WO2015181994A1

WO2015181994A1 - Retroreflector and stereoscopic display device using same

Info

Publication number: WO2015181994A1
Application number: PCT/JP2014/071654
Authority: WO
Inventors: 誠大坪
Original assignee: 株式会社アスカネット
Priority date: 2014-05-27
Filing date: 2014-08-19
Publication date: 2015-12-03
Also published as: JPWO2015181994A1

Abstract

A stereoscopic display device (34) is configured by combining a retroreflector (26) and a half mirror (35). The retroreflector is formed by a side-by-side arrangement of unit optical blocks (15) each including a first and second mirror face (11, 12) intersecting each other at a right angle, and a third and fourth mirror face (13, 14) orthogonal to the first and second mirror faces (11, 12). The first and second mirror faces (11, 12) are formed on the bottom of each unit optical block (15), and the third and fourth mirror faces (13, 14) are formed on the sides of each unit optical block (15). Incident light entering a unit optical block (15) from a prescribed direction is reflected parallel to the incident light via the first and second mirror faces (11, 12), and the third or fourth mirror face (13, 14).

Description

Retroreflector and stereoscopic image display apparatus using the same

The present invention relates to a retroreflector in which incident light and reflected light pass through substantially the same path, and a stereoscopic image display apparatus using the same.

A retroreflector using a transparent sphere or a three-surface corner cube is applied to traffic signs, image projection devices (see Patent Documents 1 and 2) and the like because the directions of incident light and reflected light substantially coincide. It is known that a retroreflector using a three-sided corner cube obtains stronger reflected light than using a transparent sphere.

JP 2004-45487 A JP 2010-72504 A

However, since the three-sided corner cube has a shape obtained by cutting out the corners of a cube, there is a problem that it is difficult to form a retroreflector by arranging a large number of three-sided corner cubes uniformly.

The present invention has been made in view of such circumstances, and an object thereof is to provide a retroreflector that can be relatively easily manufactured and a stereoscopic image display apparatus using the retroreflector.

The retroreflector according to the first aspect of the present invention that meets the above-described object has first and second mirror surfaces that intersect at right angles and third and fourth mirror surfaces that are orthogonal to the first and second mirror surfaces. The unit optical blocks are arranged in a plane. Here, the material of the unit optical block may be hollow, but it is preferable to use transparent glass or transparent plastic. The first to fourth mirror surfaces are usually formed by plating or vapor-depositing a metal. In addition, one surface (ceiling surface) which is a non-mirror surface of the unit optical block serves as both a light incident surface and a light exit surface. Rays entering from one surface are reflected by the first, second and third or fourth mirror surfaces and exit from the one surface.

A retroreflector according to a second invention is the retroreflector according to the first invention, wherein the first and second mirror surfaces are at the bottom of the unit optical block, and the third and fourth mirror surfaces are The unit optical blocks are respectively formed on the side surfaces.

A retroreflector according to a third invention is the retroreflector according to the first or second invention, wherein the distance between the third and fourth mirror surfaces is the width of the first and second mirror surfaces. It is in the range of 0.5 to 3 times the total length. Here, if the distance between the third and fourth mirror surfaces is smaller than the total width of the first and second mirror surfaces, the effective area of the third and fourth mirror surfaces is reduced. The effective area of the mirror surface is reduced.

A retroreflector according to a fourth invention is the retroreflector according to the first to third inventions, wherein a plurality of the unit optical blocks are arranged in a straight line to form a long optical block. The optical block bodies having the same shape are arranged in parallel to constitute a planar retroreflector. Here, the long optical block bodies may be arranged side by side with a gap or may be arranged side by side closely. Adjacent optical block bodies may be arranged 1) with the positions of the crests and troughs matched, and 2) the crests and troughs may be shifted. Further, adjacent optical block bodies may be arranged close to or in contact with each other.

A retroreflector according to a fifth invention is the retroreflector according to any of the first to fourth inventions, wherein the unit optical blocks are arranged in a planar shape by aligning the directions of the ceiling surfaces of the unit optical blocks. They are arranged side by side.

A stereoscopic image display device according to a sixth aspect of the present invention is a planar retroreflector according to the first to fifth aspects of the present invention, and a half mirror disposed upright on the retroreflector. Have
Here, the end of the half mirror may be in contact with the retroreflector or may have a gap. The angle between the planar retroreflector and the half mirror is preferably a right angle, but may be inclined (for example, an inclination angle θ: 60 degrees or more and less than 90 degrees).

The retroreflectors according to the first to fifth inventions are transparent units having first and second mirror surfaces intersecting at right angles and third and fourth mirror surfaces orthogonal to the first and second mirror surfaces. Since the optical blocks are formed side by side, the structure is simpler than the conventional corner cube, and unit optical blocks of any size can be manufactured at low cost.
In particular, by using a long optical block body formed by arranging a plurality of unit optical blocks in a straight line, a retroreflector can be manufactured more easily and inexpensively.
The stereoscopic image display device according to the sixth invention can be formed by combining the retroreflector according to the first to fifth inventions with a half mirror, and can be manufactured easily and inexpensively.

(A) is a front view of the unit optical block of the retroreflector according to the first embodiment of the present invention, and (B) is a side view thereof. (A) is a perspective view of an optical block body of a retroreflector according to a second embodiment of the present invention, (B) is a front view of the retroreflector, and (C) is a side view of the retroreflector. FIG. (A) is a front view of a retroreflector according to a modification of the second embodiment of the present invention, and (B) is a plan view of the retroreflector. (A) is a front view of the optical block body of the retroreflector which concerns on the 3rd Example of this invention, (B) is a side view of the same retroreflector. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the three-dimensional image display apparatus which concerns on one Example of this invention, (A) is a general view, (B), (C) is an expansion explanatory drawing of the a part of (A), respectively.

Next, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1A and 1B, the retroreflector 10 according to the first embodiment of the present invention has a large number (for example, 1000 to 50000) arranged in a planar shape (for example, a planar shape). It consists of a unit optical block 15. Each unit optical block 15 includes a first mirror surface 11 and a second mirror surface 12 connected to each other at a right angle on the bottom, and the first and

second mirror surfaces

11 and 12 are orthogonal to the front and rear side surfaces. 3 and a transparent body having

fourth mirror surfaces

13 and 14.

1A and 1B show one unit optical block 15, but when used as the retroreflector 10, a large number of unit optical blocks 15 are arranged side by side in the vertical and horizontal directions. In this case, if each unit optical block 15 is a square or a rectangle having the same size shape in plan view, each unit block can be arranged without a gap, and a more precise retroreflector 10 can be formed.
Usually, it is preferable to arrange a large number of unit optical blocks 15 in a planar shape, but they can be arranged on a deformable fabric or curved surface. Each unit optical block 15 may be hollow, and the first to fourth mirror surfaces 11 to 14 may simply be mirrors. The material of the block unit optical block 15 may be transparent glass, transparent plastic (for example, acrylic, (Polycarbonate, nylon, polypropylene, cycloolefin resin, etc.), and the first to fourth mirror surfaces 11 to 14 may be formed by metal vapor deposition.

The vertical width L of the unit optical block 15 (that is, the distance between the third and fourth mirror surfaces 13 and 14) L is a total length of the widths W1 and W2 of the first and

second mirror surfaces

11 and 12, for example, 0. It is preferably 5 to 3 times (more preferably 1 to 2 times). When the vertical width L of the unit optical block 15 is too long, reflection does not occur three times and the reflected light is easily scattered. In addition, when the vertical width L of the unit optical block 15 is short, multiple reflection occurs at the third and

fourth mirror surfaces

13 and 14 and scattering of reflected light is caused. Further, the height H of the unit optical block 15 (vertical distance from the crests of the first and

second mirror surfaces

11 and 12 to the ceiling surface 20a) is set in the range of (0.707 to 3) × W1, for example. (The same applies to the following embodiments).

Regarding the operation of the retroreflector 10, a single unit optical block 15 shown in FIGS. 1 (A) and 1 (B) will be described. The incident light A viewed in the direction of the arrows is reflected on the first and

second mirror surfaces

11 and 12. Reflected at points B and C, reflected at point D on the fourth mirror surface 14, and reflected in the same direction as incident light A (reflected light E). Note that when the dimension (size) of the unit optical block 15 is increased, the positions of the incident light and the reflected light are shifted, and the light does not return to the original position. Therefore, it is preferable to arrange a large number of unit optical blocks 15 side by side by reducing the size of each unit optical block 15 (for example, L = 0.5 to 3 mm).

Subsequently, a retroreflector 18 according to a second embodiment of the present invention will be described with reference to FIGS. 2 (A) to (C). In addition, about the component same as the retroreflector 10 which concerns on a 1st Example, the same number is attached | subjected and detailed description is abbreviate | omitted. The retroreflector 18 according to the second embodiment is a long and straight line in which a plurality of unit optical blocks 15 (one of which is indicated by a two-dot chain line in FIG. The optical block bodies 19 are arranged in parallel. Therefore, the first and

second mirror surfaces

11 and 12 arranged at right angles are continuously formed in a triangular wave shape on the bottom of the optical block body 19, and the first and

second mirror surfaces

11 and 12 are formed on the side surfaces. , Orthogonal third and fourth mirror surfaces 13 and 14 are formed. The third and fourth mirror surfaces 13 and 14 are formed in parallel on both side surfaces of the long optical block body 19. In addition, the unit optical blocks 15 are arranged so that the directions of the ceiling surface 20a (see FIG. 1) are aligned, and the unit optical blocks 15 are arranged in a plane (the same applies to the following embodiments).

The material of the base material of the optical block body 19 is made of highly transparent glass or transparent resin. In the production of the base material, a flat plate made of glass or transparent resin is produced by press molding, roller molding, or injection molding of transparent resin to produce a flat plate material. One surface of the original plate material is a flat surface, and the other surface is an uneven surface that finally forms the first and second mirror surfaces 11 and 12 in a wave shape. The original plate material is cut with a predetermined dimension (L), and the cut end surface is polished as necessary to produce a substrate. One surface (ceiling surface 20) of this base material is covered with a peelable vapor deposition prevention sheet, and metal vapor deposition is performed to form first to fourth mirror surfaces 11 to 14. Thereafter, the vapor deposition prevention sheet is peeled off, and cleaning is performed if necessary to produce a long optical block body 19.

When the retroreflector 18 is configured, the optical block bodies 19 having the same shape are arranged in parallel as described above. However, when the optical block bodies 19 are arranged side by side, the adjacent optical block bodies 19 are arranged. The case where the valley portion 21 and the mountain portion 22 formed on the bottom are made to coincide with each other, and the case where the valley portion 21 and the mountain portions 22 of the adjacent optical block body 19 are not made to coincide with each other (that is, the valley portion 21 and the mountain portion). 22). The retroreflector 18 is used in contact with the long optical block body 19 or arranged in parallel in close proximity. Therefore, the retroreflector 18 can be manufactured at low cost.

In addition, in the

retroreflectors

10 and 18 according to the first and second embodiments, the bottom portion is uneven, but the first and second mirror surfaces 11 and 12 are continuously formed trough portions. 21 can be filled with a transparent or opaque resin 24 and the bottom can be flat. 3A and 3B show a retroreflector 26 in which a valley portion 21 formed at the bottom is filled with a resin 24, and the ceiling surface 20 and the bottom surface 25 are processed into a flat shape. As a result, the first and second mirror surfaces 11 and 12 of the retroreflector 26 are not chipped or wrinkled.

Subsequently, as shown in FIGS. 4A and 4B, a retroreflector 28 according to a third embodiment of the present invention will be described. Long optical block bodies 29 constituting the retroreflector 28 are arranged side by side in an inclined state (inclination angle θ). Such a retroreflector 28 is formed by mounting the optical block 29 on the tilt table 30 and fixing it. In this case, the side surfaces of the adjacent optical block bodies 29 do not need to contact each other. This makes it closer to a cubic corner body (three-sided corner cube). Moreover, the adjacent mounting base 30 can also be formed continuously by press or injection molding. The ceiling surface (upper surface) 32 of the optical block body 29 is transparent to form a light incident surface and a light output surface.

Next, with reference to FIGS. 5A to 5C, a stereoscopic image display device 34 according to an embodiment of the present invention using the above retroreflector 26 (the same applies to 10 and 18) will be described. To do.
A planar half mirror 35 is erected on top of the planar retroreflector 26. In this embodiment, the retroreflector 26 is rectangular (width g, depth f), the width of the half mirror 35 is approximately the same as the depth f of the retroreflector 26, and the height is, for example, recursive. It is about 0.5 to 1 times the lateral width g of the reflector 26.

As shown in FIG. 5B, each of the long optical block bodies 19 constituting the retroreflector 26 faces the depth direction (that is, the direction orthogonal to the paper surface in FIG. 5), and the third and

fourth Mirrors

13 and 14 are arranged side by side in the horizontal direction. Here, as shown in FIG. 5C, each optical block body 19 may be directed in the lateral direction, and the third and

fourth mirrors

13 and 14 may be directed in the depth direction.
Further, the retroreflector 26 may be configured, and the direction of the optical block body 19 arranged in parallel may be arranged obliquely with respect to the half mirror 35 in plan view.

The operation of the stereoscopic image display device 34 will be described. When the object P that emits light or reflected light is arranged at a specific location with respect to the stereoscopic image display device 34, the light beam from the object P passes through the half mirror 35, The light enters the optical block body 19 from the oblique direction through the ceiling surface 20 to the retroreflector 26. The light rays entering the optical block body 19 are reflected by the first and second mirror surfaces 11 and 12 and the third or fourth mirror surfaces 13 and 14 arranged at right angles, and reflected from the ceiling surface 20 as reflected light. Idemitsu. This path is substantially the same as the path of light entering the optical block body 19. The reflected light from the ceiling surface 20 is reflected by the half mirror 35 to form a real image Q.

In addition, even if light is incident on the ceiling surface 20 after passing through the half mirror 35 and is not reflected by the mirror surfaces that are perpendicular to each other, the light that has not been reflected three times contributes to image formation even if it is reflected by the half mirror 35. Since it does not, it becomes scattered light.
Further, the orientation of each optical block body 19 with respect to the linear half mirror 35 in plan view is preferably determined in advance by experiments so that the real image Q to be formed has the maximum luminance. Further, when the standing angle of the half mirror 35 is changed, the image forming position and the brightness are also changed. Therefore, it is preferable to adjust to an optimum angle.
Furthermore, since the resolution of the image to be reproduced is determined by the size of each unit optical block 15 of the optical block body 19, a larger number and a finer real image can be obtained.

The present invention is not limited to the above-described embodiments, and the configuration thereof can be changed without changing the gist of the present invention.
Furthermore, the present invention is also applicable to the case where a part of the retroreflectors according to the first to third embodiments is selected to form another shape of the retroreflector.

Since the retroreflector according to the present invention has a simple structure, it can be manufactured at a lower cost than a conventional three-sided corner cube. In addition, if the sizes of the first to fourth mirror surfaces are determined according to the application, a stereoscopic image display device having pixels of any size can be formed.

10: retroreflector, 11: first mirror surface, 12: second mirror surface, 13: third mirror surface, 14: fourth mirror surface, 15: unit optical block, 18: retroreflector, 19: Optical block, 20, 20a: Ceiling, 21: Valley, 22: Mountain, 24: Resin, 25: Bottom, 26: Retroreflector, 28: Retroreflector, 29: Optical block, 30 : Tilting table, 32: ceiling surface, 34: stereoscopic image display device, 35: half mirror

Claims

Transparent unit optical blocks having first and second mirror surfaces intersecting at right angles and third and fourth mirror surfaces orthogonal to the first and second mirror surfaces are arranged in a plane. Retroreflector to do.
2. The retroreflector according to claim 1, wherein the first and second mirror surfaces are formed on a bottom portion of the unit optical block, and the third and fourth mirror surfaces are formed on a side surface of the unit optical block. A retroreflector characterized by that.
3. The retroreflector according to claim 1, wherein a distance between the third and fourth mirror surfaces is in a range of 0.5 to 3 times a total length of the widths of the first and second mirror surfaces. A retroreflector characterized by being.
The retroreflector according to any one of claims 1 to 3, wherein a plurality of the unit optical blocks are linearly arranged to form a long optical block body, and the optical block bodies having the same shape are arranged in parallel. A retroreflector characterized in that
The retroreflector according to any one of claims 1 to 4, wherein the unit optical blocks are arranged side by side in a plane with the direction of the ceiling surface of each unit optical block aligned. Retroreflector.
A stereoscopic image display device comprising: the planar retroreflector according to any one of claims 1 to 5; and a half mirror arranged upright on the retroreflector.