Display device

Abstract

The present invention addresses the problem of providing a display device capable of stereoscopically visualizing aerial images. A display device (100) according to the present invention is provided with a light source (LED lamp) (110), a retroreflective member (120), an optical member (130) including a beam splitter or a half mirror, and a three-dimensional structure (140) having optical properties of guiding light or scattering light. When the three-dimensional structure (140) is irradiated with the light (L) from the light source (110), an aerial image (140A) of the three-dimensional structure (140) is displayed. The three-dimensional structure (140) includes an upper surface (142) and a side surface (144), and the side surface (144) is provided with a taper.

Description

Technical Field

[0001] The present invention relates to a display device for displaying an image in the air by utilizing retroreflection, and more particularly to stereoscopic visualization of an image in the air. Background Art

[0002] Aerial imaging by retro-reflection (AIRR) is known. For example, Patent Document 1 discloses a display device that uses two retro-reflective components to enable an image formed in the air to be observed from a wider angle. In addition, Patent Document 2 discloses an aerial image display system having a half mirror and a reflective component selected from a group consisting of a concave mirror, a Fresnel mirror, and a retro-reflective component, the reflective component having a reflective polarizer, and the reflective polarizer constitutes a reflective surface of the reflective component.

[0003] Prior art literature:

[0004] Patent Literature:

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-107165

[0006] Patent Document 2: International Publication No. WO2022 / 138157 Summary of the invention

[0007] Problems to be solved by the invention:

[0008] In conventional aerial imaging technologies, a display is used as a light source in most cases, and even if an image on a display is projected into the air, the aerial image itself is visually recognized as a flat image. Figure 1 1 is a diagram showing a configuration example of a conventional display device for an aerial image using retroreflection. The display device 10 is configured to include: a display 20 including a liquid crystal panel, etc., a retroreflective component 30, and a beam splitter (or a half mirror) 40. If the display 20 displays an original image P1, the original image P1 emitted from the display 20 is reflected toward the retroreflective component 30 by the beam splitter 40, and the light reflected on the retroreflective component 30 passes through the beam splitter 40, so that an aerial image P2 is formed, and the aerial image P2 is displayed in the line of sight of the user U.

[0009] In order to make a two-dimensional image look three-dimensional, there is a technology that uses an eye illusion by changing the two-dimensional image according to the angle of the line of sight through the camera's line of sight detection. However, if this technology cannot achieve 100% perfect line of sight detection, deviations will occur in the tracking of image changes, causing a sense of disharmony. In addition, line of sight detection is basically limited to one person in front of the camera, and there is also the problem that multiple people cannot visually recognize a three-dimensional image at the same time. In particular, when using an aerial image as a user interface (UI), the object (aerial image) is more preferably physically three-dimensional than a plane.

[0010] An object of the present invention is to solve such conventional problems and to provide a display device that realizes three-dimensional visualization of aerial images.

[0011] Means used to solve the problem:

[0012] The display device involved in the present invention can use retroreflection to display aerial images, and includes: a light source; a three-dimensional structure having at least one of optical properties of light guiding and scattering, which is illuminated by the light source; a retroreflective component that reflects the three-dimensional structure; and an optical component that allows the reflected light of the retroreflective component to be transmitted to form an aerial image of the three-dimensional structure. The three-dimensional structure includes at least an upper surface and a side surface connected to the upper surface, and a taper is provided on at least a portion of the side surface.

[0013] In one embodiment, a space is formed on the side surface provided with the taper and the back side of the upper surface. In one embodiment, projections and depressions are formed in the height direction of the three-dimensional structure. In one embodiment, the three-dimensional structure also includes processing to change the transmission or diffusion of light at the edge where the upper surface intersects with the side surface or the edge where the side surface intersects. In one embodiment, the processing includes roughening of the edge. In one embodiment, the processing includes coating or addition of other materials.

[0014] Effect of the invention:

[0015] According to the present invention, by providing a taper on the side of the three-dimensional structure, the brightness of the taper part and the part outside it changes according to the observation position or angle, and a clearer three-dimensional vision can be achieved in the aerial image of the three-dimensional structure. Furthermore, by performing a process to change the transmission or diffusion on the edge of the three-dimensional structure, the edge of the aerial image becomes clearer, and the three-dimensional sense of the aerial image can be enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a diagram showing a configuration example of a conventional display device utilizing retroreflection.

[0017] Figure 2It is a diagram illustrating the optical properties of a retroreflective member.

[0018] Figure 3 It is a diagram showing the configuration of a display device according to an embodiment of the present invention.

[0019] Figure 4 is a diagram showing a three-dimensional structure according to a first embodiment of the present invention. Figure 4 (A) is a stereogram viewed from the front side. Figure 4 (B) is a stereoscopic view viewed from the back side. Figure 4 (C) is Figure 4 (A) is an enlarged view of the cross section along line AA.

[0020] Figure 5 It is a diagram for explaining an aerial image of a three-dimensional structure according to the first embodiment of the present invention.

[0021] Figure 6 is a diagram showing a three-dimensional structure according to a second embodiment of the present invention. Figure 6 (A) is a stereogram viewed from the front side. Figure 6 (B) and (C) are Figure 6 (A) is an enlarged view of the BB line cross section.

[0022] Description of reference numerals:

[0023] 100: display device 110: light source

[0024] 120: Retroreflective component 130: Beam splitter

[0025] 140: Three-dimensional structure 140A: Aerial image

[0026] 142: Upper surface 144: Side surface

[0027] 146: Space 200: Three-dimensional structure

[0028] 210, 220: Edge DETAILED DESCRIPTION

[0029] Next, the embodiment of the present invention is described. The display device of the present invention displays a three-dimensional aerial image using retroreflection even when no special glasses are worn. The display device of the present invention can be applied to a user input interface using aerial images. In addition, it should be noted that the drawings referred to in the description of the following embodiments include exaggerated displays for the purpose of making the invention easier to understand, and do not represent the shape or proportion of the actual product as it is.

[0030] [Example]

[0031] Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the technology of generating aerial images (AIRR method), the use of retroreflectors is indispensable. Retroreflectors are optical components that reflect light in the same direction as the incident light, and are composed of, for example, prism-type retroreflectors such as triangular pyramid-type retroreflectors and full-cube-angle retroreflectors, or bead-type retroreflectors.

[0032] Figure 2 The relationship between the cross section of the triangular pyramid retroreflective element and the incident light / reflected light is schematically shown. The reflection surfaces S1 and S2 of the triangular pyramid retroreflective element 50 are orthogonal, and the incident light L1 incident on the reflection surface S1 at an incident angle (π / 2-θ) is reflected on the reflection surfaces S1 and S2, and the reflection angle of the reflected light L2 when reflected on the reflection surface S2 is equal to the incident angle (π / 2-θ). Therefore, the reflected light L2 is reflected in the same direction as the incident light L2. However, in the retroreflective component, its structure causes the position of the incident light L1 and the reflected light L2 to deviate, so the deviation will cause the sharpness or resolution of the aerial image to deteriorate, and the visual recognition of the aerial image will be reduced.

[0033] In the case of using retroreflection to display an aerial image, the aerial image can be made three-dimensional by making the original image three-dimensional. However, as mentioned above, if the resolution of the aerial image deteriorates due to the structural reasons of the retroreflective component, it is difficult to visually recognize a clear aerial image with a three-dimensional sense just by making the original image three-dimensional. In particular, if the edge of the aerial image becomes unclear, or the edge becomes blunt, or the aerial image has no sense of depth, the user cannot see the aerial image in three dimensions. In view of this, the display device of this embodiment can display a clear aerial image with a three-dimensional sense.

[0034] Figure 3 As shown in the figure, the display device 100 of the present embodiment includes: a light source 110 , a retroreflective member 120 , an optical member 130 including a beam splitter or a half mirror, and a three-dimensional structure 140 .

[0035] The light source 110 is not particularly limited in its structure as long as it can illuminate the three-dimensional structure 140, and can be, for example, an LED lamp composed of a plurality of LEDs arranged in two dimensions. In addition, the wavelength of the light output from the light source 110 is arbitrary, for example, white light is emitted. The light source 110 can also emit polarized light as needed, and a light-emitting element or polarization filter provided for this purpose can also be used.

[0036] The retroreflective member 120 is an optical member that reflects light in the same direction as the incident light, and its structure is not particularly limited. Figure 2The retroreflective member 120 may be composed of a triangular pyramid type retroreflective element, or a prism type retroreflective element such as a full cube corner type retroreflective element, or a bead type retroreflective element. In addition, the retroreflective member 120 may include a phase difference film such as a λ / 4 plate on its reflective surface.

[0037] The optical component 130 is composed of a beam splitter or a half mirror, and has the function of transmitting a part of the incident light and reflecting a part of it. A part of the light of the three-dimensional structure 140 irradiated by the light source 110 is reflected by the optical component 130, and the reflected light is incident on the retroreflective component 120. A part of the light reflected in the same direction as the incident light is transmitted through the optical component 130, forming an aerial image 140A. The aerial image 140A is formed at a position that is plane-symmetrical with the three-dimensional structure 140 relative to the optical component 130.

[0038] The three-dimensional structure 140 is made of a material that can transmit light, such as glass, acrylic plastic, polycarbonate resin, or cycloolefin resin, and has optical properties of light guiding, scattering, or both. The three-dimensional shape, size, etc. of the three-dimensional structure 140 are not particularly limited, and the three-dimensional structure 140 has a three-dimensional shape that is intended to be displayed as an aerial image. For example, the three-dimensional structure 140 can be various three-dimensional shapes such as characters, graphics, signs, and patterns. Here, the three-dimensional structure 140 has a three-dimensional shape of the Latin letter "N".

[0039] The three-dimensional structure 140 is illuminated by light from the light source (LED unit) 110, and the illuminated light is guided into the transparent member of the three-dimensional structure 140 or scattered on the surface of the transparent member, thereby the three-dimensional structure 140 exists here like a three-dimensional light source "N".

[0040] Figure 4 is a diagram showing details of a three-dimensional structure according to the first embodiment. Figure 4 (A) is a stereoscopic view of the three-dimensional structure 140 viewed from the front side. Figure 4 (B) is a three-dimensional view of the three-dimensional structure 140 viewed from the back side. Figure 4 (C) is Figure 4 (A) is an enlarged view of the AA line cross section. In a certain embodiment, the three-dimensional structure 140 is formed by processing a thin plate-shaped transparent member with a certain thickness into an "N" shape. The upper surface 142 of the three-dimensional structure 140 shows a planar shape of "N", and the side surface 144 extending from the upper surface 142 to the bottom is provided with a taper. In other words, the intersection angle between the upper surface 142 and the side surface 144 is an obtuse angle, and the three-dimensional structure 140 is as follows. Figure 4As shown in (C), the depth increases from the upper surface 142 toward the bottom, and a trapezoidal cavity or space 146 is formed on the back side of the upper surface 142 and the side surface 144. The taper angle is appropriately selected according to the three-dimensional shape of the three-dimensional structure 140.

[0041] Figure 5 1 is a diagram for explaining an aerial image of a three-dimensional structure, schematically showing an aerial image of a portion of the three-dimensional structure. As described above, the three-dimensional structure 140 includes an upper surface 142, a tapered side surface 144, and a space 146. When the three-dimensional structure 140 is illuminated by the light source (LED light) 110, an aerial image 140A of the three-dimensional structure 140 is displayed. The installation position and installation direction of the three-dimensional structure 140 are arbitrary. For example, the three-dimensional structure 140 is configured so that the upper surface 142 of the aerial image 140A faces the line of sight of the user U.

[0042] As shown in the figure, the appearance of the three-dimensional structure 140 changes according to the sight lines U1 and U2 of the user U. In the sight line direction U1, due to the taper of the side surface 144, the thickness L1 of the transparent component becomes larger, so it is difficult to guide light in this part, and it looks darker. On the other hand, in the sight line direction U2 where there is no side surface 144, due to the space 146 on the back side, the thickness L2 of the transparent component becomes smaller, and it is easy to guide light in this part, and it looks brighter. In other words, the degree of light guidance changes according to the position or angle of observation of the user, so the appearance (brightness) changes, and the aerial image of the three-dimensional structure can be visually recognized more three-dimensionally.

[0043] As described above, according to this embodiment, by providing a taper or projections and depressions in the height direction of the three-dimensional structure, the light guiding degree of the three-dimensional structure changes according to the user's line of sight, causing a change in brightness, resulting in a clear aerial image with a three-dimensional effect that can be visually recognized.

[0044] In the above embodiment, the upper surface 142, the tapered side surface 144, and the back space 146 of the three-dimensional structure 140 are formed by bending a thin plate-like transparent member, but this is only an example. In addition to such a method, for example, the side surface of a transparent member having a certain thickness may be cut to form a taper, and a recess or depression may be formed on the back to form the space 146, or the three-dimensional structure may be injection molded using an injection molding mold.

[0045] In addition, in the above embodiment, all the side surfaces 144 of the three-dimensional structure 140 are tapered, but this is an example and is not necessarily limited to this. For example, in the three-dimensional structure 140, a taper or space may be formed only on the side surface of a portion where the three-dimensional effect is desired to be emphasized.

[0046] Next, a second embodiment of the present invention will be described. In the second embodiment, processing is performed on the edge of the three-dimensional structure 140 to change the transmission or diffusion of light. Figure 6 is a diagram showing a three-dimensional structure according to the second embodiment. Figure 6 (A) is a three-dimensional view of the three-dimensional structure viewed from the front side. Figure 6 (B) and Figure 6 (C) is Figure 6 (A) is an enlarged view of the BB line cross section.

[0047] In the second embodiment, edge processing is performed on the edge 210 where the upper surface 142 and the side surface 144 of the three-dimensional structure 200 intersect, or the edge 220 on the bottom side of the side surface 144 to change the transmission or diffusion of light. Figure 6 As shown in (B), black material (PLA: polylactic acid) is coated on the edges 210 and 220. The black material has a width of 1 mm and a thickness of about 0.5 mm, for example. By adding black paint, the light guide of the edges 210 and 220 of the three-dimensional structure 200 becomes weaker, and the contrast with other parts becomes larger. As a result, the edges 210 and 220 are relatively emphasized, which can enhance the three-dimensional sense of the aerial image. The color of the coated material is not necessarily limited to black, and the width or thickness of the coating is not particularly limited. In short, as long as the color or size of the transmission or light guide is changed by the coated material, in addition to the coating material, other materials that change the transmission or light guide can also be pasted.

[0048] In addition, as another method, edge processing can also be performed as follows. Figure 6 As shown in (C), the surfaces of the edges 210A and 220B are roughened. As a result, light is diffused or scattered at the edges 210A and 220A, the contrast between the edges 210A and 220A and other parts is increased, and the edges 210A and 220A are emphasized in the aerial image. When roughening, for example, the edges 210A and 220B may be chamfered, and roughening may be performed on the chamfered surfaces.

[0049] As described above, according to the present embodiment, by applying edge processing to the edge of a three-dimensional structure to change the transmission or diffusion of light, the edge of the three-dimensional structure can be emphasized, thereby displaying a clear aerial image with a three-dimensional effect.

[0050] In the above embodiment, edge processing is applied to a portion of the edges 210 and 220 of the three-dimensional structure 200, but the position and number of edges to be processed are arbitrary, for example, edge processing is applied to edges where the three-dimensional effect is to be emphasized. For example, in addition to the edge where the top surface intersects with the side surface, processing may also be applied to the edge where the side surface intersects with the side surface.

[0051] In the above embodiment, the character "N" is represented as a three-dimensional structure, but this is an example, and the three-dimensional structure may be a three-dimensional structure that represents numbers, symbols, graphics, letters, etc. other than characters. For example, the three-dimensional structure is determined according to the aerial image required in the user interface. In addition, the display device of this embodiment can be applied to user input, for example, it can be applied to computer devices, vehicle-mounted electronic devices, ATMs of banks, etc., ticket machines of stations, etc., input buttons of elevators, etc.

[0052] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the gist of the invention described in the claims.

Claims

1. A display device capable of displaying aerial images by using retroreflection, wherein: include: light source; A three-dimensional structure having at least one of the optical properties of light guiding and light scattering, and being illuminated by the light source; A retroreflective component, reflecting the three-dimensional structure; as well as an optical component that transmits the reflected light of the retroreflective component to form an aerial image of the three-dimensional structure; The three-dimensional structure at least includes an upper surface and a side surface connected to the upper surface, and a taper is provided on at least a portion of the side surface.

2. The display device according to claim 1, wherein: A space is formed on the side surface having the tapered shape and on the back side of the upper surface.

3. The display device according to claim 1, wherein: The three-dimensional structure portion has projections and depressions formed in a height direction.

4. The display device according to claim 1, wherein: The three-dimensional structure further includes processing to change the transmission or diffusion of light at an edge where the upper surface intersects with the side surface or at an edge where the side surface intersects.

5. The display device according to claim 4, wherein: The processing includes roughness processing of the edges.

6. The display device according to claim 4, wherein: The processing includes coating or adding other materials.

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