JPH0820563B2 - Display with diffraction grating pattern - Google Patents

Description

The present invention relates to a display formed by arranging minute diffraction gratings (gratings) on a two-dimensional plane for each dot.

<Prior Art> A display having a diffraction grating pattern by two-beam interference and a method for manufacturing the display are disclosed in JP-A-60-156004. In this method, minute interference fringes (hereinafter referred to as a diffraction grating) due to two-beam interference are changed in pitch, direction, and light intensity, and the photosensitive film is successively exposed.

In addition, as a method of manufacturing a display having a diffraction grating pattern by an electron beam, a fine diffraction grating is changed by an electron beam exposure device by changing its pitch, direction, and curvature of the diffraction grating, and sequentially drawing on the EB resist. There is.

<Problems to be Solved by the Invention> In the method using the two-beam interference described above, in order to change the brightness of the minute diffraction grating, the diffraction efficiency of the diffraction grating is changed by changing the exposure time. However, if the exposure time is simply changed, the intensity distribution of the laser beam is a gown distribution. Therefore, if the exposure time is lengthened, the central part of the beam will be overexposed and the diffraction grating will collapse, resulting in a sufficient change in diffraction efficiency. I couldn't get it.

In addition, the brightness of the minute diffraction grating cannot be changed by the method using the electron beam drawing. Therefore, a full-color image cannot be expressed by the above two methods.

The present invention has been made to solve the above problems, and it is an object of the present invention to change the lightness by changing the area of each dot forming a diffraction grating pattern, thereby making it possible to express a full-color image. To do.

<Means for Solving the Problems> The present invention, which has been made to achieve the above object, is a display comprising a flat substrate and a diffraction grating pattern formed on the surface of the substrate, and the diffraction grating pattern is provided. Is composed of a plurality of minute dots formed by a diffraction grating, and the area of each dot changes to a designated size according to the brightness of each dot.

<Operation> In the display of the present invention, since the area of each dot constituting the diffraction grating pattern is changed, the brightness can be expressed by a minute diffraction grating corresponding to the area of each dot, and a full-color image can be created. Is possible.

<Example> The present invention is a display in which minute diffraction gratings are arranged on a two-dimensional plane while changing the area of each dot, and details thereof are as shown in FIG.
Has a minute diffraction grating dot (16) arranged on a two-dimensional plane with a predetermined area, a predetermined spatial frequency, and a predetermined diffraction grating angle. The amount of the 1st-order diffracted light diffracted by the diffraction grating increases in proportion to the area of the dot, and the color of the 1st-order diffracted light diffracted by the diffraction grating is determined by the spatial frequency of the diffraction grating and diffracted by the diffraction grating. The direction of the first-order diffracted light is determined by the angle of the diffraction grating. Therefore, according to the data on the computer, a dot having a minute diffraction grating arranged on a two-dimensional plane has a large dot area at a position corresponding to a high brightness dot and a small dot area having a low brightness. The color to be expressed changes the spatial frequency of the diffraction grating, and by setting the angle of the diffraction grating calculated from the direction in which the dots should be observed, the brightness, color, and observation direction of the dots of the diffraction grating can be arbitrarily set. It can be changed. In this way, a large number of dots shining in the brightness, color, and observation direction determined in this way are arranged on a two-dimensional plane, and a pattern of the display is formed as a set thereof. The display can represent a full-color image because the brightness and color can be determined for each dot, and can also represent an image in which the observed pattern changes depending on the position of the observer's viewpoint by changing the angle of the diffraction grating. It is a thing.

A display having a diffraction grating pattern by a method of forming grating dots by intersecting two laser beams will be described with reference to FIGS. 1 to 4.

As shown in FIG. 1, two laser beams (10),
When (12) is crossed on the dry plate (14), interference fringes, that is, a diffraction grating (18) are generated in the dot (16). At this time 2
It is possible to change the area of the dot (16) by changing the thickness of the laser beams (10) and (12) of the book. In addition, the period of this diffraction grating is
It can be changed by changing the angle at which 0) and (12) intersect. The dots (16) having this diffraction grating are formed on the dry plate (14) while moving the XY stage (20) according to the instructions of the computer. The thickness of the laser beam is changed by inserting a lens in the optical path of the laser beam and moving the position of the lens parallel to the optical path. Laser beams having three different angles are prepared in order to form three kinds of dots (16) representing three colors of red, green and blue. In this way R, G, B
Follow the computer's instructions for the three color spots
It is formed at a predetermined position and a predetermined area on the dry plate (14).

FIG. 2 shows an optical system for forming dots on the dry plate. The laser beam emitted from the laser (22) changes its optical path by the total reflection mirrors (24) and (26) and enters the lens (41). The lens (41) is movable in a direction parallel to the laser beam by computer control, and it is possible to change the thickness of the laser beam on the dry plate (14).

The laser beam that has passed through the lens (41) is incident on the half mirrors (32), (34) and (36), and the four beams (B
It is divided into 1), (B2), (B3), and (B4). This time,
The four beams (B1), (B2), (B3), (B4) are set to have equal intensities. 3 beams (B1),
One of (B2) and (B3) is selected by the slit (38) and is incident on the dry plate (14) through the lens (40) and the mirror (42). Laser beam (B
4) is incident on the dry plate (14) through the mirrors (44) and (46). 4 beams (B1), (B2), (B3), (B
4) is adjusted so that it gathers at one point on the dry plate (14). Also, these four beams (B1), (B2), (B
The angles at which 3) and (B4) are incident on the dry plate (14) are set to values calculated in advance so that the diffracted light from the diffraction grating represents the three colors R, G, and B. The dry plate (14) is placed on an XY stage and can be moved by computer control. Laser beam (B1), (B
2), (B3), and (B4) pass through the shutter (48) immediately before entering the dry plate (14), and the exposure and non-exposure are controlled by opening and closing the shutter (48). The time for opening and closing the shutter (48) is changed according to the thickness of the laser beam so that the exposure amount per unit area on the dry plate (14) becomes constant.

The manufacturing process of the display having the diffraction grating pattern of the present invention will be described with reference to FIGS. 3 and 4. First,
As shown in step A, image data is read using an image scanner and input to a computer. As the data to be input at this time, information on the brightness of the image of the original is also input. Since an image read by an image scanner often needs correction in order to be used as a document, it is corrected on a computer. The corrected image data is decomposed for each color of R, G, B and stored in a recording medium such as a floppy disk. Then, specify the color to be exposed and move the slit (38) of the optical system. Laser beam (B
Only the designated laser beam of 1), (B2) and (B3) is taken out through the slit (38) (step B,
C). Next, in step D, the XY stage is moved to the origin. Next, the color data to be exposed at the location to be exposed is read, and it is determined whether or not to perform the exposure (steps E and F). When performing exposure, move the lens (41), change the area of the dot (16) according to the brightness of the dot (step G), and open the shutter (48) of the optical system for a time corresponding to this area. , Exposure is performed (step H). At this stage, the manufacturing process of the diffraction grating corresponding to the color and brightness designated for one dot is completed. Next, the XY stage is moved (step I), and it is judged whether or not the data of the designated color is completed (step J). If not completed, the process returns to step E, and steps E, F, G, H, I, and J are repeated to form a plurality of dot-shaped diffraction grating patterns corresponding to the designated color.

When the data of the designated color is completed, the process proceeds to step K, and when another color exists, the process returns to step B. Then, another color to be exposed is designated and steps B to J are repeated. When there are no more designated colors, the display having the diffraction grating pattern of the present invention is completed.

The dry plate having the diffraction grating thus formed can be used as an original plate for reproduction. The well-known embossing method is used for reproduction.

According to the method of manufacturing a diffraction grating using an electron beam,
A display having a diffraction grating pattern will be described with reference to FIGS.

As shown in FIG. 5, the electron beam exposure apparatus includes an electron gun (50), alignment (52), blanker (54), condenser lens (56), stigmator (58), deflector (60), objective lens (62). ), An XY stage (20). An EB resist (dry plate) (15) is placed on the XY stage (20). Blanker (5
4), deflector (60), and XY stage (2
0) is connected to the computer (66) via the control interface (64).

The electron beam emitted from the electron gun (50) is controlled by the computer (66) to scan the dry plate (15).

FIG. 6 shows the dry plate (15) placed on the XY stage (20). The electron beam (70) emitted from the electron gun (50) has a dot (16) as a unit and a diffraction grating (1
8) Draw. By moving the XY stage (20), the diffraction grating (18) is drawn for each dot one after another,
Form a diffraction grating pattern.

 The manufacturing process will be described below with reference to FIG.

First, in step a, image data is read using an image scanner and input to a computer. Alternatively, computer graphics image data may be input to the computer. As the data to be input at this time, information on the brightness of the image of the original is also input. The image read by the image scanner is often required to be corrected in order to be used as a document, so the image is corrected on the computer (step b). Next, in step c, the viewing zone data is input to the computer. The viewing area data defines the viewing direction and viewing area of the display for each dot when the input image data is reproduced as a display. Then in step d, X
-Move the Y stage to the origin and input the dot data from the data file to the computer in step e. This dot data consists of the position of one dot, color (spatial frequency), viewing direction, viewing range, and
And it is the data regarding the brightness. Then, using these data, the shape of the grating is determined in steps f, g, and h. In step i, the dot area is determined on the computer from the brightness data. At this time, the shape of the dot for having the area of this dot may be a halftone dot in the printed matter or a dither method. The order of steps f, g, h, i is not limited to this example, and any order may be used.

Next, in step j, the XY stage is moved to the position of the dot input in step e, and in step k, the grating of that dot is drawn. By this series of steps, drawing of the diffraction grating corresponding to one dot is completed. Next, in step 1, the address of the data file is incremented by 1 to refer to the data of the next dot. Then, in step m, when the image data at this address exists, the process returns to step e to input the data of another dot, and step f,
Repeat g, h, i, j, k, l. This series of steps is repeated until there is no image data corresponding to the dot.

The dry plate having the diffraction grating pattern thus formed can be used as an original plate for reproduction. The well-known embossing method is used for reproduction.

<Effects of the Invention> As described above, according to the present invention, in a display having a diffraction grating pattern, it is possible to change the brightness according to the dot by changing the area of the dots formed from the diffraction grating. , Can express full-color images.

[Brief description of drawings]

FIG. 1 is a schematic view of an example in which two-beam interference is used to manufacture a display having a diffraction grating pattern according to the present invention.
FIG. 4 is a diagram showing an optical system for producing the present invention by using two-beam interference, FIG. 3 is a diagram showing an outline of steps for producing the present invention by using two-beam interference, and FIG. Flowchart showing a process for manufacturing the invention using two-beam interference,
FIG. 6 is a schematic view of an example in which an electron beam is used to manufacture a display having a diffraction grating pattern according to the present invention, FIG. 6 is a view showing an EB resist placed on an XY stage, and FIG. FIG. 8 is a flowchart showing a process of manufacturing the invention using an electron beam, and FIG. 8 is a plan view of a display having a diffraction pattern of the invention. 10,12 …… Laser beam 14 …… Photoresist dry plate 15 …… EB resist dry plate 16 …… Dot 18 …… Diffraction grating 20 …… XY stage 22 …… Laser 38 …… Slit 48 …… Shutter 50 …… Electron gun 54 …… Blanker 60 …… Deflector 64 …… Control interface 66 …… Computer 70 …… Electron beam

Claims (1)

[Claims] 1. A display comprising a flat substrate and a diffraction grating pattern formed on the surface of the substrate,
The diffraction grating pattern is composed of a plurality of minute dots formed by the diffraction grating, and the area of each dot is changed to a designated size according to the brightness of each dot. A display having a diffraction grating pattern.