having to pull their arm back while wearing the glove 320. In other words, the operation of the desired keypad image 31 by the user 230's fingers 231 is appropriately sensed by the air operation detection sensor 1351.

[0275] Referring to Figure 41, an example of a procedure in which user 230 moves their fingers 231 from an arbitrary area, the first area Re1, to operate the keypad images 31 for the numbers "3" and "7" will be described. In this example, the first area Re1 is assumed to be the area to the right outside the display range 3R of the floating video 3. First, in the area to the right outside the display range 3R, the fingers 231 wearing the glove 320 are moved from the first area Re1 to the second area Re2. That is, the fingers 231 wearing the glove 320 are moved upward in the figure to a height corresponding to the keypad image 31 for the number "3". At this time, since the fingers 231 are moved outside the detection range 3Ra, the operation of the floating video 3 by the fingers 231 will not be detected by the floating video 3 by the air operation detection sensor 1351.

[0276] Next, the fingers 231 are moved from the second region Re2, across the keypad image 31 with the number "3", to the third region Re3, which is the left outer region of the display range 3R, in a leftward direction in the diagram. In other words, while maintaining the height of the keypad image 31 with the number "3", the fingers 231 are moved from the right outer edge to the left outer edge of the display range 3R, in a leftward direction in the diagram. At this time, when the fingers 231 cross the detection range 3Ra, the operation of the floating aerial image 3 is detected by the aerial operation detection sensor 1351. That is, the operation of the keypad image 31 with the number "3" is detected by the aerial operation detection sensor 1351.

[0277] Next, in the area outside the left edge of the display range 3R, move the fingers 231 from the third area Re3 to the fourth area Re4. In other words, move the fingers 231 downwards in the figure to the height corresponding to the keypad image 31 with the number "7". At this time as well, since the fingers 231 are moved outside the detection range 3Ra, the operation of the floating aerial image 3 will not be detected by the aerial operation detection sensor 1351.

[0278] Next, the fingers 231 are moved to the right in the diagram, passing over the keypad image 31 with the number "7" from the fourth region Re4 to the fifth region Re5, which is the right outer region of the display range 3R. In other words, while maintaining the height of the keypad image 31 with the number "7", the fingers 231 are moved to the left in the diagram, from the right outer region to the left outer region of the display range 3R. At this time, the operation of the floating aerial image 3 is detected by the aerial operation detection sensor 1351 when the fingers 231 cross the detection range 3Ra. That is, the operation of the keypad image 31 with the number "7" is detected by the aerial operation detection sensor 1351.

[0279] As described above, with the floating image display device 1000 according to Embodiment 5, the user 230 can appropriately operate multiple keypad images 31 by only moving their fingers 231 in the left-right and height directions (up and down directions). Therefore, the user 230 can appropriately operate the desired keypad image 31 with their fingers 231 without having to pull their arm back or perform other actions while wearing the glove 320.

[0280] In the example described above, the vertical movement of the fingers 231 was explained as occurring outside the left and right sides of the display range 3R. However, the vertical movement of the fingers 231 can occur outside the detection range 3Ra, or it can occur inside the display range 3R.

[0281] Furthermore, the above example described a case where multiple keypad images 31 are operated by moving the fingers 231 in two directions: up and down (vertical direction) and left and right (horizontal direction). However, the direction of movement of the fingers 231 is not necessarily limited to these two directions. In the above example, the keypad image 31 for the number "7" was operated by moving the fingers 231 in the order of the third region Re3, the fourth region Re4, and the fifth region Re5. However, the order of movement of the fingers 231 is not limited to this. For example, the fingers 231 may be moved diagonally from the third region Re3 to the sixth region Re6 so as to pass over the keypad image 31 for the number "7" within the detection range 3Ra. Even in this case, the operation of the keypad image 31 for the number "7" is detected by the air operation detection sensor 1351 at the moment the fingers 231 cross the detection range 3Ra.

[0282] Furthermore, in the example described above, the operation of the keypad image 31 is detected by the air operation detection sensor 1351 when the user 230's fingers 231 pass through the detection range 3Ra. That is, when the air operation detection sensor 1351 detects that the fingers 231 have passed through the detection range 3Ra, it is determined that the user 230 has operated the keypad image 31. However, the method for determining whether or not the user 230 has operated the keypad image 31 is not limited to this. For example, it may be determined that the user 230 has operated the keypad image 31 if the user 230's fingers 231 remain on one of the keypad images 31 within the detection range 3Ra for a preset time or longer. This allows for more accurate detection of the user 230's operation of the keypad image 31. Also, when making such a determination, even if multiple keypad images 31 are arranged in multiple columns and multiple rows as the floating spatial image 3, the operation of each keypad image 31 can be appropriately detected.

[0283] Furthermore, although this embodiment describes a case where multiple keypad images 31 are arranged in a line in the height direction (z1' direction) of the floating spatial image 3, the arrangement of the keypad images 31 is not limited to this. Multiple keypad images 31 may be arranged in a line in the left-right direction (x direction) of the floating spatial image 3, for example, as shown in Figure 42A. However, in this case, the aerial operation detection sensor 1351 needs to be provided not only in a part of the display range 3R in the x direction, but also over the entire display range 3R. Even when multiple keypad images 31 are arranged in this way, the operation of each keypad image 31 by the user 230 is appropriately detected by the aerial operation detection sensor 1351 by moving the fingers 231 along the left-right direction (x1 direction) and the height direction (z1' direction).

[0284] In the technology according to this embodiment, high-resolution and high-brightness video information is displayed in a state of floating in space, enabling users to operate the system without feeling anxious about contact transmission of infectious diseases. By using the technology according to this embodiment in a system used by an unspecified number of users, it becomes possible to reduce the risk of contact transmission of infectious diseases and provide a contactless user interface that can be used without anxiety. This contributes to the United Nations' Sustainable Development Goal (SDG) 3, "Good Health and Well-being."

[0285] Furthermore, the technology according to this embodiment reduces the divergence angle of the emitted image light and aligns it to a specific polarization, thereby efficiently reflecting only the normally reflected light off the retroreflector. This results in high light utilization efficiency and enables the acquisition of bright, clear floating images in space. According to the technology according to this embodiment, it is possible to provide a highly usable non-contact user interface that can significantly reduce power consumption. This contributes to the United Nations' Sustainable Development Goals (SDGs) "9. Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation" and "11. Make cities and human settlements inclusive, safe, and resilient and sustainable."

[0286] Although various embodiments have been described in detail above, the present invention is not limited to the embodiments described above, but includes various modifications. For example, the embodiments described above are detailed explanations of the entire system in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations. [Explanation of Symbols]

[0287] 1...Display device, 2...Retroreflective plate (retroreflective plate), 3...Spatial image (floating image in space), 105...Wind glass, 100...Transparent material, 101...Polarization separation material, 101B...Polarization separation material, 12...Absorbing polarizer, 13...Light source device, 54...Optical direction conversion panel, 102, 202...LED substrate, 203...Light guide, 205, 271...Reflective sheet, 206, 270...Phase difference plate, 230...User, 1000...Floating image display device, 1110...Control unit, 1160...Image control unit, 1180...Imaging unit, 1102...Image display unit, 1350...Air operation detection unit, 1351...Air operation detection sensor.

Claims

1. An optical image display device that generates an optical image for a worker performing manual work, A display device that displays the video processed by the video processing unit, An optical member that generates the optical image based on the image light emitted from the display device, Equipped with, The display device and the optical member are located outside the workspace where the manual work is performed. The optical image is generated so as to overlap with the workspace as seen from the worker. Optical image display device.

2. In the optical image display device according to claim 1, The optical component includes a retroreflective member that retroreflects the image light emitted from the display device, As the optical image, a real image of a floating object in space is generated. Optical image display device.

3. In the optical image display device according to claim 2, The aforementioned floating image is generated within the workspace. Optical image display device.

4. In the optical image display device according to claim 2, The display device and the optical member are positioned above the workspace. Optical image display device.

5. In the optical image display device according to claim 4, The optical component includes a polarization separation member, The polarization separation member is positioned diagonally to the direction of propagation of the image light on the lower side of the display device. The retroreflective member is positioned on the opposite side of the working space from the polarization separation member. Optical image display device.

6. In the optical image display device according to claim 4, The retroreflective member retroreflects the image light emitted from the display device and generates the floating image in space at a position that is mirror-image symmetrical to the retroreflective member, and is positioned diagonally to the direction of propagation of the image light on the lower side of the display device. Optical image display device.

7. In the optical image display device according to claim 1, The display device and the optical member are arranged such that the optical image is generated facing upward with respect to the horizontal direction. Optical image display device.

8. In the optical image display device according to claim 2, The display device and the optical member are positioned further back than the workspace as seen from the worker. Optical image display device.

9. In the optical image display device according to claim 1, The manual work performed by the aforementioned worker was carried out inside the glove box. The aforementioned workspace is the area that the worker can reach with their hands while wearing gloves attached to the glove box. Optical image display device.

10. In the optical image display device according to claim 9, The display device is located on the outside of the glove box. Optical image display device.

11. In the optical image display device according to claim 9, The optical component includes an image light reflecting part provided on the side of the glove box opposite to the worker and reflecting image light emitted from the display device, As the optical image, a virtual image is generated on the outside of the glove box by the image light projected onto the image light reflecting section. Optical image display device.

12. In the optical image display device according to claim 11, The display device is provided on the bottom side of the glove box. Optical image display device.

13. In the optical image display device according to claim 11, The image light reflecting portion is configured to include an optical film having the property of reflecting image light of a specific polarization emitted from the display device. Optical image display device.

14. In the optical image display device according to claim 11, The display device is positioned at a location offset to the left or right with respect to a reference line passing through the midpoint between the pair of gloves, as viewed from the worker. The image light reflecting section is positioned at a location offset by a predetermined amount from the position of the display device toward the reference line. Optical image display device.

15. In the optical image display device according to claim 14, Within the aforementioned glove box, there are multiple workspaces where multiple workers perform manual tasks. The aforementioned image light reflecting section is positioned such that, from the perspective of each worker, the optical image does not overlap with the workspace corresponding to other workers. Optical image display device.

16. In the optical image display device according to claim 9, The optical element includes a retroreflective member that reflects the image light emitted from the display device, As the optical image, a real image of a floating object in space is generated, The retroreflective member is positioned at a location offset in the left-right direction from the perspective of the worker with respect to a reference line passing through the midpoint between the pair of gloves. The display device is positioned at a location offset by a predetermined amount from the position of the retroreflective member toward the reference line. Optical image display device.

17. In the optical image display device according to claim 9, The optical element comprises a retroreflective member that retroreflects the video light emitted from the display device, and the optical image generates a floating image in space which is a real image, and the floating image in space includes a plurality of display contents operated by the operator. The system includes a detection sensor that detects the operation of the multiple display contents by the operator, and the multiple display contents are arranged in a line along the detection direction of the detection sensor. Optical image display device.

Images