Airborne display device

Abstract

To provide an aerial display device capable of improving display quality.SOLUTION: An aerial display device includes: a display element 20 for displaying an image; a light correction element 30 arranged so as to receive light emitted from the display element 20, and deflecting the light emitted from the display element 20 to the side of a normal crossing the inside of a plane; and an optical element 50 arranged so as to receive light emitted from the light correction element 30, and reflecting the light emitted from the light correction element 30 to an opposite side of the light correction element 30 so as to form an aerial image in the air.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 a large number of vertically aligned strip-shaped planar light reflecting sections at a constant pitch inside a transparent flat plate, and the first and second light control panels are arranged so that their planar light reflecting sections 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 light correction element positioned to receive light emitted from the display element and refracting the light emitted from the display element toward a normal perpendicular to the plane; and an optical element positioned to receive light emitted from the light correction element and reflecting the light emitted from the light correction element toward the opposite side from the light correction element, thereby forming an aerial image in the air.

[0008] According to a second aspect of the present invention, an aerial display device according to the first aspect is provided, wherein the optical element reflects the light component of the light emitted from the light correcting element that spreads to a first plane perpendicular to the plane toward the normal direction perpendicular to the plane, and the light correcting element refracts the light component of the light emitted from the display element that spreads to a second plane that is both in the plane and perpendicular to the first plane toward the normal direction.

[0009] According to a third aspect of the present invention, an aerial display device according to the first or second aspect is provided, wherein the light correcting element has a plurality of first lens surfaces provided on its bottom surface and a plurality of second lens surfaces provided on its top surface, the plurality of first lens surfaces constitute a convex lens, each extending in a first direction and aligned in a second direction perpendicular to the first direction, and the plurality of second lens surfaces constitute a convex lens, each extending in the first direction and aligned in the second direction.

[0010] According to a fourth aspect of the present invention, an aerial display device according to the third aspect is provided, wherein the optical element reflects light incident obliquely from the light correction element in the normal direction.

[0011] According to a fifth aspect of the present invention, an aerial display device according to the fourth aspect is provided, wherein the optical element includes a planar substrate and a plurality of optical elements provided below the substrate, each extending in the second direction and arranged in the first direction, and each of the plurality of optical elements is inclined with respect to the normal of the substrate and has an incident surface and a reflective surface that are in contact with each other.

[0012] According to a sixth aspect of the present invention, an aerial display device according to the first or second aspect is provided, wherein the display element, the light correction element, and the optical element are arranged parallel to each other.

[0013] According to a seventh aspect of the present invention, an aerial display device according to the first or second aspect is provided, further comprising an orientation control element disposed between the light correction element and the optical element, which transmits a portion of the light emitted from the display element.

[0014] According to an eighth aspect of the present invention, an aerial display device according to the seventh 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.

[0015] According to a ninth aspect of the present invention, an aerial display device according to the first or second 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]

[0016] According to the present invention, it is possible to provide an aerial display device that can improve display quality. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a perspective view of an aerial display device according to an embodiment of the present invention. [Figure 2] Figure 2 is a side view of the aerial display device shown in Figure 1 in the XZ plane. [Figure 3]FIG. 3 is a side view of the aerial display device shown in FIG. 1 in the YZ plane. [Figure 4] FIG. 4 is a perspective view of the optical correction element shown in FIG. 1. [Figure 5] FIG. 5 is a side view in the YZ plane for explaining the configuration of the optical correction element. [Figure 6A] FIG. 6A is a plan view of the alignment control element shown in FIG. 1. [Figure 6B] FIG. 6B is a cross-sectional view of the alignment control element along the line A-A' in FIG. 6A. [Figure 7] FIG. 7 is a perspective view of the optical element shown in FIG. 1. [Figure 8] FIG. 8 is a block diagram of the aerial display device. [Figure 9] FIG. 9 is a perspective view for explaining the state of light reflection in the optical element. [Figure 10] FIG. 10 is a side view in the XZ plane for explaining the state of light reflection in the optical element. [Figure 11] FIG. 11 is a side view in the YZ plane for explaining the state of light reflection in the optical element. [Figure 12] FIG. 12 is a diagram for explaining the angular conditions of the incident surface and the reflection surface in the optical element. [Figure 13] FIG. 13 is a perspective view for explaining an example of the aerial image generated by the aerial display device. [Figure 14] FIG. 14 is a side view in the YZ plane for explaining the operation of the optical correction element. [Figure 15] FIG. 15 is a schematic diagram for explaining how an observer views the aerial image. [Figure 16] FIG. 16 is a schematic diagram for explaining how an observer views the aerial image. [Figure 17] FIG. 17 is a perspective view for explaining the operation of the aerial display device corresponding to FIG. 16. [Figure 18] FIG. 18 is a schematic diagram for explaining how an observer views the aerial image. [Figure 19] FIG. 19 is a perspective view for explaining the operation of the aerial display device corresponding to FIG. 18. [Figure 20] Figure 20 is a perspective view illustrating the operation of an aerial display device according to a comparative example. [Figure 21] Figure 21 is a side view in the XZ plane of an aerial display device according to a modified example. [Modes for carrying out the invention]

[0018] 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.

[0019] [1] Configuration of the aerial display device 1 Figure 1 is a perspective view of an aerial display device 1 according to an 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 in the XZ plane. Figure 3 is a side view of the aerial display device 1 shown in Figure 1 in the YZ plane.

[0020] 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.

[0021] The aerial display device 1 comprises an illumination element (also called a backlight) 10, a display element 20, a light correction element 30, an alignment control element 40, and an optical element 50. The illumination element 10, the display element 20, the light correction element 30, the alignment control element 40, and the optical 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 light correction element 30, the alignment control element 40, and the optical element 50 are fixed in desired positions by fixing members (not shown) with a desired distance between them.

[0022] 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.

[0023] 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.

[0024] 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 display surface.

[0025] The light correction element 30 receives light emitted from the display element 20. The light correction element 30 has the function of refracting light in the Y direction. In addition, the light correction element 30 refracts the light component of the light emitted from the display element 20 that spreads in the YZ plane toward the normal direction perpendicular to the element surface of the light correction element 30. The element surface refers to a virtual plane that extends in the in-plane direction of the light correction element 30. The element surface has the same meaning as "in-plane". The same meaning applies to the element surfaces of other elements. The light correction element 30 has a plurality of convex lens surfaces provided on its bottom surface and a plurality of convex lens surfaces provided on its top surface. The detailed configuration of the light correction element 30 will be described later.

[0026] The orientation control element 40 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 50 in the normal direction. The orientation control element 40 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 in the XZ plane, and to block light components outside of the above angular range. The detailed configuration of the orientation control element 40 will be described later.

[0027] The optical element 50 reflects light incident obliquely from the bottom side to the top side. The optical element 50 also reflects the light component of the light emitted from the orientation control element 40 that spreads in the XZ plane towards the normal plane perpendicular to the element surface of the optical element 50. The optical element 50 forms an aerial image 2 in the air in front of the aerial display device 1. The detailed configuration of the optical element 50 will be described later. The aerial image 2 is parallel to the element surface of the optical element 50 and is a two-dimensional image. An observer 3 standing in front of the optical element 50 can see the aerial image 2.

[0028] [1-1] Configuration of the light correction element 30 Figure 4 is a perspective view of the light correction element 30 shown in Figure 1. Figure 4 also shows an enlarged view of a part of the light correction element 30. The enlarged view in Figure 4 is a side view in the YZ plane.

[0029] The light correcting element 30 has a plurality of first lens surfaces 31 provided on its bottom surface and a plurality of second lens surfaces 32 provided on its top surface.

[0030] Multiple first lens surfaces 31 each extend in the X direction and are arranged in a line in the Y direction. Each first lens surface 31 is composed of a columnar convex lens. In other words, the multiple first lens surfaces 31 constitute a lenticular lens.

[0031] Multiple second lens surfaces 32 each extend in the X direction and are arranged in a line in the Y direction. Each second lens surface 32 is composed of a columnar convex lens. In other words, multiple second lens surfaces 32 constitute a lenticular lens.

[0032] The first lens surface 31 and the second lens surface 32 have the same pitch. Here, pitch refers to the width in the Y direction of each of the first lens surface 31 and the second lens surface 32. The first lens surface 31 and the second lens surface 32 are positioned at the same location (so that they completely overlap) in a plan view.

[0033] The light correcting element 30 is made of glass or a transparent resin (including acrylic resin).

[0034] Figure 5 is a side view in the YZ plane illustrating the configuration of the optical correction element 30. The first lens surface 31 has a radius of curvature R1, a principal point H1, and a focal length f1. The second lens surface 32 has a radius of curvature R2, a principal point H2, and a focal length f2. The thickness of the light correcting element 30 is T, and the pitch of the first lens surface 31 and the second lens surface 32 is P.

[0035] The optical axes of the first lens surface 31 and the second lens surface 32 coincide. The radii of curvature R1 and R2 are set to be the same. The focal lengths f1 and f2 are calculated from the radii of curvature R1 and R2, respectively. The thickness T of the optical corrector element 30 is set based on the radii of curvature R1, R2, and the focal lengths f1 and f2. The pitch P can be set arbitrarily. The radii of curvature R1, R2, focal lengths f1 and f2, thickness T, pitch P, and refractive index of the optical corrector element 30 are set appropriately according to the characteristics required of the optical corrector element 30.

[0036] The light correction element 30 configured in this way refracts light incident from the bottom side through multiple first lens surfaces 31, and then further refracts it through multiple second lens surfaces 32. The light correction element 30 then refracts and focuses the light components emitted radially from a certain point on the display element 20 in the YZ plane toward the normal side perpendicular to the element surface of the light correction element 30.

[0037] [1-2] Configuration of the orientation control element 40 Figure 6A is a plan view of the orientation control element 40 shown in Figure 1. Figure 6B is a cross-sectional view of the orientation control element 40 along line AA' in Figure 6A.

[0038] The substrate 41 is planar in the XY plane and has a rectangular parallelepiped. The substrate 41 transmits light.

[0039] Multiple transparent members 43 are provided on the base material 41, each extending in the Y direction and aligned in the X direction. Additionally, multiple light-shielding members 44 are provided on the base material 41, each extending in the Y direction and aligned in the X direction. The multiple transparent members 43 and the multiple light-shielding members 44 are arranged alternately so that adjacent members are in contact with each other.

[0040] Multiple transparent members 43 and multiple light-shielding members 44 are provided on a base material 42. The base material 42 is planar in the XY plane and has a rectangular parallelepiped shape. The base material 42 transmits light.

[0041] The transparent member 43 extends in an oblique direction at an angle θ1 with respect to the normal direction of the base material 41 in the XZ plane. The transparent member 43 is a parallelogram with its side surface inclined by an angle θ1 in the XZ plane. The transparent member 43 transmits light.

[0042] The light-shielding member 44 extends in an oblique direction at an angle θ1 with respect to the normal direction of the base material 41 in the XZ plane. The light-shielding member 44 is a parallelogram with its side surface inclined by an angle θ1 in the XZ plane. The light-shielding member 44 blocks light. The thickness of the light-shielding member 44 is set to be thinner than the thickness of the transparent member 43.

[0043] The two adjacent light-shielding members 44 are arranged so that their ends slightly overlap in the Z direction.

[0044] The base materials 41, 42 and the transparent member 43 are made of glass or a transparent resin (including acrylic resin). The light-shielding member 44 is made of, for example, a resin mixed with black dye or pigment.

[0045] The orientation control element 40 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 40 is configured to block light components outside the range of 30°±30° with respect to the normal direction. Preferably, the orientation control element 40 is configured to block light components outside the range of 30°±20° with respect to the normal direction.

[0046] As a modified example, the orientation control element 40 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 40.

[0047] [1-3] Configuration of the optical element 50 Figure 7 is a perspective view of the optical element 50 shown in Figure 1. Figure 7 also includes an enlarged view of a portion of the optical element 50. The enlarged view in Figure 7 is a side view in the XZ plane.

[0048] The optical element 50 comprises a substrate 51 and a plurality of optical elements 52. The substrate 51 is planar in the XY plane and has a rectangular parallelepiped.

[0049] Multiple optical elements 52 are provided on the bottom surface of the base material 51. Each of the multiple optical elements 52 is composed of a triangular prism. The optical elements 52 are arranged such that three sides of the triangular prism are parallel to the XY plane, and one side is in contact with the base material 51. Each of the multiple optical elements 52 extends in the Y direction and is arranged in a line in the X direction. In other words, the multiple optical elements 52 have a sawtooth shape in the XZ plane.

[0050] Each of the multiple optical elements 52 has an incident surface 53 and a reflecting surface 54. When viewed from the Y direction, the left side is the incident surface 53 and the right side is the reflecting surface 54. The incident surface 53 is the surface to which light from the display element 20 is incident. The reflecting surface 54 is the surface that reflects the light incident on the incident surface 53 from the outside within the optical element 52. The angle between the incident surface 53 and the reflecting surface 54 is θ p It has.

[0051] The base material 51 and the optical element 52 are made of a transparent material. The optical element 52 is formed integrally with the base material 51, for example, using the same transparent material as the base material 51. Alternatively, the base material 51 and the optical element 52 may be formed separately, and the optical element 52 may be bonded to the base material 51 using a transparent adhesive. Glass or a transparent resin (including acrylic resin) can be used as the transparent material constituting the base material 51 and the optical element 52.

[0052] The optical element 50 configured in this way reflects incident light internally to form a real image in the air. The optical element 50 also forms an aerial image at a position directly in front of the element surface.

[0053] [1-4] Block configuration of the aerial display device 1 Figure 8 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, a sensing device 64, and an input unit 65. The control unit 60, the storage unit 61, and the input / output interface 62 are connected to each other via a bus 66.

[0054] The input / output interface 62 is connected to the display unit 63, the sensing device 64, and the input unit 65. The input / output interface 62 performs interface processing for each of the display unit 63, the sensing device 64, and the input unit 65 according to a predetermined standard.

[0055] The display unit 63 includes an illumination element 10 and a display element 20. The display unit 63 displays an image.

[0056] The sensing device 64 detects objects (subjects) present in the detection area. The sensing device 64 emits infrared light into a spatial area (detection area) that includes part or all of the aerial image 2 generated by the aerial display device 1, and detects the infrared light reflected by the objects. The sensing device 64 includes a light-emitting unit that emits infrared light and a light-receiving unit (sensor) that detects infrared light.

[0057] 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, a position calculation unit 60B, and an information processing unit 60C.

[0058] 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.

[0059] The position calculation unit 60B controls the operation of the sensing device 64. The position calculation unit 60B causes the sensing device 64 to form a detection area consisting of infrared light. Based on multiple detection signals sent from the sensing device 64, the position calculation unit 60B calculates the position of the object to be detected within the detection area. For example, based on multiple detection signals, the position calculation unit 60B calculates the position within the detection area that the user touched. A known method (such as the principle of triangulation) is used to calculate the position.

[0060] The information processing unit 60C generates the image to be displayed by the aerial display device 1. The information processing unit 60C can use image data stored in the storage unit 61. The information processing unit 60C may also acquire image data from an external source using a communication function (not shown).

[0061] 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. The storage unit 61 stores the image data displayed by the aerial display device 1.

[0062] The input unit 65 includes a touch panel and buttons, and receives information entered by the user. The information processing unit 60C can select an image to display on the display unit 63 based on the information received by the input unit 65.

[0063] [2] Operation of the aerial display device 1 Next, the operation of the aerial display device 1 configured as described above will be explained.

[0064] The arrows in Figures 2 and 3 indicate the optical path. As shown in Figures 2 and 3, light emitted from the display element 20 passes through the optical correction element 30 and then enters the orientation control element 40. The operation of the optical correction element 30 will be described later. 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 40. The light that has passed through the orientation control element 40 enters the optical element 50. The optical element 50 images the incident light into the air on the opposite side of the orientation control element 40, and displays the aerial image 2 in the air.

[0065] Figure 9 is a perspective view illustrating the reflection of light in the optical element 50. Figure 10 is a side view of the XZ plane illustrating the reflection of light in the optical element 50. Figure 10 shows the optical element 50 as seen by observer 3 with both eyes (i.e., the line connecting both eyes) parallel to the X direction. Figure 11 is a side view of the YZ plane illustrating the reflection of light in the optical element 50. Figure 11 shows the optical element 50 as seen by observer 3 with both eyes parallel to the Y direction. Note that the refractive effect of the light correction element 30 is not considered in Figure 11.

[0066] Light emitted from an arbitrary point "o" on the display surface of the display element 20 enters the incident surface 53 of the optical element 50 and reaches the reflective surface 54. Light arriving at an angle greater than the critical angle with respect to the normal direction of the reflective surface 54 is totally reflected by the reflective surface 54 and is emitted from the plane opposite to the side of the optical element 52 of the optical element 50. 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.

[0067] In the XZ plane of Figure 10, light emitted from point "o" is totally reflected by the reflective surface 54 of optical element 52, and the light is imaged in the air to generate an aerial image.

[0068] In the YZ plane of Figure 11, the light emitted from point "o" is not reflected by the reflective surface 54 of the optical element 52, and therefore does not form an image in the air, thus not contributing to the generation of an aerial image.

[0069] That is, the condition for the observer 3 to recognize the aerial image is that both eyes of the observer 3 are parallel to the X direction or in a state close thereto (for example, ±10 degrees with respect to the X direction). Further, when the observer 3 moves the viewpoint along the Y direction in a state where both eyes are parallel to the X direction or close thereto, the aerial image can always be recognized.

[0070] FIG. 12 is a diagram for explaining the angular conditions of the incident surface 53 and the reflection surface 54 in the optical element 50.

[0071] Let the angle of the incident surface 53 with respect to the Z direction (direction perpendicular to the element surface) be θ2, the angle of the reflection surface 54 with respect to the Z direction be θ3, and the angle formed by the incident surface 53 and the reflection surface 54 be θ. p Let it be so. angle θ p is represented by the following formula (1). θ p = θ2 + θ3 ··· (1)

[0072] The light emitted from the display element 20 at an angle θ1 is incident on the incident surface 53. Let the refractive index of the material of the optical element 50 be n. p Let the refractive index of air be 1. Let the incident angle on the incident surface 53 be θ4 and the refraction angle be θ5. Let the incident angle on the reflection surface 54 be θ6 and the reflection angle be θ7 (= θ6). Let the incident angle on the upper surface of the optical element 50 be θ8 and the refraction angle be θ9. The refraction angle θ9 is the emission angle. The emission angle θ9 is represented by the following formula (2). θ9 = sin -1 (n p * sin (sin -1 ((1 / n p ) * sin (90° - (θ1 + θ2)) + θ2 + 2θ3 - 90°)) ··· (2)

[0073] The critical angle on the reflection surface 54 is represented by the following formula (3). Critical angle < θ6 (= θ7) Critical angle = sin -1 (1 / n p ) ··· (3) In other words, the angle of incidence θ6 at the reflective surface 54 is set to be greater than the critical angle at the reflective surface 54. To put it another way, the angle θ3 of the reflective surface 54 is set such that the angle of incidence of light incident on the reflective surface 54 is greater than the critical angle.

[0074] Furthermore, the light incident on the incident surface 53 is set so that it is not totally reflected at the incident surface 53. In other words, the angle θ2 of the incident surface 53 is set so that the angle of incidence of the light incident on the incident surface 53 is smaller than the critical angle.

[0075] The angle between the element surface of the optical element 50 and the plane of the aerial image 2, and the distance between the element surface of the optical element 50 and the plane of the aerial image 2, can be adjusted by optimally setting the angle θ1 of the light incident on the optical element 50, the refractive index of the optical element 50, the angle θ2 of the incident surface 53 of the optical element 50, and the angle θ3 of the reflective surface 54 of the optical element 50.

[0076] Figure 13 is a perspective view illustrating an example of an aerial image generated by the aerial display device 1. The aerial display device 1 comprises a rectangular housing, and multiple elements constituting the aerial display device 1 are housed within the housing. The aerial display device 1 has a light-emitting surface 1A on its uppermost surface, and emits light from this light-emitting surface 1A to generate an aerial image 2. In Figure 13, a button is shown as an example of the aerial image 2.

[0077] The sensing device 64 included in the aerial display device 1 forms a detection area 64A in the spatial region including the aerial image 2. The detection area 64A is formed by infrared light. When the observer 3's finger 3A touches the aerial image 2, the sensing device 64 detects the observer 3's finger 3A. The position calculation unit 60B calculates the position of the observer 3's finger 3A based on multiple detection signals sent from the sensing device 64. As a result, the aerial display device 1 can display the button 2 towards the observer 3 and detect that the observer 3 has pressed the button 2.

[0078] Next, the operation of the light correction element 30 will be explained. Figure 14 is a side view of the YZ plane illustrating the operation of the light correction element 30. Figure 14 shows the display element 20 and the light correction element 30 separately. Figure 14 shows the tracking of a light ray.

[0079] The orientation control element 40 controls the orientation with respect to the spread of light in the XZ plane. Since the light-shielding member 44 of the orientation control element 40 extends in the Y direction, the orientation control element 40 hardly controls the orientation with respect to the spread of light in the YZ plane. As the orientation control element 40 has almost no effect on the action of light in the YZ plane, it is omitted from the illustration of the orientation control element 40 in the side view of the YZ plane in Figure 14. Similarly, the optical element 50 controls the reflection with respect to the spread of light in the XZ plane. Since the optical element 52 of the optical element 50 extends in the Y direction, the optical element 50 hardly controls the reflection with respect to the spread of light in the YZ plane. As the optical element 50 has almost no effect on the action of light in the YZ plane, it is omitted from the illustration of the optical element 50 in the side view of the YZ plane in Figure 14.

[0080] The display element 20 emits light toward the optical correction element 30. Figure 14 shows the light emitted from point "o" on the display element 20, and this light is emitted from the display element 20 with a predetermined spread. The light incident on the optical correction element 30 from the display element 20 is refracted by a plurality of first lens surfaces 31, and the light refracted by the plurality of first lens surfaces 31 is refracted by a plurality of second lens surfaces 32. The light refracted twice by the optical correction element 30 forms an image at point "o'" in the air. Point "o'" is the position where the airborne image 2 is formed. For example, the distance from point "o" to the optical correction element 30 is the same as the distance from the optical correction element 30 to point "o'". The position of point "o'" is appropriately set by adjusting the distance between the display element 20 and the optical correction element 30, and the optical characteristics of the optical correction element 30 shown in Figure 5.

[0081] Furthermore, since the light correction element 30 does not function as a lens for the spread of light in the XZ plane, it hardly refracts light rays in the XZ plane. In other words, the light correction element 30 has almost no effect on light rays in the XZ plane.

[0082] Figure 15 is a schematic diagram illustrating how observer 3 views the aerial image 2. Figure 15 is a side view in the YZ plane and also shows the view of observer 3 looking at the aerial display device 1 from the front. The line connecting observer 3's eyes is parallel to the X direction.

[0083] The sensing device 64 included in the aerial display device 1 forms a detection area 64A in the spatial region including the aerial image 2. The aerial image 2 is formed at the same position as the detection area 64A. The observer 3 views the aerial image 2 at the same position as the detection area 64A in a planar view. The operation in Figure 15 corresponds to the operation in Figure 13.

[0084] Figure 16 is a schematic diagram illustrating how observer 3 views the aerial image 2. Figure 16 is a side view in the YZ plane and shows the view of the aerial display device 1 from a position shifted in the Y direction from the front of the aerial display device 1.

[0085] In the case of Figure 16, observer 3 sees the light component of the left region of Figure 16 from the light refracted by the light correction element 30. As a result, observer 3 sees the aerial image 2 at the same position as the detection region 64A in a planar view.

[0086] Figure 17 is a perspective view illustrating the operation of the aerial display device 1 corresponding to Figure 16. The sensing device 64 forms a detection area 64A at a fixed position in space. Observer 3, who observes the aerial display device 1 from a position offset in the Y direction from the front of the aerial display device 1, sees the aerial image 2 in front of the aerial display device 1. As a result, the sensing device 64 can detect observer 3's finger 3A more accurately.

[0087] Figure 18 is a schematic diagram illustrating how observer 3 views the aerial image 2. Figure 18 is a side view in the YZ plane and shows the case where observer 3 views the aerial display device 1 from a position shifted in the opposite direction to the Y direction from the front of the aerial display device 1.

[0088] In the case of Figure 18, observer 3 sees the light component of the region on the right side of Figure 18 from the light refracted by the light correction element 30. As a result, observer 3 sees the aerial image 2 at the same position as the detection region 64A in a planar view.

[0089] Figure 19 is a perspective view illustrating the operation of the aerial display device 1 corresponding to Figure 18. The sensing device 64 forms a detection area 64A at a fixed position in space. Observer 3, observing the aerial display device 1 from a position offset in the opposite direction to the front of the aerial display device 1, sees the aerial image 2 in front of the aerial display device 1. This allows the sensing device 64 to detect observer 3's finger 3A more accurately.

[0090] [3] Comparative example Figure 20 is a perspective view illustrating the operation of the aerial display device 1 according to a comparative example.

[0091] The aerial display device 1 in the comparative example does not have an optical correction element 30. When the optical correction element 30 is absent, the light emitted from the display element 20 is hardly refracted in the YZ plane. That is, the light emitted from the display element 20 passes through the optical element 50 almost linearly in the YZ plane.

[0092] If observer 3 views the aerial display device 1 from a position shifted in the Y direction from the front of the aerial display device 1, the aerial image 2 moves in the Y direction along with observer 3's line of sight. Similarly, if observer 3 views the aerial display device 1 from a position shifted in the opposite direction to the Y direction from the front of the aerial display device 1, the aerial image 2 moves in the opposite direction to the Y direction along with observer 3's line of sight.

[0093] The sensing device 64 forms a detection area 64A at a fixed position in space. In this case, the two types of aerial images 2 described above do not overlap with the detection area 64A. Therefore, even if observer 3 touches the button as an aerial image 2 with their finger 3A, the sensing device 64 may not be able to detect observer 3's finger 3A.

[0094] In contrast, the aerial display device 1 according to this embodiment includes an optical correction element 30 that refracts light in the YZ plane. The operation of the aerial display device 1 according to this embodiment is as described above. Thus, this embodiment can solve the problems of the comparative example.

[0095] [4] Variant Next, a modified version of the aerial display device 1 will be described. Figure 21 is a side view of the modified aerial display device 1 in the XZ plane. The light correction element 30 may be placed between the orientation control element 40 and the optical element 50. The modified aerial display device 1 can also achieve the same operation as the embodiment described above.

[0096] [5] Effects of the embodiment According to an embodiment of the present invention, an aerial image 2 can be displayed in the air by reflecting light emitted from the display element 20 with the optical element 50. Furthermore, the aerial image 2 can be displayed in the direction in front of the aerial display device 1. In addition, an aerial display device capable of improving display quality can be realized.

[0097] Furthermore, the light correction element 30 refracts light in the YZ plane toward the normal side of the aerial display device 1. Therefore, even if the observer 3 moves their line of sight along the Y direction (the direction in which the optical element 52 of the optical element 50 extends), the aerial image 2 can be displayed in the same position as when viewed from the front of the aerial display device 1.

[0098] Furthermore, the aerial display device 1 includes a sensing device 64. The sensing device 64 forms a detection area 64A in the spatial region including the aerial image 2 and can detect objects present in this detection area 64A.

[0099] Furthermore, even if observer 3 moves their gaze along the Y direction, the aerial display device 1 can overlay the aerial image 2 onto the detection area 64A. This allows for more accurate detection of observer 3's finger 3A when observer 3 touches the aerial image 2 with their finger 3A.

[0100] Furthermore, when observer 3 views the optical element 50 with both eyes parallel to or nearly parallel to the X direction (i.e., the direction in which the multiple optical elements 52 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.

[0101] 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.

[0102] In the above embodiment, the display element 20 and the optical element 50 are arranged in parallel. However, the embodiment is not limited to this, and the display element 20 may be arranged diagonally with respect to the optical element 50. The angle between the display element 20 and the optical element 50 is set to a range greater than 0 degrees and less than 45 degrees. In this modified example, the light correction element 30 is arranged parallel to the display element 20, and the orientation control element 40 is omitted.

[0103] In the above embodiment, the left side of the optical element 52 is defined as the incident surface 53, and the right side is defined as the reflective surface 54. However, the embodiment is not limited to this, and the incident surface 53 and the reflective surface 54 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.

[0104] 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, and various types of display elements can be used. For example, the display element 20 can 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.

[0105] 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]

[0106] 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, 30...Light correction element, 31...First lens surface, 32...Second lens surface, 40...Orientation control element, 41,42...Substrate, 43...Transparent member, 44...Light shielding member, 50...Optical element, 51...Substrate, 52...Optical element, 53...Incident surface, 54...Reflective surface, 60...Control unit, 60A...Display processing unit, 60B...Position calculation unit, 60C...Information processing unit, 61...Storage unit, 62...Input / output interface, 63...Display unit, 64...Sensing device, 64A...Detection area, 65...Input unit, 66...Bus.

Claims

1. A display element that displays an image, A light correction element is positioned to receive the light emitted from the display element and refracts the light emitted from the display element toward the normal vector perpendicular to the plane, An optical element is positioned to receive light emitted from the aforementioned light correcting element, and reflects the light emitted from the aforementioned light correcting element to the opposite side of the light correcting element, thereby forming an aerial image in the air. It is equipped with, The display element, the light correction element, and the optical element are arranged parallel to each other. Aerial display device.

2. The optical element reflects the light component of the light emitted from the light correction element that spreads to a first plane perpendicular to the plane toward the normal direction perpendicular to the plane. The light correction element refracts the light component of the light emitted from the display element that spreads within the plane and onto a second plane perpendicular to the first plane toward the normal side. The aerial display device according to claim 1.

3. The light correcting element has a plurality of first lens surfaces provided on its bottom surface and a plurality of second lens surfaces provided on its top surface. The plurality of first lens surfaces constitute a convex lens, each extending in a first direction and aligned in a second direction perpendicular to the first direction. The plurality of second lens surfaces constitute a convex lens, each extending in the first direction and aligned in the second direction. The aerial display device according to claim 1 or 2.

4. The optical element reflects light incident at an oblique angle from the light correction element in the direction of the normal. The aerial display device according to claim 3.

5. The optical element includes a planar substrate and a plurality of optical elements provided beneath the substrate, each extending in the second direction and arranged in the first direction. Each of the plurality of optical elements has an incident surface and a reflective surface that are inclined with respect to the normal of the substrate and are in contact with each other. The aerial display device according to claim 4.

6. The system further comprises an orientation control element disposed between the light correcting element and the optical element, which transmits a portion of the light emitted from the display element. The aerial display device according to claim 1 or 2.

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. It further comprises an illumination element that emits light, 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 or 2.

Images