JP2024064078A - Aerial Display Device - Google Patents

Abstract

[Problem] To provide an aerial display device that allows a user to more clearly recognize that an aerial image has been touched. [Solution] The aerial display device includes a display element 20 that displays an image, an optical element 40 that is arranged to receive light from the display element 20 and reflects the light from the display element 20 to the opposite side of the display element 20 to form an aerial image in the air, a sensing element 50 that forms a detection area in a spatial area that includes the aerial image and detects an object within the detection area, and an illumination element 61 that irradiates light onto the object when the object is present in the area of the aerial image. [Selected Figure] Figure 1

Description

The present invention relates to an aerial display device.

Aerial display devices capable of displaying images and videos as aerial images are being researched, and are expected to become a new human-machine interface. For example, an aerial display device may be equipped with a two-sided corner reflector array in which two-sided corner reflectors are arranged in an array, and it reflects light emitted from the display surface of a display element to form 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.

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 dihedral corner reflector, and multiple rectangular prisms are arranged in an array on a flat surface. Patent Document 2 discloses an optical element in which each of the first and second light control panels is formed by arranging multiple planar light reflecting sections vertically inside a transparent flat plate, and the first and second light control panels are arranged so that the planar light reflecting sections are orthogonal to each other. The optical elements of Patent Documents 1 and 2 reflect light emitted from a display element twice at orthogonal reflecting surfaces to generate an aerial image.

For example, if a push button is displayed as a mid-air image, the observer can operate the button without touching the device. In this case, it is necessary to make it clearer that the observer has pressed the button.

JP 2011-191404 A JP 2011-175297 A

The present invention provides an aerial display device that allows users to more clearly recognize when they have touched an aerial image.

According to a first aspect of the present invention, there is provided an aerial display device comprising: a display element for displaying an image; an optical element arranged to receive light from the display element and reflect the light from the display element to the opposite side of the display element to form an aerial image in the air; a sensing element for forming a detection area in a spatial region including the aerial image and detecting an object in the detection area; and an illumination element for irradiating light onto the object when the object is present in the area of the aerial image.

According to a second aspect of the present invention, there is provided an aerial display device according to the first aspect, in which the lighting elements include a plurality of first light-emitting elements arranged along the surface of the detection area.

According to a third aspect of the present invention, there is provided an aerial display device according to the second aspect, further comprising a determination unit that causes one of the plurality of first light-emitting elements to emit light corresponding to the position of the target object.

According to a fourth aspect of the present invention, there is provided an aerial display device according to the first aspect, in which the lighting element irradiates a blinking light on the object when the object is present at the edge of the area of the aerial image.

According to a fifth aspect of the present invention, there is provided an aerial display device according to the first aspect, further comprising a warm lighting element that irradiates the object with far-infrared light when the object is present in the area of the aerial image.

According to a sixth aspect of the present invention, there is provided an aerial display device according to the fifth aspect, in which the warm lighting element includes a plurality of second light-emitting elements arranged along the surface of the detection area.

According to a seventh aspect of the present invention, there is provided an aerial display device according to the sixth aspect, further comprising a determination unit that causes one of the plurality of second light-emitting elements to emit light corresponding to the position of the target object.

According to an eighth aspect of the present invention, there is provided an aerial display device according to the first aspect, in which the sensing element includes a light-emitting section that emits light toward the detection area and a light-receiving section that receives the light reflected by the object.

According to a ninth aspect of the present invention, there is provided an aerial display device according to the first aspect, in which the optical element includes a planar substrate and a plurality of optical elements disposed below the substrate, each extending in a first direction and aligned in a second direction perpendicular to the first direction, each of the plurality of optical elements being inclined with respect to the normal direction of the substrate and having an entrance surface and a reflection surface that are in contact with each other.

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

According to an eleventh aspect of the present invention, there is provided an aerial display device according to the tenth aspect, in which the alignment control element includes a plurality of transparent members and a plurality of light blocking members arranged alternately, and the plurality of light blocking members are inclined with respect to the normal to the alignment control element.

According to a twelfth aspect of the present invention, there is provided an aerial display device according to the first aspect, in which the display element and the optical element are arranged parallel to each other.

The present invention provides an aerial display device that allows users to more clearly recognize when they have touched an aerial image.

FIG. 1 is a perspective view of an aerial display device according to a first embodiment of the present invention. FIG. 2 is a perspective view of a portion of the aerial display device. FIG. 3 is a side view of the main part of the aerial display device in the XZ plane. FIG. 4A is a plan view of the alignment control element shown in FIG. FIG. 4B is a cross-sectional view of the alignment control element taken along line AA' in FIG. 4A. FIG. 5 is a perspective view of the optical element shown in FIG. FIG. 6 is a side view of a partial area of a lighting element included in the lighting device. FIG. 7 is a perspective view of one light emitting element shown in FIG. FIG. 8 is a block diagram of an aerial display device. FIG. 9 is a perspective view illustrating the state of light reflection in an optical element. FIG. 10 is a side view of the XZ plane for explaining how light is reflected in the optical element. FIG. 11 is a side view of the YZ plane for explaining how light is reflected in the optical element. FIG. 12 is a diagram for explaining the angular conditions of the incident surface and the reflecting surface in the optical element. FIG. 13 is a perspective view illustrating the light irradiation operation. FIG. 14 is a bottom view illustrating the light irradiation operation. FIG. 15 is a flowchart explaining the overall operation of the aerial display device. FIG. 16 is a bottom view illustrating a light irradiation operation according to the second embodiment of the present invention. FIG. 17 is a flowchart explaining the overall operation of the aerial display device. FIG. 18 is a perspective view of a portion of an aerial display device according to a third embodiment of the present invention. FIG. 19 is a side view of a partial area of the warm lighting element. FIG. 20 is a bottom view illustrating the light irradiation operation. FIG. 21 is a flowchart explaining the overall operation of the aerial display device. FIG. 22 is a perspective view of an aerial display device according to a fourth embodiment of the present invention. FIG. 23 is a perspective view of a portion of the aerial display device. FIG. 24A is a side view of the optical element shown in FIG. 22 in the X'Z' plane. FIG. 24B is a bottom view of the optical element shown in FIG.

The following describes the embodiments with reference to the drawings. However, the drawings are schematic or conceptual, and the dimensions and ratios of each drawing are not necessarily the same as those in reality. Furthermore, even when the same parts are shown in different drawings, the dimensional relationships and ratios between the drawings may be different. In particular, the following embodiments are examples of devices and methods for embodying the technical idea of the present invention, and the shape, structure, arrangement, etc. of the components do not specify the technical idea of the present invention. In the following description, elements having the same function and configuration are given the same reference numerals, and duplicate descriptions are omitted.

[1] First embodiment [1-1] Configuration of the aerial display device 1 Fig. 1 is a perspective view of the aerial display device 1 according to the first embodiment of the present invention. In Fig. 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). Fig. 2 is a perspective view of a part of the aerial display device 1 (sensing element 50 and lighting device 60). Fig. 3 is a side view of the main part of the aerial display device 1 in the XZ plane.

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 emission surface. The light emission surface of the aerial display device 1 refers to the upper surface of the component that is arranged in the uppermost layer among multiple components used to display the aerial image. An aerial image is a real image that is formed in the air.

The aerial display device 1 comprises a backlight 10, a display element 20, an orientation control element 30, an optical element 40, a sensing element 50, an illumination device 60, and a housing 70. The backlight 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 parallel to one another. The backlight 10, the display element 20, the orientation control element 30, and the optical element 40 are fixed at desired positions with fixing members (not shown) so as to leave a desired distance between each other.

The backlight 10 emits illumination light and outputs the illumination light toward the display element 20. The backlight 10 includes a light source unit 11, a light guide plate 12, and a reflective sheet 13. The backlight 10 is, for example, a side light type backlight. The backlight 10 constitutes a surface light source. The backlight 10 may be configured so that the light intensity reaches a peak in an oblique direction at an angle _θ1 , which will be described later.

The light source unit 11 is disposed 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, for example, 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 reflection 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 backlight 10 may be provided with a member (including a prism sheet and a diffusion sheet) that improves optical characteristics on the upper surface of the light guide plate 12.

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

The orientation control element 30 has a function of reducing unnecessary light. The unnecessary light is a light component that does not contribute to generating an aerial image, and includes a light component that transmits through the optical element 40 in the normal direction. The orientation control element 30 is configured to transmit light components in a predetermined angular range centered on an oblique direction at an angle θ ₁ with respect to the normal direction, and to block light components outside the above-mentioned angular range. The area of the orientation control element 30 is set to be approximately the same as the area of the display element 20. A detailed configuration of the orientation control element 30 will be described later.

The optical element 40 reflects light incident from the bottom side to the top side. The optical element 40 also reflects light incident obliquely from the bottom side, for example, in the front direction (normal direction). The area of the optical element 40 is set to be equal to or larger than the area of the display element 20. The detailed configuration of the optical element 40 will be described later. The optical element 40 forms an aerial image 2 in the air. The aerial image 2 is parallel to the element surface of the optical element 40 and is a two-dimensional image. The element surface refers to a virtual plane on which the optical element 40 extends in the in-plane direction. The element surface has the same meaning as in-plane. The element surfaces of the other elements have the same meaning. An observer 3 in front of the optical element 40 can view the aerial image 2.

The sensing element 50 is disposed on one side of the aerial display device 1, above the optical element 40 and at approximately the same level as the aerial image 2. The sensing element 50 forms a detection area in a two-dimensional spatial area including a part or all of the aerial image 2 generated by the aerial display device 1. The sensing element 50 detects an object (body) present in the detection area. The sensing element 50 emits infrared light into the detection area and detects the reflected light reflected by the object. The sensing element 50 includes a light-emitting unit that emits infrared light toward the detection area and a light-receiving unit (sensor) that detects the reflected light reflected by the object. The sensing element 50 is, for example, composed of a line sensor in which multiple light-emitting elements and multiple light-receiving elements are alternately arranged in a row. The line sensor can scan space in a line using infrared light, and can scan a two-dimensional space consisting of the direction in which multiple light-emitting elements are arranged and the direction in which light travels. The direction of the infrared light emitted by the sensing element 50 can be set appropriately.

The lighting device 60 has the function of irradiating light onto an object present in the detection area of the sensing element 50. The lighting device 60 comprises four lighting elements 61-1 to 61-4 arranged on each of the four sides of the aerial display device 1. Each of the lighting elements 61-1 to 61-4 is arranged above the optical element 40 and at approximately the same level as the aerial image 2. Each of the lighting elements 61-1 to 61-4 is configured to be able to irradiate light onto the entire detection area. Each of the lighting elements 61-1 to 61-4 comprises a substrate extending in one direction and a plurality of light-emitting elements mounted on the substrate. The multiple light-emitting elements are aligned in one direction. The specific configuration of the lighting device 60 will be described later.

The housing 70 houses the sensing element 50 and the lighting device 60. The housing 70 is disposed above the optical element 40. The housing 70 has a rectangular shape in a plan view. The sensing element 50 and the lighting device 60 are attached to the inner surface of the housing 70 using a support member (not shown). The housing 70 has an opening 71 at the top that exposes the optical element 40. The aerial image 2 is viewed by the observer 3 through the opening 71. The housing 70 is made of a colored resin, for example, black.

[1-1-1] Configuration of the alignment control element 30 Fig. 4A is a plan view of the alignment control element 30 shown in Fig. 1. Fig. 4B is a cross-sectional view of the alignment control element 30 taken along the line AA' in Fig. 4A.

The substrate 31 is configured to be planar in the XY plane and has a rectangular parallelepiped shape. The substrate 31 transmits light.

On the base material 31, a plurality of transparent members 33 are provided, each extending in the Y direction and aligned in the X direction. Also, on the base material 31, a plurality of light-shielding members 34 are provided, each extending in the Y direction and aligned in the X direction. The plurality of transparent members 33 and the plurality of light-shielding members 34 are alternately arranged such that adjacent ones are in contact with each other.

A substrate 32 is provided on the plurality of transparent members 33 and the plurality of light-shielding members 34. The substrate 32 is configured to be planar in the XY plane and has a rectangular parallelepiped shape. The substrate 32 transmits light.

The transparent member 33 extends in an oblique direction at an angle θ ₁ with respect to the normal direction of the base material 31 in the XZ plane. The transparent member 33 is a parallelogram with a side surface inclined by the angle θ ₁ in the XZ plane. The transparent member 33 transmits light.

The light blocking member 34 extends in an oblique direction at an angle θ ₁ with respect to the normal direction of the base material 31 in the XZ plane. The light blocking member 34 is a parallelogram with side surfaces inclined by an angle θ ₁ in the XZ plane. The light blocking member 34 blocks light. The thickness of the light blocking member 34 is set to be thinner than the thickness of the transparent member 33.

Two adjacent light blocking members 34 are positioned so that their ends slightly overlap in the Z direction.

Glass or transparent resin (including acrylic resin) is used for the base materials 31 and 32 and the transparent member 33. For example, resin mixed with black dye or pigment is used for the light blocking member 34.

The alignment control element 30 may be constructed by omitting one or both of the substrates 31 and 32. The function of the alignment control element 30 can be realized if multiple transparent members 33 and multiple light blocking members 34 are arranged alternately.

The orientation control element 30 configured in this manner can transmit the display light so that the light intensity in the oblique direction at an angle θ ₁ with respect to the normal direction becomes a peak. For example, the orientation control element 30 is configured to block light components other than the range of 30°±30° with respect to the normal direction. Desirably, the orientation control element 30 is configured to block light components other than the range of 30°±20° with respect to the normal direction.

As a modified example, the alignment control element 30 may be disposed between the backlight 10 and the display element 20. Also, the alignment control element 30 may be omitted to configure the aerial display device 1.

[1-1-2] Configuration of the Optical Element 40 Fig. 5 is a perspective view of the optical element 40 shown in Fig. 1. Fig. 5 also shows an enlarged view of a portion of the optical element 40. The enlarged view in Fig. 5 is a side view in the XZ plane.

The optical element 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.

A plurality of optical elements 42 are provided on the bottom surface of the substrate 41. Each of the plurality of optical elements 42 is formed as a triangular prism. The optical element 42 is arranged so that three side surfaces of the triangular prism are parallel to the XY plane, and one side surface is in contact with the substrate 41. The plurality of optical elements 42 each extend in the Y direction and are arranged side by side in the X direction. In other words, the plurality of optical elements 42 have a sawtooth shape in the XZ plane.

Each of the multiple optical elements 42 has an incident surface 43 and a reflective surface 44. When viewed from the Y direction, the left side surface is the incident surface 43, and the right side surface is the reflective surface 44. The incident surface 43 is a surface onto which light from the display element 20 is incident. The reflective surface 44 is a surface that reflects light that has been incident on the incident surface 43 from the outside, within the optical element 42. The incident surface 43 and the reflective surface 44 form an angle θ _p .

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

The optical element 40 configured in this way internally reflects incident light and forms a real image in the air. The optical element 40 also forms an aerial image 2 at a position in front of the element surface.

[1-1-3] Configuration of Illumination Device 60 As shown in Fig. 2, illumination device 60 includes four illumination elements 61-1 to 61-4. Fig. 6 is a side view of a partial area of illumination element 61-1 included in illumination device 60. Illumination elements 61-2 to 61-4 have the same configuration as illumination element 61-1.

The lighting element 61-1 is positioned so that it can irradiate light toward the detection area of the sensing element 50. The lighting element 61-1 includes a substrate 62 and a plurality of light-emitting elements 63. The substrate 62 is configured to extend in one direction. The substrate 62 includes an insulating substrate made of resin or the like, and a wiring layer provided on the upper surface and/or inside the insulating substrate.

The multiple light-emitting elements 63 are arranged in a row along the extension direction of the substrate 62 with a predetermined distance between adjacent elements. The number of the multiple light-emitting elements 63 and the size of each element can be set appropriately.

Figure 7 is a perspective view of one light-emitting element 63 shown in Figure 6. The light-emitting element 63 includes a substrate 64, a red LED (light-emitting diode) 65R, a green LED 65G, a blue LED 65B, lead frames 66-1 and 66-2, and a sealing resin 67.

The substrate 64 comprises an insulating substrate made of resin or the like, and a wiring layer provided on the upper surface and/or inside the insulating substrate. The substrate 64 may be a metal-based substrate with excellent heat dissipation properties. The metal-based substrate is formed by laminating a metal substrate, an insulating layer, and a wiring layer in this order.

The red LED 65R emits red light. The green LED 65G emits green light. The blue LED 65B emits blue light. The red LED 65R, the green LED 65G, and the blue LED 65B are mounted on the substrate 64 and electrically connected to a wiring layer included in the substrate 64.

The lead frames 66-1 and 66-2 are electrically connected to the wiring layer of the substrate 62. A ground voltage and a positive voltage are applied to the lead frames 66-1 and 66-2.

The sealing resin 67 seals the substrate 64, the red LED 65R, the green LED 65G, and the blue LED 65B. The sealing resin 67 is made of a transparent resin.

The lighting elements 61-1 to 61-4 configured in this manner can emit red light, green light, blue light, or a mixed color light that is a mixture of two of these three colors. Furthermore, each of the lighting elements 61-1 to 61-4 can irradiate light at a specific position in the detection area of the sensing element 50 by causing at least one light-emitting element 63 corresponding to the position of the target object to emit light.

[1-1-4] 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 includes a control unit 80, a memory unit 81, an input/output interface (input/output IF) 82, a display unit 83, a sensing element 50, a lighting device 60, and an input unit 84. The control unit 80, the memory unit 81, and the input/output interface 82 are connected to each other via a bus 85.

The input/output interface 82 is connected to the display unit 83, the sensing element 50, the lighting device 60, and the input unit 84. The input/output interface 82 performs interface processing according to a predetermined standard for each of the display unit 83, the sensing element 50, the lighting device 60, and the input unit 84.

The display unit 83 includes a backlight 10 and a display element 20. The display unit 83 displays an image.

The sensing element 50 includes a light-emitting unit 51 and a light-receiving unit 52. The light-emitting unit 51 emits infrared light toward a detection area 53. The light-receiving unit 52 detects the light reflected by an object.

The control unit 80 is composed of one or more processors such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The control unit 80 realizes various functions by executing programs stored in the memory unit 81. The control unit 80 includes a display processing unit 80A, an information processing unit 80B, a detection position calculation unit 80C, and a light irradiation determination unit 80D.

The display processing unit 80A controls the operation of the display unit 83 (specifically, the backlight 10 and the display element 20). The display processing unit 80A controls the on and off of the backlight 10. The display processing unit 80A transmits an image signal to the display element 20, causing the display element 20 to display an image.

The information processing unit 80B generates an image to be displayed by the aerial display device 1. The information processing unit 80B can use image data stored in the memory unit 81. The information processing unit 80B may also acquire image data from outside using a communication function (not shown).

The detection position calculation unit 80C controls the operation of the sensing element 50. The detection position calculation unit 80C controls the light emitting unit 51 included in the sensing element 50 to emit infrared light, and forms a detection area consisting of infrared light in a specified spatial region. The detection position calculation unit 80C calculates the position of the target object based on multiple detection signals sent from the light receiving unit 52 included in the sensing element 50.

The light irradiation determination unit 80D uses the calculation result by the detection position calculation unit 80C to determine whether or not the object is present within the set area (the area occupied by the aerial image 2). If the object is present within the set area, the light irradiation determination unit 80D controls the lighting device 60 to irradiate the object with light.

The storage unit 81 includes non-volatile storage devices such as a ROM (Read Only Memory), a HDD (Hard Disk Drive), and a SSD (Solid State Drive), and volatile storage devices such as a RAM (Random Access Memory) and a register. The storage unit 81 stores the programs executed by the control unit 80. The storage unit 81 stores various data necessary for the control of the control unit 80. Furthermore, the storage unit 81 stores data for images displayed by the aerial display device 1.

The input unit 84 includes, for example, a touch panel or buttons, and receives information input by the user. The information processing unit 80B can select an image to be displayed on the display unit 83 based on the information received by the input unit 84.

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

[1-2-1] Display Operation of the Aerial Image 2 First, the display operation of the aerial image 2 will be described.

The arrows in Fig. 3 indicate optical paths. As shown in Fig. 3, light emitted from an arbitrary point "o" of the display element 20 is incident on the orientation control element 30. Of the light emitted from the display element 20, a light component at an angle _θ1 (including a light component in a predetermined angle range centered on the angle _θ1 ) is transmitted through the orientation control element 30. The light transmitted through the orientation control element 30 is incident on the optical element 40. The optical element 40 reflects the incident light to the opposite side to the orientation control element 30, and forms an aerial image 2 in the air.

Figure 9 is a perspective view illustrating how light is reflected in the optical element 40. Figure 10 is a side view of the XZ plane illustrating how light is reflected in the optical element 40. Figure 10 is a diagram of the optical element 40 viewed with both eyes of the observer 3 (i.e., the line connecting the eyes) parallel to the X direction. Figure 11 is a side view of the YZ plane illustrating how light is reflected in the optical element 40. Figure 11 is a diagram of the optical element 40 viewed with both eyes of the observer 3 parallel to the Y direction.

Light emitted from an arbitrary point "o" of the display element 20 enters the incident surface 43 of the optical element 40 and reaches the reflecting surface 44. Light that reaches the reflecting surface 44 at an angle greater than the critical angle with respect to the normal direction of the reflecting surface 44 is totally reflected by the reflecting surface 44 and is emitted from the flat surface opposite the side on which the optical element 40's optical elements 42 are formed. The critical angle is the smallest incident angle above which total reflection occurs. The critical angle is the angle with respect to the normal to the incident surface.

In the XZ plane of FIG. 10, the light emitted from point "o" is totally reflected by the reflecting surface 44 of the optical element 42, and the light is focused in the air to generate an aerial image.

In the YZ plane of FIG. 11, the light emitted from point "o" is not reflected by the reflecting surface 44 of the optical element 42, and the light does not form an image in the air, so it does not contribute to the generation of an aerial image.

In other words, the condition for observer 3 to be able to see the aerial image is that both eyes of observer 3 are parallel to the X direction or close to it (for example, ±10 degrees with respect to the X direction). Also, if observer 3's eyes are parallel to the X direction or close to it and the viewpoint is moved along the Y direction, the aerial image can always be recognized.

Figure 12 is a diagram explaining the angular conditions of the incident surface 43 and the reflecting surface 44 of the optical element 40.

The angle of the incident surface 43 with respect to the Z direction (the direction perpendicular to the element surface) is θ ₂ , the angle of the reflecting surface 44 with respect to the Z direction is θ ₃ , and the angle between the incident surface 43 and the reflecting surface 44 is θ _p . The angle θ _p is expressed by the following formula (1).
θ _p = θ ₂ + θ ₃ ... (1)

Light emitted from orientation control element 30 at an angle θ ₁ is incident on incident surface 43. The refractive index of the material of optical element 40 is n _p , and the refractive index of air is 1. The incident angle at incident surface 43 is θ ₄ , and the refraction angle is θ _5. The incident angle at reflecting surface 44 is θ ₆ , and the reflection angle is θ ₇ (=θ ₆ ). The incident angle at the top surface of optical element 40 is θ ₈ , and the refraction angle is θ _9. The refraction angle θ ₉ is the emission angle. The emission angle θ ₉ is expressed by the following equation (2).
θ ₉ = sin ⁻¹ (n _p * sin (sin ⁻¹ ((1/n _p ) * sin (90° - (θ ₁ + θ ₂ )))) + θ ₂ + 2θ ₃ - 90°)) ... (2)

The critical angle at the reflecting surface 44 is expressed by the following formula (3).
Critical angle < θ ₆ (= θ ₇ )
Critical angle = sin ⁻¹ (1/n _p ) (3)

That is, the angle of incidence _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 angle of incidence of light incident on the reflecting surface 44 is larger than the critical angle.

Moreover, the angle θ2 of the incident surface 43 is set so that the light incident on the incident surface 43 is not totally reflected by the incident surface 43. In other words, the angle _θ2 of the incident surface 43 is set so that the angle of incidence of the light incident on the incident surface 43 is smaller than the critical angle.

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 θ ₁ of light incident on the optical element 40, the refractive index of the optical element 40, the angle θ ₂ of the incident surface 43 of the optical element 40, and the angle θ ₃ of the reflecting surface 44 of the optical element 40.

[1-2-2] Light Irradiation Operation Next, the light irradiation operation for irradiating an object with light will be described. Fig. 13 is a perspective view for explaining the light irradiation operation. Fig. 14 is a bottom view (a view of the aerial image 2 seen from below) for explaining the light irradiation operation. The light-emitting elements 63 included in the illumination elements 61-1 to 61-4, respectively, are represented as light-emitting elements 63-1 to 63-4.

The aerial display device 1 displays an aerial image 2. The aerial image 2 is, for example, a push button. The sensing element 50 forms a detection area 53 in a two-dimensional spatial region that includes the aerial image 2. The detection area 53 is composed of infrared light.

The observer 3 presses the aerial image 2 with his/her finger 3A. The sensing element 50 detects the object (the observer's finger 3A) included in the detection area 53. The detection result of the sensing element 50 is sent to the detection position calculation unit 80C. The detection position calculation unit 80C calculates the position of the object based on the detection result of the sensing element 50.

The light irradiation determination unit 80D determines whether the position of the object calculated by the detection position calculation unit 80C is included in the area of the aerial image 2. If the position of the object is included in the area of the aerial image 2, the light irradiation determination unit 80D controls the lighting device 60 to irradiate the object with light. That is, the lighting elements 61-1 to 61-4 each cause the light-emitting elements 63-1 to 63-4 corresponding to the position of the object to emit light of a predetermined color. The number of light-emitting elements emitted by each of the lighting elements 61-1 to 61-4 may be one or two or more. In addition, the number of light-emitting elements emitted by each of the lighting elements 61-1 to 61-4 may be set according to the size of the object. The number of light-emitting elements that emit light may be increased as the size of the object increases. The color of light emitted by the light-emitting elements 63-1 to 63-4 can be set arbitrarily.

The light emitted from the light-emitting elements 63-1 to 63-4 is irradiated onto the target object (the finger 3A of the observer 3). The observer 3 visually recognizes the light of a specific color irradiated onto his or her finger 3A. This allows the observer 3 to recognize that the push button on the aerial image 2 has been pressed.

[1-2-3] Flow of Overall Operation Next, a description will be given of a flow of overall operation in the aerial display device 1. FIG.

The control unit 80 displays the aerial image 2 (step S100). The display processing unit 80A displays an image on the screen of the display element 20. The optical element 40 reflects light from the display element 20 and forms the aerial image 2 in the air.

Next, the sensing element 50 performs a sensing operation (step S101). The light-emitting unit 51 included in the sensing element 50 emits infrared light to a detection area 53 including the area where the aerial image 2 is displayed.

Next, the sensing element 50 monitors whether or not an object is present within the detection area 53 (step S102). That is, the light receiving unit 52 included in the sensing element 50 monitors the infrared light reflected by the object.

If the sensing element 50 detects an object (S102 = Yes), the detection position calculation unit 80C calculates the position of the object based on the detection signal of the sensing element 50 (step S103).

Next, the light irradiation determination unit 80D determines whether or not the target object is present within the set area (step S104). The set area refers to the area occupied by the aerial image 2. Information on the set area is set in advance according to the image of the aerial image 2, and the information is stored in the storage unit 81.

If the object is present within the set area (S104 = Yes), the light irradiation determination unit 80D controls the lighting device 60 to irradiate the object with light (step S105). The operation of the lighting device 60 is as described above.

[1-3] Advantages of the First Embodiment According to the first embodiment, when it is detected that an object (for example, the finger of the observer 3) has touched the aerial image 2, it is possible to irradiate the finger of the observer 3 with light of any color. This allows the observer to more clearly recognize that he or she has touched the aerial image 2.

The aerial display device 1 can display an aerial image 2 in the air by reflecting light emitted from the display element 20 by the optical element 40. The aerial display device 1 can display the aerial image 2 in the front direction, parallel to the element surface of the optical element 40. It is also possible to realize an aerial display device 1 that can improve display quality.

When the observer 3 looks at the optical element 40 with both eyes parallel to or close to the X direction (i.e., the direction in which the multiple optical elements 42 are arranged), the observer 3 can see an aerial image. When the observer 3 moves the viewpoint along the Y direction with both eyes parallel to or close to the X direction, the observer 3 can always see an aerial image. When the observer 3's eyes are parallel to or close to the X direction, a wider viewing angle can be achieved.

In addition, the multiple elements that make up the aerial display device 1 can be arranged in parallel. This makes it possible to realize an aerial display device 1 that can be made smaller in size in the Z direction.

[2] Second Embodiment In the second embodiment, when the finger of the observer 3 is present at the edge of the aerial image 2, a blinking light is irradiated onto the finger of the observer 3.

Figure 16 is a bottom view (aerial image 2 viewed from below) explaining the light irradiation operation according to the second embodiment of the present invention. The configuration of the aerial display device 1 is the same as that of the first embodiment.

The aerial display device 1 displays an aerial image 2. The sensing element 50 forms a detection area 53 in a two-dimensional spatial region that includes the aerial image 2. The observer 3 presses the aerial image 2 with his or her finger 3A. At this time, the position of the observer 3's finger 3A is assumed to be the edge of the aerial image 2. The edge of the aerial image 2 refers to the outer periphery edge of the region occupied by the aerial image 2.

The sensing element 50 detects an object (the finger 3A of the observer 3) included in the detection area 53. The detection result of the sensing element 50 is sent to the detection position calculation unit 80C. The detection position calculation unit 80C calculates the position of the object based on the detection result of the sensing element 50.

The light irradiation determination unit 80D determines whether the position of the object calculated by the detection position calculation unit 80C is an edge of the aerial image 2. If the position of the object is an edge of the aerial image 2, the light irradiation determination unit 80D controls the lighting device 60 to irradiate the object with blinking light. That is, the lighting elements 61-1 to 61-4 each cause the light-emitting element 63-1 to 63-4 corresponding to the position of the object to emit blinking light of a predetermined color.

The light emitted from the light-emitting elements 63-1 to 63-4 is irradiated onto the target object (the finger 3A of the observer 3). The observer 3 visually recognizes a blinking light of a specific color irradiated onto his or her finger 3A. This allows the observer 3 to recognize that he or she has pressed the end of the push button as the aerial image 2.

Next, the overall operation flow of the aerial display device 1 will be described. FIG. 17 is a flowchart explaining the overall operation of the aerial display device 1. The operations of steps S100 to S103 are the same as those in the first embodiment.

Next, the light irradiation determination unit 80D determines whether or not the target object is present in the center of the set area (step S200). The set area refers to the area occupied by the aerial image 2.

If the object is present in the center of the set area (S200 = Yes), the light irradiation determination unit 80D controls the lighting device 60 to irradiate the object with light (step S201). The light in step S201 is continuously lit light.

If the object is not present in the center of the set area (S200 = No), the light irradiation determination unit 80D determines whether the object is present at the edge of the set area (step S202). The edge of the set area is the area surrounding the center of the set area.

If the object is located at the edge of the set area (S202 = Yes), the light irradiation determination unit 80D controls the lighting device 60 to irradiate the object with blinking light (step S203).

Then, the flow in FIG. 17 is repeated, and if the object moves from the edge to the center of the set area, the object is illuminated with a continuous light.

According to the second embodiment, the observer 3 can be made to recognize that he is pressing the end of the push button as the aerial image 2. Also, the observer 3 can be made to recognize that he is pressing the center of the push button as the aerial image 2. This makes it possible to guide the finger 3A of the observer 3 to the center of the aerial image 2.

[3] Third Embodiment In the third embodiment, when an object exists in the area of the aerial image 2, the object is irradiated with far-infrared light.

Figure 18 is a perspective view of a portion (sensing element 50 and lighting device 60) of an aerial display device 1 according to a third embodiment of the present invention. The configuration other than the lighting device 60 is the same as in Figure 1.

The lighting device 60 comprises four warm lighting elements 90-1 to 90-4 arranged on each of the four sides of the housing 70. Each of the warm lighting elements 90-1 to 90-4 is arranged above the optical element 40 and at approximately the same level as the aerial image 2. Each of the warm lighting elements 90-1 to 90-4 is configured to be able to irradiate light over the entire detection area.

Figure 19 is a side view of a partial area of the warm lighting element 90-1. The configuration of the warm lighting elements 90-2 to 90-4 is the same as that of the warm lighting element 90-1.

The warm lighting element 90-1 is positioned so that it can irradiate light toward the detection area of the sensing element 50. The warm lighting element 90-1 includes a substrate 91 and a plurality of light-emitting elements 92. The substrate 91 is configured to extend in one direction. The substrate 91 includes an insulating substrate made of resin or the like, and a wiring layer provided on the upper surface and/or inside the insulating substrate.

The multiple light-emitting elements 92 are arranged in a row along the extension direction of the substrate 91 with a predetermined distance between adjacent elements. The number of the multiple light-emitting elements 92 and the size of each element can be set appropriately. The light-emitting elements 92 emit light in the far-infrared wavelength range (far-infrared light). The far-infrared light can increase the temperature of a substance.

Next, we will explain the operation of the aerial display device 1 configured as described above.

Figure 20 is a bottom view (aerial image 2 viewed from below) explaining the light irradiation operation. The light-emitting elements 92 included in the warm lighting elements 90-1 to 90-4 are referred to as light-emitting elements 92-1 to 92-4. The operation up to calculating the position of the target object (finger 3A of observer 3) is the same as in the first embodiment.

The light irradiation determination unit 80D determines whether the position of the object calculated by the detection position calculation unit 80C is included in the area of the aerial image 2. If the position of the object is included in the area of the aerial image 2, the light irradiation determination unit 80D controls the lighting device 60 to irradiate the object with far-infrared light. That is, the warm lighting element 90-1 causes the light-emitting elements 92-1 to 92-4 corresponding to the position of the object to emit far-infrared light. The number of light-emitting elements that each of the warm lighting elements 90-1 to 90-4 emits may be one or two or more. In addition, the number of light-emitting elements that each of the warm lighting elements 90-1 to 90-4 emits may be set according to the size of the object. The number of light-emitting elements that emit light may be increased as the size of the object increases.

The far-infrared light emitted from the light-emitting elements 92-1 to 92-4 is irradiated onto the object (the finger 3A of the observer 3). The observer 3 recognizes that his or her finger 3A has become warm. This enables the observer 3 to recognize that he or she has pressed the push button on the aerial image 2.

The operation of emitting visible light by the lighting elements 61-1 to 61-4 is the same as in the first and second embodiments.

Next, the overall operation flow of the aerial display device 1 will be described. Figure 21 is a flowchart explaining the overall operation of the aerial display device 1. The operations of steps S100 to S104 are the same as those in the first embodiment.

Next, if the object is present within the set area (S104 = Yes), the light irradiation determination unit 80D controls the lighting device 60 to irradiate the object with far-infrared light (step S300). The operation of the lighting device 60 is as described above.

In addition, in parallel with the operation of irradiating the object with far-infrared light, the operation of irradiating the object with visible light is performed.

According to the third embodiment, the observer 3 can be made aware through a temperature sensation that he or she is pressing the end of the push button as the aerial image 2.

As a modified example, only far-infrared light may be emitted without emitting visible light. In other words, the lighting device 60 may be equipped with only the warmth lighting elements 90-1 to 90-4, and the observer 3 may only sense a temperature. In this modified example, light is not emitted by the lighting elements 61-1 to 61-4.

[4] Fourth Embodiment The fourth embodiment is an example of a configuration in which the display element 20 is disposed at an angle with respect to the optical element 40 , and the aerial image 2 is displayed at a position plane-symmetrical with respect to the display element 20 .

Figure 22 is a perspective view of an aerial display device 1 according to a fourth embodiment of the present invention. In Figure 22, the X direction is a direction along one side of the housing 70, the Y direction is a direction perpendicular to the X direction in the horizontal plane of the housing 70, and the Z direction is a direction perpendicular to the XY plane. Figure 23 is a perspective view of a portion of the aerial display device 1 (sensing element 50 and lighting device 60).

The aerial display device 1 includes a backlight 10, a display element 20, an optical element 40, a sensing element 50, an illumination device 60 (illumination elements 61-1 to 61-4), and a housing 70.

The configuration of the backlight 10 and the display element 20 is the same as in the first embodiment. In FIG. 22, the light guide plate 12 and the reflective sheet 13 are illustrated as a single unit. When viewed from the YZ plane, the display element 20 is disposed at an angle to the optical element 40. The angle between the display element 20 and the optical element 40 is, for example, 10 degrees or more and 60 degrees or less.

The optical element 40 is positioned to receive light from the display element 20. The optical element 40 is composed of a dihedral corner reflector array in which dihedral corner reflectors are arranged in an array. The optical element 40 reflects light incident from the bottom side to the top side. The optical element 40 also forms an image of the display element 20 at a plane-symmetrical position, forming an aerial image in the air.

Figure 24A is a side view of the optical element 40 shown in Figure 22 in the X'Z' plane. Figure 24B is a bottom view of the optical element 40 shown in Figure 22. In Figures 24A and 24B, the X' direction is a direction along one side of the optical element 40, the Y' direction is a direction perpendicular to the X' direction within the plane of the optical element 40, and the Z' direction is a direction perpendicular to the X'Y' plane.

The optical element 40 includes a substrate 41 and a plurality of optical elements 45. FIG. 24A shows an extracted perspective view of one optical element 45. The substrate 41 and the plurality of optical elements 45 are made of a transparent material such as acrylic resin. The substrate 41 and the plurality of optical elements 45 may be integrally formed, or may be bonded with a transparent adhesive.

The multiple optical elements 45 are provided on the bottom surface of the substrate 41. The optical elements 45 are rectangular parallelepipeds or cubes. The planar shape of the optical elements 45 is, for example, a square. The optical elements 45 have two reflecting surfaces 46, 47. The reflecting surfaces 46, 47 correspond to two side surfaces of the rectangular parallelepiped and are in contact with each other. The reflecting surfaces 46, 47 form a so-called two-sided corner reflector.

The optical elements 45 are arranged such that one side is inclined at an angle θ ₁₀ with respect to the X' direction. The angle θ ₁₀ is, for example, 45 degrees. Note that the angle θ ₁₀ is not limited to 45 degrees, and can be set within a range of 30 degrees to 60 degrees. The optical elements 45 are arranged in a staggered pattern. That is, the optical elements 45 are arranged such that one row extends in a direction at 45 degrees with respect to the X direction, and multiple rows are arranged in a direction at 45 degrees with respect to the Y direction. The optical elements 45 are also arranged with gaps between each other.

As shown in FIG. 23, the lighting device 60 includes four lighting elements 61-1 to 61-4. The lighting elements 61-1 to 61-4 are arranged in a two-dimensional spatial region that includes the aerial image 2, and are arranged on the four sides of the rectangular spatial region in which the aerial image 2 is displayed. The configuration of the lighting elements 61-1 to 61-4 is the same as in the first embodiment.

The sensing element 50 is disposed near the two-dimensional spatial region that includes the aerial image 2, and is disposed near one side of the rectangular spatial region in which the aerial image 2 is displayed. The sensing element 50 forms a detection region in the two-dimensional spatial region that includes part or all of the aerial image 2 generated by the aerial display device 1. The configuration of the sensing element 50 is the same as in the first embodiment.

The housing 70 houses the sensing element 50 and the lighting device 60. The housing 70 is disposed in a two-dimensional spatial region including the aerial image 2. That is, when viewed from the YZ plane, the housing 70 is disposed above the optical element 40 and disposed at an angle to the optical element 40. The housing 70 has a rectangular shape in a plan view. The sensing element 50 and the lighting device 60 are attached to the inner surface of the housing 70 using a support member (not shown). The housing 70 has an opening 71 that exposes a rectangular spatial region in which the aerial image 2 is displayed.

The operation of the aerial display device 1 according to the fourth embodiment is the same as that according to the first embodiment. The fourth embodiment can also achieve the same effects as those according to the first embodiment. It is also possible to apply the second or third embodiment to the fourth embodiment.

[5] Modifications In each of the above embodiments, the lighting device 60 is configured to include four lighting elements 61-1 to 61-4. However, the present invention is not limited to this configuration, and the lighting device 60 may include one lighting element 61 or two or more lighting elements 61. The same applies to the warm lighting elements 90-1 to 90-4.

In the first embodiment, the display element 20 and the optical element 40 are arranged parallel to each other. However, this is not limited to the above, and the display element 20 may be arranged at an angle to the optical element 40. The angle between the display element 20 and the optical element 40 is set to, for example, 10 degrees or more and 60 degrees or less. In this modified example, the orientation control element 30 can be omitted.

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

In each of the above embodiments, a liquid crystal display element is used as an example of the display element 20, but the present invention is not limited to this. The display element 20 may be a self-luminous organic EL (electroluminescence) display element or a micro LED (Light Emitting Diode) display element. A micro LED display element is a display element that uses LEDs to emit the R (red), G (green), and B (blue) that make up a pixel. When a self-luminous display element 20 is used, the backlight 10 is not required.

The present invention is not limited to the above-described embodiments, and can be modified in various ways in the implementation stage without departing from the gist of the invention. The embodiments may also be implemented in appropriate combination, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combinations selected from the multiple constituent elements disclosed. For example, if the problem can be solved and an effect can be obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiments, the configuration from which these constituent elements are deleted can be extracted as an invention.

1...aerial display device, 2...aerial image, 3...observer, 10...backlight, 11...light source unit, 12...light guide plate, 13...reflective sheet, 20...display element, 30...orientation control element, 31, 32...substrate, 33...transparent member, 34...light-shielding member, 40...optical element, 41...substrate, 42...optical element, 43...incident surface, 44...reflective surface, 45...optical element, 46, 47...reflective surface, 50...sensing element, 51...light-emitting unit, 52...light-receiving unit, 53...detection area, 60...illumination device, 61-1 to 61-4...illumination element, 62 ...substrate, 63...light-emitting element, 64...substrate, 65B...blue LED, 65G...green LED, 65R...red LED, 66-1, 66-2...lead frame, 67...sealing resin, 70...housing, 71...opening, 80...control unit, 80A...display processing unit, 80B...information processing unit, 80C...detection position calculation unit, 80D...light irradiation determination unit, 81...memory unit, 82...input/output interface, 83...display unit, 84...input unit, 85...bus, 90-1 to 90-4...warm lighting element, 91...substrate, 92...light-emitting element.

Claims (12)

A display element for displaying an image;
an optical element that is arranged to receive light from the display element, and that reflects the light from the display element to an opposite side to the display element to form an aerial image in the air;
a sensing element that forms a detection area in a spatial region including the aerial image and detects an object within the detection area;
a lighting element that irradiates light onto the object when the object is present in the area of the aerial image;
An aerial display device comprising: The aerial display device according to claim 1 , wherein the lighting element includes a plurality of first light-emitting elements arranged along a surface of the detection area. The aerial display device according to claim 2 , further comprising a determination unit that causes one of the plurality of first light-emitting elements corresponding to the position of the target object to emit light. The aerial display device according to claim 1 , wherein the lighting element illuminates the object with a blinking light when the object is present at an edge of the area of the aerial image. The aerial display device according to claim 1 , further comprising a warm lighting element that irradiates the object with far-infrared light when the object is present in the area of the aerial image. The aerial display device according to claim 5 , wherein the warm lighting element includes a plurality of second light-emitting elements arranged along a surface of the detection area. The aerial display device according to claim 6 , further comprising a determination unit that causes one of the plurality of second light-emitting elements corresponding to the position of the target to emit light. The aerial display device according to claim 1 , wherein the sensing element includes a light-emitting section that emits light toward the detection area and a light-receiving section that receives light reflected by the object. The optical element includes a planar substrate and a plurality of optical elements provided under the substrate, each of the optical elements extending in a first direction and aligned in a second direction perpendicular to the first direction;
The aerial display device according to claim 1 , wherein each of the optical elements has an incident surface and a reflecting surface that are inclined with respect to a normal direction of the base material and are in contact with each other. The aerial display device according to claim 1 , further comprising an orientation control element disposed between the display element and the optical element, which transmits oblique light components of the light from the display element. the alignment control element includes a plurality of transparent members and a plurality of light blocking members arranged alternately;
The aerial display device according to claim 10 , wherein the plurality of light blocking members are inclined with respect to a normal to the alignment control element. The aerial display device according to claim 1 , wherein the display element and the optical element are arranged parallel to each other.