JP6236663B2 - Screen and multi-directional video display system - Google Patents

Description

  The present invention relates to a multidirectional video display technique for presenting different videos in a plurality of observation areas.

  An apparatus for observing by changing the viewpoint position by operating an orientation of a camera or switching a plurality of cameras by an observer is commercialized in many fields such as monitoring and a WEB camera. On the other hand, a technique has been proposed in which the angle of a video is changed according to the movement of the viewpoint position of the observer rather than the operation by the observer (see, for example, Non-Patent Document 1).

  In the video display device described in Non-Patent Document 1, the position of the observer and the video are linked. Therefore, there is an advantage that an image taken by the camera can be observed with an intuitive and high presence and presence. On the other hand, in the video display device described in Non-Patent Document 1, a camera, an observer, and a display device are combined on a one-to-one basis. Therefore, the user of a video display apparatus will be limited to one person. That is, there is a problem that many people cannot observe at the same time. In order to solve such a problem, a multi-directional video display device capable of observing different videos simultaneously by a large number of people has been proposed (for example, see Non-Patent Documents 2 and 3).

Kei Kato and two others, strengthening social telepresence with movable cameras, Transactions of Information Processing Society of Japan 52 (4), 1635-1643, 2011-04-15 Shiro Ozawa and 6 others "Novel Multi-View Display using QDA Screen with Short Projection Distance by Tiled Image Method", SID Symposium Digest of Technical Papers, June 2011, Volume 42, Issue 1, pp. 894-897 Tohru Kawakami, Takahiro Ishinabe, Mutsumi Sasai, Mitsuru Kano, Yoshito Suzuki, Senshi Nasu, Tatsuya Uchida, Shiro Ozawa, Satoshi Mieda, Yasuhiro Yao, Munekazu Date, Hideki Takada, "Large High-Definition Multiview Display System With Wide Observation Area", Euro Display 2013, (2013.9, London, Great Britain), 28.5L, pp.350-353

In the multidirectional video display devices described in Non-Patent Documents 2 and 3, it is necessary to project a video from the opposite side of the person who watches the video on the screen. Therefore, there is a problem that a space for projecting behind the screen is generated.
In view of the above circumstances, an object of the present invention is to provide a technique capable of presenting different images in a plurality of observation areas in a smaller space.

  One embodiment of the present invention includes a Fresnel lens provided with unevenness so that light emitted from a plurality of projectors forms a plurality of iris images on an iris surface, and reflection that reflects light emitted from the projectors And a body.

  One aspect of the present invention is the screen described above, wherein the reflector is directly formed on the inclined surface of the Fresnel lens.

  One embodiment of the present invention is the above-described screen, wherein the reflector is a black plate having a smooth surface.

  One aspect of the present invention is the above-described screen, in which a vertical and horizontal anisotropic diffusion shape is provided on the inclined surface of the Fresnel lens.

  One embodiment of the present invention is the above-described screen, in which a glare suppressor is provided at a position closer to the projector than the Fresnel lens.

  One embodiment of the present invention is the above-described screen, in which a lens having almost no light diffusion is used as the Fresnel lens.

  One aspect of the present invention includes the above-described screen and a plurality of projectors that irradiate the screen with images, and the plurality of projectors are arranged so that the respective iris images do not overlap continuously. Is a multi-directional video display system.

  According to the present invention, different images can be presented in a plurality of observation areas in a smaller space.

1 is a system configuration diagram of a multidirectional video display system 100 according to an embodiment of the present invention. It is the figure which expanded and represented a part of Fresnel lens with which the screen 2 of 1st embodiment is provided. It is the figure which showed the form of the inclined surface of the Fresnel lens with which the screen 2 of 2nd embodiment is provided. It is a block diagram of the screen 2 of 3rd embodiment. It is a block diagram of the screen 2 of 4th embodiment. It is a block diagram of the screen 2 of 5th embodiment. It is a block diagram of the screen 2 of 6th embodiment.

[System overview]
FIG. 1 is a system configuration diagram of a multidirectional video display system 100 according to an embodiment of the present invention. The multidirectional video display system 100 includes a plurality of projectors 1 and a screen 2. In the multidirectional video display system 100, light of images projected from the plurality of projectors 1 is reflected by the screen 2, thereby generating a plurality of iris images 3 corresponding to the number of projectors 1. The iris image is an image in which the aperture of the aperture of the projection lens of the projector 1 is imaged by a lens or a concave mirror. Generally, the iris image is flat because it is an image of an aperture. The plurality of iris images 3 are equidistant from the screen 2 and are included in one iris surface 4. The iris plane refers to a plane when a plurality of iris images are included in one plane. In FIG. 1, for convenience of illustration, a part of the iris surface 4 is represented by a two-dot chain line. The iris surface 4 is a plane located at a predetermined distance from the screen 2 and parallel to the screen 2. Since the iris surface 4 is generated by the reflected light from the screen 2, the projector 1 and the iris surface 4 are positioned in the same direction with respect to the screen 2.

The screen 2 includes an aspherical and non-axial Fresnel lens. The uneven surface of the Fresnel lens is provided on the observer side. A reflector is provided on the screen 2 (for example, the inclined surface of the Fresnel lens).
The plurality of projectors 1 are arranged at an equal distance from the Fresnel lens of the screen 2. The light emitted from the projector 1 is collected by a screen 2 including a reflector and a Fresnel lens. The iris surface 4 exists at a conjugate position via the Fresnel lens of the aperture (iris) of the projector 1. The opening of the projector 1 is imaged on the iris surface 4. That is, the light emitted from one projector 1 can be observed only when the iris image 3 corresponding to the projector on the iris surface 4 has a viewpoint. Therefore, it is possible to realize a directivity display that can be observed only at a specific viewpoint position. By using a plurality of projectors 1 and generating iris images 3 on the iris surface 4 continuously and without overlapping, multidirectional video display is realized.

  The size of the iris image 3 is determined by the image magnification of the Fresnel lens. For this reason, the conventional technique cannot freely design the directivity number density. Therefore, by appropriately setting the toric shape of the surface of the reflecting surface, the light is appropriately diffused vertically and horizontally. By such an action, the iris image 3 can be enlarged, and a multi-viewpoint video display with a wide observation range can be realized by a smaller number of projectors 1.

When a plurality of projectors 1 project from the same distance, an image of an aperture (iris) of the projector 1 is generated at a conjugate position via a Fresnel lens. For example, by appropriately setting the toric shape of the surface of the reflecting surface, the iris images 3 of the projectors 1 can be prevented from being continuously and overlapping. Therefore, it is possible to realize multi-view video display that can present different videos depending on the viewpoint position. Further, by making the luminance distribution in the iris image 3 in top hat shape by suitably forming the preparative chromatography click shapes, it can be realized glare-free natural video display.

In this embodiment, refraction is not used as a principle. Therefore, it is possible to display a high-quality video without chromatic aberration.
There are a plurality of embodiments of the screen 2 included in the multidirectional video display system 100. Hereinafter, each embodiment of the screen 2 will be described.

[First embodiment]
FIG. 2 is an enlarged view of a part of the Fresnel lens included in the screen 2 of the first embodiment. A reflector is provided on the inclined surface of the Fresnel lens provided in the screen 2 of the first embodiment. The Fresnel lens has an unnecessary surface 201 that does not function as a Fresnel lens. A light absorber is provided on the unnecessary surface 201 of the Fresnel lens. The light absorber may be configured using, for example, a black material. By configuring the screen 2 in this way, the contrast is improved. Further, since the concentric edges are black, the hot bar is suppressed and the quality of the display image is improved.

[Second Embodiment]
FIG. 3 is a view showing the form of the inclined surface of the Fresnel lens provided in the screen 2 of the second embodiment. A reflector is provided on the inclined surface of the Fresnel lens provided in the screen 2 of the second embodiment. The surface of the reflection surface of the Fresnel lens has a two-dimensional toric shape 202. Thus, in the second embodiment, the surface structure of the inclined surface is non-smooth. The reflection surface of the Fresnel lens configured in this manner realizes anisotropic top hat diffusion vertically and horizontally. Further, since the arc-shaped edge portion of the Fresnel lens has a wavy shape, a hot bar can be avoided.
In the second embodiment, a light absorber may be provided on the unnecessary surface 201 as in the first embodiment. By being configured in this way, it is possible to obtain the same effect as in the first embodiment.

[Third embodiment]
FIG. 4 is a configuration diagram of the screen 2 of the third embodiment.
A longitudinal and lateral anisotropic diffusion DLC (Diffused Light Control) film 212 is provided on the front surface of the Fresnel lens 211. A surface shape diffusion film (AG film) 213 is provided on the front surface (outermost surface of the screen 2) of the vertical and horizontal anisotropic diffusion DLC film 212.

  In the third embodiment, the surface of the Fresnel lens 211 is smooth. By providing the vertical and horizontal anisotropic diffusion DLC film 212 on the front surface of the Fresnel lens 211, a predetermined amount of light is diffused, and a plurality of iris images 3 are formed. Since the surface of the DLC film 212 for anisotropic diffusion in the vertical and horizontal directions is a flat surface, there is a possibility that a bright spot (hot spot) and a hot bar due to the reflected Fresnel edge are generated by the direct reflected light of the projector 1. In order to solve this problem, the surface shape diffusion film 213 is provided on the outermost surface of the screen 2 as a dazzling suppressor. With such a configuration, a good display image can be obtained.

  In addition, the structure which provides the vertical and horizontal anisotropic diffusion DLC film 212 in the inclined surface of the Fresnel lens 211 may be employ | adopted in other embodiment. With such a configuration, it is possible to enhance the diffusion effect. Moreover, it is possible to expand the iris image 3 to a desired range by enhancing the diffusion effect. Therefore, the effect that the freedom degree of design increases is also acquired.

[Fourth embodiment]
FIG. 5 is a configuration diagram of the screen 2 according to the fourth embodiment.
A vertical and horizontal anisotropic diffusion DLC film 222 is provided on the front surface of the plane mirror 221. A transparent Fresnel lens 223 is provided on the front surface of the longitudinal and lateral anisotropic diffusion DLC film 222. A surface shape diffusion film (AG film) 224 is provided on the front surface of the Fresnel lens 223 (the outermost surface of the screen 2).
By providing the vertical and horizontal anisotropic diffusion DLC film 222, a predetermined amount of light is diffused, and a plurality of iris images 3 are formed.

  If the outermost surface of the screen 2 is the Fresnel lens 223, since the surface of the Fresnel lens 223 is a flat surface, a bright spot (hot spot) due to the direct reflected light of the projector 1 may occur. In order to solve this problem, the surface shape diffusion film 224 is provided on the outermost surface of the screen 2 as a dazzling suppressor. With such a configuration, a good display image can be obtained.

In the fourth embodiment, light passes through the Fresnel lens 223 twice. Therefore, the image quality can be improved by using the highly transparent Fresnel lens 223 with little diffusion.
In addition, the structure which provides a glare suppression body in the front surface of the screen 2 may be employ | adopted in other embodiment. With such a configuration, it is possible to improve the image quality.

  When the reflector is provided on the inclined surface and the uneven surface of the Fresnel lens is provided on the projector 1 side as in the first embodiment, there is no flat surface and a hot spot hardly appears. Therefore, although the effect of improving the image quality is limited, it is possible to suppress bright spots due to specular reflection by the inclined surface of the Fresnel lens.

In addition, a configuration using a highly transparent Fresnel lens with little light diffusion may be adopted in other embodiments. With such a configuration, it is possible to improve the image quality.
In FIG. 5, the distance between the Fresnel lens 223 and the mirror surface of the plane mirror 221 is equal to the thickness of the longitudinal and lateral anisotropic diffusion DLC film 222, but this distance may be made larger. For example, a gap may be provided between the Fresnel lens 223 and the plane mirror 221. By adjusting the gap interval, the combined focal length of the Fresnel lens 223 can be changed and the position of the iris image 3 can be adjusted.

[Fifth embodiment]
FIG. 6 is a configuration diagram of the screen 2 according to the fifth embodiment.
A Fresnel lens 232 is provided on the front surface of the plane mirror 231. On the front surface of the Fresnel lens 232 (the outermost surface of the screen 2), a surface shape diffusion film 233 that is a dazzling suppressor is provided.

  If the outermost surface of the screen 2 is the Fresnel lens 232, since the surface of the Fresnel lens 232 is a flat surface, a bright spot (hot spot) due to the direct reflected light of the projector 1 may occur. In order to solve this problem, the surface shape diffusion film 233 is provided on the outermost surface of the screen 2 as a dazzling suppressor. With such a configuration, a good display image can be obtained.

  Further, by setting the position of the projector 1 according to the amount of anisotropic diffusion of the surface shape diffusion film 233, the iris image 3 can be generated continuously and without overlapping to form the multi-imaging iris surface 4. It becomes possible.

  In the fifth embodiment, light passes through the Fresnel lens 232 twice. Therefore, it is possible to improve image quality by using a highly transparent Fresnel lens 232 that hardly diffuses.

In the fifth embodiment, the surface shape diffusion film 233 also serves two functions. Therefore, it becomes easy to manufacture the screen 2 at a low price. Further, the Fresnel lens 232 may be formed by UV-transferring the shape of the Fresnel lens 232 on the surface shape diffusion film 233. By forming the Fresnel lens 232 in this way, the screen 2 can be created simply by applying a film to the plane mirror 231.
Moreover, since there is only one diffuser, it is easy to obtain sharp directivity. Therefore, there is little loss and it is possible to improve efficiency and directivity density.
In FIG. 6, the Fresnel lens 232 and the mirror surface of the plane mirror 231 are in close contact with each other, but a gap may be provided between the Fresnel lens 232 and the plane mirror 231. By adjusting the gap interval, the combined focal length of the Fresnel lens 232 can be changed and the position of the iris image 3 can be adjusted.

[Sixth embodiment]
FIG. 7 is a configuration diagram of the screen 2 according to the sixth embodiment.
A Fresnel lens 242 is provided on the front surface of a black plate 241 (for example, an acrylic plate). A surface shape diffusion film 243 is provided on the front surface of the Fresnel lens 242 (the outermost surface of the screen 2).

The black plate 241 is made of a black material having a smooth surface. The black plate 241 plays the same role as the plane mirror 221 in the fourth embodiment and the plane mirror 231 in the fifth embodiment. That is, the black plate 241 reflects light that has passed through the Fresnel lens 242 from the front side. In the sixth embodiment configured as described above, although the light efficiency is reduced as compared with the fourth and fifth embodiments in which a plane mirror is used, a high contrast can be realized because the background is black.
In FIG. 7, the Fresnel lens 242 and the mirror surface of the plane mirror 241 are in close contact, but a gap may be provided between the Fresnel lens 242 and the plane mirror 241. By adjusting the gap interval, the combined focal length of the Fresnel lens 242 can be changed and the position of the iris image 3 can be adjusted.

[Modification]
The Fresnel lens provided in the screen 2 does not necessarily need to be aspheric and non-axial. Whether or not the Fresnel lens is configured to be non-axial may be determined according to the positional relationship between the projector 1 and the iris image 3. An iris image 3 is formed on a straight line connecting the mirror image of the projector 1 and the lens center of the Fresnel lens. Therefore, when the Fresnel lens is not non-axial, an iris image 3 is generated in the vicinity of the projector 1. That is, when the Fresnel lens is not non-axial, the specular reflection of the light source of the projector 1 by the screen 2 is coaxial with the iris image 3. This may cause inconvenience. When the area is large (the diameter of the Fresnel lens is large), the iris image 3 becomes unclear due to aberration. Therefore, it is desirable that the Fresnel lens is configured as an aspherical surface. However, when the screen 2 is small and the projection distance is long, the iris image 3 can be generated sufficiently clearly even if the Fresnel lens is spherical. As described above, it is possible to effectively improve the characteristics by adopting an aspheric structure for the Fresnel lens.

  The uneven surface of the Fresnel lens of the screen 2 may be provided on the side opposite to the observer. In this case, chromatic aberration occurs due to refraction on the flat surface of the Fresnel lens. However, since the effective focal length of the Fresnel lens can be shortened, it is easy to display a large screen with a short projection distance. Furthermore, since the inclination angle of the inclined surface of the Fresnel lens becomes small, it is possible to project from the projector 1 at an angle close to parallel to the screen 2.

  When the uneven surface of the Fresnel lens is provided on the side opposite to the observer, in the fifth embodiment, the configuration can be simplified by providing a reflector on the smooth surface of the Fresnel lens 232.

  As mentioned above, although embodiment of this invention has been described with reference to drawings, the said embodiment is only the illustration of this invention, and it is clear that this invention is not limited to the said embodiment. is there. Accordingly, additions, omissions, substitutions, and other changes of the components may be made without departing from the technical idea and scope of the present invention.

  The present invention is applicable to a system that provides different images at a plurality of positions.

DESCRIPTION OF SYMBOLS 1 ... Projector, 2 ... Screen, 3 ... Iris image, 4 ... Iris surface, 201 ... Unnecessary surface, 202 ... Two-dimensional toric shape, 211 ... Fresnel lens, 212 ... Vertical / horizontal anisotropic diffusion DLC film, 213 ... Surface shape diffusion film , 221 ... Planar mirror, 222 ... Vertical and horizontal anisotropic DLC film, 223 ... Fresnel lens, 224 ... Surface shape diffusion film, 231 ... Plane mirror, 232 ... Fresnel lens, 233 ... Surface shape diffusion film, 241 ... Black plate, 242 ... Fresnel lens, 243 ... Surface shape diffusion film

Claims (3)

A fresnel lens provided with irregularities so that light emitted from a plurality of projectors forms a plurality of iris images on the iris surface;
A reflector that reflects light emitted from the projector;
A screen comprising:
A screen in which a vertical and horizontal anisotropic diffusion shape having a toric shape is provided on an inclined surface of the Fresnel lens. A fresnel lens provided with irregularities so that light emitted from a plurality of projectors forms a plurality of iris images on the iris surface;
A reflector that reflects light emitted from the projector;
A screen comprising:
A vertical and horizontal anisotropic diffuser is provided between the Fresnel lens and the reflector,
A screen provided with a dazzling suppressor at a position closer to the projector than the Fresnel lens. A screen according to claim 1 or claim 2 ,
A plurality of projectors for illuminating the screen with an image;
With
The multi-directional video display system in which the plurality of projectors are arranged so that respective iris images do not continuously overlap.

Images