Airborne display device

Abstract

To provide an aerial display device capable of improving display quality.SOLUTION: An aerial display device comprises a display element 20, an optical element 40 and a switching element 50. The display element 20 displays an image. The optical element 40 is configured to receive light from the display element 20 and includes a plurality of first areas and a plurality of second areas which are alternately arranged. The plurality of first areas is configured to reflect the light from the display element 20 in a direction opposite the display element 20 to form an aerial image in the air. The plurality of second areas transmits the light from the display element 20. The switching element 50 is arranged to receive light from the optical element 40, and to shade the plurality of second areas in a first display mode and shade the plurality of first areas in a second display mode.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an aerial display device. [Background technology]

[0002] Aerial display devices capable of displaying images and videos as aerial images are being researched and are expected to be a new human-machine interface. For example, an aerial display device may include a two-sided corner reflector array in which two-sided corner reflectors are arranged in an array, reflecting light emitted from the display surface of a display element and forming a real image in the air. The display method using a two-sided corner reflector array is aberration-free and can display a real image (aerial image) in a plane-symmetrical position.

[0003] Patent Document 1 discloses an optical element in which a transparent rectangular prism protruding from the surface of a transparent flat plate is used as a two-sided corner reflector, and multiple rectangular prisms are arranged in an array on a plane. Patent Document 2 discloses an optical element in which each of the first and second light control panels is formed by arranging multiple planar light reflecting parts perpendicularly inside a transparent flat plate, and the first and second light control panels are arranged so that their planar light reflecting parts are orthogonal to each other. The optical elements of Patent Documents 1 and 2 generate an aerial image by reflecting light emitted from a display element twice on orthogonal reflective surfaces.

[0004] The display devices using optical elements described in Patent Documents 1 and 2 can recognize an aerial image by observing the optical element from an oblique direction, but it is difficult to recognize a good aerial image by observing it from the direction normal to the optical element. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2011-191404 [Patent Document 2] Japanese Patent Publication No. 2011-175297 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The present invention provides an aerial display device capable of improving display quality. [Means for solving the problem]

[0007] According to a first aspect of the present invention, an aerial display device is provided, comprising: a display element for displaying an image; a plurality of alternately arranged first regions and a plurality of second regions positioned to receive light from the display element, wherein the plurality of first regions are configured to reflect light from the display element to the opposite side of the display element and form an aerial image in the air; and the plurality of second regions each comprises an optical element that transmits light from the display element, and a switching element positioned to receive light from the optical element, which in a first display mode blocks light from the plurality of second regions and in a second display mode blocks light from the plurality of first regions.

[0008] According to a second aspect of the present invention, an aerial display device according to the first aspect is provided, the optical element includes a planar substrate and a plurality of optical elements provided below the substrate, each extending in a first direction and arranged in a second direction perpendicular to the first direction, each provided in a plurality of first regions, each of the plurality of optical elements being inclined with respect to the normal direction of the substrate and having an incident surface and a reflective surface in contact with each other, and each of the plurality of second regions of the optical element being composed of a plurality of planes.

[0009] According to a third aspect of the present invention, an aerial display device according to a second aspect is provided, wherein the switching element has a plurality of first element pixels and a plurality of second element pixels extending in a first direction and arranged alternately in a second direction, each of the plurality of first element pixels is provided in the plurality of first regions, each of the plurality of second element pixels is provided in the plurality of second regions, and each of the plurality of first element pixels and the plurality of second element pixels can be set to a transparent state and a light-shielding state.

[0010] According to a fourth aspect of the present invention, an aerial display device according to the third aspect is provided, wherein each of the plurality of first element pixels and the plurality of second element pixels has a plurality of pixels arranged in the first direction, and the plurality of pixels can be set to a transparent state and a light-shielding state.

[0011] According to a fifth aspect of the present invention, an aerial display device according to the second aspect is provided, wherein the optical element includes a reflective layer provided on the reflective surface that reflects light, and an absorbing layer provided on the reflective layer that absorbs light.

[0012] According to a sixth aspect of the present invention, an aerial display device according to the first aspect is provided, further comprising an orientation control element disposed between the display element and the optical element, which transmits the oblique light component of the light from the display element.

[0013] According to a seventh aspect of the present invention, an aerial display device according to the sixth aspect is provided, wherein the orientation control element includes a plurality of alternately arranged transparent members and a plurality of light-shielding members, and the plurality of light-shielding members are inclined with respect to the normal of the orientation control element.

[0014] According to an eighth aspect of the present invention, an aerial display device according to the sixth aspect is provided, further comprising a light-diffusing element disposed between the orientation control element and the optical element, wherein the light-diffusing element is set to a light-transmitting state in the first display mode and to a light-diffusing state in the second display mode.

[0015] According to a ninth aspect of the present invention, an aerial display device according to the first aspect is provided, wherein the display element, the optical element, and the switching element are arranged parallel to each other.

[0016] According to a tenth aspect of the present invention, an aerial display device according to the first aspect is provided, further comprising an illumination element that emits light, wherein the display element is arranged to receive light from the illumination element and is composed of a liquid crystal display element. [Effects of the Invention]

[0017] According to the present invention, an aerial display device capable of improving display quality can be provided.

Brief Description of the Drawings

[0018] [Figure 1] FIG. 1 is a perspective view of an aerial display device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a side view of the aerial display device shown in FIG. 1. [Figure 3A] FIG. 3A is a plan view of the orientation control element shown in FIG. 1. [Figure 3B] FIG. 3B is a cross-sectional view of the orientation control element taken along the line A-A' of FIG. 3A. [Figure 4] FIG. 4 is a partial side view of the optical element shown in FIG. 1. [Figure 5] FIG. 5 is a partial plan view of the switching element shown in FIG. 1. [Figure 6] FIG. 6 is a block diagram of the aerial display device. [Figure 7] FIG. 7 is a perspective view for explaining the state of light reflection in the optical element. [Figure 8] FIG. 8 is a side view of the XZ plane for explaining the state of light reflection in the optical element. [Figure 9] FIG. 9 is a side view of the YZ plane for explaining the state of light reflection in the optical element. [Figure 10] FIG. 10 is a diagram for explaining the angular conditions of the incident surface and the reflection surface in the optical element. [Figure 11] FIG. 11 is a partial side view of the aerial display device for explaining the first display mode. [Figure 12] FIG. 12 is a partial side view of the aerial display device for explaining the second display mode. [Figure 13] FIG. 13 is a flowchart for explaining the display operation of the aerial display device. ​​​​Figure 15 is a perspective view of an aerial display device according to a third embodiment of the present invention. [Figure 16] Figure 16 is a perspective view of an aerial display device according to a fourth embodiment of the present invention. [Figure 17] Figure 17 is a partial cross-sectional view of the optical element shown in Figure 16, along the X direction. [Figure 18] Figure 18 is a side view illustrating the operation of the aerial display device. [Figure 19] Figure 19 is a partial side view illustrating the operation of an optical element. [Figure 20] Figure 20 is a perspective view of an aerial display device according to a fifth embodiment of the present invention. [Figure 21] Figure 21 is a side view of the aerial display device shown in Figure 20. [Figure 22] Figure 22 is a perspective view of the optical element shown in Figure 1. [Figure 23] Figure 23 is a block diagram of the aerial display device. [Figure 24] Figure 24 is a perspective view illustrating the reflection of light in an optical element. [Figure 25] Figure 25 is a side view of the XZ plane illustrating the reflection of light in an optical element. [Figure 26] Figure 26 is a perspective view of an aerial display device illustrating the first display mode. [Figure 27] Figure 27 is a perspective view of an aerial display device illustrating the second display mode. [Figure 28] Figure 28 is a flowchart illustrating the display operation of the aerial display device. [Figure 29] Figure 29 is a diagram illustrating the operation of an aerial display device according to the sixth embodiment of the present invention. [Modes for carrying out the invention]

[0019] The embodiments will be described below with reference to the drawings. However, the drawings are schematic or conceptual, and the dimensions and proportions in each drawing are not necessarily the same as those in reality. Furthermore, even when the same part is represented between drawings, the relationship between dimensions and proportions may be represented differently. In particular, the embodiments shown below are illustrative examples of devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention is not determined by the shape, structure, arrangement, etc. of the components. In the following description, elements having the same function and configuration are denoted by the same reference numerals, and redundant descriptions are omitted.

[0020] [1] First Embodiment [1-1] Configuration of the aerial display device 1 Figure 1 is a perspective view of an aerial display device 1 according to the first embodiment of the present invention. In Figure 1, the X direction is the direction along one side of the aerial display device 1, the Y direction is the direction perpendicular to the X direction in the horizontal plane, and the Z direction is the direction perpendicular to the XY plane (also called the normal direction). Figure 2 is a side view of the aerial display device 1 shown in Figure 1.

[0021] The aerial display device 1 is a device that displays images (including videos). The aerial display device 1 displays an aerial image in the air above its own light-emitting surface. The light-emitting surface of the aerial display device 1 refers to the upper surface of the uppermost component among the multiple components that make up the aerial display device 1. An aerial image is a real image formed in the air.

[0022] The aerial display device 1 comprises an illumination element (also called a backlight) 10, a display element 20, an orientation control element 30, an optical element 40, and a switching element 50. The illumination element 10, the display element 20, the orientation control element 30, the optical element 40, and the switching element 50 are arranged in this order along the Z direction and are arranged parallel to each other. The illumination element 10, the display element 20, the orientation control element 30, the optical element 40, and the switching element 50 are fixed in desired positions by fixing members (not shown) with a desired distance between them.

[0023] The illumination element 10 emits illumination light and directs this illumination light toward the display element 20. The illumination element 10 comprises a light source unit 11, a light guide plate 12, and a reflective sheet 13. The illumination element 10 is, for example, a side-light type illumination element. The illumination element 10 constitutes a surface light source. The illumination element 10 may be configured so that the light intensity peaks in an oblique direction at an angle θ1, as described later.

[0024] The light source unit 11 is positioned to face the side of the light guide plate 12. The light source unit 11 emits light toward the side of the light guide plate 12. The light source unit 11 includes a plurality of light-emitting elements, such as white LEDs (Light Emitting Diodes). The light guide plate 12 guides the illumination light from the light source unit 11 and emits the illumination light from its upper surface. The reflective sheet 13 reflects the illumination light emitted from the bottom surface of the light guide plate 12 back toward the light guide plate 12. The illumination element 10 may have members (including a prism sheet and a diffusion sheet) on the upper surface of the light guide plate 12 to improve optical properties.

[0025] The display element 20 is a transmissive display element. The display element 20 is composed of, for example, a liquid crystal display element. The driving mode of the display element 20 is not particularly limited, and TN (Twisted Nematic) mode, VA (Vertical Alignment) mode, or homogeneous mode can be used. The display element 20 receives illumination light emitted from the illumination element 10. The display element 20 transmits the illumination light from the illumination element 10 and performs light modulation. Then, the display element 20 displays a desired image on its screen.

[0026] The orientation control element 30 has the function of reducing unwanted light. Unwanted light is light components that do not contribute to the generation of an aerial image and includes light components that are transmitted through the optical element 40 in the normal direction. The orientation control element 30 is configured to transmit light components within a predetermined angular range centered on an oblique direction at an angle θ1 with respect to the normal direction, while blocking light components outside of the above angular range. The area of ​​the orientation control element 30 is set to be approximately the same as the area of ​​the display element 20. The detailed configuration of the orientation control element 30 will be described later.

[0027] The optical element 40 reflects light incident from the bottom side to the top side. It also reflects incident light obliquely incident from the bottom side, for example, in the front direction (normal direction). The area of ​​the optical element 40 is set to be greater than or equal to the area of ​​the display element 20. The detailed configuration of the optical element 40 will be described later. The optical element 40 forms an aerial image 2 in the air. The aerial image 2 is parallel to the element plane of the optical element 40 and is a two-dimensional image. The element plane refers to a virtual plane that extends in the in-plane direction of the optical element 40. The element plane has the same meaning as "in-plane". The same meaning applies to the element planes of other elements. An observer 3 standing in front of the optical element 40 can see the aerial image 2.

[0028] The switching element 50 has the function of switching between a first display mode, which displays an aerial image in the air above the aerial display device 1, and a second display mode, which displays an image displayed on the screen of the display element 20. The switching element 50 has multiple element pixels, each extending in the Y direction and arranged in the X direction. Each of the multiple element pixels of the switching element 50 can be set to a transparent state, which transmits light, or a light-blocking state, which blocks light. In this embodiment, the depth position of the display image visible to the observer 3 can be switched by switching the display mode using the switching element 50. The area of ​​the switching element 50 is set to be approximately the same as the area of ​​the optical element 40. The detailed configuration of the switching element 50 will be described later.

[0029] [1-1-1] Configuration of the orientation control element 30 Figure 3A is a plan view of the orientation control element 30 shown in Figure 1. Figure 3B is a cross-sectional view of the orientation control element 30 along line AA' in Figure 3A.

[0030] The substrate 31 is planar in the XY plane and has a rectangular parallelepiped. The substrate 31 transmits light.

[0031] Multiple transparent members 33 are provided on the base material 31, each extending in the Y direction and aligned in the X direction. Additionally, multiple light-shielding members 34 are provided on the base material 31, each extending in the Y direction and aligned in the X direction. The multiple transparent members 33 and the multiple light-shielding members 34 are arranged alternately so that adjacent members are in contact with each other.

[0032] Multiple transparent members 33 and multiple light-shielding members 34 are provided on a base material 32. The base material 32 is planar in the XY plane and has a rectangular parallelepiped shape. The base material 32 transmits light.

[0033] The transparent member 33 extends in an oblique direction at an angle θ1 with respect to the normal direction of the base material 31 in the XZ plane. The transparent member 33 is a parallelogram with its side surface inclined at an angle θ1 in the XZ plane. The transparent member 33 transmits light.

[0034] The light-shielding member 34 extends in an oblique direction at an angle θ1 with respect to the normal direction of the base material 31 in the XZ plane. The light-shielding member 34 is a parallelogram with its side surface inclined by an angle θ1 in the XZ plane. The light-shielding member 34 blocks light. The thickness of the light-shielding member 34 is set to be thinner than the thickness of the transparent member 33.

[0035] The two adjacent light-shielding members 34 are arranged so that their ends slightly overlap in the Z direction.

[0036] The base materials 31, 32, and transparent member 33 are made of glass or a transparent resin (including acrylic resin). The light-shielding member 34 is made of, for example, a resin mixed with a black dye or pigment.

[0037] The orientation control element 30 may be constructed by omitting one or both of the base materials 31 and 32. The function of the orientation control element 30 can be realized if multiple transparent members 33 and multiple light-shielding members 34 are arranged alternately.

[0038] The orientation control element 30 configured in this way can transmit display light such that the light intensity in the oblique direction at an angle θ1 with respect to the normal direction is at its peak. For example, the orientation control element 30 is configured to block light components outside the range of 30°±30° with respect to the normal direction. Preferably, the orientation control element 30 is configured to block light components outside the range of 30°±20° with respect to the normal direction.

[0039] As a modified example, the orientation control element 30 may be placed between the illumination element 10 and the display element 20. Alternatively, the aerial display device 1 may be configured without the orientation control element 30.

[0040] [1-1-2] Configuration of the optical element 40 Figure 4 is a partial side view of the optical element 40 shown in Figure 1.

[0041] The optical element 40 comprises a substrate 41 and a plurality of optical elements 42. The substrate 41 is planar in the XY plane and has a rectangular parallelepiped.

[0042] Multiple optical elements 42 are provided on the bottom surface of the base material 41. Each of the multiple optical elements 42 is composed of a triangular prism. The optical elements 42 are arranged so that three sides of the triangular prism are parallel to the XY plane, and one side is in contact with the base material 41. Each of the multiple optical elements 42 extends in the Y direction and is arranged in a line in the X direction. In addition, adjacent optical elements 42 are arranged with a certain distance between them.

[0043] The region where the optical element 42 is placed is called the first region Sa, and the region where the optical element 42 is not placed is called the second region Sb. Multiple first regions Sa and multiple second regions Sb are arranged alternately. For example, the length of the first region Sa in the X direction is the same as the length of the second region Sb in the X direction. The configuration is not limited to this, and the length of the first region Sa in the X direction may be different from the length of the second region Sb in the X direction.

[0044] Each of the multiple optical elements 42 has an incident surface 43 and a reflecting surface 44. When viewed from the Y direction, the left side is the incident surface 43 and the right side is the reflecting surface 44. The incident surface 43 is the surface to which light from the display element 20 is incident. The reflecting surface 44 is the surface that reflects light incident on the incident surface 43 from the outside within the optical element 42.

[0045] The second region Sb of the optical element 40 corresponds to the space between adjacent optical elements 42. The bottom surface of the optical element 40 in the second region Sb is composed of a plane 45. The plane 45 is a plane horizontal to the XY plane.

[0046] The base material 41 and the optical element 42 are made of a transparent material. The optical element 42 is formed integrally with the base material 41, for example, using the same transparent material as the base material 41. Alternatively, the base material 41 and the optical element 42 may be formed separately, and the optical element 42 may be bonded to the base material 41 using a transparent adhesive. As the transparent material constituting the base material 41 and the optical element 42, glass or a transparent resin (including acrylic resin) can be used.

[0047] The first region Sa of the optical element 40 reflects light incident from below the optical element 40 internally, forming a real image in the air. The first region Sa of the optical element 40 also forms an aerial image at a position directly in front of the element surface.

[0048] The second region Sb of the optical element 40 transmits light incident from below the optical element 40 without reflection. In the second region Sb of the optical element 40, the planar image displayed on the screen of the display element 20 is directly visible to the observer without forming an aerial image. The planar image refers to the image displayed on the screen of the display element 20.

[0049] [1-1-3] Configuration of the switching element 50 Figure 5 is a partial plan view of the switching element 50 shown in Figure 1. Figure 5 also shows a partial side view of the optical element 40 so that the correspondence between the optical element 40 and the switching element 50 can be understood. Note that Figure 4, mentioned above, also shows a side view of the switching element 50. In the configuration example in Figure 4, the switching element 50 is in contact with the upper surface of the optical element 40.

[0050] The switching element 50 comprises multiple element pixels 51a and 51b, each extending in the Y direction and aligned in the X direction. The multiple element pixels 51a and multiple element pixels 51b are arranged alternately. Each of the multiple element pixels 51a and 51b is composed of, for example, multiple pixels.

[0051] Multiple element pixels 51a are each positioned above multiple first regions Sa of the optical element 40. The length of element pixels 51a in the X direction and the length in the Y direction are the same as the length of the first region Sa in the X direction and the Y direction, respectively. Multiple element pixels 51b are each positioned above multiple second regions Sb of the optical element 40. The length of element pixels 51b in the X direction and the Y direction are the same as the length of the second region Sb in the X direction and the Y direction, respectively.

[0052] The switching element 50 can be set for each of the multiple element pixels 51a and 51b to either a light-transmitting state or a light-blocking state.

[0053] The switching element 50 can be made of liquid crystal elements. The liquid crystal elements are equipped with polarizing plates, and each pixel can be set to either a light-transmitting state or a light-blocking state.

[0054] Furthermore, the switching element 50 may be composed of an electrochromic element or a polymer dispersed liquid crystal (PDLC) element.

[0055] Another possible configuration is that the switching element 50 has multiple light-shielding plates arranged alternately in the regions of multiple element pixels. The positions of the transparent region and the light-shielding region can then be mechanically switched by simultaneously shifting the multiple light-shielding plates by the width of one element pixel.

[0056] [1-1-4] Block configuration of the aerial display device 1 Figure 6 is a block diagram of the aerial display device 1. The aerial display device 1 comprises a control unit 60, a storage unit 61, an input / output interface (input / output IF) 62, a display unit 63, and an input unit 64. The control unit 60, the storage unit 61, and the input / output interface 62 are connected to each other via a bus 65.

[0057] The input / output interface 62 is connected to the display unit 63 and the input unit 64. The input / output interface 62 performs interface processing for each of the display unit 63 and the input unit 64 according to a predetermined standard.

[0058] The display unit 63 comprises an illumination element 10, a display element 20, and a switching element 50. The display unit 63 displays an image.

[0059] The control unit 60 is composed of one or more processors, such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The control unit 60 implements various functions by executing programs stored in the storage unit 61. The control unit 60 includes a display processing unit 60A and an information processing unit 60B.

[0060] The display processing unit 60A controls the operation of the display unit 63 (specifically, the illumination element 10, the display element 20, and the switching element 50). The display processing unit 60A controls the on and off of the illumination element 10. The display processing unit 60A transmits an image signal to the display element 20 and causes the display element 20 to display an image. Depending on the display mode, the display processing unit 60A sets the element pixels 51a and 51b of the switching element 50 to either a transparent or light-shielding state.

[0061] The information processing unit 60B generates the image to be displayed by the aerial display device 1. The information processing unit 60B can use image data stored in the storage unit 61. The information processing unit 60B may also acquire image data from an external source using a communication function (not shown).

[0062] The storage unit 61 includes non-volatile storage devices such as ROM (Read Only Memory), HDD (Hard Disk Drive), and SSD (Solid State Drive), and volatile storage devices such as RAM (Random Access Memory) and registers. The storage unit 61 stores the program executed by the control unit 60. The storage unit 61 stores various data necessary for controlling the control unit 60. Furthermore, the storage unit 61 stores the image data displayed by the aerial display device 1.

[0063] The input unit 64 includes, for example, a touch panel or buttons, and receives information entered by the user. The information processing unit 60B can select an image to display on the display unit 63 based on the information received by the input unit 64.

[0064] [1-2] Operation of the aerial display device 1 Next, the operation of the aerial display device 1 configured as described above will be explained.

[0065] [1-2-1] Display operation of aerial image 2 First, let's explain the display operation of aerial image 2. The arrows in Figure 2 indicate the optical path. As shown in Figure 2, light emitted from any point "o" on the display element 20 enters the orientation control element 30. Of the light emitted from the display element 20, the optical component at angle θ1 (including the optical component within a predetermined angular range centered on angle θ1) passes through the orientation control element 30. The light that has passed through the orientation control element 30 enters the optical element 40. The optical element 40 images the incident light into the air on the opposite side of the orientation control element 30, displaying an aerial image 2 in the air.

[0066] Figure 7 is a perspective view illustrating the reflection of light in the optical element 40. Figure 8 is a side view of the XZ plane illustrating the reflection of light in the optical element 40. Figure 8 shows the optical element 40 as seen by observer 3 with both eyes (i.e., the line connecting both eyes) parallel to the X direction. Figure 9 is a side view of the YZ plane illustrating the reflection of light in the optical element 40. Figure 9 shows the optical element 40 as seen by observer 3 with both eyes parallel to the Y direction.

[0067] Light emitted from any point "o" of the display element 20 enters the incident surface 43 of the optical element 40 and reaches the reflective surface 44. Light that reaches the reflective surface 44 at an angle greater than the critical angle with respect to the normal direction of the reflective surface 44 is totally reflected by the reflective surface 44 and is emitted from the plane opposite to the side of the optical element 42 of the optical element 40. The critical angle is the smallest angle of incidence beyond which total reflection occurs. The critical angle is the angle with respect to the perpendicular to the incident surface.

[0068] In the XZ plane of Figure 8, light emitted from point "o" is totally reflected by the reflective surface 44 of the optical element 42, and the light is imaged in the air to generate an aerial image.

[0069] In the YZ plane of Figure 9, the light emitted from point "o" is not reflected by the reflective surface 44 of the optical element 42, and therefore does not form an image in the air, thus not contributing to the generation of an aerial image.

[0070] In other words, the condition under which observer 3 can perceive the aerial image is that both of observer 3's eyes are parallel to or nearly parallel to the X direction (for example, ±10 degrees relative to the X direction). Furthermore, if observer 3 moves their viewpoint along the Y direction while both of their eyes are parallel to or nearly parallel to the X direction, they can always perceive the aerial image.

[0071] Figure 10 illustrates the angular conditions of the incident surface 43 and the reflective surface 44 in the optical element 40.

[0072] The angle of the incident surface 43 with respect to the Z direction (direction perpendicular to the element surface) is θ2, the angle of the reflecting surface 44 with respect to the Z direction is θ3, and the angle between the incident surface 43 and the reflecting surface 44 is θ p Let's assume the angle is θ. p This can be expressed by the following equation (1). θ p =θ² + θ³···(1)

[0073] Light emitted from the orientation control element 30 at an angle θ1 is incident on the incident surface 43. The refractive index of the material of the optical element 40 is n p, the refractive index of air is set to 1. Let the incident angle on the incident surface 43 be θ4 and the refraction angle be θ5. Let the incident angle on the reflection surface 44 be θ6 and the reflection angle be θ7 (= θ6). Let the incident angle on the upper surface of the optical element 40 be θ8 and the refraction angle be θ9. The refraction angle θ9 is the exit angle. The exit angle θ9 is expressed by the following formula (2). θ9 = sin -1 (n p *sin(sin -1 ((1 / n p )*sin(90° - (θ1 + θ2)))+θ2 + 2θ3 - 90°)) ···(2)

[0074] The critical angle on the reflection surface 44 is expressed by the following formula (3). Critical angle < θ6(= θ7) Critical angle = sin -1 (1 / n p ) ···(3)

[0075] That is, the incident angle θ6 on the reflection surface 44 is set to be larger than the critical angle on the reflection surface 44. In other words, the angle θ3 of the reflection surface 44 is set so that the incident angle of the light incident on the reflection surface 44 is larger than the critical angle.

[0076] Also, the light incident on the incident surface 43 is set so as not to be totally reflected at the incident surface 43. That is, the angle θ2 of the incident surface 43 is set so that the incident angle of the light incident on the incident surface 43 is smaller than the critical angle.

[0077] The angle between the element surface of the optical element 40 and the surface of the virtual image 2, and the distance between the element surface of the optical element 40 and the surface of the virtual image 2 can be adjusted by optimally setting the angle θ1 of the light incident on the optical element 40, the refractive index of the optical element 40, the angle θ2 of the incident surface 43 of the optical element 40, and the angle θ3 of the reflection surface 44 of the optical element 40.

[0078] [1 - 2 - 2] Two types of display modes Next, the operation in the two display modes will be described. The aerial display device 1 is capable of executing two display modes: a first display mode that displays an aerial image 2, and a second display mode that displays a planar image of the screen of the display element 20. Switching between display modes is performed using a switching element 50.

[0079] Figure 11 is a partial side view of the aerial display device 1 for illustrating the first display mode for displaying the aerial image 2. In the first display mode, the switching element 50 sets the element pixel 51a corresponding to the first region Sa to a transparent state and the element pixel 51b corresponding to the second region Sb to a light-shielding state. In Figure 11, the element pixels in the light-shielding state are shown with diagonal hatching.

[0080] The display element 20 displays an image on its screen. Of the light incident from the display element 20 to the optical element 40 via the orientation control element 30, the light component in the first region Sa is reflected by the optical element 42 of the optical element 40 and passes through the first region Sa of the switching element 50. The light component that has passed through the first region Sa of the switching element 50 generates an aerial image 2 at the position of the display surface Ai shown in Figure 11.

[0081] Of the light incident on the optical element 40 via the orientation control element 30 from the display element 20, the light component in the second region Sb (the light component incident on the plane 45 of the optical element 40) is transmitted through the optical element 40 and blocked by the second region Sb of the switching element 50. Therefore, the light component in the second region Sb of the light incident on the optical element 40 does not contribute to the display of the aerial image 2.

[0082] Figure 12 is a partial side view of the aerial display device 1 to illustrate the second display mode, which displays a planar image of the screen of the display element 20. In the second display mode, the switching element 50 sets the element pixel 51a corresponding to the first region Sa to a light-shielding state and the element pixel 51b corresponding to the second region Sb to a transparent state. In Figure 12, the element pixels in the light-shielding state are shown with diagonal hatching.

[0083] The display element 20 displays an image on its screen. Of the light incident from the display element 20 to the optical element 40 via the orientation control element 30, the light component in the first region Sa is reflected by the optical element 42 of the optical element 40 and blocked by the first region Sa of the switching element 50. Therefore, the optical element 40 does not form an image in the air.

[0084] Of the light incident on the optical element 40 via the orientation control element 30 from the display element 20, the light component in the second region Sb (the light component incident on the plane 45 of the optical element 40) passes through the optical element 40 and through the second region Sb of the switching element 50. The light component that passes through the second region Sb of the switching element 50 is directly visible to the observer 3. Therefore, the planar image 21 is displayed at the position of the display surface Bi shown in Figure 12.

[0085] Thus, in the first display mode, the aerial display device 1 can display an aerial image 2 at the position of the display surface Ai above the aerial display device 1. In addition, in the second display mode, the aerial display device 1 can display a planar image 21 at the position of the display surface Bi corresponding to the screen of the display element 20.

[0086] Figure 13 is a flowchart illustrating the display operation of the aerial display device 1. The information processing unit 60B selects image data to be displayed by the aerial display device 1 (step S100). For example, the information processing unit 60B reads information about image data set as an initial value from the storage unit 61, and reads image data from the storage unit 61 based on this read information. The information processing unit 60B may also read image data from the storage unit 61 based on information entered by the user using the input unit 64. The information processing unit 60B may also select image data transmitted from an external source using the communication function.

[0087] Next, the display processing unit 60A determines whether or not aerial display (first display mode) is selected, that is, which of the first display mode and the second display mode is selected (step S101). For example, the display processing unit 60A reads information about the display mode set as an initial value from the storage unit 61 and determines the display mode based on this read information. The display processing unit 60A may also determine the display mode based on information entered by the user using the input unit 64.

[0088] Next, if the first display mode is selected (step S101 = Yes), the display processing unit 60A sets the element pixels 51b of the switching element 50 to a light-shielding state and the element pixels 51a of the switching element 50 to a light-transmitting state (step S102).

[0089] Next, the display processing unit 60A displays the image selected in step S100 on the display element 20 (step S103). As a result, the light components reflected by the optical element 42 of the optical element 40 are imaged in the air, and the aerial image 2 is displayed.

[0090] On the other hand, if the second display mode is selected (step S101=No), the display processing unit 60A sets the element pixel 51a of the switching element 50 to a light-shielding state and the element pixel 51b of the switching element 50 to a light-transmitting state (step S104).

[0091] Next, the display processing unit 60A displays the image selected in step S100 on the display element 20 (step S103). As a result, the light component transmitted through the second region Sb of the optical element 40 is visible to the observer 3, and the planar image 21 displayed on the screen of the display element 20 is visible to the observer 3.

[0092] [1-3] Variant As a variation, a portion of the image displayed on the display element 20 may be displayed in the first display mode, and another portion may be displayed in the second display mode.

[0093] The display processing unit 60A sets the element pixels 51b of the switching element 50 to a light-shielding state and the element pixels 51a of the switching element 50 to a transparent state in the area where the aerial image is displayed. In addition, the display processing unit 60A sets the element pixels 51a of the switching element 50 to a light-shielding state and the element pixels 51b of the switching element 50 to a transparent state in the area where the image of the display element 20 is displayed.

[0094] According to the modified version, some of the images displayed on the display element 20 can be displayed as an aerial image, while other parts of the images can be displayed on the screen of the display element 20.

[0095] [1-4] Effects of the first embodiment According to the first embodiment, the aerial display device 1 can perform two types of display modes: a first display mode and a second display mode. In the first display mode, the aerial display device 1 can display an aerial image 2 at the position of the display surface Ai above the aerial display device 1. In the second display mode, the aerial display device 1 can display a planar image 21 at the position of the display surface Bi corresponding to the screen of the display element 20. Furthermore, the aerial display device 1 can display two-dimensional images at two different positions in the depth direction.

[0096] Furthermore, the aerial display device 1 can display an aerial image in the air by reflecting light emitted from the display element 20 with the optical element 40. In addition, the aerial display device 1 can display the aerial image parallel to the element surface of the optical element 40 in the direction in front of it. Moreover, it is possible to realize an aerial display device 1 that can improve the display quality.

[0097] Furthermore, when observer 3 views the optical element 40 with both eyes parallel to or nearly parallel to the X direction (i.e., the direction in which the multiple optical elements 42 are aligned), observer 3 can perceive the aerial image. Also, when observer 3 moves their viewpoint along the Y direction with both eyes parallel to or nearly parallel to the X direction, they can always perceive the aerial image. In addition, a wider field of view can be achieved when observer 3's eyes are parallel to or nearly parallel to the X direction.

[0098] Furthermore, multiple elements constituting the aerial display device 1 can be arranged in parallel. This makes it possible to realize an aerial display device 1 that can be miniaturized in the Z direction.

[0099] [2] Second embodiment In the second embodiment, the switching element 50 is composed of multiple pixels arranged in a matrix, and each pixel is configured to switch between a transparent state and a light-shielding state.

[0100] Figure 14 is a partial plan view of the switching element 50 according to a second embodiment of the present invention. Figure 14 also shows a partial side view of the optical element 40 so that the correspondence between the optical element 40 and the switching element 50 can be understood.

[0101] The switching element 50 comprises multiple element pixels 51a and 51b, each extending in the Y direction and aligned in the X direction. The multiple element pixels 51a and multiple element pixels 51b are arranged alternately.

[0102] Each elemental pixel 51a comprises multiple pixels 52a arranged in the Y direction. Each elemental pixel 51b comprises multiple pixels 52b arranged in the Y direction. That is, the multiple pixels 52a and 52b are arranged in a matrix. Each of the multiple pixels 52a and 52b has, for example, a square shape. The switching element 50 can set each of the multiple pixels 52a and 52b to either a light-transmitting state or a light-blocking state.

[0103] The display processing unit 60A sets the pixel 52b of the switching element 50 to a light-shielding state and the pixel 52a of the switching element 50 to a transparent state in the area where the aerial image is displayed. In addition, the display processing unit 60A sets the pixel 52a of the switching element 50 to a light-shielding state and the pixel 52b of the switching element 50 to a transparent state in the area where the image of the display element 20 is displayed.

[0104] According to the second embodiment, some of the images displayed on the display element 20 can be displayed as an aerial image, while other parts of the images can be displayed on the screen of the display element 20. Furthermore, the aerial image and the planar image (the image displayed on the screen of the display element 20) can be displayed adjacent to each other in the Y direction.

[0105] [3] Third embodiment In the third embodiment, in the second display mode, the light emitted diagonally from the orientation control element 30 is diffused using the light diffusion element 70.

[0106] Figure 15 is a perspective view of an aerial display device 1 according to a third embodiment of the present invention. The aerial display device 1 further comprises a light diffusion element 70. The light diffusion element 70 is arranged between the orientation control element 30 and the optical element 40.

[0107] The light diffusion element 70 can be set to either a light-transmitting state or a light-diffusing state across its entire surface. The entire surface of the light diffusion element 70 refers to the entire light modulation region, and if there is a peripheral region where the circuit driving the light diffusion element 70 is located, this peripheral region is excluded. The area of ​​the light diffusion element 70 is set to be approximately the same as the area of ​​the alignment control element 30. The light diffusion element 70 is composed of, for example, a polymer-dispersed liquid crystal (PDLC) element.

[0108] In the first display mode, the entire surface of the light diffusion element 70 is set to a transparent state, and in the second display mode, the entire surface is set to a diffused state. In the first display mode, the display processing unit 60A sets the light diffusion element 70 to a transparent state, and in the second display mode, it sets the light diffusion element 70 to a diffused state.

[0109] According to the third embodiment, the light emitted obliquely from the orientation control element 30 can be diffused by the light diffusion element 70. This makes it possible to suppress the deterioration of the displayed image depending on the viewing angle of the aerial display device 1. Furthermore, the quality of the displayed image can be improved in the second display mode.

[0110] [4] Fourth Embodiment In the fourth embodiment, the optical element 40 further includes an absorption layer 47 that absorbs light components unnecessary for forming an aerial image. The orientation control element 30 is omitted to configure the aerial display device 1.

[0111] Figure 16 is a perspective view of an aerial display device 1 according to a fourth embodiment of the present invention. The aerial display device 1 comprises an illumination element 10, a display element 20, an optical element 40, and a switching element 50. In the fourth embodiment, the orientation control element 30 shown in the first embodiment is omitted. The illumination element 10, the display element 20, the optical element 40, and the switching element 50 are arranged in this order along the Z direction and are arranged parallel to each other. The illumination element 10, the display element 20, the optical element 40, and the switching element 50 are fixed at desired positions by fixing members (not shown) with a desired distance between them.

[0112] Figure 17 is a partial cross-sectional view of the optical element 40 shown in Figure 16, along the X direction. A reflective layer 46 is provided on the reflective surface 44 of the optical element 42. The reflective layer 46 is configured to cover the entire reflective surface 44. The reflective layer 46 has the function of reflecting light. The reflective layer 46 is made of a material with high reflectivity. For example, aluminum (Al), silver (Ag), or an alloy containing one of these can be used as the reflective layer 46.

[0113] An absorbing layer 47 is provided on the reflective layer 46. The absorbing layer 47 is configured to cover the entire reflective layer 46. The absorbing layer 47 has the function of absorbing light. The absorbing layer 47 is made of a material with a high light absorption rate. For example, a resin mixed with a black dye or pigment can be used as the absorbing layer 47.

[0114] Next, the operation of the aerial display device 1 configured as described above will be explained. Figure 18 is a side view illustrating the operation of the aerial display device 1. Figure 19 is a partial side view illustrating the operation of the optical element 40. The arrows in Figures 18 and 19 indicate the optical path.

[0115] Light is emitted radially from point "o" on the display element 20. Of the light emitted from the display element 20, the light component at angle θ1 (including the light component within a predetermined angular range centered on angle θ1) is incident on the incident surface 43 of the optical element 42. The light that is incident on the incident surface 43 and reaches the reflective surface 44 is reflected by the reflective surface 44 and the reflective layer 46. Furthermore, the presence of the reflective layer 46 ensures that the light that reaches the reflective surface 44 is reflected more reliably.

[0116] On the other hand, light that directly enters the absorption layer 47 from outside the optical element 40 is absorbed by the absorption layer 47. Specifically, of the light incident on the optical element 40, the light component on the side where the incident surface 43 is tilted with respect to the direction perpendicular to the element surface of the optical element 40 (Z direction) is absorbed by the absorption layer 47. Light that directly enters the absorption layer 47 is not reflected by the optical element 40 and is not visible to the observer 3.

[0117] In this way, the optical element 40 functions to reflect only the light necessary to generate the aerial image 2, and not to reflect any other light. In other words, the optical element 40 can block unwanted light that does not contribute to the generation of the aerial image 2.

[0118] The operation of the switching element 50 is the same as in the first embodiment.

[0119] According to the fourth embodiment, the aerial display device 1 can be configured by omitting the orientation control element 30. This makes it possible to realize an aerial display device 1 that can be miniaturized in the Z direction.

[0120] [5] Fifth embodiment The fifth embodiment displays an aerial image using the optical element 40, and by changing the orientation of the optical element 40 relative to the observer, it executes a first display mode and a second display mode.

[0121] [5-1] Configuration of the aerial display device 1 Figure 20 is a perspective view of the aerial display device 1 according to the fifth embodiment of the present invention. Figure 21 is a side view of the aerial display device 1 shown in Figure 20.

[0122] The aerial display device 1 comprises an illumination element 10, a display element 20, an orientation control element 30, an optical element 40, and a rotation mechanism 80. The illumination element 10, the display element 20, the orientation control element 30, and the optical element 40 are arranged in this order along the Z direction and are parallel to each other. The illumination element 10, the display element 20, the orientation control element 30, and the optical element 40 are fixed in desired positions by fixing members (not shown) with a desired distance between them.

[0123] The rotation mechanism 80 has the function of rotating a unit consisting of an illumination element 10, a display element 20, an orientation control element 30, and an optical element 40 by 90 degrees in the XY plane. The rotation mechanism 80 is attached to a fixing member (not shown) that fixes the illumination element 10, the display element 20, the orientation control element 30, and the optical element 40 together, and by rotating this fixing member, the unit is rotated simultaneously. Alternatively, the unit consisting of the illumination element 10, the display element 20, the orientation control element 30, and the optical element 40 is fixed to each other, and the rotation mechanism 80 is attached to the illumination element 10 at the bottom of the unit. Then, by rotating the illumination element 10, the rotation mechanism 80 rotates the unit simultaneously.

[0124] [5-1-1] Configuration of the optical element 40 Figure 22 is a perspective view of the optical element 40 shown in Figure 1. Figure 22 also shows an enlarged view of a part of the optical element 40. The enlarged view in Figure 22 is a side view in the XZ plane.

[0125] The optical element 40 comprises a substrate 41 and a plurality of optical elements 42. The substrate 41 is planar in the XY plane and has a rectangular parallelepiped.

[0126] Multiple optical elements 42 are provided on the bottom surface of the substrate 41. The configuration of each of the multiple optical elements 42 is the same as in the first embodiment. The multiple optical elements 42 are arranged in a line in the X direction, and are also arranged so that adjacent elements are in contact with each other. In other words, the multiple optical elements 42 have a sawtooth shape in the XZ plane.

[0127] The base material 41 and the optical element 42 are made of a transparent material. The optical element 42 is formed integrally with the base material 41, for example, using the same transparent material as the base material 41. Alternatively, the base material 41 and the optical element 42 may be formed separately, and the optical element 42 may be bonded to the base material 41 using a transparent adhesive. As the transparent material constituting the base material 41 and the optical element 42, glass or a transparent resin (including acrylic resin) can be used.

[0128] The optical element 40 configured in this way reflects incident light internally to form a real image in the air. The optical element 40 also forms an aerial image at a position directly in front of the element surface.

[0129] [5-1-2] Block configuration of the aerial display device 1 Figure 23 is a block diagram of the aerial display device 1.

[0130] The display unit 63 includes an illumination element 10 and a display element 20. The display unit 63 displays an image.

[0131] The input / output interface 62 is connected to the rotating mechanism 80. The input / output interface 62 performs interface processing on the rotating mechanism 80 according to a predetermined standard.

[0132] The display processing unit 60A controls the operation of the display unit 63 (specifically, the illumination element 10 and the display element 20). The display processing unit 60A controls the on and off of the illumination element 10. The display processing unit 60A transmits an image signal to the display element 20 and causes the display element 20 to display an image.

[0133] The control unit 60 further comprises a rotation drive unit 60C. The rotation drive unit 60C rotates the rotation mechanism 80. When the first display mode is selected, the rotation drive unit 60C uses the rotation mechanism 80 to rotate the unit (illumination element 10, display element 20, orientation control element 30, and optical element 40) to the position for the first display mode (a position where the X direction of the optical element 40 is parallel to both eyes of the observer 3). When the second display mode is selected, the rotation drive unit 60C uses the rotation mechanism 80 to rotate the unit to the position for the second display mode (a position where the Y direction of the optical element 40 is parallel to both eyes of the observer 3).

[0134] The other components are the same as in the first embodiment.

[0135] [5-2] Operation of the aerial display device 1 Next, the operation of the aerial display device 1 configured as described above will be explained.

[0136] [5-2-1] Display operation of aerial image 2 The arrows in Figure 21 indicate the optical path. As shown in Figure 21, light emitted from any point "o" on the display element 20 enters the orientation control element 30. Of the light emitted from the display element 20, the optical component at angle θ1 (including the optical component within a predetermined angular range centered on angle θ1) passes through the orientation control element 30. The light that has passed through the orientation control element 30 enters the optical element 40. The optical element 40 images the incident light into the air on the opposite side of the orientation control element 30, displaying an aerial image 2 in the air.

[0137] Figure 24 is a perspective view illustrating the reflection of light in the optical element 40. Figure 25 is a side view of the XZ plane illustrating the reflection of light in the optical element 40. Figure 25 shows the optical element 40 as seen by observer 3 with both eyes (i.e., the line connecting both eyes) parallel to the X direction.

[0138] Light emitted from any point "o" on the display element 20 enters the incident surface 43 of the optical element 40 and reaches the reflective surface 44. Light that reaches the reflective surface 44 at an angle greater than the critical angle with respect to the normal direction of the reflective surface 44 is totally reflected by the reflective surface 44 and is emitted from the plane opposite to the side of the optical element 42 of the optical element 40. In the XZ plane of Figure 25, light emitted from point "o" is totally reflected by the reflective surface 44 of the optical element 42, and that light is imaged in the air to generate an aerial image.

[0139] The side view of the YZ plane illustrating the reflection of light in the optical element 40 is the same as Figure 9 described in the first embodiment. Figure 9 shows the optical element 40 as seen by observer 3 with both eyes parallel to the Y direction. In the YZ plane of Figure 9, light emitted from point "o" is not reflected by the reflective surface 44 of the optical element 42, and therefore does not form an image in the air and does not contribute to the generation of an aerial image.

[0140] In other words, the condition for observer 3 to perceive the aerial image is that both of observer 3's eyes are parallel to or close to the X direction (for example, ±10 degrees to the X direction). Furthermore, if observer 3 moves their viewpoint along the Y direction while both of their eyes are parallel to or close to the X direction, they can always perceive the aerial image.

[0141] [5-2-2] Two types of display modes Next, the operation in the two display modes will be described. The aerial display device 1 is capable of executing two display modes: a first display mode that displays an aerial image 2, and a second display mode that displays a planar image on the screen of the display element 20. Switching between display modes is performed using the rotation mechanism 80.

[0142] Figure 26 is a perspective view of the aerial display device 1 to illustrate the first display mode for displaying the aerial image 2. In the first display mode, the rotation mechanism 80 rotates the unit consisting of the illumination element 10, the display element 20, the orientation control element 30, and the optical element 40 so that the X direction of the optical element 40 is parallel to both eyes of the observer 3.

[0143] The display element 20 displays an image on its screen. In the first display mode, the light component incident from the display element 20 to the optical element 40 via the orientation control element 30 is reflected by the optical element 42 of the optical element 40. The aerial display device 1 then displays the aerial image 2 at the position of the display surface Ai shown in Figure 26.

[0144] Figure 27 is a perspective view of the aerial display device 1 to illustrate the second display mode, in which a planar image is displayed on the screen of the display element 20. In the second display mode, the rotation mechanism 80 rotates the unit so that the Y-direction of the optical element 40 is parallel to both eyes of the observer 3.

[0145] The display element 20 displays an image on its screen. In the second display mode, the light component incident on the optical element 40 from the display element 20 via the orientation control element 30 passes through the optical element 40. In the second display mode, the optical element 40 does not form an aerial image. The aerial display device 1 then displays a planar image 21 at the position of the display surface Bi shown in Figure 27.

[0146] Thus, in the first display mode, the aerial display device 1 can display an aerial image 2 at the position of the display surface Ai above the aerial display device 1. In addition, in the second display mode, the aerial display device 1 can display a planar image 21 at the position of the display surface Bi corresponding to the screen of the display element 20.

[0147] Figure 28 is a flowchart illustrating the display operation of the aerial display device 1. The operations in steps S100 and S101 are the same as in the first embodiment.

[0148] Next, if the first display mode is selected (step S101 = Yes), the rotation drive unit 60C uses the rotation mechanism 80 to rotate the unit to the position for the first display mode (step S200). That is, the rotation drive unit 60C rotates the unit so that the X direction of the optical element 40 is parallel to both eyes of the observer 3.

[0149] Next, the display processing unit 60A displays the image selected in step S100 on the display element 20 (step S103). As a result, the light components reflected by the optical element 42 of the optical element 40 are imaged in the air, and the aerial image 2 is displayed.

[0150] On the other hand, if the second display mode is selected (step S101=No), the rotation drive unit 60C uses the rotation mechanism 80 to rotate the unit to the position for the second display mode (step S201). That is, the rotation drive unit 60C rotates the unit so that the Y direction of the optical element 40 is parallel to both eyes of the observer 3.

[0151] Next, the display processing unit 60A displays the image selected in step S100 on the display element 20 (step S103). As a result, the light component transmitted through the optical element 40 is visible to the observer 3, and the planar image 21 displayed on the screen of the display element 20 is visible to the observer 3.

[0152] [5-3] Effects of the fifth embodiment According to the fifth embodiment, similar to the first embodiment, the aerial display device 1 can display two-dimensional images at two different positions in the depth direction.

[0153] Furthermore, it is also possible to apply the third and fourth embodiments to the fifth embodiment.

[0154] [6] Sixth Embodiment The sixth embodiment is a modification of the fifth embodiment.

[0155] Figure 29 is a diagram illustrating the operation of the aerial display device 1 according to the sixth embodiment of the present invention. In Figure 29, the horizontal axis represents the rotation angle (degrees) by the rotation mechanism 80, and the vertical axis represents the height of the perceived image. The rotation angle is set to 0 degrees for the display surface Ai in the first display mode and 90 degrees for the display surface Bi in the second display mode.

[0156] The basic configuration of the aerial display device 1 is the same as in the fifth embodiment. The rotation mechanism 80 is capable of rotating a unit consisting of an illumination element 10, a display element 20, an orientation control element 30, and an optical element 40 within a range of 0 to 90 degrees.

[0157] As shown in Figure 29, the perceived height of the image changes linearly with respect to the change in rotation angle. In this embodiment, as an example, the Z-direction positional relationship of the illumination element 10, display element 20, orientation control element 30, and optical element 40 is set such that when the rotation angle is 45 degrees, the image is displayed on the upper surface of the optical element 40 (i.e., the uppermost surface of the aerial display device 1).

[0158] When the third display mode is selected, the rotary drive unit 60C uses the rotary mechanism 80 to rotate the unit to the position for the third display mode, i.e., a position with a rotation angle of 45 degrees. This allows the image displayed on the uppermost surface of the aerial display device 1 to be seen by the observer. The orientation of the image to be seen can be adjusted based on the orientation of the image displayed on the display element 20.

[0159] Furthermore, the rotation angle in the third display mode can be set to any angle within the range greater than 0 degrees and less than 90 degrees. Accordingly, the image height in the third display mode is set to a specific position having the relationship shown in Figure 29.

[0160] [7] Variant In the above embodiment, the display element 20 and the optical element 40 are arranged in parallel. However, the embodiment is not limited to this, and the display element 20 may be arranged diagonally to the optical element 40. The angle between the display element 20 and the optical element 40 is set to a range greater than 0 degrees and less than 45 degrees. In this modified example, the orientation control element 30 can be omitted.

[0161] In the above embodiment, the left side of the optical element 42 is defined as the incident surface 43, and the right side is defined as the reflective surface 44. However, the embodiment is not limited to this, and the incident surface 43 and the reflective surface 44 may be configured in reverse. In this case, the operation of the aerial display device 1 described in the embodiment will also be reversed left and right.

[0162] In the above embodiment, a liquid crystal display element is used as an example for the display element 20, but it is not limited to this. The display element 20 can also be a self-emissive organic EL (electroluminescence) display element or a micro-LED (light-emitting diode) display element. A micro-LED display element is a display element that emits R (red), G (green), and B (blue) light, which constitute the pixels, using LEDs. When a self-emissive display element 20 is used, the illumination element 10 is not required.

[0163] The present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. Furthermore, each embodiment may be combined as appropriate, and in that case, the combined effects can be obtained. Moreover, the above embodiments include various inventions, and various inventions can be extracted by selecting combinations from the multiple constituent elements disclosed. For example, if the problem can be solved and effects obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiment, then the configuration with these deleted constituent elements can be extracted as an invention. [Explanation of Symbols]

[0164] 1...Aerial display device, 2...Aerial image, 3...Observer, 10...Illumination element, 11...Light source unit, 12...Light guide plate, 13...Reflective sheet, 20...Display element, 21...Planar image, 30...Orientation control element, 31,32...Substrate, 33...Transparent member, 34...Light shielding member, 40...Optical element, 41...Substrate, 42...Optical element, 43...Incident surface, 44...Reflective surface, 45...Plane, 46...Reflective layer, 47...Absorption layer, 50...Switching element, 51a,51b...Elemental pixel, 52a,52b...Pixel, 60...Control unit, 60A...Display processing unit, 60B...Information processing unit, 60C...Rotation drive unit, 61...Storage unit, 62...Input / output interface, 63...Display unit, 64...Input unit, 65...Bus, 70...Light diffusion element, 80...Rotation mechanism.

Claims

1. A display element that displays an image, The display element has a plurality of alternately arranged first regions and a plurality of second regions, the plurality of first regions being configured to reflect the light from the display element to the opposite side of the display element and to form an aerial image in the air, and the plurality of second regions being optical elements that transmit the light from the display element. A switching element is arranged to receive light from the optical element, and in the first display mode, it blocks light from the plurality of second regions, and in the second display mode, it blocks light from the plurality of first regions. An aerial display device equipped with the following.

2. The optical element includes a planar substrate and a plurality of optical elements provided beneath the substrate, each extending in a first direction and arranged in a second direction perpendicular to the first direction, and each provided in a plurality of first regions. Each of the plurality of optical elements has an incident surface and a reflective surface that are inclined with respect to the normal direction of the substrate and are in contact with each other. Each of the multiple second regions of the optical element is composed of multiple planes. The aerial display device according to claim 1.

3. The switching element has a plurality of first element pixels and a plurality of second element pixels that extend in the first direction and are arranged alternately in the second direction, Each of the plurality of first element pixels is provided in the plurality of first regions, Each of the plurality of second element pixels is provided in the plurality of second regions, Each of the plurality of first element pixels and the plurality of second element pixels can be set to either a transparent state or a light-shielding state. The aerial display device according to claim 2.

4. Each of the plurality of first element pixels and the plurality of second element pixels has a plurality of pixels arranged in the first direction, The aforementioned plurality of pixels can be set to either a transparent state or a light-shielding state. The aerial display device according to claim 3.

5. The optical element includes a reflective layer provided on the reflective surface that reflects light, and an absorbing layer provided on the reflective layer that absorbs light. The aerial display device according to claim 2.

6. The system further comprises an orientation control element disposed between the display element and the optical element, which transmits the oblique light component of the light from the display element. The aerial display device according to claim 1.

7. The orientation control element includes a plurality of transparent members and a plurality of light-shielding members arranged alternately. The plurality of light-shielding members are inclined with respect to the normal of the orientation control element. The aerial display device according to claim 6.

8. The system further comprises a light-diffusing element disposed between the orientation control element and the optical element, The light-diffusing element is set to a light-transmitting state in the first display mode, and to a light-diffusing state in the second display mode. The aerial display device according to claim 6.

9. The display element, the optical element, and the switching element are arranged parallel to each other. The aerial display device according to claim 1.

10. It further comprises a light-emitting illuminating element, The display element is arranged to receive light from the illumination element and is composed of a liquid crystal display element. The aerial display device according to claim 1.

Images