This application claims the benefit of Japanese Priority Patent Application JP 2014-066891 filed Mar. 27, 2014, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a spatial image display apparatus that displays an image in a space, and a spatial image display method.
An optical system using a plane-symmetric imaging element is disclosed in Japanese Unexamined Patent Application Publication No. 2008-158114. In the optical system, an image of an object placed under the back surface of the element is formed at a position that is plane symmetric above the upper surface of the element. The substrate of the plane-symmetric imaging element used in this optical system is provided with a plurality of vertical holes having a rectangular cross-sectional view in a matrix, and two mirror surfaces perpendicular to each other, which is called a dihedral corner reflector (DCR), are formed on the inner wall of each vertical hole. In an imaging element including a dihedral corner reflector array (DCRA) element provided with a plurality of dihedral corner reflectors like this on a substrate, when light emitted from an object is transmitted through the vertical holes of the substrate, the light is reflected on the two mirror surfaces constituting the dihedral corner reflector one time on each of the mirror surfaces. Then, the reflected light forms an image at a position that is plane symmetric with respect to the substrate. As a result, for an observer, the formed image (real image) looks as if it is floating in a space above the upper surface of the imaging element.
In the plane-symmetric imaging element as described above, a real image is formed by retro-reflection on the substrate surface. As a result, the distance from an object to the substrate becomes equal to the distance from the substrate to the real image in a direction perpendicular to the substrate surface. Accordingly, if the floating feeling of a real image is attempted to be increased, the depth of the housing including the entire apparatus becomes large in proportion to the increase. Also, light rays that are not retro-reflected form a virtual image, and thus the use of the light rays is restricted. Also, it is difficult to create an imaging element including a dihedral corner reflector.
On the other hand, it is noted that there is a light-ray reproduction type method of stereoscopic displaying, which was proposed by Gabriel Lippman in 1908, and is called integral photography or integral imaging. However, in the integral imaging, which is generally noted, the amount of display data for conducting stereoscopic display increases. Also, a display device having a large number of pixels (high resolution) are demanded, and the like, and thus it is difficult to achieve the integral imaging.
It is desirable to provide a spatial image display apparatus that is small in size and is highly possible for obtaining a spatial image, and a spatial image display method.
According to an embodiment of the present disclosure, there is provided a spatial image display apparatus including: a display section including a plurality of pixels disposed in a two-dimensional array, the plurality of pixels configured to radiate light rays at different radiation angles with each other respectively so as to form a planar image including a plurality of image points disposed in a two-dimensional array in a space apart from an array face of the plurality of pixels, wherein two or more predetermined number of pixels out of the plurality of pixels radiate the predetermined number of light rays so as to intersect to form one of the image points, and an interval of two adjacent light rays out of the predetermined number of light rays having passed one of the image points is equal to or less than a predetermined observation interval at a predetermined observation position.
According to another embodiment of the present disclosure, there is provided a method of displaying a spatial image, the method including: when a plurality of pixels, disposed in a two-dimensional array, radiate light rays at different radiation angles with each other respectively so as to form a planar image including a plurality of image points disposed in a two-dimensional array in a space apart from an array face of the plurality of pixels, two or more predetermined number of pixels out of the plurality of pixels radiating the predetermined number of light rays so as to intersect to form one of the image points, and wherein an interval of two adjacent light rays out of the predetermined number of light rays having passed one of the image points is equal to or less than a predetermined observation interval at a predetermined observation position.
In a spatial image display apparatus or a method of displaying a spatial image according to the present disclosure, a planar image including a plurality of image points is formed in a space apart from an array face of a plurality of pixels. Two or more predetermined number of pixels out of the plurality of pixels radiate the predetermined number of light rays so as to intersect to form one of the image points. An interval of two adjacent light rays out of the predetermined number of light rays having passed one of the image points becomes equal to or less than a predetermined observation interval at a predetermined observation position.
With a spatial image display apparatus or a method of displaying a spatial image according to the present disclosure, when a planar image including a plurality of image points is formed in a space apart from an array face of a plurality of pixels, light rays forming each image point are optimized so that it is possible to obtain a spatial image that is small in size and is highly possible.
In this regard, the advantages described here are not limited, and any one of the advantages described in this disclosure may be sufficient.
In the following, a detailed description will be given of embodiments of the present disclosure with reference to the drawings. In this regard, the description will be given in the following order.
1. First embodiment (
2. Second embodiment (spatial image display apparatus using hologram diffraction element)(
3. Third embodiment (application of spatial image display apparatus)(
4. The other embodiments
1.1 Example of Overall Configuration of Spatial Image Display Apparatus
In this regard, in
In the spatial image display apparatus 1, a plurality of pixels P radiate light rays at different radiation angles, respectively, on the display panel 40 so as to form a planar image including a plurality of image points S in a space apart from the array face of the plurality of pixels P. It is possible for an observer 1000 to recognize a planar image including a plurality of image points S as a spatial image.
Two or more predetermined number of (m pieces of) pixels P out of the plurality of pixels P radiate a predetermined number of light rays so as to intersect to form one of the image points S. As illustrated in
The display panel 40 is driven by the drive circuit section 50, and radiate light rays from the individual pixels P with light intensities based on image data from the image data supply section 51. The display panel 40 is a tabular display panel, for example a liquid crystal panel having a sufficient number of pixels, an organic EL panel, or the like.
As illustrated in
Each of the pixels P of the display panel 40 emits light rays in the visible range, for example. Thereby, it is possible for the observer 1000 to recognize a planar image in the visible range as a spatial image. As illustrated in
The display panel 40 may be provided with a plurality of imaging elements that control the radiation angles of the individual light rays emitted from the plurality of pixels P. For example, as illustrated in
In this regard, for an imaging element that controls the radiation angle of a light ray, a Fresnel lens, a zone plate, a prism, or a diffraction element, or the like may be used in place of a micro lens L.
1.2 Display Principle
A more specific description will be given of the display principle a spatial image produced by the spatial image display apparatus 1 with reference to
As described above, the display panel 40 includes n×n pieces of pixel units U that are disposed in a two-dimensional array, for example, and each pixel unit U includes m×m pixels that are disposed in a two-dimensional array. However, in order to make it easy to understand here, a description will be given on the assumption that each pixel unit U, and each pixel P are disposed in a one-dimensional array for simplification.
In order to form a plurality of (n (=2 or more) pieces of) image points S, the display panel 40 includes a plurality of (n pieces of) pixel units U in a one-dimensional direction, and each pixel unit U includes a predetermined number of (m (=2 or more) pieces of) pixels P in a one-dimensional direction. One image point S is formed by light rays emitted from one pixel P in each of a predetermined number of (m pieces of) adjacent pixel units U out of a plurality of (n pieces of) pixel units U.
As illustrated in
Also, any j-th pixel unit Uj is responsible for the image points S from i=j-th to the (j+m)-th. At this time, the radiation angle is controlled by an optical element, such as a micro lens L, or the like such that a light ray toward the i-th image point Si is emitted from each of the pixels P that form the i-th image point Si in all the pixel units U that form the i-th image point Si.
The pixels P in each of the pixel units U that is responsible for the i-th image point Si may be any pixel P in each of the pixel units U. However, it is convenient to dispose pixels on a regular basis in designing and manufacturing the display panel 40. For example, it is possible to set the pixel that is responsible for the i-th image point Si in the j-th pixel unit Uj to the pixel Pkj of the kj=(j−i+1)-th (condition 1).
Specifically, for example, as illustrated in
As illustrated in
Specific Design Example
As the display panel 40, a 4K flat panel having a pixel pitch of 50 μm was used, and m=20 pixels in one-dimensional direction (400 pixels in two dimensions) were set to one pixel unit U. Also, m=20 pieces of (400 pieces in two dimensions) pixel units U in one-dimensional direction were designed to form one image point S, and at this time, the radiation direction of the light ray from each of the pixels P was set in accordance with the expression of the above-described angle θjkj such that a planar image is formed in a space that is 93.5 mm apart from the panel face.
Thereby, a planar image having a resolution of 200 pixels×100 pixels, and an image size of 198 mm×98 mm was formed at a position in a space that is 93.5 mm apart from the panel face. When this planar image was observed at the observation position that is 500 mm apart, the distance Da (refer to
Also, the Db range of the spread of all the light rays that had passed one image point S (refer to
1.3 Advantages
With the present embodiment, when a planar image formed by a plurality of image points S is formed in a space that is apart from the array face of the pixels P, the light rays forming each image point S are optimized, and thus it is possible to obtain a spatial image that is small in size and is highly possible. In particular, by limiting the positions of all the image points S on a plane, and by limiting the range of forming image points S to a natural movement range of the eyes of the single observer 100, it is possible to reduce the amount of data and the number of display pixels, and to form a two-dimensional spatial image having a high resolution in the horizontal direction and the vertical direction compared with a display method by normal integral imaging, which forms a three-dimensional image.
In this regard, the advantages described in this specification are only examples, thus are not limited, and the other advantages may be included. This is the same in the other embodiments.
Next, a description will be given of a spatial image display apparatus according to a second embodiment of the present disclosure. In this regard, in the following, a same symbol is given to a substantially same part as a component in the spatial image display apparatus according to the first embodiment, and the description thereof is suitably omitted.
Compared with the configuration of the spatial image display apparatus 1 according to the first embodiment, the spatial image display apparatus 1A according to the present embodiment includes a point light source array 300, and a hologram diffraction element 400 as a display element in place of the display panel 40. The point light source array 300 and the hologram diffraction element 400 constitute a display section.
The point light source array 300 includes a plurality of point light sources I disposed in a two-dimensional array. The point light source array 300 irradiates illumination light to a plurality of pixels P made of hologram diffraction elements 400. The hologram diffraction element 400 includes a plurality of pixels P, and controls the illumination light from the point light source array 300 such that the illumination light is to be emitted as light rays having different radiation angles at a plurality of individual pixels P.
The display principle of a spatial image by the spatial image display apparatus 1A is basically the same as that of the first embodiment. To give a simplified explanation in one dimension on the arrays of each pixel unit U and each pixel P, the hologram diffraction element 400 includes a plurality of (n pieces of) pixel units U in a one-dimensional direction, and each pixel unit U includes a predetermined number of (m (=2 or more) pieces of) pixels P in a one-dimensional direction in order to form a plurality of (n (=2 or more) pieces of) image points S in a one-dimensional direction. One image point S is formed by light rays individually emitted from each one pixel P in the predetermined number of (m pieces of) adjacent pixel units U out of the plurality of (n pieces of) pixel units U.
Individual light sources I of the point light source array 300 correspond to respective image points S. One light source I out of the plurality of light sources I emits illumination light to a predetermined number of (m pieces of) pixel units U out of the plurality of (n pieces of) pixel units U. Each of the pixel units U is illuminated with illumination light by free space radiation. For example, if it is assumed that m=20 pieces, as illustrated in
In this regard, in place of the hologram diffraction element 400, a very little mirror array for controlling the radiation direction of the light ray from each light source I, or the other diffraction element array may be disposed.
Specific Design Example
For example, the hologram diffraction element 400 is disposed at 10 mm above the point light source array 300 in which the point light sources I are disposed two-dimensionally at intervals of 2 mm. The hologram diffraction element 400 may have the same shape for each pixel unit U. Each of the pixel units U of the hologram diffraction element 400 is designed by iterative Fourier transform calculation such that the light rays from the point light source array 300 are diffracted at different angles from the incident angles and emitted. Thereby, it is possible to generate a planar image in a space.
It is possible to apply the spatial image display apparatuses 1 or 1A according to the first or the second embodiment, respectively, to the following fields, for example.
In this regard, as illustrated in
It is possible to apply such an interactive information display to a display unit in a medical field, for example. For example, at medical services and medical examination sites in a medical field, if a doctor who has touched a patient with a gloved hand then touches an object other than the patient, it might cause infection. With the use of an interactive image interface using a spatial image, such as a spatial image display apparatus according to the present disclosure, there becomes no such risk.
Also, it is possible to apply the spatial image display apparatus according to the present disclosure to a digital signage (an electronic billboard), such as a poster, a guide plate, and the like.
Also, it is possible to apply the spatial image display apparatus according to the present disclosure to an in-vehicle display unit, such as a car navigation system, a head up display, and the like.
Also, it is possible to apply the spatial image display apparatus according to the present disclosure to a safety sign on a road, or the like. Spatial images are used for safety signs on a road, and or like, so that it is possible to achieve a display that does not hinder traffic.
The technique according to this disclosure is not limited to the above-described embodiments, and it is possible to make various variations.
For example, it is possible to configure the present technique as follows.
a display section including a plurality of pixels disposed in a two-dimensional array, the plurality of pixels configured to radiate light rays at different radiation angles with each other respectively so as to form a planar image including a plurality of image points disposed in a two-dimensional array in a space apart from an array face of the plurality of pixels,
wherein two or more predetermined number of pixels out of the plurality of pixels radiate the predetermined number of light rays so as to intersect to form one of the image points, and
an interval of two adjacent light rays out of the predetermined number of light rays having passed one of the image points is equal to or less than a predetermined observation interval at a predetermined observation position.
wherein the display section includes a plurality of pixel units,
each of the pixel units includes the predetermined number of pixels, and
out of the plurality of pixel units, light rays radiated from one pixel in each of the predetermined adjacent pixel units form one of the image points.
wherein the display section includes
a display panel including the plurality of pixels disposed in a two-dimensional array, and
a plurality of imaging elements configured to control radiation angles of individual light rays radiated from the plurality of pixels.
wherein the display section includes
a light source array including a plurality of light sources disposed in a two-dimensional array, and configured to emit illumination light to the plurality of pixels, and
a display element including the plurality of pixels, and configured to control the illumination light to be radiated from the plurality of pixels as individual light rays having different radiation angles with each other.
wherein the display section includes a plurality of pixel units,
each of the pixel units includes the predetermined number of pixels,
out of the plurality of pixel units, light rays radiated from one pixel in each of the predetermined adjacent pixel units form one of the image points, and
one light source out of the plurality of light sources emits the illumination light to the predetermined number of pixel units out of the plurality of pixel units.
wherein the predetermined observation interval is a size of a pupil.
wherein at the predetermined observation position, a size of a spread of all the predetermined number of light rays having passed one of the image points is equal to or wider than an interval of both eyes.
wherein each of the pixels includes a plurality of sub-pixels configured to emit different color light rays with each other, and the plurality of sub-pixels emit light rays at different radiation angles, respectively so as to form a planar image including image points of a plurality of colors in a space apart from an array face of the plurality of pixels.
when a plurality of pixels, disposed in a two-dimensional array, radiate light rays at different radiation angles with each other respectively so as to form a planar image including a plurality of image points disposed in a two-dimensional array in a space apart from an array face of the plurality of pixels,
two or more predetermined number of pixels out of the plurality of pixels radiating the predetermined number of light rays so as to intersect to form one of the image points, and
wherein an interval of two adjacent light rays out of the predetermined number of light rays having passed one of the image points is equal to or less than a predetermined observation interval at a predetermined observation position.
Number | Date | Country | Kind |
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2014-066891 | Mar 2014 | JP | national |
Number | Date | Country | |
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Parent | 14661094 | Mar 2015 | US |
Child | 16107161 | US |