Spatial projection device and retroreflective member

Abstract

To provide a space projection device which achieves quality improvement in a space projection image.SOLUTION: A space projection device 100 includes: an optical medium 20 for diffusing projection light P1; and a light guide optical system 30 for guiding projection light (space projection light P2) diffused by the optical medium 20 so as to form an image at a space image formation part 40. The light guide optical system 30 includes a retroreflective member 32. The retroreflective member 32 includes a concave-convex structure 320 for suppressing a ghost image M.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to a spatial projection device and a retroreflective member constituting the spatial projection device.

Background Art

[0007] A retroreflective member according to one aspect of the present invention constitutes the spatial projection device described above. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a spatial projection device that improves the quality of spatial projection images, and retroreflective members that constitute such a spatial projection device. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic plan view of a spatial projection device according to an embodiment of the present invention. [Figure 2] This is a perspective view showing a part of the retroreflective member in a spatial projection device according to an embodiment of the present invention. [Figure 3] This is a perspective view showing a part of a retroreflective member related to a modified example of a spatial projection device according to an embodiment of the present invention. [Figure 4] This is a schematic plan view of a conventional spatial projection device. [Modes for carrying out the invention]

[0010] The embodiments for carrying out the present invention will be described below. Figure 1 is a schematic plan view of the spatial projection device 100. The spatial projection device 100 comprises a projection device 10 (projector) which is a display unit, an optical medium 20 which is irradiated (projected), imaged and diffused by projection light P1 emitted from the projection device 10, a light guide optical system 30 which guides the light projected and diffused onto the optical medium 20, and a spatial imaging unit 40 which re-images the light guided by the light guide optical system 30 in space.

[0011] The spatial projection device 100 allows the viewer 50 to see a spatially projected image 4a floating in the air, which is emitted from the projection device 10, projected onto the optical medium 20 and formed into an image. The projected image 2a diffuses and is transmitted (emitted) from the optical medium 20 and enters the light guide optical system 30, where it is formed into an image in the spatial imaging unit 40.

[0012] In this embodiment, a projection device 10 is used as the display unit that emits the projected light P1, but other display devices such as a display can also be used. Furthermore, the viewer 50 is assumed to be standing with respect to the plane of Figure 1 (with their head facing the positive side of the Z-axis and their feet facing the negative side).

[0013] The optical medium 20 has any shape and size such that it includes the projection range of the projected light P1. Alternatively, the optical medium 20 is placed at any position that includes the projection range of the projected light P1. The optical medium 20 in Figure 1 is configured as a flat, plate-shaped or film-shaped transmissive screen.

[0014] The optical medium 20 is a transmissive member that, when projection light P1 (including light L1) emitted from the projection device 10 is irradiated onto the first surface 21 on the projection device 10 side and an image is formed, diffuses and emits spatial projection light P2 (including light L2) from the second surface 22, which is the opposite side of the first surface 21, toward the light guide optical system 30.

[0015] The light guide optical system 30 is provided on the second surface 22 side of the optical medium 20. The light guide optical system 30 comprises a beam splitter 31 and a retroreflective member 32 (retroreflective mirror). The retroreflective member 32 is positioned along an arrangement surface S2 (a surface including the Y and Z directions in Figure 1) perpendicular to the arrangement surface S1 (a surface including the X and Z directions in Figure 1) of the optical medium 20.

[0016] Furthermore, the beam splitter 31 is formed in a flat plate shape and is positioned at a 45-degree angle with respect to the placement surface S1 of the optical medium 20 and the placement surface S2 of the retroreflective member 32. The beam splitter 31 in this embodiment is a half-mirror that reflects a portion of the incident light and transmits the other portion. The beam splitter 31 reflects the light diffused and emitted from the optical medium 20 towards the retroreflective member 32, and transmits the light reflected by the retroreflective member 32 to the spatial imaging unit 40.

[0017] The retroreflective member 32 reflects incident light in the opposite direction to the direction of incidence (opposite direction). The retroreflective member 32 has a bumpy structure 320 to suppress ghost images (virtual images) generated by the specular reflection component of the incident light on the retroreflective member 32. Specifically, as shown in Figure 2, the bumpy structure 320 has a plurality of plate-shaped retroreflective material 321 as plate-shaped retroreflective parts 325 that are arranged alternately at a predetermined angle θ on one side of the retroreflective member 32 and on the other side opposite to the one side. In other words, the bumpy structure 320 has a plurality of plate-shaped retroreflective material 321 (plate-shaped retroreflective parts 325) that are arranged in a zigzag pattern, each having a plurality of protrusions 323a and a plurality of recesses 323b, and the angle between them is a predetermined angle θ. In other words, the multiple protrusions 323a and multiple recesses 323b formed by the multiple plate-shaped retroreflective portions 325 (plate-shaped retroreflective material 321) are formed by the ends of the multiple plate-shaped retroreflective material 321 (plate-shaped retroreflective portions 325) and the connecting portions 322, which will be described later.

[0018] The plate-like retroreflective material 321 can be formed by cutting out a single rectangular plate-like retroreflective member into strip shapes. In the present embodiment, the connection portions 322 of adjacent plate-like retroreflective materials 321 are linearly provided so as to be parallel to the Z-axis direction. Further, in the present embodiment, the retroreflective member 32 (concavo-convex structure 320) is formed by 12 plate-like retroreflective materials 321 having the same shape.

[0019] As shown in FIG. 3 regarding a modification example of the retroreflective member 32, the concavo-convex structure 320 can also be provided with a plurality of plate-like retroreflective portions 325 by zigzagging a single rectangular plate-like retroreflective member. Also in this case, it includes a plurality of convex portions 323a and a plurality of concave portions 323b, the bent portion is the connection portion 322, and the angle formed at this connection portion 322 is a predetermined angle θ.

[0020] Returning to FIG. 1, the spatial imaging portion 40 is a spatial region where the projected image 2a projected and imaged on the optical medium 20 and diffused is re-imaged by the light guide optical system 30 after being diffused and emitted from the optical medium 20 as spatial projection light P2 (P3), and the spatial projection image 4a is displayed.

[0021] Next, the operation of the spatial projection device 100 will be described. The light L1, which is the light of one pixel in the projection light P1 emitted from the projection device 10, forms an image at the imaging point F1 on the optical medium 20. The optical medium 20 is irradiated with the light of the pixels emitted from the projection device 10 in the optical path exemplified by the light L1 over the irradiation range of the projection light P1. In this way, the projection image 2a is projected onto the optical medium 20.

[0022] In FIG. 1, only one imaging point F1 is shown, but actually, there are many imaging points F1 in the Z-axis direction and the X-axis direction (that is, the irradiation range of the projection light P1).

[0023] Light from any point constituting the projected image 2a, which is projected and imaged onto the first surface 21 of the optical medium 20, is transmitted to the second surface 22 and emitted from the second surface 22 after being diffused at a predetermined diffusion angle. For example, the aforementioned light L1, which is imaged at the image point F1, is diffused as light L2 at a predetermined diffusion angle and incident on the beam splitter 31. A portion of the light L2 is reflected by the beam splitter 31 towards the retroreflective member 32. That is, the light L2 of one pixel of the projected image 2a is guided as diffused light in the optical path from the optical medium 20 to the retroreflective member 32.

[0024] The retroreflective member 32 reflects the incident light in the opposite direction to the direction of incidence (opposite direction). Therefore, the light L2 incident on the retroreflective member 32 is reflected towards the beam splitter 31 as focused light that is focused at the same angle as the diffusion angle.

[0025] The light L3 reflected by the retroreflective member 32 is partially transmitted through the beam splitter 31 and guided to the spatial imaging unit 40. In the spatial imaging unit 40, the light L3 is imaged again at the imaging point F2. The optical path lengths of light L2 and light L3 are approximately the same.

[0026] Then, the light L3 formed at the imaging point F2 of the spatial imaging unit 40 is guided as light L4, which has a diffusion angle similar to the focusing angle of light L3 and the diffusion angle of light L2.

[0027] Here, the retroreflective member 32 (plate-shaped retroreflective portion 325, plate-shaped retroreflective material 321) has a protective layer on its surface. Due to the influence of this protective layer, some of the light L2 incident on the retroreflective member 32 may be specularly reflected, generating specular reflection components M11, M12, M21, and M22. When this happens, the specular reflection components M11, M12, M21, and M22 are extended to the back side of the retroreflective member 32 (the positive side of the X-axis), and an image (ghost image M) appears from the position where the specular reflection components M11, M12 and specular reflection components M21, M22 intersect (ghost image positions M1, M2).

[0028] However, in this embodiment, the ghost image M is located outside the field of view E on the back side of the retroreflective member 32 (in other words, the side opposite the spatial imaging unit 40) when the retroreflective member 32 is viewed from the viewer's viewpoint through the spatial imaging unit 40 and the beam splitter 31. Therefore, the ghost image M is not visible to the viewer 50.

[0029] In other words, as shown in Figure 4 relating to the conventional spatial projection device 100A, when the retroreflective member 32A is a single flat retroreflective member 32A, when the light L2 reflected by the beam splitter 31 is incident on the retroreflective member 32A and reflected, specular reflection components K1 and K2 are generated by the protective film of the retroreflective member 32A. Since the specular reflection components K1 and K2 intersect at the ghost image position KM1 within the field of view E, the viewer 50 will see as if the image is being projected from the ghost image KM at the ghost image position KM1.

[0030] On the other hand, as shown in Figure 1, in the spatial projection device 100 of this embodiment, even if each inclined plate-shaped retroreflective part 325 (plate-shaped retroreflective material 321) is specularly reflected by the retroreflective member 32 having an uneven structure 320, the ghost image M is displayed at an angle to the spatial projection image 4a formed by the spatial imaging unit 40, and since the ghost image M is located outside the field of view E, the viewer 50 will not be able to see the ghost image M.

[0031] The uneven structure 320 has a plurality of adjacent plate-shaped retroreflective parts 325 (plate-shaped retroreflective material 321) that form a predetermined angle θ, and the predetermined angle θ is preferably between 100 and 160 degrees. If the predetermined angle θ is within this range, even if a part of the ghost image M enters the field of view E, the appearance of the ghost image M can be suppressed to an extent that is not noticeable to the viewer 50.

[0032] Furthermore, 4 to 30 plate-shaped retroreflective sections 325 (plate-shaped retroreflective material 321) can be provided. In other words, the retroreflective member 32 can be formed by cutting or bending a single plate-shaped retroreflective material to divide it into 4 to 30 sections. In this embodiment, the length of the retroreflective member 32 in the Y-axis direction is 50 cm. This 50 cm length can then be divided into 4 to 30 sections (to produce 4 to 30 plate-shaped retroreflective sections 325 (plate-shaped retroreflective material 321)) to constitute the retroreflective member 32.

[0033] Furthermore, although the connecting portion 322 connecting the plate-shaped retroreflective portions 325 (plate-shaped retroreflective material 321) is oriented in the Z-axis direction (vertical direction in the image formed by the spatial imaging unit 40) in this embodiment, it may also be oriented in the Y-axis direction (horizontal direction). Arranging the connecting portion 322 in the Z-axis direction, as in this embodiment, makes it difficult to visually identify the connecting portion 322, as the left and right eyes will see different connecting portions 322 among the multiple connecting portions 322.

[0034] As described above, according to embodiments of the present invention, the spatial projection device 100 comprises an optical medium 20 that diffuses projection light P1, and a light guiding optical system 30 that guides the projection light (spatial projection light P2) diffused by the optical medium 20 and forms an image on the spatial imaging unit 40. The light guiding optical system 30 includes a retroreflective member 32, and the retroreflective member 32 has an uneven structure 320 for suppressing ghost images M.

[0035] As a result, the viewer 50 has difficulty seeing the ghost image M, so that the spatial projection image 4a projected onto the spatial imaging unit 40 can be seen clearly, and a spatial projection device 100 with improved projection image quality can be provided.

[0036] Furthermore, the uneven structure 320 has a plurality of protrusions 323a and a plurality of recesses 323b. This makes it possible to shift the position in which the ghost image M is positioned relative to the viewer's line of sight 50.

[0037] Furthermore, the uneven structure 320 has a plurality of plate-shaped retroreflective portions 325 (plate-shaped retroreflective material 321) arranged alternately at a predetermined angle θ on one side of the retroreflective member 32 and on the other side facing that side, forming a plurality of protrusions 323a and a plurality of recesses 323b. As a result, the uneven structure 320 can be easily formed simply by dividing a single plate-shaped retroreflective mirror into multiple parts.

[0038] Furthermore, the connection points 322 of the multiple plate-shaped retroreflective sections 325 (plate-shaped retroreflective material 321) are parallel to the vertical direction (Z-axis direction) with respect to the image formed in the spatial imaging section 40. This makes it difficult for viewers to see the connection points 322 even when viewing the spatial image.

[0039] Furthermore, the predetermined angle θ is between 100 and 160 degrees. This makes it possible to provide a spatial projection device that can project a good spatial image in which ghost images M are difficult to see.

[0040] Furthermore, 4 to 30 plate-shaped retroreflective materials 321 are provided. This makes it possible to perform spatial projection in which the connection points 322 between the plate-shaped retroreflective materials 321 are less likely to appear in the spatial projection image 4a.

[0041] Furthermore, the uneven structure 320 is configured to tilt the ghost image M relative to the spatial projection image 4a formed in the spatial imaging unit 40. This makes it possible to move the ghost image M away from the center of the field of view E or to position it outside the field of view E, making the ghost image M difficult to see.

[0042] Furthermore, the ghost image M is positioned outside the field of view E of the retroreflective member 32 on the opposite side of the spatial imaging unit 40. This makes it even more difficult for the viewer 50 to see the ghost image M.

[0043] Furthermore, the light guide optical system 30 includes a beam splitter 31, which reflects the light (spatial projection light P2) diffused and emitted from the optical medium 20 toward the retroreflective member 32, and transmits the light (spatial projection light P3) reflected by the retroreflective member 32 toward the spatial imaging unit 40. As a result, the projection light P1 (image) from the projection device 10 can be spatially projected onto the spatial imaging unit 40 at a position symmetrical to the beam splitter 31.

[0044] The embodiments described above are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and essence of the invention, as well as in the claims of the invention and its equivalents.

[0045] The invention described in the first claim of this application is listed below. [1] An optical medium that diffuses projected light, A light-guiding optical system that guides the projected light diffused by the optical medium and forms an image in a spatial imaging unit, Equipped with, The aforementioned light guide optical system includes a retroreflective member, The retroreflective member is a spatial projection device having an uneven structure for suppressing ghost images. [2] The spatial projection device according to [1], wherein the uneven structure has a plurality of protrusions and a plurality of recesses. [3] The spatial projection device according to [2], wherein the plurality of plate-shaped retroreflective portions are formed by a plurality of plate-shaped retroreflective portions arranged alternately at a predetermined angle on one side of the retroreflective member and on the other side opposite to the one side. [4] The spatial projection apparatus according to [3], wherein the connection between the plurality of plate-shaped retroreflective sections is parallel to the vertical direction with respect to the image formed in the spatial imaging section. [5] The spatial projection device according to [3] or [4], wherein the predetermined angle is 100 degrees to 160 degrees. [6] The spatial projection device according to any one of [3] to [5], wherein 4 to 30 plate-shaped retroreflective sections are provided. [7] The spatial projection device according to any one of [1] to [6], wherein the uneven structure is configured to tilt the ghost image relative to the spatial projection image formed in the spatial imaging unit. [8] The spatial projection device according to any one of [1] to [7], wherein the ghost image is positioned outside the field of view of the retroreflective member opposite to the spatial imaging unit. [9] The light guide optical system includes a beam splitter, The spatial projection apparatus according to any one of [1] to [8], wherein the beam splitter reflects light diffused and emitted from the optical medium toward the retroreflective member and transmits the light reflected by the retroreflective member toward the spatial imaging unit.

[10] A retroreflective member constituting the spatial projection device described in any of [1] to [9] above. [Explanation of Symbols]

[0046] 2a Projected image 4a Spatial projection image 10 Projection device 20 Optical medium 21 First page 22 Second page 30 Light guide optics 31 Beam splitter 32,32A Retroreflective material 40 Spatial imaging section 50 Viewers 100,100A Spatial Projection Device 320 Uneven structure 321 Plate-shaped retroreflective material 322 Connection part 323a Convex portion 323b Recessed portion 325 Plate-shaped retroreflective section E Field of View F1, F2 imaging points M11,M12,M21,M22,K1,K2 Specular reflection component M,KM Ghost Statue M1, M2, KM1 Ghost Locations L1~L4 light P1 projection light P2, P3 Spatial Projection Light S1, S2 configuration surfaces θ is the angle

Claims

1. An optical medium that diffuses projected light, A light-guiding optical system that guides the projected light diffused by the optical medium and forms an image in a spatial imaging unit, Equipped with, The aforementioned light guide optical system includes a retroreflective member and a beam splitter. The retroreflective member comprises a retroreflective member body and a protective layer provided on the surface of the retroreflective member body. The beam splitter reflects the light diffused and emitted from the optical medium toward the retroreflective member, and transmits the light reflected by the retroreflective member toward the spatial imaging unit, thereby forming an image on the spatial imaging unit. The retroreflective member has an uneven structure for suppressing the visibility of ghost images caused by other light specularly reflected by the protective layer, in a spatial projection device.

2. The spatial projection device according to claim 1, wherein the uneven structure has a plurality of protrusions and a plurality of recesses.

3. The spatial projection device according to claim 2, wherein the plurality of plate-shaped retroreflective portions are formed by a plurality of plate-shaped retroreflective portions arranged alternately at a predetermined angle on one side of the retroreflective member and on the other side opposite to the one side.

4. The spatial projection apparatus according to claim 3, wherein the connection portions of the plurality of plate-shaped retroreflective portions are parallel to the vertical direction with respect to the image formed in the spatial imaging portion.

5. The spatial projection device according to claim 3 or claim 4, wherein the predetermined angle is 100 degrees to 160 degrees.

6. The spatial projection device according to any one of claims 3 to 5, wherein 4 to 30 plate-shaped retroreflective portions are provided.

7. The spatial projection apparatus according to any one of claims 1 to 6, wherein the uneven structure is configured to display the ghost image at an angle with respect to the spatial projection image formed in the spatial imaging unit.

8. The spatial projection device according to any one of claims 1 to 7, wherein the ghost image is positioned outside the field of view of the retroreflective member opposite to the spatial imaging unit.

9. A retroreflective member constituting a spatial projection device according to any one of claims 1 to 8.

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