JP2000047341A - Stereoscopic picture display sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stereoscopic picture display sheet formed so that a stereoscopic picture is bright and the color tone thereof is changed according to an angle at which it is viewed. SOLUTION: The stereoscopic picture display sheet 30 is formed by recording patterns being the left and the right square patterns 1, the left and the right round patterns 2 and the left and the right triangular patterns 3 each constituting a picture for a left eye and a picture for a right eye in order to display the stereoscopic picture as hologram and laminating a substance obtained by recording them as the hologram on a substrate 4. It is preferable that the hologram is the diffusion type hologram. Besides, it is preferable that the hologram is obtained by recording the picture of a recursive diffusion film so as to condense diffracted light beams within an almost prescribed spatial range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binocular stereoscopic image display sheet, and more particularly to a stereoscopic image display sheet having a high degree of interest.

[0002]

2. Description of the Related Art In recent years, the form of expression such as printing and advertisement has been diversified, and the form of expression of not only a planar image but also a three-dimensional stereoscopic image has been demanded. Various types of stereoscopic image display methods have been developed for a long time. Parallax stereograms, lenticular plate type stereoscopic images, and the like are used as binocular stereoscopic image display methods that obtain a stereoscopic effect by using parallax between both eyes. Many are known.

[0003] As a relatively simple display method, a pattern forming a left-eye image and a pattern forming a right-eye image are arranged on the same plane so as to be divided substantially right and left. There is a twin-lens type stereoscopic image display system in which stereoscopic display is performed by adjusting the intervals of the display patterns of the corresponding parts on the left and right in accordance with stereoscopic perspective (depth of depth).

FIG. 5 shows an example of a conventional three-dimensional image.
It is a three-dimensional image in which these patterns are arranged in the order of triangle, circle, and square from the front to the back, and prints an image for the right eye and an image for the left eye on one sheet of paper. In accordance with the depth of the pattern, an adjustment is made so as to widen the interval between the corresponding left and right patterns constituting the part of the image arranged farther (deeper). That is, L1 is a square, L2 is a circle, L
Assuming that 3 is the interval of the triangular pattern, L1>L2> L3
So that By observing this image with both eyes and fusing the left and right images (by shifting the focus of the eyes from the paper so that the left and right images overlap), a triangle from the near side to the back
An image with a three-dimensional effect in which patterns are arranged in the order of a circle and a square can be observed.

FIG. 6 shows another example of a conventional three-dimensional image. The pattern shown in FIG. 6 is called a random dot or a random pattern. The display principle is the same as that of FIG. 5, but instead of drawing the outline of the display pattern as shown in FIG. 5, a figure (pattern) stippled with random dots is determined according to the depth as described above. Adjust and arrange the intervals. When FIG. 6 is observed in such a manner that two marks (black circles) serving as indications of the fusion are overlapped, a stereoscopic image in which a square is raised from the background can be seen. In this display method, the obtained three-dimensional image is hidden in random dots, and the three-dimensional image is obtained only after fusion,
This is a method of displaying a stereoscopic image that is surprising and has excellent taste.

[0006]

In the above-mentioned conventional stereoscopic image display system, efforts have been made to give variety to the expression by devising colors and designs. However, diversification based on color and design alone has its limits.

[0007] In expression forms such as printing, advertising, and packaging, novelty and attractiveness of expressions are required, and new expression forms are always required. From such a viewpoint, the expression method of the conventional two-lens stereoscopic image expression method is insufficient, and a satisfactory expression form cannot be provided.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a new stereoscopic image expression form which has not been known.

[0009]

According to the present invention, a pattern constituting an image for a left eye and a pattern constituting an image for a right eye are arranged on the same plane by being divided into substantially left and right sides, and an image to be displayed is provided. In a binocular stereoscopic image display sheet that performs stereoscopic display by adjusting the intervals of the respective left and right corresponding parts according to the three-dimensional perspective of each part, the patterns are recorded as holograms. A three-dimensional image display sheet is provided. Preferably, the hologram is a diffusive hologram, and the hologram is preferably recorded with an image of a retroreflective film so as to converge diffracted light in a substantially predetermined spatial range.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.
FIG. 1 is a conceptual diagram showing a stereoscopic image display sheet of the present invention. Similar to FIG. 5, it is a three-dimensional image in which display patterns are arranged in the order of triangle, circle, and square from the front to the back.
A feature of the present invention is that patterns such as triangles, circles, and squares to be displayed are recorded as holograms, that is, these patterns are recorded on a hologram photosensitive material. The stereoscopic image display sheet 30 has a configuration in which, for example, a hologram photosensitive material in which these patterns are recorded is laminated on the base material 4. The substrate 4 may be thick or thin. Further, the hologram photosensitive material itself on which a pattern is recorded may be used. Hereinafter, a hologram photosensitive material on which a pattern is recorded is referred to as a hologram sheet, and is distinguished from an unrecorded hologram photosensitive material.

The three-dimensional image display sheet 30 is observed under the illumination light source 10 as shown in FIG. Here, FIG. 2 is a schematic diagram when the stereoscopic image display sheet of the present invention is observed using illumination light. The illumination light 11 from the illumination light source 10 is diffracted by the pattern of the hologram sheet and becomes a diffracted light 12. By observing the displayed image with both eyes 20 and fusing the respective images for the left and right eyes, a display image having a three-dimensional appearance can be obtained in which patterns such as triangles, circles, and squares shine.

In general, a hologram has a wavelength selecting function and its diffraction wavelength has an angle dependency. Therefore, the diffraction wavelength changes depending on the observation angle, and the color of the pattern changes accordingly.

When a conventional three-dimensional image is formed by a normal printing technique, the pattern does not look shiny. The color tone of the pattern is determined by the color at the time of printing and does not change. On the other hand, the three-dimensional image according to the present invention is a three-dimensional image in which a pattern that appears three-dimensionally appears as illuminated by the diffraction function of the hologram as described above. Further, the color tone of the pattern changes depending on the viewing angle. in this way,
According to the present invention, it is possible to obtain a three-dimensional image in which the color tone changes and shines, which is a new appearance that has been difficult in the conventional three-dimensional image display, and can solve the above-described problems in the conventional three-dimensional image display.

Originally, a hologram can record the wavefront of light from an object in a perfect form, so that a three-dimensional image can be obtained without using parallax between both eyes. However, in the present invention, instead of utilizing the function of recording / reproducing a hologram stereoscopic image,
It utilizes the function of diffracting light selectively.

The pattern to be displayed may be not only a recognizable figure as shown in FIG. 1, but also a random dot. In that case, each dot is formed as a hologram. The pattern is formed by performing laser exposure on the hologram photosensitive material through a photomask in which the pattern portion is an opening and the other portions are shielded from light. In addition, the pattern portion to be displayed is shielded, the hologram photosensitive material is exposed in advance to the other portions with non-coherent light to lose sensitivity to light, and then the pattern portion is irradiated with coherent laser light. May be exposed.

When a hologram is used, even if it is a single-color display, the expressive power is richer than a conventional three-dimensional image, but a multi-color display is more preferable. The diffraction wavelength of the hologram is determined by the wavelength of the laser beam used for exposure and the incident angle at the time of exposure. For multi-coloring, an incident angle of one type of laser light may be changed and used, or a plurality of types of laser light of different wavelengths may be used. A three-dimensional image display sheet may be manufactured by laminating hologram sheets exposed with laser beams of different wavelengths or hologram sheets of different patterns.
A hologram photosensitive material may be subjected to multiple exposure to produce a three-dimensional image display sheet. Alternatively, the hologram sheet may be duplicated using the hologram sheet produced as described above as an original plate.

The type of hologram used is preferably a diffusive hologram in order to widen the observation range. This diffusive hologram can diffract light over a wide range.

In order to obtain a brighter three-dimensional image, it is preferable that the diffracted light be converged on the observation range of the observer. A hologram recording an image of a retro-reflective film in which incident light is reflected in the incident direction while being partially diffused is particularly preferable because it has both diffusivity and light-collecting properties. That is, while diffracting weak light over a wide range, strong light can be diffracted in a specific range.

Further, if the diffracted light from the hologram and the mere reflected light on the surface overlap, it is difficult to observe a three-dimensional image. Therefore, it is preferable that the hologram has a different incident angle and diffraction angle. Further, the hologram may be a reflection hologram or a transmission hologram.

The type of hologram is preferably a volume phase type hologram having high diffraction efficiency, but may be an emboss type hologram having a reflection layer on the back surface. As the hologram photosensitive material, a photopolymer, gelatin dichromate, a silver salt-based material, a photoresist and the like can be used. For the embossed hologram, a material such as a thermoplastic resin sheet such as vinyl chloride or polystyrene is used.

FIG. 3 is a schematic view of the case where the three-dimensional image display sheet of the present invention is observed by an edge irradiation method. As shown in FIG. 3, a three-dimensional image display sheet 30 is formed on a thick transparent base material.
And an edge lid type in which the illumination light 11 emitted from the illumination light source 10 is emitted from the side surface of the base material and the diffracted light 12 is observed by both eyes 20 can be adopted. A form in which a hologram sheet is sandwiched between two transparent substrates can also be adopted.

The use form of the three-dimensional image display sheet of the present invention is preferably such that a hologram sheet is laminated on a base material. Any substrate can be used as long as a hologram sheet can be laminated. For example, a thin material such as paper or a resin film, or a book or wrapping paper made of the same can be exemplified. Further, a sheet material such as a glass plate and a resin plate may be used.
It may be a part of a building such as a door, a wall or a roof, or a sign.
It can also be applied to emblems that are attached to vehicles such as automobiles and motorcycles to enhance the taste. In addition, it can be attached to the surface of various articles such as furniture, home appliances, OA equipment, tableware, and ornaments.

The substrate may be transparent or opaque, or may be colored. A more complex design can be obtained by layering on top of what is normally printed. Further, the hologram sheet may be stuck on the entire surface of the base material, or may be stuck on only a part thereof. Since it is difficult to duplicate a hologram sheet, a security effect can be obtained by stacking the hologram sheet on a highly important one such as an identification card or a credit card. If necessary, a protective layer may be provided on the surface of these hologram sheets. The adhesive or pressure-sensitive adhesive for adhering the base material and the hologram sheet is preferably one that can adhere with required strength and ensure long-term reliability. Those having high transparency and low scattering are particularly preferable because of low loss of light.

The illumination light may include any light having a diffraction wavelength of the hologram. In addition to sunlight, incandescent lamps and fluorescent lamps, light emitting diodes and semiconductor lasers may be used. Since the edge-lid type illumination light uniformly illuminates the width direction of the substrate, a linear light source such as a cathode ray tube is preferable.

[0025]

[Embodiment 1] This embodiment will be described with reference to FIG. FIG.
3 shows a three-dimensional image sheet in which display patterns are arranged in the order of triangle, circle, and square from the front to the back. Each pattern was recorded as a hologram by laser exposure, and the hologram sheet was laminated on the base material 4 with an adhesive to produce a three-dimensional image display sheet. Plain paper was used as the base material.

An acrylic photopolymer was used as the hologram photosensitive material. FIG. 4 is a schematic view showing an example of a method for producing a hologram used for the stereoscopic image display sheet of the present invention. The laser light 41 from the laser device 40 is applied to a spatial filter 4 comprising an objective lens and a pinhole.
The hologram photosensitive material 43 is emitted as divergent light through 2.

The hologram photosensitive material 43 was previously irradiated with a non-coherent ultraviolet lamp light so as to cover the shape of the pattern to be displayed. Hologram photosensitive material 4
3 has a recursive diffusion film 44 (Sumitomo 3M 76
10 films). The coherent laser beam 41 transmitted through the hologram photosensitive material is reflected by the retroreflective film 44 while being partially diffused. The reflected light and the first incident light interfere to form a hologram.

The square, circle, and triangle patterns are each represented by K
r laser light (wavelength 647 nm), dye laser light (wavelength 5
70 nm) and exposed to Ar laser light (wavelength 515 nm) to form a hologram. Diffracted light of red, yellow and green tones was obtained, respectively.

Further, since the hologram photosensitive material was exposed with the normal direction inclined at about 8 ° with respect to the optical axis, a non-specular reflection hologram having a diffraction angle of 35 ° was obtained when the incident angle was 55 °. Accordingly, when the stereoscopic image display sheet is picked up for observation, illumination light obliquely from above is diffracted in the direction of the viewpoint. Because of the non-specular reflection, the reflected light from the surface does not overlap, so that an easy-to-view three-dimensional image was obtained. In addition, since exposure was performed using the retroreflective film, most of the diffracted light was converged on the observation range, so that a very bright stereoscopic image was obtained.

When the three-dimensional image was observed, the pattern that emerged three-dimensionally was a three-dimensional image that appeared to shine due to the diffraction function of the hologram. Furthermore, the color tone changed depending on the viewing angle. As described above, according to the present invention, a stereoscopic image having a new appearance, which is difficult with the conventional stereoscopic image display, can be observed.

Example 2 In this example, a three-dimensional image display sheet in which each of random dots was formed by a hologram was manufactured. First, a random dot pattern as shown in FIG. 6 was prepared, and a hologram photosensitive material irradiated with a non-coherent ultraviolet lamp was used as a photomask in Example 1.
Laser exposure was performed using the same optical system. Kr laser light was used for exposure.

When observed under illumination light, a monochromatic random dot type stereoscopic image which glows red was obtained. When the viewing angle was changed, the color tone changed from red to orange, yellow, etc., and an unexpected stereoscopic image could be observed.

[0033]

According to the present invention, a new and excellent stereoscopic image display sheet can be obtained in which a three-dimensional image shines and its color tone changes depending on the viewing angle by the light diffraction function of the hologram.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a stereoscopic image display sheet of the present invention.

FIG. 2 is a schematic diagram when the stereoscopic image display sheet of the present invention is observed using illumination light.

FIG. 3 is a schematic diagram when the stereoscopic image display sheet of the present invention is observed by an edge irradiation method.

FIG. 4 is a schematic view illustrating an example of a method for producing a hologram used for the stereoscopic image display sheet of the present invention.

FIG. 5 is a conceptual diagram showing an example of a conventional stereoscopic image.

FIG. 6 is a schematic diagram showing another example of a conventional stereoscopic image.

[Explanation of symbols]

 1: Square pattern 2: Round pattern 3: Triangular pattern 4: Base material 10: Illumination light source 11: Illumination light 12: Diffracted light 15: Reflector 20: Binocular 30: Stereoscopic image display sheet 40: Laser device 41: Laser Light 42: Spatial filter 43: Holographic photosensitive material 44: Recursive diffusion film

Claims (3)

[Claims] 1. A pattern forming an image for a left eye and a pattern forming an image for a right eye are arranged on the same plane by being separated into substantially right and left, and according to a three-dimensional perspective of each part of an image to be displayed. In a two-lens stereoscopic image display sheet that performs stereoscopic display by adjusting the intervals of the patterns of the respective parts corresponding to the right and left sides, the patterns are recorded as holograms. Image display sheet. 2. The three-dimensional image display sheet according to claim 1, wherein the hologram is a diffusive hologram. 3. The stereoscopic image display sheet according to claim 1, wherein an image of a retroreflective film is recorded so that the hologram condenses the diffracted light in a substantially predetermined spatial range.