Display device
By placing inclined regression reflectors and opposing optical components on both sides of the light source, the problems of expanding the field angle and increasing the cost of the aerial image display device are solved, and a low-cost wide field angle display is realized.
Patent Information
- Application Number
- CN202510083284.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-01-22
- Filing Date
- 2025-01-20
- Publication Date
- 2025-07-22
AI Technical Summary
In the prior art, the optical system size becomes larger when the aerial image display device increases the field of view, resulting in problems such as increasing components and increasing costs.
The first and second regression reflectors that are inclined outwards on both sides of the light source, and the first and second optical components, such as semi-transparent half-mirror or polarized beam splitter, are arranged in an opposite manner to realize the display of two aerial images.
A low-cost wide-field angle display is realized, and users can observe aerial images of the same content from different directions, reducing the number of components of the optical system.
Smart Images
Figure CN120353044A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a display device having a function of displaying an image in the air using retroreflection. Background Art
[0002] There is known aerial display using retroreflection (Aerial Imaging by Retro-Reflection: AIRR). For example, the display device of Patent Document 1 includes: a first retroreflective portion disposed at a position in the emission direction of light emitted from a light source; and a light branching portion that reflects at least a part of the light transmitted through the first retroreflective portion as first reflected light and transmits at least a part of the first reflected light retroreflected by the first retroreflective portion, enabling observation of an aerial image from a relatively large angle.
[0003] Prior Art Documents
[0004] Patent Documents
[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2021-47438 Summary of the Invention
[0006] Due to reasons such as the improvement of the operability of non-contact devices and the improvement of spatial design, the display device of the AIRR method has attracted attention. In such a case, the user does not necessarily observe the aerial image from the front, and sometimes observes it from the side according to the situation, and a display device with a wide viewing angle is required. Figure 1 (A) and (B) are diagrams showing the schematic structure of a conventional wide viewing angle display device. In the figure, solid lines represent incident light, and dashed lines represent retroreflected light.
[0007] Figure 1 The display device 10 shown in (A) includes a display light source 20, a beam splitter 30, and a retroreflective member 40. By tilting the beam splitter 30 with respect to the retroreflective member 40, a wide viewing angle of the aerial image is achieved. A part of the incident light emitted from the display light source 20 is reflected by the beam splitter 30, and the reflected light is reflected by the retroreflective member 40 in the same direction as the incident light. The retroreflected light transmits through the beam splitter 30 to display the aerial image P. The aerial image P is formed at a position symmetric to the display 20 with respect to the plane of the beam splitter 30. Users U1 and U2 can visually confirm the aerial image P within the viewing angle θ capable of observing the retroreflective member 40.
[0008] Figure 1 The display device 50 shown in (B) is configured with two Figure 1A display device with an optical system whose size is reduced as shown in (A) of the figure, that is, it includes a set of display light sources 60A and 60B, a set of beam splitters 70A and 70B, and a set of retroreflective members 80A and 80B. The display light sources 60A and 60B emit images of the same content, so that users U1 and U2 can visually confirm the same aerial images PA and PB at the same time. In fact, a wide viewing angle of the aerial image is achieved.
[0009] However, Figure 1 The display device 10 as shown in (A) of the figure increases the viewing angle of the aerial image and can be observed from the side. On the other hand, the size of the optical system becomes larger, so there is a technical problem that it is difficult to observe from the side depending on the image content. In addition, Figure 1 The display device 50 as shown in (B) of the figure arranges a plurality of optical systems with a narrowed viewing angle, so there is a technical problem that more components are required and the cost becomes higher.
[0010] An object of the present invention is to solve such conventional technical problems and provide a display device that can achieve cost reduction and expand the viewing angle of the aerial image.
[0011] The display device of the present invention can display an aerial image by retroreflection and includes: a light source that emits an image from an emission surface; a first retroreflective member arranged on one end side of the light source and inclined outward at a first inclination angle with respect to the normal of the emission surface; a second retroreflective member arranged on the other end side of the light source and inclined outward at a second inclination angle with respect to the normal of the emission surface; a first optical component that separates incident light into reflected light and transmitted light and is arranged opposite to the first retroreflective member; and the second optical component that separates incident light into reflected light and transmitted light and is arranged opposite to the second retroreflective member.
[0012] In a certain mode, the first optical component is arranged parallel to the first retroreflective member, and the second optical component is arranged parallel to the second retroreflective member. In a certain mode, the first retroreflective member and the second retroreflective member are spherical or curved. In a certain mode, the display device displays a first aerial image in the direction facing the retroreflective surface of the first retroreflective member and a second aerial image in the direction facing the retroreflective surface of the second retroreflective member, and the first aerial image and the second aerial image are the same. In a certain mode, the first optical component and the second optical component are a semi-transmissive semi-reflective mirror, a beam splitter, or a polarization beam splitter. In a certain mode, the display device is arranged in the vehicle interior space between the driver's seat and the passenger seat.
[0013] [Effects of the Invention]
[0014] According to the present invention, the first and second retroreflective members are arranged on both sides of the light source so as to be inclined outward, and the first and second optical members are arranged so as to face the first and second retroreflective members. Therefore, two aerial images of the same content can be displayed in different directions. In fact, the viewing angle of the aerial image can be increased. In addition, since one light source is used to display two aerial images, the number of components of the optical system can be reduced, and the cost of the display device can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 FIG. 1 is a schematic view showing a schematic structure of a conventional display device.
[0016] Figure 2 FIG. 2 is a view showing the structure of a display device according to an embodiment of the present invention. Figure 2 (A) of FIG. 2 is a front view thereof. Figure 2 (B) of FIG. 2 is a perspective view thereof. Figure 2 (C) of FIG. 2 is a side view thereof.
[0017] Figure 3 FIG. 3 is a ray diagram when the display device of the present embodiment displays an aerial image.
[0018] Figure 4 FIG. 4 is a ray diagram showing the relationship between the viewpoint position of the user and the aerial image.
[0019] Figure 5 FIG. 5 is a view showing a modified example of the display device of the present embodiment.
[0020] Figure 6 FIG. 6 is a view showing an application example of the display device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION
[0021] The display device of the present invention displays an aerial image or an aerial image using retroreflection in a three-dimensional space that can be visually confirmed without wearing special glasses or the like. It should be noted that the drawings referred to in the following description of the embodiments include displays exaggerated for easy understanding of the invention, and do not directly represent the actual shape and ratio of the product.
[0022] [Embodiment]
[0023] Next, an embodiment of the present invention will be described in detail. Figure 2 FIG. 2 is a view showing the structure of a display device according to an embodiment of the present invention. Figure 2 (A) of FIG. 2 is a front view thereof. Figure 2 (B) of FIG. 2 is a perspective view thereof. Figure 2 (C) of FIG. 2 is a top view thereof.
[0024] The display device 100 of this embodiment is configured to include a light source 110, a set of retroreflective elements 120A and 120B, and a set of beam splitters 130A and 130B. Although not illustrated here, these components can be mounted on a frame, a housing, etc., for example.
[0025] The light source 110 only needs to have the function of emitting an image or a picture, and is not particularly limited. For example, it is a display light source such as a liquid crystal display device, an organic EL display device, or a projection display device. The display light source has, for example, a rectangular emission surface and emits an image in the normal direction (optical axis direction) of the emission surface. Such a display light source is not particularly limited. For example, it can be Figure 2 the screen of a smart phone as shown in (A) below, and in addition, it can also be the screen of a portable terminal, the screen of a personal computer, the screen of a projector, etc.
[0026] The retroreflective elements 120A and 120B are optical components that reflect light in the same direction as the incident light. For example, they are composed of prism-type retroreflective elements such as triangular pyramid-type retroreflective elements and full-angle corner-type retroreflective elements, and bead-type retroreflective elements. The set of retroreflective elements 120A and 120B illustrated here are respectively composed of rectangular sheets or thin plates of equal size. However, the sizes of the retroreflective element 120A and the retroreflective element 120B can also be different.
[0027] Specifically, one retroreflective element 120A approaches in such a way that its end EA matches one end D1 of the light source 110 (or its emission surface), and is arranged such that the retroreflective surface of the retroreflective element 120A is inclined outward at an angle θA with respect to the normal (optical axis) of the emission surface (refer to Figure 2 (C) below). The other retroreflective element 120B approaches in such a way that its end EB matches the other end D2 of the light source 110 (or its emission surface), and is arranged such that the retroreflective surface of the retroreflective element 120B is inclined outward at an angle θB with respect to the normal (optical axis) of the emission surface.
[0028] The tilt angles θA and θB are set such that most of the light emitted from the light source 110 does not directly enter the retroreflective elements 120A and 120B and corresponds to the viewing positions of the users. In addition, the sizes of the retroreflective surfaces of the retroreflective elements 120A and 120B are determined to be able to sufficiently receive the light reflected by the beam splitters 130A and 130B. Assuming that the viewing positions of the left and right users are symmetric with respect to the display device 100, let θA = θB, and the set of retroreflective elements 120A and 120B can be arranged symmetrically with respect to the light source 110. In addition, when the viewing positions of the left and right users are asymmetric with respect to the display device 100 or in different directions, the tilt angle θA of the retroreflective element 120A and the tilt angle θB of the retroreflective element 120B can be set to different angles respectively.
[0029] The beam splitters 130A and 130B are optical components that separate incident light into transmitted light and reflected light. For example, a semi-transmissive semi-reflective mirror is used, or a polarization beam splitter is used when using polarized light. The beam splitters 130A and 130B illustrated here are each composed of rectangular sheets or thin plates of equal size. However, the sizes of the beam splitter 130A and the beam splitter 130B may also be different.
[0030] Specifically, the beam splitter 130A is arranged to face the retroreflector 120B, and the beam splitter 130B is arranged to face the retroreflector 120A. The beam splitter 130A illustrated here is separately arranged in parallel with the retroreflector 120B, and the beam splitter 130B is separately arranged in parallel with the retroreflector 120A. However, they do not necessarily have to be parallel.
[0031] The end FA of the beam splitter 130A and the end FB of the beam splitter 130B may be arranged to be in contact, or may be arranged such that the end FA and the end FB are separated. For example, the ends of the two beam splitters may be joined by an adhesive material, or one beam splitter may be bent to form two beam splitters.
[0032] The angles θC formed by the main surfaces of the beam splitters 130A and 130B, the sizes of the main surfaces of the beam splitters 130A and 130B, and the distances from the light source 110 to the beam splitters 130A and 130B are set such that the light emitted from the light source 110 can be sufficiently incident, and the light retroreflected by the retroreflectors 120A and 120B can be sufficiently incident. When the tilt angles θA = θB, the angle θC = 2θA = 2θB, and the optical system of the display device 100 is symmetric about the normal line (optical axis) passing through the center of the light source 110.
[0033] Next, the operation of the display device of this embodiment will be described. Figure 3 It is a ray diagram when displaying a virtual image in the air. Here, only the rays emitted from the center of the emission surface of the light source 110 are shown. In addition, solid lines represent incident light, and dashed lines represent retroreflected light. As shown in this figure, the light (image) emitted from the emission surface of the light source 110 in the direction of the normal line (optical axis) is incident on a set of beam splitters 130A and 130B respectively.
[0034] The light reflected by the beam splitter 130A is incident on the opposing retroreflector 120B, where it is retroreflected, and the retroreflected light is incident on the beam splitter 130A. The light transmitted here forms an image to generate a virtual image PA in the air. In addition, the light reflected by the beam splitter 130B is incident on the opposing retroreflector 120A, where it is retroreflected, and the retroreflected light is incident on the beam splitter 130B. The light transmitted here forms an image to generate a virtual image PB in the air.
[0035] The aerial image PA is generated at a position symmetrical to the light source 110 with respect to the plane of the beam splitter 130A, and the aerial image PB is generated at a position symmetrical to the light source 110 with respect to the plane of the beam splitter 130B. In addition, since the aerial images PA and PB share the image emitted from the light source 110, the two are aerial images of the same content.
[0036] Figure 4 It is a ray diagram when observing the aerial image from the viewpoint positions in the left and right directions. The user U1 located on the left side in the direction of the tilt angle θB of the retroreflector 120B can observe the retroreflector 120B from the viewpoint through the beam splitter 130A, and thus can visually confirm the aerial image PA in the direction of his line of sight. In addition, the user U2 located on the right side in the direction of the tilt angle θA of the retroreflector 120A can observe the retroreflector 120A from the viewpoint through the beam splitter 130B, and thus can visually confirm the aerial image PB in the direction of his line of sight.
[0037] Thus, according to the present embodiment, by arranging a set of retroreflectors 120A and 120B that are inclined outward on both sides of the light source 110 and arranging a set of beam splitters 130A and 130B so as to face the set of retroreflectors 120A and 120B, it is possible to display aerial images of the same content in two directions, and in fact, a wide viewing angle of the aerial image can be achieved. In addition, according to the configuration of the optical system, both users can observe the aerial image from the front side, so it has the advantage of being easy to observe the content. And by sharing the expensive display light source also in the optical system components of the aerial image, it is not necessary to use 2 light sources as in the past ( Figure 1 of (B)), and the cost of the display device can be reduced.
[0038] As a mode of the present embodiment, when the light emitted from the light source 110 is polarized light (such as the image of a liquid crystal display device, etc.), a λ / 4 film can be provided on the surfaces of the retroreflectors 120A and 120B as a phase difference film, and the beam splitters 130A and 130B use polarization beam splitters. The polarization beam splitter transmits a part of the light in a certain polarization state and reflects the remaining part. The polarization direction of the polarization beam splitter is determined in relation to the polarization direction of the light emitted from the light source 110. For example, it is set such that the polarization direction of the light source 110 is substantially orthogonal to the polarization direction of the polarization beam splitter.
[0039] In addition, in the above embodiment, in order to display two aerial images in the left - right direction, a set of retroreflectors 120A and 120B are respectively arranged on the left and right of the light source 110. However, in the case of displaying two aerial images in the up - down direction, as long as a set of retroreflectors 120A and 120B and a set of beam splitters 130A and 130B are arranged so thatFigure 2 It is only necessary to rotate the display device 100 shown by 90 degrees to obtain the positional relationship.
[0040] Next, a modified example of the display device of the present embodiment will be described. Figure 5 It is a top view of the display device 100A of the modified example. In the previous embodiment, the retroreflective surfaces of the retroreflective members 120A and 120B are flat surfaces. However, in the display device 100A of the modified example, the retroreflective members 140A and 140B have curved surfaces or spherical surfaces with curved retroreflective surfaces. The curvature or the center of curvature of the retroreflective members 140A and 140B is appropriately determined according to the viewing positions of the left and right users U1 and U2. By using such retroreflective members with a curved surface shape, two aerial images can be displayed on the more frontal side.
[0041] In addition, the display devices 100 / 100A of the present embodiment can be installed, for example, as Figure 6 shown, in the in-vehicle space (for example, the instrument panel, instrument panel part) between the driver's seat 200 and the front passenger seat 210. The driver sitting on the driver's seat 200 and the passenger sitting on the front passenger seat 210 can visually confirm the aerial image displayed by the display device 100 / 100A from their respective viewing directions.
[0042] Moreover, in addition to the in-vehicle space, the display device of the present embodiment can also be applied to devices and systems having a use for viewing from the left and right. For example, it can also be applied to the front of the seats for two people riding on a tractor (attraction), or it can also be applied to the front of the seats of trams, buses, aircraft, etc.
[0043] As described above, the preferred embodiments of the present invention have been described in detail. However, the present invention is not limited to specific embodiments, and various modifications and changes can be made within the scope of the gist of the invention described in the claims.
[0044] [Description of Reference Numerals]
[0045] 100, 100A: Display device
[0046] 110: Light source
[0047] 120A, 120B, 140A, 140B: Retroreflective member
[0048] 130A, 130B: Beam splitter
[0049] 200: Driver's seat
[0050] 210: Front passenger seat
[0051] PA, PB: Aerial image.
Claims
1. A display device capable of displaying a virtual image in the air by retroreflection, characterized in that, Comprising: A light source that emits an image from an exit surface; A first retroreflective member disposed on one end side of the light source and inclined outward at a first inclination angle with respect to the normal of the exit surface; A second retroreflective member disposed on the other end side of the light source and inclined outward at a second inclination angle with respect to the normal of the exit surface; A first optical component that separates incident light into reflected light and transmitted light and is disposed opposite to the first retroreflective member; And A second optical component that separates incident light into reflected light and transmitted light and is disposed opposite to the second retroreflective member.
2. The display device according to claim 1, wherein: The first optical component is disposed parallel to the first retroreflective member, and the second optical component is disposed parallel to the second retroreflective member.
3. The display device according to claim 1, wherein: The first retroreflective member and the second retroreflective member are spherical or curved.
4. The display device according to claim 1, wherein: The display device displays a first aerial image in the direction in which the retroreflective surface of the first retroreflective member faces, and displays a second aerial image in the direction in which the retroreflective surface of the second retroreflective member faces, and the first aerial image and the second aerial image are the same.
5. The display device according to claim 1, wherein: The first optical component and the second optical component are a semi-transmissive semi-reflective mirror, a beam splitter, or a polarization beam splitter.
6. The display device according to claim 1, wherein: The display device is disposed in the vehicle interior space between the driver's seat and the passenger seat.
Citation Information
Patent Citations
Display device
JP2021047438A