Display device

Abstract

The present invention addresses the problem of providing a display device capable of displaying an aerial image at a wide angle of view. An aerial image display device (100) according to the present invention is provided with: a plurality of light sources (110 - 1, 110 - 2, 110 - 3) that output the same image; a retroreflective sheet (120) that includes a first retroreflective surface (120 - 1), a second retroreflective surface (120 - 2), and a third retroreflective surface (120 - 3) that face the plurality of light sources; and a beam splitter (130) that is disposed facing the retroreflective sheet (120). The first, second, and third retroreflective surfaces (120 - 1, 120 - 2, 120 - 3) are respectively provided with a plurality of slits (122) for transmitting or passing images of the light sources (110), 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 on the first, second, and third retroreflective surfaces (120 - 1, 120 - 2, 120 - 3).

Description

Technical Field

[0001] The present invention relates to a display device for displaying an image in the air by utilizing retroreflection, and to a technology for displaying an image in the air with a wide viewing angle. 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 observation of an image formed in the air from a wider angle. In addition, Patent Document 2 discloses a display device in which a light source and a retro-reflective component are positioned so that light that is regularly reflected on the retro-reflective component does not enter the observation range, thereby suppressing a decrease in contrast or visual recognition.

[0003] Prior art literature:

[0004] Patent Literature:

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

[0006] Patent Document 2: Japanese Patent Application Publication No. 2022-150245 Summary of the invention

[0007] Problems to be solved by the invention:

[0008] As things we see in daily life, we can visually identify things that emit light by themselves or are illuminated by external light. Most of them exist physically, so when considering the design of space, even if they are necessary, they may damage the design of the space. As one of the means to solve this problem, the use of aerial images can be cited.

[0009] Figure 1 1 is a diagram showing an example of a display device for displaying an aerial image. As shown in the figure, an aerial image 20 showing the operation status of the elevator (e.g., the floor at which the elevator stops, etc.) is displayed near the elevator door 10. The aerial image 20 is displayed with spatial design like a lantern (lighting equipment) installed on a wall. The user U1 visually recognizes the aerial image 20 from the direction Y1 to confirm the operation status of the elevator.

[0010] Figure 2 The display device 30 is a top view showing a schematic structure of a display device for displaying such an aerial image. The display device 30 includes: a light source (e.g., a display for outputting an image) 40, a beam splitter 50 for splitting incident light into reflected light and transmitted light in a predetermined ratio, a decorative sheet 60 formed on the surface of the beam splitter 50 and having a decoration or pattern, and a retroreflective sheet 70.

[0011] If an image is displayed on the light source 40, a part of the light representing the image is reflected on the beam splitter 50, and the reflected light travels toward the retroreflective sheet 70. The retroreflective sheet 70 is an optical component that reflects light in the same direction as the incident light. The light reflected on the retroreflective sheet 70 travels toward the beam splitter 50 again, and the light transmitted through the beam splitter 50 and the decorative sheet 60 is converged and then diffused again, showing as Figure 1 An aerial image 20 ("A" in the example of the drawing) is shown.

[0012] 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. In addition, the aerial image 20 that the user can observe is limited to the range in which the retroreflective sheet 70 can be seen from the user's viewpoint through the beam splitter 50. In other words, the viewing angle is limited. Figure 1 , Figure 2 In the figure, users U1, U2, and U3 on the front side of the aerial image 20 can visually recognize the aerial image 20 in their viewpoint direction, but user U4 on the back side cannot visually recognize the aerial image 20 in the viewpoint direction Y2, and as a result cannot confirm the operating status of the elevator.

[0013] An object of the present invention is to solve such conventional problems and to provide a display device capable of displaying an aerial image at a wide viewing angle.

[0014] Means used to solve the problem:

[0015] The display device involved in the present invention can use retroreflection to display aerial images, and includes: multiple light sources that output the same image in different directions; an optical component that separates incident light into reflected light and transmitted light in a certain ratio; and a retroreflective component that provides a retroreflective surface within a range of approximately 180 degrees relative to the main surface of the optical component. The light of the images respectively output by the multiple light sources is incident on the retroreflective component via the optical component, and the light reflected on the retroreflective component is transmitted through the optical component, thereby displaying multiple aerial images corresponding to the images of the multiple light sources.

[0016] In a certain embodiment, the retroreflective component is arranged between the plurality of light sources and the optical component, and a plurality of openings are formed on the retroreflective component for transmitting or passing the light from the plurality of light sources. In a certain embodiment, at least three light sources are arranged at different angles relative to the main surface of the optical component, and the retroreflective component has a plurality of retroreflective surfaces matching the positions of the plurality of light sources, and a plurality of cutouts are formed on the plurality of retroreflective surfaces for transmitting or passing the images output by the plurality of light sources toward the optical component. In a certain embodiment, the retroreflective component has a concave shape, and the light source is arranged close to the side and bottom surfaces of the concave shape.

[0017] Effect of the invention:

[0018] According to the present invention, a plurality of aerial images corresponding to the same video output by a plurality of light sources are displayed, so that the viewing angle of the aerial image can be expanded compared to the case of displaying a single aerial image, thereby improving the visibility of the aerial image. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram showing an example of installation of a conventional display device.

[0020] Figure 2 It is a plan view schematically showing the structure of a conventional display device.

[0021] Figure 3 (A) is a plan view showing a schematic configuration of a display device according to an embodiment of the present invention, Figure 3 (B) is its front view.

[0022] Figure 4 It is a diagram for explaining the operation of the display device involved in the embodiment of the present invention.

[0023] Description of reference numerals:

[0024] 100: Display device

[0025] 110, 110_1, 110_2, 110_3: Light source

[0026] 120: Retroreflective sheeting

[0027] 120_1, 120_2, 120_3: Reflective surface

[0028] 122: Incision

[0029] 130: Beam splitter

[0030] 140: Decorative sheet

[0031] 150: Aerial Image DETAILED DESCRIPTION

[0032] The display device involved in the present invention has the function of displaying an aerial image with a wide field of view by the AIRR method. In addition, the display device involved in the present invention can display an aerial image with a wide field of view and spatial design. Furthermore, the display device involved in the present invention can also be applied to a user input interface using an aerial image. 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.

[0033] [Example]

[0034] Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 3 (A) is a plan view showing a schematic configuration of a display device according to an embodiment of the present invention, Figure 3 (B) is a front view, and the display device is, for example, arranged as shown in Figure 1 An aerial image is shown near the elevator door 10.

[0035] The display device 100 of this embodiment is constructed to include: at least three light sources 110_1, 110_2, and 110_3 (these light sources are collectively referred to as light source 110) arranged at different positions to output images in different directions, a retroreflective sheet 120 arranged close to the light source 110, a beam splitter 130 arranged opposite to the retroreflective sheet 120, and a decorative sheet 140 formed on the surface of the beam splitter 130 and having a decoration or pattern applied thereto.

[0036] The light source 110 outputs the original image of the aerial image, for example, using a display or projector such as a liquid crystal. The light sources 110_1, 110_2, and 110_3 output images in at least three directions in order to display the aerial image with a wide field of view. For example, the light source 110_1 is configured such that its optical axis (the normal direction of the display surface of the display) forms an angle θ1 (= 30 degrees) relative to the main surface of the beam splitter 130, the light source 110_2 is configured such that its optical axis forms an angle θ2 (= 90 degrees) relative to the main surface of the beam splitter 130, and the light source 110_3 is configured such that its optical axis forms an angle θ3 (= 150 degrees) relative to the main surface of the beam splitter 130.

[0037] The sizes of the light sources 110_1, 110_2, and 110_3 (for example, the size of the display) may be different, 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. Figure 1 In the example shown, light sources 110_1, 110_2, and 110_3 output images of the floors where the elevator is stopped. In addition, light source 110 may emit light with controlled polarization, for example, a polarizing plate may be mounted on the display surface to emit light with controlled polarization.

[0038] The retroreflective sheet 120 is an optical component that reflects light in the same direction as the incident light, and is composed of, for example, a corner cube type retroreflective element, a triangular pyramid type retroreflective element, a bead type retroreflective element, etc. In order to display an aerial image with a wide viewing angle, the retroreflective sheet 120 provides a retroreflective surface that is approximately 180 degrees relative to the main surface of the beam splitter 130. Specifically, the retroreflective sheet 120 has a concave shape that matches the position 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 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 substantially equal, but this is only an example. The first, second and third retroreflective surfaces 120_1, 120_2, 120_3 may be formed by bending one retroreflective member or by bonding three retroreflective members with an adhesive or the like.

[0039] Furthermore, a plurality of cutouts 122 are formed on the first retroreflective surface 120_1, the second retroreflective surface 120_2, and the third retroreflective surface 120_3 of the retroreflective sheet 110 for transmitting or passing light from the image of the light source 110 disposed on the back side. The number, pitch, shape, size, etc. of the cutouts 122 are appropriately selected according to the size of the light source 110, the brightness or resolution of the image output by the light source 110, etc. Figure 3 As shown in (B), the cutout 122 is an elongated rectangular opening (through hole), but the cutout 122 may be an opening in another shape, such as a grid. In addition, in addition to the through hole, a transmission window formed by a transparent member that transmits light may also be used.

[0040] The beam splitter 130 is an optical component that separates incident light into transmitted light and reflected light in a certain ratio (the beam splitter 130 may also be a half mirror). A decorative sheet 140 is attached to the surface of the beam splitter 130. The decorative sheet 140 is decorated or patterned, thereby providing a design suitable for the space where the aerial image is displayed.

[0041] Figure 4This is a diagram for explaining the display of an aerial image involved in the display device of this embodiment. If the same image is displayed on the light sources 110_1, 110_2, and 110_3, respectively, the light of the image travels toward the beam splitter 130 via the cutout 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, thereby displaying aerial images 150_1, 150_2, and 150_5 corresponding to the images displayed by the light sources 110_1, 110_2, and 110_3.

[0042] For example, the light of the image displayed by the light source 110_1 passes through the cutout 122 of the first retroreflective surface 120_1, and a part of the light is reflected on the beam splitter 130, and the reflected light is incident on the second retroreflective surface 120_2 and the third retroreflective surface 120_3, for example. These incident lights are reflected in the same direction as when they were incident, and the reflected light is transmitted through the beam splitter 130, and an aerial image 150_1 is displayed. The light incident on the third retroreflective surface 120_3 is also reflected in the same direction as when it was incident, and the reflected light is transmitted through the beam splitter 130 and the decorative sheet 140, and an aerial image 150_1 is displayed. In this way, an aerial image 150_1 corresponding to the image of the light source 110_1 is displayed.

[0043] The light of the image displayed by the light source 110_2 passes through the cutout 122 of the second retroreflective surface 120_2, and a part of the light is reflected on the beam splitter 130, and the reflected light is incident on the first retroreflective surface 120_1, the second retroreflective surface 120_2, and the third retroreflective surface 120_3. These incident lights are reflected in the same direction as when they were incident, and the reflected light passes through the beam splitter 130 and the decorative sheet 140 to display an aerial image 150_2. In this way, an aerial image 150_2 corresponding to the image of the light source 110_2 is displayed.

[0044] Similarly, light of an image displayed by light source 110_3 passes through cutout 122 of third retroreflective surface 120_2, part of the light is reflected by beam splitter 130, and the reflected light is reflected by retroreflective sheet 120, thereby displaying aerial image 150_3 corresponding to the image of light source 110_3.

[0045] 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. The user U5 on the front side of the light source 110_1 can visually recognize the aerial image 150_1 in the direction of his viewpoint, the user U6 on the front side of the light source 110_2 can visually recognize the aerial image 150_2 in the direction of his viewpoint, and the user U7 on the front side of the light source 110_3 can visually recognize the aerial image 150_3 in the direction of his viewpoint.

[0046] As described above, according to this embodiment, multiple light sources that output images in multiple directions are used to display multiple aerial images corresponding to the images of the multiple light sources, thereby expanding the viewing angle of the aerial image and improving the visual recognition of the aerial image. Even if the viewing angle of a single aerial image is expanded, it is difficult to convey its display content to a person observing from other than the front, but in this embodiment, multiple fronts corresponding to the multiple aerial images are generated, thereby increasing the directions from which the aerial image can be easily visually recognized.

[0047] In the above embodiment, three light sources are illustrated, but the number of light sources may be more than four. In this case, the multiple light sources are configured so that each optical axis is at a different angle relative to the main surface of the beam splitter. The number of aerial images increases accordingly with the increase in the number of light sources, so it is easier to observe the aerial image from the front, which can improve the visual recognition of the aerial image. In addition, in the above embodiment, an example of three light sources composed of three displays is shown, but for example, one light source may be composed of a display, and the other light sources may be composed of an optical device that copies the image displayed on the display through a reflector or the like.

[0048] In the above embodiment, a concave retroreflective sheet having a plurality of retroreflective surfaces is exemplified, but the retroreflective sheet can be any shape as long as it can provide a retroreflective surface within a range of approximately 180 degrees relative to the main surface of the beam splitter, and can also be a structure other than the above. In addition, the above embodiment exemplifies a retroreflective sheet of a single structure, but the retroreflective sheet can also be composed of a plurality of retroreflective sheets. Furthermore, a phase difference film such as a λ / 4 plate can also be provided on the surface of the retroreflective sheet, and the beam splitter transmits or reflects the light after polarization control.

[0049] In the above embodiment, an example of applying the display device to a space such as an elevator hall is shown, but this is only one example and it can also be applied to other spaces. Furthermore, the display device of this embodiment can also be applied to a user interface, for example, the aerial image can be applied to a computer device, an on-board electronic device, an ATM in a bank, a ticket machine in a station, an input button in an elevator, etc.

[0050] 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 an aerial image by utilizing retroreflection, wherein: include: Multiple light sources output the same image in different directions; Optical components that separate incident light into reflected light and transmitted light in a certain proportion; as well as A retroreflective member providing a retroreflective surface within a range of approximately 180 degrees relative to the main surface of the optical member, Light of images respectively outputted from the plurality of light sources enters the retroreflective member via the optical member, and light reflected from the retroreflective member passes through the optical member, thereby displaying a plurality of aerial images corresponding to the images of the plurality of light sources.

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 a plurality of openings are formed in the retroreflective member for transmitting or passing the light from the plurality of light sources.

3. The display device according to claim 1, wherein: At least three light sources are arranged at different angles relative to the main surface of the optical component, The retroreflective component has a plurality of retroreflective surfaces that match the positions of the plurality of light sources, and a plurality of cutouts are formed on the plurality of retroreflective surfaces for allowing images output by the plurality of light sources to transmit or pass toward the optical component.

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

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