JP2012008298A - Three dimensional picture display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three dimensional (3D) picture display device enabling the viewing person to see, without having to use special eyeglasses or the like that would give a parallax between two eyes, a display image projected in the air without screen or the like with parallaxes both horizontally and perpendicularly, and making possible displaying of moving images observable from 360 degrees around.SOLUTION: A 3D picture display device comprises a 3D picture display means for displaying a 3D picture, a scanning element that changes the angle of emission of incident light from a display unit relative to the angle of incidence by curving the incident light and can rotate in a state in which the element surface is inclined relative to the incident direction of light, and a concave mirror that causes the incident light from the scanning element to form an image.

Description

The present invention relates to a stereoscopic display device that forms a three-dimensional image in the air without a screen or a display panel, and can be observed by a large number of people from around 360 degrees without the need for wearing items such as glasses.

Currently, there are many three-dimensional image display methods, but there are an integral photography method, a volume scanning method, a holography, and the like as a method capable of natural autostereoscopic display without using special glasses.

The integral photography method is a ray reproduction type 3D display that displays 3D images on the display by acquiring and reproducing the light rays from the subject, and can present 3D images to multiple observers at the same time, Even if a person turns his / her face sideways, stereoscopic viewing is possible.

The volume scanning method is a method in which an image of a two-dimensional cut surface at each position of an object is switched and displayed at high speed in synchronization with the movement of the imaging system, and an image is reproduced in space using the afterimage effect of the eyes. . In this method, a three-dimensional image satisfying all the stereoscopic factors can be reproduced.

Holography is a technique for recording a light wavefront as a hologram on a certain surface by skillfully utilizing the interference phenomenon of lightwaves, and reproducing the wavefront recorded by diffraction by irradiating the hologram with reproduction light. If a hologram with sufficient resolution can be created, the wavefront from the actual object can be faithfully reproduced.

Patent Document 1 below discloses a video apparatus that can display an equal image on a display as an image projected in space and floating in the air by a reflected image of a concave mirror.

Utility Model Registration No. 306300

However, in any method, there is still no display that can display a stereoscopic image in a free space where nothing is present and can observe all around 360 degrees as if an object exists. Several display techniques with a viewing angle of 360 degrees have been developed, but the image can be formed on a rotating screen or inside a holographic cylindrical recording plate. In addition, although a technique capable of displaying in space has been developed, the field of view through which the display image can be observed is limited. There is an air plasma method that satisfies the two elements of spatial display and 360-degree field of view at the same time, but there are problems with the expression, colorization, safety, etc. of occlusion. Note that the video device of Patent Document 1 projects a two-dimensional image as a video floating in the space, and does not display a stereoscopic image in a free space.

Therefore, in this method, a full parallax three-dimensional image by an integral photography method, an image formed by a concave mirror, and a three-dimensional image having a viewing angle of 360 degrees in space by using a rotating mechanism of a scanning element such as a mirror scanner. We propose a display system that displays

The three-dimensional image display device of the present invention is a device for changing the emission angle with respect to the incident angle by bending the incident light from the three-dimensional image display means for displaying a three-dimensional image, and the element surface is light. A scanning element that is rotatable in an inclined state with respect to the incident direction, and a concave mirror that forms an image of light incident from the scanning element. This scanning element is arranged near the center of the concave mirror.

As the three-dimensional image display means, a two-dimensional display for displaying a two-dimensional image and an optical path control means for controlling the direction of light rays emitted from the two-dimensional display may be used. For example, a fly-eye lens or a pinhole can be used as the optical path control means. The scanning element may be a mirror scanner that reflects incident light from the display to the concave mirror, a prism that refracts incident light from the display, or the like. Furthermore, the 3D image display apparatus of the present invention further includes an image forming means for forming an image of the light from the 3D image display means, and the scanning element bends the incident light from the image forming means. Also good.

With the above configuration, the light beam emitted from the three-dimensional image display means forms an image in the vicinity of the scanning element, and this formed image is reflected by the concave mirror to create a real image near the center of the concave mirror again. It can be seen as if an image is emerging in the dimensional space.

According to the three-dimensional image display device of the present invention, a display image can be projected in the air without a screen or the like without using special glasses that give binocular parallax, and can give parallax both in the horizontal and vertical directions. It is possible to observe from 360 degrees around and display a moving image.

1 is a schematic configuration diagram of a three-dimensional image display device according to a first embodiment. Illustration of shooting and display of integral photography system Diagram for explaining the principle of integral photography The figure explaining arrangement | positioning of the convex lens in 1st Embodiment Schematic configuration diagram of a three-dimensional image display apparatus according to the second embodiment Schematic configuration diagram of a prism sheet in the second embodiment Schematic configuration diagram of a three-dimensional image display device according to a third embodiment

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a three-dimensional image display apparatus according to the present embodiment. The three-dimensional image display device 1 is classified into an integral imaging optical system A, a relay optical system B, and an all-around scanning optical system C.

First, the integral imaging optical system A will be described. The integral imaging optical system A is a three-dimensional image display means for displaying a three-dimensional image. In this embodiment, the integral imaging optical system A controls a two-dimensional display for displaying a two-dimensional image and the direction of light emitted from the two-dimensional display. A three-dimensional image by an integral photography system having an optical path control mechanism is used. The 3D image display means is not particularly limited as long as it can display a 3D image.

Here, the integral photography method (Integral
The basic principle of the photography method (hereinafter referred to as IP method) will be described. FIG. 2 is an explanatory diagram of IP-based shooting and display.

In the IP system used in this embodiment, a photographic dry plate is placed on the focal plane of a lens array such as a fly-eye lens, and innumerable minute isometric images (element images) viewed from various different directions are photographed and recorded on the dry plate. When a positive image baked to the same size as the dry plate is accurately placed at the position of the original dry plate and viewed through the compound eye lens plate, a real image is reproduced at the same position as when photographing (see FIG. 2).

This image has the disadvantage that the depth appears to be reversed, but in order to overcome this, the photographed image is taken again with a compound eye lens. Unlike the lenticular method, images with parallax can be displayed both horizontally and vertically. Since the intersection (convergence point) of the binocular line of sight and the image focus adjustment point (display surface) substantially coincide, there is little fatigue.

In the present embodiment, the display device requires a relatively small resolution and calculation processing amount, and it is also possible to create a display image by ray tracing and computer graphics without performing photographing. Although a method is adopted, other than the IP method, for example, a known three-dimensional image display technique such as a volume scanning method or holography may be used.

The volume scanning method is a method in which an image of a two-dimensional cut surface at each position of an object is displayed while being switched at high speed in synchronization with the movement of the imaging system, and an image is reproduced in space using the afterimage effect of the eyes. In this method, a three-dimensional image satisfying all the stereoscopic factors can be reproduced.

Holography is a technique for recording a light wavefront as a hologram on a certain surface by skillfully utilizing the interference phenomenon of lightwaves, and reproducing the wavefront recorded by diffraction by irradiating the hologram with reproduction light. If a hologram with sufficient resolution can be created, the wavefront from the real object can be faithfully reproduced.

In this embodiment, since the IP system is adopted, the two-dimensional display 2 and the lens array 3 are used, and light from the two-dimensional display 2 is passed through the lens array 3 so that different images depending on the observation direction are displayed. Present.

Here, the two-dimensional display 2 includes not only a display device in a general sense of displaying an image on a screen but also a general display capable of displaying an image such as a screen that projects an image projected by a projector, The display surface may be a curved surface as well as a flat surface. Various things such as a liquid crystal display, a plasma display, and an organic EL display can be used.

The two-dimensional display 2 of the present embodiment creates a cut surface image of an object to be displayed by irradiating light from a light source and using the reflected light. A display that has already been put into practical use may be used. For example, a “DMD Discover1100 ControllerBoard” manufactured by Texas Instruments that can switch images at high speed can be used.

The lens array 3 includes a fly-eye lens in which a plurality of convex lenses 3a are arranged on the same surface, and forms an image of light passing through each convex lens 3a. The principle of integral photography will be described with reference to FIG. The observer can observe the actual object because light hits the object and the reflected light reaches the observer's eyes. In the IP system, the same light beam as this reflected light is reproduced.

Light emitted from one point (point light source) on the focal plane of the convex lens 3a travels as parallel light with a diameter equivalent to that of the lens in a linear direction passing through the point light source and the center of the lens 3a (FIG. 3A). Using this principle, if several parallel rays are collected at a certain point in the three-dimensional space, when the light is observed from the direction in which the parallel rays travel, it is as if the viewer is emitting light from that one point. (FIG. 3B). A surface can be created by arranging a number of these points, and a three-dimensional image can be projected onto the space.

How much the projected three-dimensional image O is projected from the screen and how much it can be observed depends on the number of rays entering the observer's eyes and the angle of rays that can be realized. The number and angle of light rays are determined by the number of pixels behind the one convex lens 3a of the lens array 3, the lens diameter, and the focal length.

Note that a pinhole array or other diffractive elements can be used in place of the fly-eye lens as an optical path control means for controlling the direction of light rays emitted from the two-dimensional display.

Next, the relay optical system B will be described. The relay optical system B is composed of two plano-convex lenses 4a and 4b, and is an imaging optical system for guiding light from the integral imaging optical system to the omnidirectional scanning optical system.

Each light beam of the three-dimensional image displayed based on the principle of integral photography passes through two plano-convex lenses 4a and 4b. Here, the reason why the two plano-convex lenses 4a and 4b are incorporated will be described.

FIG. 4 is a diagram for explaining the arrangement of convex lenses in the present embodiment. In order to increase the resolution and size of a three-dimensional image by the integral photography system, it is advantageous to make the formation position of the three-dimensional image close to the integral imaging optical system. Then, the distance between the three-dimensional image and the rotating mirror 5 described later becomes longer.

It is impossible to install the two-dimensional display 2 and the fly-eye lens 3 in the vicinity of the rotary mirror 5 because the three-dimensional image is finally covered. If only the image forming position is extended, a single convex lens can be used, but the light from the image cannot accurately reproduce the light from the fly-eye lens. This is shown in FIG. Since the light emitted from the image becomes a light that spreads outward, it becomes impossible to observe both ends of the image simultaneously.

Further, as shown in FIG. 4B, it is not possible to reproduce the light beam by simply inserting two plano-convex lenses separated by twice the focal length. By adjusting the delta f as shown in FIG. 4C, it is possible to reproduce the exact light direction.

As described above, the light beam emitted from each pixel of the two-dimensional display 2 passes through the fly-eye lens 3 and the two plano-convex lenses 4a and 4b.

Next, the omnidirectional scanning optical system C will be described. The omnidirectional scanning optical system C includes a rotating mirror 5 and a concave mirror 6, and forms a stereoscopic image that can be observed from different directions by rotating the mirror 5 and changing the incident position of light on the concave mirror 6.

The rotating mirror 5 reflects light that has passed through the plano-convex lenses 4a and 4b, and is not particularly limited in size, material, and the like. The rotating mirror 5 is provided in a state of being inclined with respect to the axial direction of the light incident from the plano-convex lenses 4a and 4b, and is rotatable around the optical axis.

By rotating the rotating mirror 5 at a high speed and displaying an image that can be seen according to the angle, it is possible to form an all-around stereoscopic image. That is, the rotating mirror 5 is rotated in the horizontal direction at a speed of 18 Hz or more, which is the afterimage threshold value of the human eye, and an image synchronized with the direction of the rotating mirror 5 is displayed on the two-dimensional display 2. A three-dimensional image O having a viewing angle of degrees and smooth parallax can be reproduced.

As described above, the three-dimensional image formed in the vicinity of the rotating mirror 5 by the two plano-convex lenses 4a and 4b is formed again in the space near the center of the concave mirror 6 by the concave mirror 6, and this is formed as a three-dimensional image O. Can be observed.

Next, the 3D image display apparatus 51 according to the second embodiment will be described. Description of points common to the first embodiment will be omitted, and different points will be mainly described. FIG. 5 is a schematic configuration diagram of a three-dimensional image display device 51 according to the present embodiment. The difference between this embodiment and the first embodiment is that a prism sheet 55 is used as a scanning element. The two-dimensional display 52, the fly-eye lens 53, the convex lenses 54a and 54b, and the concave mirror 56 are the first embodiment. It has the same configuration as the form. The prism sheet 55 of FIG. 5 is in a state where the element surface is orthogonal to the incident direction of incident light, but may be inclined.

FIG. 6 is a conceptual diagram of the prism sheet 55 according to the present embodiment as viewed obliquely from above. The prism sheet 55 is formed by arranging slit-like elongated prisms 55A in a sawtooth cross section, and refracts and emits light incident from the element surface in another direction. Accordingly, by rotating in the in-plane direction around an axis perpendicular to the element surface, the prism angle with respect to the incident light changes, and light beam scanning can be performed.

Light is incident on the lower flat portion in FIG. 6 and is emitted from the upper saw-tooth portion. Thus, by using the prism sheet 55 in the scanning portion, the configuration of the optical system becomes simpler than that of the reflective optical system, and the system can be miniaturized. As shown in FIG. 6, the prism sheet 55 of the present embodiment has a saw-tooth cross section only on one side of the prism sheet (that is, the surface opposite to the surface on which incident light is incident). However, for the purpose of improving the focusing state of the light beam, the opposite surface (that is, the surface on which the incident light is incident) may be formed so that the cross section thereof is a saw-tooth shape.

Next, a 3D video display apparatus according to the third embodiment will be described. Description of points common to the first embodiment will be omitted, and different points will be mainly described. FIG. 7 is a schematic configuration diagram of a three-dimensional image display device 71 according to the present embodiment. Similar to the first embodiment, the three-dimensional image display device 71 of the present embodiment includes a two-dimensional display 72, a lens array 73, convex lenses 74A and 74B, a rotating mirror 75, and a concave mirror 76. .

The difference between this embodiment and the first embodiment is the arrangement of components. That is, the integral imaging optical system (two-dimensional display 2, lens array 3) of the first embodiment is disposed on the front side of the concave mirror 6 (that is, the focal side on which the concave mirror forms an image). The integral imaging optical system (two-dimensional display 72, lens array 73) of the embodiment is disposed on the back side, which is the opposite side to the focal side of the concave mirror 76.

As a result, light from the integral imaging optical system enters the rotary mirror 75 from the back side of the concave mirror 76, and a three-dimensional image O is formed on the front side of the concave mirror 76. By doing so, the integral imaging optical system (two-dimensional display 72, lens array 73) does not cover the position where the three-dimensional image O is finally reproduced. Further, the observer viewing from the focal side of the concave mirror 76 does not block the optical path from the integral imaging optical system (the optical path from the two-dimensional display 72 to the rotating mirror 75).

DESCRIPTION OF SYMBOLS 1 3D image display apparatus 2 2D display 3 Lens array 4a, 4b Plano-convex lens 5 Rotating mirror 6 Concave mirror

Claims (5)

3D image display means for displaying a 3D image;
A rotatable scanning element that bends incident light from the three-dimensional image display means and changes an output angle with respect to an incident angle;
A concave mirror for imaging light incident from the scanning element;
A three-dimensional image display device. The three-dimensional image display means
A two-dimensional display for displaying a two-dimensional image;
Optical path control means for controlling the direction of light rays emitted from the two-dimensional display;
The three-dimensional image display apparatus according to claim 1, further comprising: 3. The mirror scanner, wherein the scanning element is a mirror scanner that reflects incident light from the three-dimensional image display means to the concave mirror and is rotatable with the element surface inclined with respect to the incident light incident direction. 3D image display device. 3. The prism according to claim 1, wherein the scanning element is a prism that refracts incident light from the three-dimensional image display means and is rotatable in a state where the element surface is orthogonal or inclined with respect to the incident direction of the incident light. Dimensional image display device. Furthermore, an image forming means for forming an image of light from the three-dimensional image display means is provided,
The three-dimensional image display apparatus according to claim 1, wherein the scanning element bends incident light from the imaging unit.