Display device

Abstract

To provide a display device capable of displaying an aerial image at a wide viewing angle.SOLUTION: An aerial video display device 100 according to the present invention includes: a plurality of light sources 110_1, 110_2, 110_3 that output the same video, respectively; a retroreflection sheet 120 including a first retroreflection surface 120_1, a second retroreflection surface 120_2, and a third retroreflection surface 120_3 facing the plurality of light sources; and a beam splitter 130 located so as to face the retroreflection sheet 120. Each of the first, second and third retroreflection surfaces 120_1, 120_2, 120_3 forms therein a plurality of notches 122 for letting the video of the light source 110 pass through or pass by, and a plurality of aerial images 150_1, 150_2, 150_3 corresponding to the plurality of light sources 110_1, 110_2, 110_3 are displayed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a display device that displays an image in the air by utilizing retroreflection, and to a technology for displaying an aerial image with a wide viewing angle. [Background technology]

[0002] Aerial imaging by retroreflection (AIRR) is known. For example, Patent Document 1 discloses a display device using two retroreflection members so that an image formed in the air can be observed from a wider angle. Patent Document 2 discloses a display device that suppresses deterioration of contrast and visibility by positioning a light source and a retroreflection member so that light regularly reflected by the retroreflection member does not enter the observation range. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-107165 A [Patent Document 2] Patent Publication No. 2022-150245 Summary of the Invention [Problem to be solved by the invention]

[0004] The things we see in our daily lives emit light or are illuminated by external light, which allows us to visually recognize what we are looking at. Since most of these things exist physically, when adding design to a space, there is a risk that they may detract from the design of the space, even if they are necessary. One way to solve this problem is to use mid-air images.

[0005] Fig. 1 is a diagram showing an example of a display device that displays an aerial image. As shown in the figure, an aerial image 20 that indicates the operation status of the elevator (e.g., the floor where the elevator will stop) is displayed near the elevator door 10. The aerial image 20 is displayed with a spatial design as if it were a lantern (lighting fixture) attached to a wall. A user U1 visually recognizes the aerial image 20 from a direction Y1 to confirm the operation status of the elevator.

[0006] 2 is a top view showing a schematic configuration of a display device that displays such an aerial image. The display device 30 includes a light source (e.g., a display that outputs an image) 40, a beam splitter 50 that separates incident light into reflected light and transmitted light at a predetermined ratio, a decorative sheet 60 that is formed on the surface of the beam splitter 50 and has a decoration or design, and a retroreflective sheet 70.

[0007] When an image is displayed on the light source 40, a portion of the light representing the image is reflected by the beam splitter 50, and the reflected light travels to the retroreflective sheet 70. The retroreflective sheet 70 is an optical component that reflects light in the same direction as the incident light, and the light reflected by the retroreflective sheet 70 travels again to the beam splitter 50, and the light that passes through the beam splitter 50 and the decorative sheet 60 converges and then diffuses again, displaying an aerial image 20 as shown in Fig. 1 ("A" in the example shown in the figure).

[0008] As an optical characteristic of the aerial image 20, the aerial image 20 is formed at a position symmetrical to the light source 40 with respect to the surface of the beam splitter 50. Moreover, the aerial image 20 that can be observed by the user is limited to a range in which the retroreflective sheet 70 can be seen from the user's viewpoint through the beam splitter 50. In other words, there is a limit to the viewing angle. For this reason, in Figs. 1 and 2, users U1, U2, and U3 on the front side of the aerial image 20 can view the aerial image 20 in their viewpoint direction, but user U4 on the rear side cannot view the aerial image 20 in the viewpoint direction Y2, and as a result, cannot check the operating state of the elevator.

[0009] An object of the present invention is to solve such conventional problems and to provide a display device capable of displaying an aerial image with a wide viewing angle. [Means for solving the problem]

[0010] The display device of the present invention is capable of displaying aerial images using retroreflection, and includes a plurality of light sources that output the same image in different directions, an optical element that separates incident light into reflected light and transmitted light at a certain ratio, and a retroreflective element that provides a retroreflective surface within a range of approximately 180 degrees relative to the main surface of the optical element, and image light output from each of the plurality of light sources is incident on the retroreflective element via the optical element, and the light reflected by the retroreflective element passes through the optical element, thereby displaying a plurality of aerial images corresponding to the images of the plurality of light sources.

[0011] In one embodiment, the retroreflective member is disposed between the plurality of light sources and the optical member, and the retroreflective member has a plurality of openings for transmitting or passing light from the plurality of light sources. In one embodiment, at least three light sources are disposed at different angles with respect to the main surface of the optical member, and the retroreflective member has a plurality of retroreflective surfaces that match the positions of the plurality of light sources, and the plurality of retroreflective surfaces are formed with a plurality of notches for transmitting or passing images output by the plurality of light sources toward the optical member. In one embodiment, the retroreflective member has a concave shape, and light sources are disposed close to the side and bottom surfaces of the concave shape. Effect of the Invention

[0012] According to the present invention, since a plurality of aerial images corresponding to the same video output from a plurality of light sources are displayed, the viewing angle of the aerial image can be widened compared to the case where a single aerial image is displayed, thereby improving the visibility of the aerial image. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing an example of installation of a conventional display device. [Diagram 2] FIG. 1 is a top view showing a schematic configuration of a conventional display device. [Diagram 3] FIG. 3(A) is a top view showing a schematic configuration of a display device according to an embodiment of the present invention, and FIG. 3(B) is a front view thereof. [Figure 4] FIG. 4 is a diagram illustrating the operation of the display device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The display device according to the present invention has a function of displaying an aerial image at a wide viewing angle by the AIRR method. The display device according to the present invention is also capable of displaying an aerial image at a wide viewing angle that also combines spatial design. Furthermore, the display device according to the present invention can be applied to a user input interface that utilizes an aerial image. It should be noted that the drawings referred to in the following description of the embodiments include exaggerated representations to facilitate understanding of the invention, and do not directly represent the shape and scale of the actual product. EXAMPLES

[0015] Next, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 3(A) is a top view showing a schematic configuration of a display device according to an embodiment of the present invention, and Fig. 3(B) is a front view. The display device is installed, for example, near an elevator door 10 as shown in Fig. 1, and displays an aerial image.

[0016] The display device 100 of this embodiment is composed of at least three light sources 110_1, 110_2, 110_3 (these light sources are collectively referred to as light source 110) arranged at different positions so as to output images in different directions, a retroreflective sheet 120 arranged close to the light source 110, a beam splitter 130 arranged opposite the retroreflective sheet 120, and a decorative sheet 140 with decorations and designs formed on the surface of the beam splitter 130.

[0017] The light source 110 outputs an original image of the aerial image, and may be, for example, a liquid crystal display or a projector. The light sources 110_1, 110_2, and 110_3 output images in at least three directions to enable the display of the aerial image at a wide viewing angle. For example, the light source 110_1 is arranged so that its optical axis (the normal direction to the display surface of the display) is at an angle θ1 (=30 degrees) with respect to the main surface of the beam splitter 130, the light source 110_2 is arranged so that it is at an angle θ2 (=90 degrees), and the light source 110_3 is arranged so that it is at an angle θ3 (=150 degrees).

[0018] The light sources 110_1, 110_2, and 110_3 may have different sizes (e.g., display sizes), but the light sources 110_1, 110_2, and 110_3 display the same image. For example, a display controller (not shown) controls the light source 110 so that the light sources 110_1, 110_2, and 110_3 display the same image. For example, in the example shown in FIG. 1, the light sources 110_1, 110_2, and 110_3 output an image of a floor where the elevator is stopped. The light source 110 may also emit polarization-controlled light, and may, for example, have a polarizing plate attached to the display surface so as to emit polarization-controlled light.

[0019] The retroreflective sheet 120 is an optical member that reflects light in the same direction as the incident light, and is composed of, for example, corner cube type retroreflective elements, triangular pyramid type retroreflective elements, bead type retroreflective elements, etc. The retroreflective sheet 120 provides a retroreflective surface of approximately 180 degrees with respect to the main surface of the beam splitter 130 to enable the display of an aerial image with a wide viewing angle. Specifically, the retroreflective sheet 120 has a concave shape that matches the positions of the light sources 110_1, 110_2, and 110_3, and is composed of a first retroreflective surface 120_1 that is approximately parallel to the main surface of the light source 110_1, a second retroreflective surface 120_2 that is approximately parallel to the main surface of the light source 110_2, and a third retroreflective surface 110_3 that is approximately parallel to the main surface of the light source 110_3. In this example, the planar shape of the second retroreflective surface 120_2 is larger than those of the first and third retroreflective surfaces 120_1 and 120_3, and the planar shapes of the first retroreflective surface 120_1 and the third retroreflective surface 120_3 are approximately equal, but this is just an example. The first, second and third retroreflective surfaces 120_1, 120_2 and 120_3 may be formed by folding one retroreflective member, or may be formed by bonding three retroreflective members with an adhesive or the like.

[0020] Furthermore, the first retroreflective surface 120_1, the second retroreflective surface 120_2, and the third retroreflective surface 120_3 of the retroreflective sheet 110 are formed with a plurality of notches 122 for transmitting or passing the light of the image from the light source 110 arranged on the back side. The number, pitch, shape, size, etc. of the notches 122 are appropriately selected according to the size of the light source 110, the brightness and resolution of the image output by the light source 110, etc. Here, as shown in FIG. 3(B), the notches 122 are elongated rectangular openings (through holes), but the notches 122 may have other shapes, for example, grid-shaped openings. In addition to the through holes, the notches 122 may be transparent windows made of a transparent member that transmits light.

[0021] The beam splitter 130 is an optical member that splits incident light into transmitted light and reflected light at a certain ratio (the beam splitter 130 may be a half mirror). A decorative sheet 140 is attached to the surface of the beam splitter 130. The decorative sheet 140 is decorated with a design, thereby providing a design suitable for the space in which the aerial image is displayed.

[0022] 4 is a diagram illustrating the display of an aerial image by the display device of this embodiment. When the same image is displayed on the light sources 110_1, 110_2, and 110_3, the light of the image advances toward the beam splitter 130 through the notch 122 of the retroreflective sheet 120, the light reflected by the beam splitter 130 enters the retroreflective sheet 120, and the light reflected by the retroreflective sheet 120 passes through the beam splitter 130 and the decorative sheet 140, whereby aerial images 150_1, 150_2, and 150_5 corresponding to the images displayed on the light sources 110_1, 110_2, and 110_3 are displayed.

[0023] For example, the light of the image displayed on the light source 110_1 passes through the notch 122 of the first retroreflective surface 120_1, and a part of the light is reflected by the beam splitter 130, and the reflected light is incident on, for example, the second retroreflective surface 120_2 and the third retroreflective surface 120_3. The incident light is reflected in the same direction as when it was incident, and the reflected light passes through the beam splitter 130, and the aerial image 150_1 is displayed. Similarly, the light incident on the third retroreflective surface 120_3 is reflected in the same direction as when it was incident, and the reflected light passes through the beam splitter 130 and the decorative sheet 140, and the aerial image 150_1 is displayed. In this way, the aerial image 150_1 corresponding to the image of the light source 110_1 is displayed.

[0024] Light of the image displayed by the light source 110_2 passes through the notch 122 of the second retroreflective surface 120_2, and a part of the light is reflected by the beam splitter 130, and the reflected light is incident on, for example, the first retroreflective surface 120_1, the second retroreflective surface 120_2, and the third retroreflective surface 120_3. The incident light is reflected in the same direction as when it was incident, and the reflected light passes through the beam splitter 130 and the decorative sheet 140, and an aerial image 150_2 is displayed. In this way, an aerial image 150_2 corresponding to the image of the light source 110_2 is displayed.

[0025] Similarly, light of the image displayed by light source 110_3 passes through cutout 122 of third retroreflective surface 120_2, a portion of the light is reflected by beam splitter 130, and the reflected light is reflected by retroreflective sheet 120, thereby displaying an aerial image 150_3 corresponding to the image of light source 110_3.

[0026] The aerial images 150_1, 150_2, 150_3 and the images of the light sources 110_1, 110_2, 130_3 are line-symmetric with respect to the beam splitter 130. A user U5 on the front side of the light source 110_1 can view the aerial image 150_1 in the viewpoint direction, a user U6 on the front side of the light source 110_2 can view the aerial image 150_2 in the viewpoint direction, and a user U7 on the front side of the light source 110_3 can view the aerial image 150_3 in the viewpoint direction.

[0027] In this manner, according to the present embodiment, a plurality of light sources that output images in a plurality of directions are used to display a plurality of aerial images corresponding to the images of the plurality of light sources, so that the viewing angle of the aerial images can be increased and the visibility of the aerial images can be improved. Even if the viewing angle of a single aerial image is widened, it is difficult to convey the displayed content to people viewing it from a position other than the front, but in this embodiment, multiple fronts for the plurality of aerial images are created, so that the directions from which the aerial image is easily visible can be increased.

[0028] In the above embodiment, three light sources are exemplified, but the number of light sources may be four or more. In this case, the multiple light sources are arranged so that the optical axes of the light sources are at different angles with respect to the main surface of the beam splitter. Since the number of aerial images increases as the number of light sources increases, the aerial images become easier to see from the front, and the visibility of the aerial images can be improved. In addition, in the above embodiment, an example in which three light sources are configured from three displays is shown, but, for example, one light source may be configured from a display, and the other light source may be configured from an optical device that replicates an image displayed on a display using a mirror or the like.

[0029] In the above embodiment, a concave retroreflective sheet having multiple retroreflective surfaces is illustrated, but the retroreflective sheet may have a configuration other than the above as long as it can provide a retroreflective surface in a range of approximately 180 degrees with respect to the main surface of the beam splitter. In addition, in the above embodiment, a single-structure retroreflective sheet is illustrated, but the retroreflective sheet may be composed of multiple retroreflective sheets. Furthermore, a phase difference film such as a λ / 4 plate may be provided on the surface of the retroreflective sheet so that the beam splitter transmits or reflects polarization-controlled light.

[0030] In the above embodiment, the display device is applied to a space such as an elevator hall, but this is only one example and the display device can be applied to other spaces. Furthermore, the display device of this embodiment can be applied to a user interface, and for example, the aerial image can be applied to a computer device, an in-vehicle electronic device, an ATM in a bank, a ticket vending machine in a station, an input button in an elevator, etc.

[0031] 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 are possible within the scope of the gist of the invention described in the claims. [Explanation of symbols]

[0032] 100:Display device 110, 110_1, 110_2, 110_3: Light source 120: Retroreflective sheet 120_1, 120_2, 120_3: Reflective surface 122:Notch 130: Beam splitter 140:Decorative sheet 150: Aerial image

Claims

1. A display device capable of displaying an aerial image using retroreflection, A plurality of light sources each outputting the same image in a different direction; an optical member that separates incident light into reflected light and transmitted light at a constant ratio; A retroreflective member that provides a retroreflective surface in a range of approximately 180 degrees relative to the main surface of the optical member, A display device in which image light output from each of the multiple light sources is incident on the retroreflective member via the optical member, the light reflected by the retroreflective member passes through the optical member, and multiple aerial images corresponding to the images of the multiple light sources are displayed.

2. The display device according to claim 1 , wherein the retroreflective member is disposed between the plurality of light sources and the optical member, and the retroreflective member has a plurality of openings formed therein for transmitting or passing light from the plurality of light sources.

3. At least three light sources are disposed at different angles relative to a major surface of the optical element; The display device described in claim 1, wherein the retroreflective member has a plurality of retroreflective surfaces that match the positions of the plurality of light sources, and the plurality of retroreflective surfaces are formed with a plurality of notches for transmitting or passing images output by the plurality of light sources toward the optical member.

4. The display device according to claim 3 , wherein the retroreflective member has a concave shape, and a light source is disposed adjacent to a side surface and a bottom surface of the concave shape.

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