JPH0272319A - Method for manufacturing a display with a diffraction grating pattern - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for manufacturing a display formed by arranging minute diffraction gratings dot by dot on a two-dimensional plane.

"Prior Art" A method for manufacturing a display having a diffraction grating pattern using two-beam interference is disclosed in Japanese Patent Laid-Open No. 156004/1983. This method involves sequentially exposing a photosensitive film to minute interference fringes caused by two-beam interference while changing their pitch, direction, and light intensity.

"Problems to be Solved by the Invention" In the conventional method described above, it was necessary to move the optical system of the exposure head each time the pitch, direction, and light intensity of interference fringes were changed. In this way, in the conventional method,
Since the optical system cannot be fixed, it is vulnerable to vibrations and easily influenced by external vibrations, which poses the problem that a highly accurate diffraction grating cannot be formed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a display having a diffraction grating pattern that is resistant to external vibrations and can thus form a highly accurate diffraction grating pattern.

"Means for Solving the Problems" A method for manufacturing a display having a diffraction grating pattern according to the present invention to achieve the above object includes a step of reading image data, specifying a color to be exposed, and adjusting a slit of an optical system to that direction. a step of moving to a position corresponding to the color, a step of moving the origin of the X-Y stage and setting the beginning of the data of the specified color, and a step of reading the address data of the image data and setting the data of the specified color. When data exists, the shutter of the optical system is opened and exposed; next, the X-Y stage is moved and the address is incremented by 1; the exposure process is repeated until the data is completed; and then the designated color and repeating the series of steps described above until the specified color is used up.

"Operation" In the manufacturing method of the present invention, a color is first designated, and a diffraction grating corresponding to the designated color is formed for each dot by moving the X-Y stage. When the fabrication of the diffraction grating corresponding to the designated color is completed, the next color is changed and a diffraction grating corresponding to that color is similarly fabricated for each dot. In this way, in the present invention, the X-Y stage is moved for each color to form a diffraction grating, so the optical system for forming two-beam interference fringes can be fixed.

``Example'' A method of manufacturing grating dots by intersecting two laser beams according to the present invention will be described in detail with reference to the drawings.

The present invention operates two laser beams according to image information on a computer to produce red (R), green (G), and blue (B) laser beams.
In this method, dots are directly exposed onto a photosensitive material, and a display having a diffraction grating pattern is produced by combining the dots. As shown in Figure 1, 2
When the laser beams 10, 12 of the book are mixed into dots on the dry plate 14, interference fringes 18 are produced at the dots 16. The period of this interference fringe can be changed by changing the angle at which the two laser beams 10.12 intersect. This interference fringe dot 16 is formed on the dry plate 14 while moving the X-Y stage 20 according to instructions from the computer. 16 dots of 3 types representing the 3 colors of red, green, and blue
In order to form a laser beam with three different angles, a laser beam is prepared.

In this way, spots of the three colors R, G, and B are formed at arbitrary positions on the dry plate 14 according to instructions from the computer.

FIG. 2 shows an optical system for forming dots on a dry plate. The laser beam emitted from the laser 22 changes its optical path by total reflection mirrors 24 and 26, and passes through the half mirror 32.
, 34, 36, and the four beams B1, B2, B3
, B4.

At this time, the four beams B1, B2, B3, and B4 are set to have equal intensity. Three beams B1, B2,
B3 is selected as one by the slit 38, and the lens 4
0, and is incident on the dry plate 14 through the mirror 42. Laser beam B4 serving as reference light is mirrored 44.46
and is incident on the dry plate 14. 4 beams B1,
B2, B3, and B4 are adjusted so that they converge at one point.

Also, the angle at which these four beams B1, B2, B3, and B4 are incident on the dry plate 14 is such that the diffracted light from the diffraction grating is R.
The values are set in advance to represent the three colors SG and B.

The dry plate 14 is placed on an XY stage and can be moved under computer control. The laser beams B1, B2, B3, and B4 pass through a shutter 48 just before entering the dry plate 14, and exposure and non-exposure are controlled by opening and closing the shutter 48.

A method for manufacturing a display having a diffraction grating pattern according to 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 into a computer. Images read by an image scanner have jagged edges, so the images are corrected using a computer.

Also, if you are unable to enlarge or reduce the image to match the size, you can modify the image on the computer.

The corrected image data is separated into each color of R, G, and B and stored on a floppy disk.

Next, the color to be exposed is designated and the slit 38 of the optical system is moved, and only the designated laser beam among the laser beams B1, B2, and B3 is taken out through the slit 38 (steps B and C). Next, in step D%E, the origin of the X-Y stage is moved and the leading data of the designated color is set. Next, the data at the specified address is read (step F), and it is detected whether data of the specified color exists in the data (step G). When data of the designated color exists, the shutter of the optical system is opened and the dry plate is exposed to form a diffraction grating corresponding to the designated color (step H). The dry plate is not exposed when the specified color data does not exist. At this stage, the process of forming a diffraction grating corresponding to the color specified for one dot is completed.

Next, the XY stage is moved (step 1), the address is incremented by 1 (step J), and it is detected whether the data of the designated color has been completed (Step K). If it has not finished, return to step F and step FSG, H.
SI and JSK are repeated to form a plurality of dot-shaped diffraction grating patterns corresponding to the specified color.

When the data of the designated color is completed, the process advances to step L, and when another color exists, the process returns to step B. Then specify another color to be exposed and step B to K.
Repeat. When the designated color is exhausted, the display having the diffraction grating pattern of the present invention is completed.

As shown in FIG. 5A, in the present invention, two laser beams are made to intersect on a dry plate 14, and interference fringes 18 are created at that time.
The dots 16 consisting of the dots 16 are recorded, and an image is created by a collection of the dots 16. As shown in FIG. 5B, the red dot is created by a combination of laser beam B4 incident at an angle of 110 degrees and laser beam B1 incident at an angle of 15 degrees. The spatial frequency of interference fringes formed by laser beams B1 and 84 is 944/111 as follows:
It becomes 11.

(SINIO' +5IN15°)/(457,9X
to-6)-944 pieces l The green dot is created by a combination of laser beam B4 incident at an angle of 110 degrees and laser beam B2 incident at an angle of 20 degrees.

The spatial frequency of the interference fringes formed by the laser beams B2 and 84 is 1126 lines/mm as shown below.

(SIN10°+5IN20°)/(457,9X 1
O-6)-1120 pieces/ll11 blue dots are 110
It is created by a combination of a laser beam B4 incident at an angle of 25 degrees and a laser beam B3 incident at an angle of 25 degrees. The spatial frequency of the interference fringes formed by the laser beams B3 and 84 is 1302 lines/■ as shown below.

(SIN10°+5IN25°)/(457,9X 1
O-6)-1302 lines 1III Now, in order to reproduce red dots into red, green dots into green, and blue dots into blue, as shown in Figure 6, from an upward angle of 37 degrees, Dry plate 1
4 is illuminated with white light and observed from a direction perpendicular to the dry plate 14. At this time, 944 pieces/■, 1126 pieces/■, 13
The wavelengths of the first-order diffracted light generated by interference fringes with a spatial frequency of 02/row are 637rv, or red light, 534na+, or green light, respectively.
462 na, which means blue light. This is shown by the following equation.

5IN37°/944-637tv 5IN87°/
1126534nn+5IN37@Ha302-462n
11 A photographic plate with a diffraction grating formed in this way can be used as an original for reproduction. The well-known embossing method is used to perform the reproduction.

"Effects of the Invention" According to the present invention, since a dot having a diffraction grating is formed for each color using an X-Y stage, there is no need to move the optical system, and therefore a highly accurate diffraction grating pattern can be formed. . Being able to form a highly accurate diffraction grating pattern means that a clear display can be created.

Furthermore, since the diffraction grating pattern is produced using an X-Y stage and a computer, a finely colored fine pattern made of minute dots can be obtained.

Such displays can be used for security checks.

Furthermore, since the image data on the computer can be reproduced as is using the computer, the manufacturing process can be further simplified.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the method of manufacturing a display having a diffraction grating pattern using two-beam interference according to the present invention, and FIG.
The figure shows an optical system for carrying out the method of the present invention, Figure 3 shows an outline of the method of the present invention, Figure 4 is a flowchart of the method of the present invention, and Figures 5A and 5B. 6 is an explanatory diagram of the diffraction grating of the display of the present invention, and FIG. 6 is an explanatory diagram of the display of the present invention when observed. 10.12...Laser beam, 14...Dry plate, 16
...Dot, 18...Interference fringe, 20...X-Y stage, 22...Laser, 38...Slit, 48
... Shutter Applicant's Representative Patent Attorney Takehiko Suzue Figure 2 Figure 5A Figure 5B Figure 6

Claims (1)

[Claims] (1) A process of reading image data, a process of specifying the color to be exposed and moving the slit of the optical system to a position corresponding to that color, and a process of moving the origin of the X-Y stage and data of the specified color. a step of setting the beginning of the image data, a step of reading the address data of the image data and opening the shutter of the optical system to expose when data of the specified color exists, and then moving the X-Y stage. A diffraction grating comprising the steps of increasing the address by 1 and repeating the exposure step until the data is completed, and then changing the designated color and repeating the series of steps until the designated color is exhausted. A method for producing a display having a pattern.