JPH04311916A - Display with diffraction grating pattern - Google Patents

Abstract

PURPOSE:To freely draw a continuous stereoscopic image and realize a simple design and a low cost by forming a diffraction grating with a group of lines as parallel-moved curves and providing a light shielding means on the incoming side of illumination light from the diffraction grating. CONSTITUTION:A diffraction grating 1 constituting a dot is formed with a group of lines as parallel-moved curves and provided with a light shielding means 2 which employs printing ink or space modulating element, on the incoming side of illumination light from the diffraction grating 1 or on the outgoing side of diffraction light from the diffraction grating. As a result, there are portions which receive and do not receive illumination light or portions which transmit and do not transmit diffraction light on a display, so that observing the display from the front view causes the appearance of an image which has a visual difference between right and left eyes to allow the observation of a stereoscopic image on the display. As the diffraction grating 1 is formed with parallel curves, diffraction light is wide in horizontal and the image has no uncontinuous part and no color change if view points move in horizontal.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a display formed by arranging minute diffraction gratings dot by dot on the surface of a substrate, and particularly relates to a three-dimensional (three-dimensional) display with no image skipping. The present invention relates to a display having a diffraction grating pattern that is easy to produce and inexpensive, and that can freely express images such as ().

0002

2. Description of the Related Art Conventionally, many displays have been used in which a diffraction grating pattern is formed by arranging a plurality of minute dots made of a diffraction grating on the surface of a substrate. As a method for manufacturing a display having this type of diffraction grating pattern, for example, Japanese Patent Laid-Open No. 60-15
There is a method as disclosed in Japanese Patent No. 6004. This method involves sequentially exposing a photosensitive film to minute interference fringes (hereinafter referred to as diffraction gratings) created by two-beam interference while changing their pitch, direction, and light intensity.

On the other hand, recently, a plurality of minute dots made of diffraction gratings are formed on the surface of a substrate by using, for example, an electron beam exposure device and moving an XY stage on which a substrate is placed under computer control. By placing
The present inventor has proposed a method for manufacturing a display in which a diffraction grating pattern of a certain picture is formed. The method is disclosed in US Patent Application Serial No. 276,469, filed November 25, 1988.

0004

[Problems to be Solved by the Invention] However, in a display manufactured by such a manufacturing method, the display pattern having a diffraction grating pattern may be an image inputted with an image scanner or the like, or a pattern created by computer graphics. Created two-dimensional images are used. For this reason, the pattern expressed by the diffraction grating pattern is located on the plane of the substrate on which the diffraction grating is arranged, so it can only express a two-dimensional (two-dimensional) pattern, and three-dimensional ( There is a problem that it is not possible to express three-dimensional (three-dimensional) patterns.

[0005] The present invention has been made to solve the above-mentioned problems.
It is an object of the present invention to provide a display having a diffraction grating pattern that is easy to produce and inexpensive, which can freely express images.

[0006]

[Means for Solving the Problems] In order to achieve the above object, a display having a diffraction grating pattern according to the invention as set forth in claim 1 provides a display having a diffraction grating pattern in which a plurality of diffraction gratings constituting dots are moved in parallel along a curved line. The diffraction grating is composed of a collection of lines, and a light shielding means having a predetermined shape is disposed on the illumination light incident side of the diffraction grating.

[0007] Furthermore, in the display having a diffraction grating pattern according to the invention as set forth in claim 2, the diffraction grating constituting the dot is constituted by a collection of a plurality of lines obtained by moving parallel curves, and the diffraction grating of the diffraction grating is A light shielding means having a predetermined shape is arranged on the light output side. Here, particularly as the light shielding means, printing ink or a spatial modulation element is used.

[0008]

[Operation] Therefore, in the display having the diffraction grating pattern of the invention as claimed in claim 1, by providing the light shielding means on the illumination light incident side of the diffraction grating, the part of the display that is hit by the illumination light is prevented from hitting the display. In the display having the diffraction grating pattern of the invention according to claim 2, a light shielding means is provided on the diffraction light output side of the diffraction grating, so that the diffraction light from the display is transmitted through the display. When the viewer views the display, the viewer sees images with parallax on the left, front, and right, creating a three-dimensional (three-dimensional) image. can be observed. In addition, even if there is only one type of diffraction grating, it is possible to create a three-dimensional (3-dimensional) grating by replacing only the light shielding means and changing its shape.
You can freely express dimensional (dimensional) images.

Furthermore, even if the pattern changes, the diffraction grating remains constant regardless of the pattern, and there is no need to create a diffraction grating each time using an electron beam lithography system, which saves both time and cost. , can greatly improve efficiency.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS A display having a diffraction grating pattern according to the present invention will be described below with reference to the drawings. First, a method for inputting a plurality of planar images will be explained using FIG. 1.

A planar image 80 of an object 85 desired to be displayed three-dimensionally is photographed using a television camera 81. That is, one television camera 81 is arranged at a plurality of positions defined by the interval p, and a plurality of planar images 85 of the object 85 corresponding to each position are photographed. The data of these planar images 85 is input into the computer 82 using the digitizer 83 and stored as image data. by the way,
In order to input the data of these planar images 85 to the computer 82, data recorded on a video tape, data of photographs or movies may be used. Further, the object 85 to be displayed three-dimensionally is not limited to an existing object, but may be a computer graphics object. Next, Figure 2
A method for determining the direction Ω of the diffraction grating and the pitch d of the diffraction grating will be explained with reference to FIG.

Assume that a viewer views a display 15 having dots 16 made in accordance with the present invention, as shown in FIG. As shown in FIG. 2, if the incident angle of the illumination light 91 is θ, the direction of the first-order diffracted light 92 diffracted by the diffraction grating 18 is α, and the wavelength of the first-order diffracted light 92 is λ, then as shown in FIG. The direction Ω of the grating 18 and the pitch d (reciprocal of the spatial frequency) of the diffraction grating 18 can be determined using the following equations. Note that the illumination light 91 is Y-
It is assumed that the diffracted light passes on the Z plane, and that the diffracted light passes on the X-Z plane. tan(Ω)=sin(α)/sin(θ)d=λ/{
sin2 (θ)+sin2 (α)}1/2

001
3] By using the above equation, it is possible to determine the direction Ω and pitch d of the diffraction grating 18 for diffracting the illumination light 91 in an arbitrary direction. That is, illumination light 9
If the incident angle θ of 1, the direction α of the first-order diffracted light 92, and the wavelength λ of the first-order diffracted light 92 are given, the direction Ω and pitch d of the diffraction grating 18 can be obtained.

[0014] Here, the pitch d' of the diffraction grating that causes diffraction toward the front (α=0) is determined. d'=λ/sin(θ) Therefore, d=d'・sin(θ)/{sin2 (
θ)+sin2 (α)}1/2 =
d´・cos(Ω)

As shown in FIG. 4, in the configuration in which the curve is moved in parallel, the above equation is always satisfied, so the diffraction grating is such that the wavelength of the same color can always be observed at the viewpoint where the diffracted light moves in the horizontal direction. The structure is as follows. In the dots in FIG. 4, the slope of the curve forming the dot changes from Ω1 to Ω2, and the curves are arranged at a pitch d'. That is, in order to obtain grating dots in which the horizontal diffracted range of the diffracted light is at an angle α1 to α2 with respect to the normal to the surface where the grating exists, tan(Ω1)=sin(α1 )/sin(θ
)tan(Ω2)=sin(α2)/sin(θ)d=
λ/sin(θ), and the curve changing from slope Ω1 to Ω2 with pitch d
It is sufficient to use a grating that has been translated in parallel by ''. Therefore, in the present invention, one basic dot of a diffraction grating image is formed by a collection of a plurality of lines obtained by moving a curved line in parallel, as shown in FIG.

Furthermore, in the present invention, by disposing a light shielding means having a shape as shown in FIG. Either block the diffracted light and create areas on the display that are illuminated and areas that are not illuminated.
Alternatively, the display may have portions through which the diffracted light from the display is transmitted and portions through which the diffracted light is not transmitted.

Now, the display having the diffraction grating pattern thus obtained is reproduced as shown in FIG. At this time, "T" in the left direction and "O" in the middle.
”, and “P” can be observed in the right direction.
Here, three images are used, but by using more parallax images, it is possible to make the images that appear to the left and right eyes of the observer different. That is,
The viewer observes images with parallax for the left and right eyes separately, and can obtain a three-dimensional (three-dimensional) image. Furthermore, even if the observer's observation position is moved horizontally, parallax images seen from other directions can be obtained.
You can get a natural three-dimensional effect. Next, a specific example of a display having a diffraction grating pattern according to the present invention will be described.

The light blocked by the light blocking means may be either illumination light or diffracted light. That is, for example, FIG.
As shown in FIG. 2, this can be realized by disposing a light shielding means 2 on the diffraction light emission side of a transparent type diffraction grating 1. Further, as shown in FIG. 8, for example, it can be realized by disposing a light shielding means 2 on the illumination light incident side of a transparent type diffraction grating 1. Furthermore, for example, FIG.
As shown in FIG. 2, this can be realized by disposing the light shielding means 2 on the diffraction light output side of the reflection type diffraction grating 3, that is, on the illumination light input side.

On the other hand, in this case, as the light shielding means, for example, as shown in FIG. 10, by printing using printing ink 4, it can be placed on the diffraction grating 1 to provide a light shielding effect, and the Three-dimensional images can be obtained while simplifying the process. Furthermore, by overlapping the patterns by printing, it is possible to create the effect of overlapping a three-dimensional image and a two-dimensional image by printing. Furthermore, by using a spatial modulation element (for example, a liquid crystal display panel) 5 as a light shielding means, as shown in FIG. I can do it,
Three-dimensional moving images can be obtained.

As described above, in the display having the diffraction grating pattern of this embodiment, the diffraction grating 1 constituting the dots is composed of a collection of a plurality of lines obtained by moving parallel curves, and Diffraction grating 1
Since the light shielding means 2 using the printing ink 4 or the spatial modulation element 5 is arranged on the incident side of the illumination light of the diffraction grating or the output side of the diffracted light of the diffraction grating, the viewer can see from the front of the display. When observed, an image with parallax can be seen between the left and right eyes, so a three-dimensional image (three-dimensional image) can be observed on the display. When the viewer moves his/her viewpoint in the horizontal direction, the observed image changes smoothly accordingly, giving the effect of looking around the viewer, creating a natural three-dimensional effect.

[0021] Furthermore, since the diffraction grating is composed of parallel curves, it is possible to create diffracted light that spreads in the horizontal direction, so there is no jump in the image, and moreover, it is possible to move the viewpoint in the horizontal direction. At times, it is possible to observe 3D images with good reproduction without color change. That is, conventionally, since a diffraction grating is composed of parallel straight lines, diffracted light becomes a light beam for light of a certain wavelength, and it is not possible to create light that spreads in the horizontal direction. Therefore, if such a display is observed while moving horizontally from a distance, there will be positions where the image is visible and positions where the image is not visible (image skipping). Therefore, if the image is not visible to either the left or right eye, stereoscopic vision cannot be achieved, and the skipping of the image will cause discomfort to the viewer, but with the display of this embodiment. , all these problems can be solved.

Furthermore, even if there is only one type of diffraction grating 1,
By replacing only the light shielding means 2 and changing its shape, the pattern can be freely changed. In other words, normally it would be necessary to create a diffraction grating using an electron beam lithography device or the like every time the pattern changes, but in this example, the diffraction grating is always constant regardless of the pattern (an electron beam lithography device, etc.) It is no longer necessary to create a diffraction grating each time), and by replacing only the light shielding means 2, a three-dimensional (three-dimensional) image can be expressed freely. To be more specific, creating a diffraction grating using an electron beam lithography system is a very time-consuming task, so this example greatly improves efficiency in terms of time and cost. can be done. Furthermore, the display of this embodiment can provide a brighter image with less noise than a stereoscopic display such as a hologram.

[0023]

As explained above, according to the present invention, the diffraction grating constituting the dot is composed of a collection of a plurality of lines whose curves are shifted in parallel, and the diffraction grating is arranged on the incident side of the illumination light. , a light shielding means of a predetermined shape is provided, or a light shielding means of a predetermined shape is provided on the output side of the diffracted light of the diffraction grating, so that three-dimensional (three-dimensional) images can be obtained without image skipping. It is possible to provide a display having a diffraction grating pattern that is easy to produce and inexpensive, and can freely express images.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a method of photographing an original image according to the present invention.

FIG. 2 is an explanatory diagram of a method for observing dots created according to the present invention.

FIG. 3 is an enlarged view of dots according to the present invention.

FIG. 4: Basic 1 of the diffraction grating image according to the present invention
Enlarged view of the dots.

FIG. 5 is an explanatory diagram of a method for manufacturing a display according to the present invention.

FIG. 6 is an explanatory diagram of a method for observing a display made according to the present invention.

FIG. 7 is a schematic diagram showing an example of the configuration of a display according to the present invention.

FIG. 8 is a schematic diagram showing a configuration example of a display according to the present invention.

FIG. 9 is a schematic diagram showing an example of the configuration of a display according to the present invention.

FIG. 10 is a schematic diagram showing a specific configuration example of a display according to the present invention.

FIG. 11 is a schematic diagram showing a specific configuration example of a display according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Diffraction grating, 2... Light shielding means, 3... Diffraction grating, 4... Printing ink, 5... Spatial modulation element, 6... Liquid crystal drive device, 16
...dot, 18...diffraction grating pattern, 80...plane image,
81...TV camera, 82...Computer, 83...Digitizer, 85...Object.

Claims (6)

[Claims] Claim 1: In a display formed by arranging minute diffraction gratings dot by dot on the surface of a substrate, the diffraction gratings constituting the dots are arranged in parallel to each other in a curved line. What is claimed is: 1. A display having a diffraction grating pattern, characterized in that the display is formed by a collection of diffraction gratings, and a light shielding means having a predetermined shape is disposed on the illumination light incident side of the diffraction grating. 2. In a display formed by arranging minute diffraction gratings dot by dot on the surface of a substrate, the diffraction gratings constituting the dots are arranged in parallel to each other in a curved line. 1. A display having a diffraction grating pattern, characterized in that the display is composed of a collection of diffraction gratings, and a light shielding means having a predetermined shape is disposed on the diffraction light emission side of the diffraction grating. 3. The display having a diffraction grating pattern according to claim 1, wherein printing ink is used as the light shielding means. 4. The display having a diffraction grating pattern according to claim 2, wherein printing ink is used as the light shielding means. 5. The display having a diffraction grating pattern according to claim 1, wherein a spatial modulation element is used as the light shielding means. 6. The display having a diffraction grating pattern according to claim 2, wherein a spatial modulation element is used as the light shielding means.