Aerial display device

Abstract

An aerial display device includes: a display element (20) that displays an image; an orientation control element (30) that receives the light emitted from the display element (20) and refracts the light emitted from the display element (20) in an inclined direction with respect to a normal direction orthogonal to the in-plane direction; and an optical element (40) configured to receive the light emitted from the orientation control element (30), reflect the light emitted from the orientation control element (30) to a side opposite to the orientation control element (30), and image an aerial image in the air.

Description

Technical Field

[0001] The invention relates to an aerial display device. Background Art

[0002] Currently, research is underway to develop an aerial display device that can display images or dynamic images as aerial images, and it is expected to become a new human-machine interface. The aerial display device, for example, includes a dihedral corner reflector array in which dihedral corner reflectors are arranged in an array, and reflects light emitted from the display surface of the display element to form a real image in the air. The display method performed by the dihedral corner reflector array can display a real image (aerial image) at a plane-symmetrical position without aberration.

[0003] Patent document 1 discloses an optical element that uses a transparent quadrangular prism protruding from the surface of a transparent flat plate as a dihedral corner reflector, and arranges a plurality of quadrangular prisms in an array on a plane. In addition, Patent document 2 discloses an optical element that vertically arranges a plurality of strip-shaped planar light reflecting portions at a certain interval inside a transparent flat plate to form a first and a second light control panel, respectively, and arranges the first and the second light control panels so that the planar light reflecting portions are orthogonal to each other. The optical elements of Patent documents 1 and 2 reflect light emitted from a display element twice using orthogonal reflection surfaces to form an aerial image.

[0004] In the display device using the optical element of Patent Documents 1 and 2, an aerial image can be recognized by observing from an oblique direction of the optical element, but it is difficult to recognize a good aerial image when observing from a normal direction of the optical element.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2011-191404

[0008] Patent Document 2: Japanese Patent Application Publication No. 2011-175297 Summary of the invention

[0009] Problems to be solved by the invention

[0010] The present invention provides an aerial display device capable of improving display quality.

[0011] Means used to solve problems

[0012] According to the first technical solution of the present invention, there is provided an aerial display device, comprising: a display element for displaying an image; an orientation control element configured to receive light emitted from the display element and refract the light emitted from the display element in an inclined direction relative to a normal direction orthogonal to an in-plane surface; and an optical element configured to receive light emitted from the orientation control element and reflect the light emitted from the orientation control element to a side opposite to the orientation control element, thereby forming an aerial image in the air.

[0013] According to a second aspect of the present invention, there is provided an aerial display device according to the first aspect, wherein the alignment control element transmits a portion of light components within an angle range including the normal direction, among light emitted from the display element.

[0014] According to the third technical solution of the present invention, an aerial display device related to the second technical solution is provided, wherein the orientation control element includes: a planar first substrate; a plurality of first optical element portions, which are arranged under the first substrate, extend in a first direction respectively, and are arranged in a second direction orthogonal to the first direction; and a plurality of shading layers, which are respectively arranged on the plurality of first optical element portions to block light; the plurality of first optical element portions respectively have refractive surfaces and shading surfaces which are respectively inclined relative to the normal direction and connected to each other, and the plurality of shading layers are respectively arranged on the shading surfaces.

[0015] According to a fourth aspect of the present invention, there is provided the aerial display device according to the third aspect, wherein the angle of the refractive surface is larger than the angle of the light shielding surface.

[0016] According to a fifth aspect of the present invention, there is provided an aerial display device according to the first aspect, wherein the optical element reflects light incident from the orientation control element in the oblique direction toward the normal direction.

[0017] According to the sixth technical solution of the present invention, an aerial display device related to the fifth technical solution is provided, wherein the optical element includes: a planar second substrate; and a plurality of second optical element portions, which are arranged under the second substrate, extend in a first direction respectively, and are arranged in a second direction orthogonal to the first direction; the plurality of second optical element portions respectively have incident surfaces and reflection surfaces which are respectively inclined relative to the normal direction and connected to each other.

[0018] According to a seventh aspect of the present invention, there is provided an aerial display device according to the first aspect, wherein the display element, the alignment control element, and the optical element are arranged in parallel with each other.

[0019] According to an eighth technical solution of the present invention, there is provided an aerial display device related to the first technical solution, wherein the aerial display device further comprises an illumination element that emits light, wherein the display element is configured to receive light from the illumination element and is composed of a liquid crystal display element.

[0020] Effects of the Invention

[0021] According to the present invention, an aerial display device capable of improving display quality can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a perspective view of an aerial display device according to an embodiment of the present invention.

[0023] Figure 2 yes Figure 1 A side view of the XZ plane of the aerial display device shown.

[0024] Figure 3 yes Figure 1 A perspective view of the orientation control element is shown.

[0025] Figure 4 yes Figure 2 A side view of the XZ plane of the orientation control element is shown.

[0026] Figure 5 It is a diagram for explaining the angles of the refractive surface and the light shielding surface of the orientation control element.

[0027] Figure 6 yes Figure 1 A perspective view of the optical element shown.

[0028] Figure 7 It is a block diagram of the aerial display device.

[0029] Figure 8 It is a perspective view for explaining the state of reflection of light in an optical element.

[0030] Fig. 9 This is a side view of the XZ plane for explaining the state of reflection of light in the optical element.

[0031] Fig.10 It is a side view taken along the YZ plane for explaining the state of reflection of light in the optical element.

[0032] Fig.11 It is a diagram for explaining the angle conditions of the incident surface and the reflecting surface in the optical element.

[0033] Fig.12 This is a ray tracing diagram of the aerial display device.

[0034] Fig.13 It is a graph explaining the light distribution characteristics of a display element.

[0035] Fig.14 It is a graph explaining the light distribution characteristics of the orientation control element.

[0036] Fig.15 It is a graph illustrating the light distribution characteristics of an optical element.

[0037] Fig.16 It is a cross-sectional view for explaining the method of manufacturing an orientation control element.

[0038] Fig.17 It is a cross-sectional view for explaining the method of manufacturing an orientation control element.

[0039] Fig.18 It is a cross-sectional view for explaining the method of manufacturing an orientation control element.

[0040] Fig.19 It is a cross-sectional view for explaining the method of manufacturing an orientation control element.

[0041] Fig. 20 It is a cross-sectional view for explaining the method of manufacturing an orientation control element.

[0042] Fig.21 It is a cross-sectional view for explaining the method of manufacturing an orientation control element.

[0043] Fig. 22 It is a side view of the XZ plane of the aerial display device of the modified example. DETAILED DESCRIPTION

[0044] Hereinafter, the embodiments will be described with reference to the accompanying drawings. However, the drawings are schematic or conceptual, and the dimensions and ratios of the drawings are not necessarily the same as in reality. In addition, even in the case of representing the same parts between the drawings, there are cases where the relationship or ratio of the mutual dimensions is represented differently. In particular, the several embodiments shown below are merely examples of devices and methods for concretizing the technical ideas of the present invention, and are not intended to limit the technical ideas of the present invention by the shapes, structures, configurations, etc. of the constituent parts. In addition, in the following description, the same figure marks are given to elements having the same functions and structures, and repeated descriptions are omitted.

[0045] [1] Structure of the aerial display device 1

[0046] Figure 1 1 is a perspective view of an aerial display device 1 according to an embodiment of the present invention. Figure 1 In the figure, the X direction is a direction along a certain side of the aerial display device 1, the Y direction is a direction perpendicular to the X direction in the horizontal plane, and the Z direction is a direction perpendicular to the XY plane (also called a normal direction). Figure 2 yes Figure 1 The side view of the XZ plane of the aerial display device 1 is shown.

[0047] The aerial display device 1 is a device for displaying images (including dynamic images). The aerial display device 1 displays an aerial image in the air above its own light emitting surface. "Displaying an aerial image" has the same meaning as "imaging an aerial image". The light emitting surface of the aerial display device 1 refers to the upper surface of the component arranged at the uppermost layer among the multiple components constituting the aerial display device 1. The aerial image is a real image imaged in the air.

[0048] The aerial display device 1 includes an illumination element (also referred to as a backlight) 10, a display element 20, an orientation control element 30, and an optical element 40. 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 arranged parallel to each other. The illumination element 10, the display element 20, the orientation control element 30, and the optical element 40 are fixed at desired positions by a fixing member (not shown) in a manner that they are spaced apart from each other at desired intervals.

[0049] The lighting element 10 emits illumination light and emits the illumination light toward the display element 20. The lighting element 10 includes a light source unit 11, a light guide plate 12, and a reflective sheet 13. The lighting element 10 is, for example, a side-light type lighting element. The lighting element 10 constitutes a surface light source. The lighting element 10 may also be configured so that the light intensity is at a peak in an inclined direction of an angle θ1 described later.

[0050] The light source unit 11 is arranged to face the side surface of the light guide plate 12. The light source unit 11 emits light toward the side surface of the light guide plate 12. The light source unit 11 includes, for example, a plurality of light emitting elements composed of 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 toward the light guide plate 12 again. The lighting element 10 may also have components (including a prism sheet and a diffuser sheet) on the upper surface of the light guide plate 12 that improve optical characteristics.

[0051] The display element 20 is a transmissive display element. The display element 20 is composed of, for example, a liquid crystal display element. There is no particular limitation on the driving mode of the display element 20, and a TN (Twisted Nematic) mode, a VA (Vertical Alignment) mode, or a homogeneous mode, etc., can be used. The display element 20 receives the 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. In addition, the display element 20 displays a desired image on its own display surface.

[0052] The orientation control element 30 has the function of refracting the incident light and reducing the useless light. The useless light is the light component that does not contribute to the generation of the aerial image. The orientation control element 30 refracts the light emitted from the display element 20 in an inclined direction relative to the normal direction orthogonal to the plane. The detailed structure of the orientation control element 30 will be described later.

[0053] The optical element 40 reflects light incident from the bottom surface side toward the upper surface side. In addition, the optical element 40 reflects incident light incident from the bottom surface side in an inclined direction relative to the normal direction orthogonal to the in-plane, for example, toward the front direction (normal direction). The optical element 40 forms an aerial image 2 in the air in front of the aerial display device 1. The detailed structure of the optical element 40 will be described later. The aerial image 2 is parallel to the element surface of the optical element 40 and is a two-dimensional image. "Element surface" refers to a virtual plane of the optical element 40 unfolded in the in-plane direction. "Element surface" has the same meaning as "in-plane". The same meaning is also true for the "element surfaces" of other elements. The observer 3 in front of the optical element 40 can see the aerial image 2.

[0054] [1-1] Structure of the Orientation Control Element 30

[0055] Figure 3 yes Figure 1 A perspective view of the orientation control element 30 is shown. Figure 4 yes Figure 2 A side view of the XZ plane of the orientation control element 30 is shown.

[0056] The orientation control element 30 includes a substrate 31, a plurality of optical elements 32, and a plurality of light shielding layers 35. The substrate 31 is configured to be planar in the XY plane and has a rectangular parallelepiped shape.

[0057] A plurality of optical element portions 32 are provided on the bottom surface of the substrate 31. The plurality of optical element portions 32 are respectively constituted by triangular prisms. The optical element portions 32 are arranged in a manner that the three sides of the triangular prism are parallel to the XY plane, and one side is in contact with the substrate 31. The plurality of optical element portions 32 extend in the Y direction, respectively, and are arranged in an array in the X direction. In other words, the plurality of optical element portions 32 have a sawtooth shape in the XZ plane.

[0058] The plurality of optical elements 32 each have a refractive surface 33 and a light shielding surface 34. When viewed from the Y direction, the side surface on the left is the refractive surface 33, and the side surface on the right is the light shielding surface 34. The refractive surface 33 is a surface that refracts light incident from the bottom surface side of the orientation control element 30. The light shielding surface 34 is a surface that shields light from the bottom surface side of the orientation control element 30.

[0059] The substrate 31 and the optical element portion 32 are made of a transparent material. The optical element portion 32 is formed integrally with the substrate 31, for example, by the same transparent material as the substrate 31. The substrate 31 and the optical element portion 32 may be formed separately, and the optical element portion 32 may be bonded to the substrate 31 using a transparent adhesive. As the transparent material constituting the substrate 31 and the optical element portion 32, for example, glass or a transparent resin (including an acrylic resin) is used.

[0060] A light shielding layer 35 is provided on the light shielding surface 34 of each optical element 32. The light shielding layer 35 has a function of shielding light. The light shielding layer 35 is made of, for example, a material containing a black dye or pigment, a material containing carbon black, or a material containing graphite.

[0061] Figure 5 It is a diagram for explaining the angles of the refractive surface 33 and the light shielding surface 34 of the orientation control element 30.

[0062] The refractive surface 33 is oriented at an angle θ to the normal direction perpendicular to the element surface of the orientation control element 30. 11 The light shielding surface 34 is tilted at an angle θ relative to the normal direction perpendicular to the element surface of the orientation control element 30. 12 The angle θ of the light shielding surface 34 is 12 This has the same meaning as the inclination angle of the light shielding layer 35. The angle θ of the refractive surface 33 11 For example, the angle is set to be in the range of 45 degrees or more and 65 degrees or less. 12 For example, the angle is set to be within the range of 0 degrees or more and 25 degrees or less. 11 is set to be larger than the angle θ of the light shielding surface 34 12 big.

[0063] The orientation control element 30 refracts the light incident from the display element 20 toward the refractive surface 33, and blocks the light incident from the display element 20 toward the light shielding layer 35. The light incident on the refractive surface 33 includes light components that travel within a specified angle range including the normal direction. The light incident on the light shielding layer 35 includes light components that travel within a range to the left and right of the angle range incident on the refractive surface 33. In addition, among the light traveling in the normal direction, the light component of the region occupied by the refractive surface 33 when viewed from above is incident on the refractive surface 33, and the light component of the region occupied by the light shielding layer 35 when viewed from above is incident on the light shielding layer 35. As a result, the orientation control element 30 transmits a portion of the light components of the specified angle range including the normal direction among the light emitted from the display element 20, and blocks a portion of the light components of the light emitted from the display element 20 that travel within a range to the left and right of the above-mentioned specified angle range.

[0064] The alignment control element 30 emits light components in a predetermined angle range centered at angle θ1. Angle θ1 can be adjusted by optimally setting the distance between the alignment control element 30 and the display element 20, the refractive index of the alignment control element 30, the angle of the refractive surface 33, and the angle of the light shielding surface 34.

[0065] [1-2] Structure of the optical element 40

[0066] Figure 6 yes Figure 1 The perspective view of the optical element 40 shown in FIG. Figure 6 An enlarged view of a portion of the optical element 40 is also shown. Figure 6 The enlarged image is a side view of the XZ plane.

[0067] The optical device 40 includes a substrate 41 and a plurality of optical elements 42. The substrate 41 is configured to be planar in the XY plane and has a rectangular parallelepiped shape.

[0068] A plurality of optical element portions 42 are provided on the bottom surface of the substrate 41. The plurality of optical element portions 42 are respectively constituted by triangular prisms. The optical element portion 42 is arranged in a manner that the three sides of the triangular prism are parallel to the XY plane, and one side is in contact with the substrate 41. The plurality of optical element portions 42 extend in the Y direction, respectively, and are arranged in an array in the X direction. In other words, the plurality of optical element portions 42 have a sawtooth shape in the XZ plane.

[0069] The plurality of optical element portions 42 each have an incident surface 43 and a reflective surface 44. When viewed from the Y direction, the side surface on the left is the incident surface 43, and the side surface on the right is the reflective surface 44. The incident surface 43 is a surface on which light from the display element 20 is incident. The reflective surface 44 is a surface on which light incident from the outside to the incident surface 43 is reflected inside the optical element portion 42. The incident surface 43 and the reflective surface 44 have an angle θ p .

[0070] The substrate 41 and the optical element portion 42 are made of a transparent material. The optical element portion 42 is formed integrally with the substrate 41 by, for example, the same transparent material as the substrate 41. The substrate 41 and the optical element portion 42 may be formed separately, and the optical element portion 42 may be bonded to the substrate 41 using a transparent adhesive. As the transparent material constituting the substrate 41 and the optical element portion 42, for example, glass or a transparent resin (including an acrylic resin) is used.

[0071] The optical element 40 configured in this way reflects the incident light inside and forms a real image in the air. In addition, the optical element 40 forms an image in the air at a position in front of the element surface.

[0072] [1-3] Frame structure of aerial display device 1

[0073] Figure 71 is a block diagram of the air display device 1. The air display device 1 includes a control unit 50, a storage unit 51, an input / output interface (I / O IF) 52, a display unit 53, and an input unit 54. The control unit 50, the storage unit 51, and the I / O interface 52 are connected to each other via a bus 55.

[0074] The input / output interface 52 is connected to the display unit 53 and the input unit 54. The input / output interface 52 performs interface processing corresponding to a predetermined standard on the display unit 53 and the input unit 54, respectively.

[0075] The display unit 53 includes the lighting element 10 and the display element 20. The display unit 53 displays an image.

[0076] The control unit 50 is composed of one or more processors such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit). The control unit 50 realizes various functions by executing programs stored in the storage unit 51. The control unit 50 includes a display processing unit 50A and an information processing unit 50B.

[0077] The display processing unit 50A controls the operation of the display unit 53 (specifically, the lighting element 10 and the display element 20). The display processing unit 50A controls the on and off of the lighting element 10. The display processing unit 50A sends an image signal to the display element 20 to cause the display element 20 to display an image.

[0078] The information processing unit 50B generates an image to be displayed on the in-air display device 1. The information processing unit 50B may use image data stored in the storage unit 51. The information processing unit 50B may acquire image data from the outside using a communication function (not shown).

[0079] The storage unit 51 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 51 stores programs executed by the control unit 50. The storage unit 51 stores various data required for the control of the control unit 50. The storage unit 51 stores data of images displayed by the aerial display device 1.

[0080] The input unit 54 includes a touch panel, buttons, etc., and receives information input by a user. The information processing unit 50B can select an image to be displayed on the display unit 53 based on the information received by the input unit 54 .

[0081] [2] Operation of the aerial display device 1

[0082] Next, the operation of the in-air display device 1 configured as described above will be described.

[0083] Figure 2 The arrows indicate the light path. Figure 2 As shown, light is emitted radially from an arbitrary point “o” on the display surface of the display element 20 , with the normal direction as the center. The light emitted from the point “o” of the display element 20 enters the alignment control element 30 .

[0084] Of the light incident on the orientation control element 30, a portion of the light components in a predetermined angle range including the normal direction is incident on the refractive surface 33 of the orientation control element 30. The light incident on the refractive surface 33 of the optical element portion 32 is refracted at the refractive surface 33, and further refracted at the upper surface of the orientation control element 30. Then, the light components in a predetermined angle range centered at the angle θ1 are emitted from the orientation control element 30.

[0085] On the other hand, part of the light components that travel in the range to the left and right of the above-mentioned predetermined angle range among the light incident on the orientation control element 30 is incident on the light shielding layer 35 of the orientation control element 30 and is shielded by the light shielding layer 35. Therefore, part of the useless light that does not contribute to the generation of the aerial image among the light incident on the orientation control element 30 does not pass through the orientation control element 30.

[0086] The light emitted from the alignment control element 30 and traveling in the oblique right direction is incident on the optical element 40. The optical element 40 forms an image of the incident light in the air on the side opposite to the alignment control element 30, and displays an aerial image 2 in the air.

[0087] Figure 8 It is a perspective view for explaining the state of reflection of light in the optical element 40 . Fig. 9 It is a side view taken along the XZ plane for explaining the state of reflection of light in the optical element 40 . Fig. 9 This is a diagram in which the optical element 40 is observed in a state in which both eyes of the observer 3 (that is, a line connecting both eyes) are parallel to the X direction. Fig.10 It is a side view taken along the YZ plane for explaining the state of reflection of light in the optical element 40 . Fig.10 This is a diagram showing the optical element 40 in a state where both eyes of the observer 3 are parallel to the Y direction.

[0088] Light emitted from an arbitrary point "o'" of the orientation control element 30 is incident on the incident surface 43 of the optical element 40 and reaches the reflecting surface 44. Light that arrives at an angle greater than the critical angle relative to the normal direction of the reflecting surface 44 is totally reflected by the reflecting surface 44 and is emitted from the plane on the opposite side of the optical element 40 to the side where the optical element portion 42 is formed. The critical angle is the minimum incident angle at which total reflection occurs if the incident angle is exceeded. The critical angle is an angle relative to the perpendicular line of the incident surface.

[0089] exist Fig. 9 In the XZ plane of FIG. 4 , light emitted from the point “o′” is totally reflected by the reflection surface 44 of the optical element portion 42 , and the light forms an image in the air, thereby generating an aerial image.

[0090] exist Fig.10 In the YZ plane, the light emitted from the point “o′” is not reflected by the reflection surface 44 of the optical element portion 42 , and the light does not form an image in the air, so it does not contribute to the generation of the aerial image.

[0091] That is, the condition for the observer 3 to recognize the aerial image is that the observer's eyes are parallel to or close to the X direction (for example, ±10 degrees relative to the X direction). In addition, when the observer's eyes are parallel to or close to the X direction and the viewpoint is moved along the Y direction, the aerial image can always be recognized.

[0092] Fig.11 1 and 2 are diagrams for explaining the angle conditions of the incident surface 43 and the reflecting surface 44 in the optical element 40 .

[0093] The angle of the incident surface 43 with respect to the Z direction (the direction perpendicular to the element surface) is θ2, the angle of the reflection surface 44 with respect to the Z direction is θ3, and the angle between the incident surface 43 and the reflection surface 44 is θ p Angle θ p It is represented by the following formula (1).

[0094] θ p =θ2+θ3…(1)

[0095] Light emitted from the orientation control element 30 at an angle of θ1 is incident on the incident surface 43. Assume that the refractive index of the material of the optical element 40 is np, and the refractive index of air is 1. Assume that the angle of incidence on the incident surface 43 is θ4, and the angle of refraction on the incident surface 43 is θ5. Assume that the angle of incidence on the reflection surface 44 is θ6, and the angle of reflection on the reflection surface 44 is θ7 (=θ6). Assume that the angle of incidence on the upper surface of the optical element 40 is θ8, and the angle of refraction on the upper surface of the optical element 40 is θ9. The angle of refraction θ9 is the exit angle. The exit angle θ9 is represented by the following formula (2).

[0096] θ9=sin- 1 (n p *sin(sin -1 ((1 / n p )*sin(90°-(θ1+θ2)))+θ2+2θ3-90°))…(2)

[0097] The critical angle on the reflection surface 44 is expressed by the following equation (3).

[0098] Critical angle <θ6(=θ7)

[0099] Critical angle = sin -1 (1 / n9)…(3)

[0100] That is, the incident angle θ6 on the reflecting surface 44 is set to be larger than the critical angle on the reflecting surface 44. In other words, the angle θ3 of the reflecting surface 44 is set so that the incident angle of light incident on the reflecting surface 44 is larger than the critical angle.

[0101] Furthermore, the light incident on the incident surface 43 is set so as not to be totally reflected on 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.

[0102] The angle between the element surface of the optical element 40 and the surface of the aerial image 2 and the distance between the element surface of the optical element 40 and the surface of the aerial 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 reflecting surface 44 of the optical element 40.

[0103] Fig.12 This is a ray tracing diagram of the aerial display device 1.

[0104] Light is emitted radially from an arbitrary point “o” on the display surface of the display element 20 , with the normal direction as the center. Light incident on the alignment control element 30 from the display element 20 is refracted by the alignment control element 30 and passes through the alignment control element 30 .

[0105] according to Fig.12 It can be seen that a light component tilted to the right than the normal direction is emitted from the orientation control element 30. Since the light components to the left and right of the light components emitted from the orientation control element 30 are blocked by the light shielding layer 35 of the orientation control element 30, almost all of them do not pass through the orientation control element 30.

[0106] Light incident obliquely from the orientation control element 30 to the optical element 40 is reflected in the front direction by the optical element 40. Then, the light reflected by the optical element 40 forms an image at point "o". The position of point "o" is the position where the aerial image 2 is displayed.

[0107] Fig.13 It is a graph explaining the light distribution characteristics of the display element 20 . Fig.13 The horizontal axis represents the angle (degrees) at which the observer views the display element 20 along the X direction, and the vertical axis represents the light output ratio (%). An angle of 0 degrees corresponds to the case where the display element 20 is viewed from the normal direction (front). The light distribution characteristics of the lighting element 10 are also similar to Fig.13 The curve graphs are roughly the same.

[0108] When the display element 20 is viewed at an angle of 0 degrees, the output ratio (light intensity) is the maximum. As the angle at which the display element 20 is viewed increases, the output ratio decreases.

[0109] Fig.14 It is a graph explaining the light distribution characteristics of the orientation control element 30 . Fig.14 The horizontal axis represents the angle (degrees) at which the observer views the alignment control element 30 along the X direction, and the vertical axis represents the light output ratio (%). Fig.14 Is has Fig.13 Graph showing the light distribution characteristics when light from the display element 20 enters the alignment control element 30 .

[0110] In the light distribution characteristics of the orientation control element 30, the light intensity peaks at about 25 degrees. With 25 degrees as the center, the output ratio decreases as the viewing angle moves away from the center. More than 60% of the light intensity can be obtained in the angle range of 5 degrees to 45 degrees.

[0111] Fig.15 It is a graph explaining the light distribution characteristics of the optical element 40 . Fig.15 The horizontal axis represents the angle (degrees) at which the observer views the optical element 40 along the X direction, and the vertical axis represents the light output ratio (%). Fig.15 Is has Fig.14 A graph showing the light distribution characteristics of when light is incident on the optical element 40 from the orientation control element 30 .

[0112] In the light distribution characteristics of the optical element 40, the peak of the light intensity is included in the angle range of -10 degrees to 5 degrees. That is, when the observer 3 looks at the aerial display device 1 from the normal direction (front), the aerial image 2 can be seen more clearly. In addition, when the angle is -25 degrees to 10 degrees, a sufficiently large light intensity can also be obtained. Therefore, the aerial display device 1 can display an aerial image with a specified viewing angle.

[0113] [3] Method for manufacturing the orientation control element 30

[0114] Next, a method for manufacturing the orientation control element 30 will be described. Figures 16 to 21 It is a cross-sectional view for explaining a method of manufacturing the orientation control element 30 .

[0115] like Fig.16As shown, an orientation control element 30 without a light-shielding layer 35 is prepared. The orientation control element 30 without a light-shielding layer 35 is called an orientation control element component 30A. The orientation control element component 30A is a component composed of a substrate 31 and a plurality of optical element parts 32. The orientation control element component 30A has a plurality of refractive surfaces 33 and a plurality of light-shielding surfaces 34 that are alternately arranged. The orientation control element component 30A is made of a transparent material, for example, glass or a transparent resin (including an acrylic resin). The orientation control element component 30A is manufactured using an arbitrary manufacturing method. In the manufacturing process, for example, the orientation control element component 30A is configured in a manner such that the plurality of refractive surfaces 33 and the plurality of light-shielding surfaces 34 face upward.

[0116] Then, if Fig.17 As shown, a black UV (ultraviolet) curing paint 35A is uniformly applied on a plurality of refractive surfaces 33 and a plurality of light shielding surfaces 34. The UV curing paint 35A is composed of a resin that cures when irradiated with ultraviolet rays. The UV curing paint 35A contains a black dye or pigment. The UV curing paint 35A is a positive resin whose exposed portion is easily dissolved in a developer.

[0117] Next, the UV curing paint 35A is subjected to a primary curing treatment (pre-baking). The primary curing treatment is a heat treatment. Through the primary curing treatment, the solvent contained in the UV curing paint 35A evaporates. Thus, the UV curing paint 35A is dried and cured.

[0118] Then, if Fig.18 As shown, the UV curing coating 35A is irradiated with ultraviolet light from an oblique direction so that the ultraviolet light is irradiated to the UV curing coating 35A on the refractive surface 33. The ultraviolet irradiation step is performed at an angle such that the ultraviolet light is irradiated to the UV curing coating 35A on the refractive surface 33 but not to the UV curing coating 35A on the light shielding surface 34. Specifically, the ultraviolet light is irradiated to the UV curing coating 35A at an angle equal to or slightly larger than the inclination angle of the light shielding surface 34 relative to the normal direction.

[0119] Then, if Fig.19 As shown, the UV curing paint 35A is developed. That is, the UV curing paint 35A is immersed in a developer 60, and the photosensitive portion (the UV curing paint 35A on the refractive surface 33) is removed.

[0120] Then, if Fig. 20 As shown, the UV curing paint 35A is subjected to a secondary curing process (post-baking). The secondary curing process is a heat treatment. Through the secondary curing process, the light shielding layer 35 is dried, and the adhesion of the light shielding layer 35 is improved.

[0121] In this way, Fig.21 As shown, an orientation control element 30 including a light shielding layer 35 is formed.

[0122] [4] Modifications

[0123] Next, a modification of the in-air display device 1 will be described. Fig. 22 It is a side view of the XZ plane of the air display device 1 of the modification. The orientation control element 30 may be arranged between the lighting element 10 and the display element 20. In the air display device 1 of the modification, the same operation as that of the above-mentioned embodiment can be realized.

[0124] [5] Effects of implementation

[0125] According to the embodiment of the present invention, the aerial image 2 can be displayed in the air by reflecting the light emitted from the display element 20 by the optical element 40. In addition, the aerial image 2 can be displayed in the front direction of the aerial display device 1. In addition, the aerial display device 1 can improve the display quality.

[0126] Furthermore, the alignment control element 30 refracts light emitted from the display element 20 in an oblique direction relative to the normal direction perpendicular to the plane. Thus, the optical element 40 can receive oblique light, and as a result, the display quality of the aerial image 2 can be improved.

[0127] Furthermore, the alignment control element 30 can block a portion of unnecessary light that does not contribute to the display of the aerial image 2 among the light emitted from the display element 20. Thus, the display quality of the aerial image 2 can be improved.

[0128] In addition, when the eyes of the observer 3 view the optical element 40 in a state parallel to or close to the X direction (i.e., the direction in which the plurality of optical element portions 42 are arranged), the observer 3 can see the aerial image. In addition, when the eyes of the observer 3 move the viewpoint along the Y direction in a state parallel to or close to the X direction, the aerial image can always be seen. That is, when the eyes of the observer 3 are parallel to or close to the X direction, the viewing angle can be ensured.

[0129] Furthermore, a plurality of elements constituting the aerial display device 1 can be arranged in parallel. Thus, the aerial display device 1 capable of being miniaturized in the Z direction can be realized.

[0130] In the above-mentioned embodiment, the side surface on the left side of the optical element portion 42 is defined as the incident surface 43, and the side surface on the right side of the optical element portion 42 is defined as the reflection surface 44. However, this is not limited to this, and the incident surface 43 and the reflection surface 44 may be configured inversely. In this case, the positional relationship between the refractive surface 33 and the light shielding surface 34 of the orientation control element 30 is also reversed. In addition, the function of the aerial display device 1 described in the embodiment is also reversed left and right.

[0131] In the above embodiment, as the display element 20, a liquid crystal display element is used as an example for description, but it is not limited to this, and various types of display elements can be used. The display element 20 can use, for example, a self-luminous organic EL (electroluminescence) display element or a micro LED (Light Emitting Diode) display element. The micro LED display element is a display element that makes the R (red), G (green), and B (blue) constituting the pixel emit light using LEDs. When using a self-luminous display element 20, the lighting element 10 is not required.

[0132] The present invention is not limited to the above-mentioned embodiments, and various modifications can be made in the implementation stage without departing from the scope of the main purpose. In addition, each embodiment can also be implemented in combination as appropriate, in which case the effect of the combination can be obtained. Moreover, the above-mentioned embodiments include various inventions, and various inventions can be extracted by combining selected from the disclosed multiple constituent elements. For example, in the case where the problem can be solved and the effect can be obtained even if some constituent elements are removed from all the constituent elements shown in the embodiments, the structure in which the constituent elements are removed can be extracted as an invention.

[0133] Description of Reference Numerals

[0134] 1…aerial display device; 2…aerial image; 3…observer; 10…illumination element; 11…light source unit; 12…light guide plate; 13…reflection sheet; 20…display element; 30…orientation control element; 30A…orientation control element component; 31…substrate; 32…optical element unit; 33…refractive surface; 34…light shielding surface; 35…light shielding layer; 35A…UV curing coating; 40…optical element; 41…substrate; 42…optical element unit; 43…incident surface; 44…reflection surface; 50…control unit; 50A…display processing unit; 50B…information processing unit; 51…storage unit; 52…input / output interface; 53…display unit; 54…input unit; 55…bus; 60…developer

Claims

1. An aerial display device, characterized in that: have: A display component for displaying an image; an alignment control element configured to receive light emitted from the display element and refract the light emitted from the display element in an inclined direction relative to a normal direction orthogonal to the plane; as well as The optical element is configured to receive the light emitted from the alignment control element, reflect the light emitted from the alignment control element to the side opposite to the alignment control element, and form an aerial image in the air.

2. The aerial display device according to claim 1, characterized in that: The alignment control element transmits a portion of light components within an angle range including the normal direction, among the light emitted from the display element.

3. The aerial display device according to claim 2, characterized in that: The orientation control element comprises: A planar first substrate; a plurality of first optical elements disposed under the first substrate, extending in a first direction and arranged in a second direction orthogonal to the first direction; and A plurality of light shielding layers are respectively provided on the plurality of first optical element portions to shield light; The plurality of first optical elements respectively have refractive surfaces and light shielding surfaces which are inclined with respect to the normal direction and are in contact with each other. The plurality of light shielding layers are respectively arranged on the light shielding surfaces.

4. The aerial display device according to claim 3, characterized in that: The angle of the refractive surface is larger than the angle of the light shielding surface.

5. The aerial display device according to claim 1, characterized in that: The optical element reflects light incident from the alignment control element in the oblique direction toward the normal direction.

6. The aerial display device according to claim 5, characterized in that: The optical element comprises: a planar second substrate; and A plurality of second optical elements are provided under the second substrate, extend in the first direction, and are arranged in a second direction orthogonal to the first direction; The plurality of second optical element portions each include an incident surface and a reflecting surface that are inclined with respect to the normal direction and are in contact with each other.

7. The aerial display device according to claim 1, characterized in that: The display element, the alignment control element, and the optical element are arranged in parallel with each other.

8. The aerial display device according to claim 1, characterized in that: The aerial display device further comprises a lighting element for emitting light. The display element is configured to receive light from the illumination element and is composed of a liquid crystal display element.

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