JPH0667006A - Manufacture of diffraction grating assembly - Google Patents

Abstract

PURPOSE:Not to make the processes up to a failure in photographing a certain partial area useless even in case of the failure and generate no grating-absence area or not overlap area between partial diffraction gratings of a finished product even if there is a position deviation by manufacturing specific diffraction grating assemblies in respective partial areas. CONSTITUTION:A substrate 1 is coated with, for example, a positive type photoresist and the entire surface of the resist layer 2 is exposed to interference fringes, which have a direction and a pitch corresponding to the 1st diffraction grating at the 1st area part of the diffraction grating assembly to be manufactured, by interference between two pieces of luminous flux. Then, the exposed surface is coated with, for example, an ultraviolet-ray setting type resin, which is irradiated with ultraviolet rays to form a 1st replica 3 where the 1st diffraction rating is transferred to the entire surface; and the replica 3 is coated with a photoresist and the entire surface of the photoresist layer 4 is exposed to interference fringes, which have a direction and a pitch corresponding to the 2nd diffraction grating at the 2nd partial area of the assembly to be manufacture, by interference between two pieces of luminous flux. Thus, the exposure to the two-luminous-flux interference fringes and the exposure to the lower diffraction grating at a specific part by the light irradiation are repeated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a diffraction grating assembly, and more particularly to a method of manufacturing a display body or the like in which a plurality of diffraction gratings having different directions or pitches are arranged in parallel.

[0002]

2. Description of the Related Art Conventionally, it is known that each minute dot is formed by a diffraction grating and the dots are arranged two-dimensionally to form a display body. The direction of the diffraction grating of each dot and the grating pitch are known. Japanese Patent Application Laid-Open No. 2-73220 proposes various patterns in which the pattern changes depending on the viewing direction.

However, this does not display the display pattern by dividing it by the contour of the diffraction grating, and the change of the display pattern due to the movement of the viewpoint is not smooth. In addition, since one screen is formed by regularly arranging an extremely large number of dots such as halftone dots, it is not easy to manufacture.

In view of such a situation, the present applicant has proposed in Japanese Patent Application No. 4-220074 that the outer contour or the inner contour of a diffraction grating composed of a group of partial linear diffraction gratings forming a polygonal line that is a linear approximation of a smooth curve. We proposed a display that divides and displays the display pattern such as characters and images. This is because when the viewpoint of the display is changed, the brightly shining position moves smoothly and variously, and when illuminated with white light, this brightly shining area becomes an area with a rainbow color. Not only can the pattern be easily recognized, it is visually interesting and the display effect and design effect are extremely excellent.

Further, a machine-readable information recording body, not a display body, in which a plurality of diffraction gratings having different directions or pitches are arranged in parallel is disclosed in, for example, Japanese Patent Laid-Open No. 3-21.
1096.

A two-beam interference method is usually used for manufacturing such a diffraction grating assembly. This is to prepare one set of masks in the shape of each partial area of the diffraction grating assembly, position and mask one photosensitive plate while exchanging these masks, and perform interference with the grating direction and pitch of each mask area. The fringes are exposed on the photosensitive plate through the openings of the mask, and finally exposed so as to cover the entire area of the diffraction grating assembly of the photosensitive plate, and developed to produce a diffraction grating assembly or a master thereof.

[0007]

However, in the conventional method of manufacturing a diffraction grating assembly using the two-beam interference, if the image capturing through a certain mask fails, all the steps up to that point are performed. It may be wasted. Further, if the positioning of a certain mask is incorrect, a region without a grating or an overlapping region will be generated between the partial diffraction gratings of the finally completed diffraction grating assembly, which makes the product unattractive.

The present invention has been made in view of such a situation, and an object thereof is to use a mask when exposing interference fringes due to two-beam interference, and to take an image of a certain partial area even if the image pickup fails. It is an object of the present invention to provide a method for producing a diffraction grating assembly in which the steps up to that point are not wasted and a region where no grating exists or an overlapping region does not occur between the partial diffraction gratings of the final product even if the positioning is incorrect.

[0009]

A method of manufacturing a diffraction grating assembly of the present invention that achieves the above object is a method of manufacturing a diffraction grating assembly in which a plurality of diffraction gratings having different directions or pitches are arranged in parallel. Is coated with a photosensitive material, and the entire surface thereof is exposed with a two-beam interference fringe having the direction and pitch of the first partial region to produce a first diffraction grating, and then the diffraction grating is duplicated and duplicated. The plate is used as a new substrate, the photosensitive material is coated again, and the entire surface thereof is exposed with two-beam interference fringes having the direction and pitch of the second partial region to form the second diffraction grating, and then the second portion is formed. The region including at least the first partial region other than the region is irradiated with light, and the photosensitive material in the light-irradiated region is peeled off or removed by the development process, and at least the first diffraction grating is formed in the first partial region. The second diffraction pattern in the second partial region There was prepared formed diffraction grating member,
Next, by making a copy of the diffraction grating body and repeating the same steps for the third and subsequent partial regions, it is possible to manufacture a diffraction grating assembly in which a predetermined diffraction grating is formed in each partial region. This is a characteristic method.

In this case, the photosensitive material is preferably a photosensitive material which can be recorded as a relief pattern depending on the irradiation amount of light and which can be decomposed or dissolved by irradiation with ultraviolet rays or the like.

It should be noted that the diffraction gratings in the partial regions of the diffraction grating assembly are adjacent to each other, and the inclination of the grating gradually changes smoothly, and the grating pitch also changes smoothly or almost the same. When connecting the diffraction grating of each partial area or a straight line parallel to it, it becomes a polygonal line that approximates a smooth curve to a straight line, and each partial area has characters, images, etc. depending on its outer contour or inner contour. It can be applied to the production of the display pattern which is arranged so as to be divided and displayed.

[0012]

In the present invention, the coating of the photosensitive material, the exposure of the two-beam interference fringes to the entire surface, the duplication, the coating of the photosensitive material, the exposure of the two-beam interference fringes to the entire surface, the lower part of the predetermined portion by the light irradiation. By repeating the exposure of the diffraction grating, a diffraction grating assembly in which a predetermined diffraction grating is formed in each partial area is manufactured, so even if the imaging of a certain partial area fails, the steps up to that point are not wasted. It is possible to easily manufacture a high-quality diffraction grating assembly in which a region where no grating exists or an overlapping region does not occur between the partial diffraction gratings of the final product even if the positioning is incorrect.

[0013]

EXAMPLES Examples of the method for producing a diffraction grating assembly of the present invention will be described below with reference to the drawings. Prior to the description of the embodiments, Japanese Patent Application No. 4-22 proposed by the present applicant is proposed.
A display body using the diffraction grating of No. 0074 will be briefly described. As shown in the plan view of FIG. 1A, when a reflection type diffraction grating A composed of a curve group convex on a predetermined pitch d is examined, when the light source is located on the front side in the drawing,
When the viewpoint is moved from left to right, the area that appears bright on the lattice plane moves from left to right in the same direction as the viewpoint moves.
The movement is indicated by the arrow below the lattice plane. On the contrary, when the viewpoint is moved, the area that appears to be shining moves in the opposite direction of the arrow. When the light source is a white light source, the brightly visible area is a strip-shaped area with a rainbow color in the vertical direction. As the radius of curvature of the curve forming the diffraction grating increases, the moving speed of the bright area increases. As shown in FIG. 1 (b),
Regarding the diffraction grating B formed by a downward convex convex curve group of the diffraction grating A, the diffraction grating B moves from right to left opposite to the direction of movement of the viewpoint, contrary to the case of FIG.

As described above, the diffraction grating composed of the upward convex curve group and the diffraction grating composed of the downward convex curve group are combined,
For example, as shown in FIGS. 2 (a) and 2 (b), when diffraction gratings C and D composed of a group of wavy lines are configured, a light source is arranged in the same manner as above, and the viewpoint is moved, as shown by arrows in FIG. , The area that looks bright on the grid surface moves. Therefore, when observing such diffraction gratings C and D while moving the viewpoint, the shining region also moves in the same direction or the opposite direction, and the region shines iridescent, so that the display effect, The design effect becomes remarkable.

Further, as described above, in the diffraction grating consisting of a group of curves, if the grating pitch d is also changed according to the place, the area of the brightly visible region and the moving direction are further varied, and the display effect is obtained. The design effect becomes more remarkable.

When the display pattern of characters, images, etc. is divided and expressed by the contour of the diffraction grating composed of such smooth curved lines, the character "DNP" is displayed in the background as shown in FIG. 3, for example. In the case of displaying the above, the diffraction grating A (FIG. 1A), which has a relatively small radius of curvature and a convex curve group, is used for each character portion, and the letters “D”, “N”,
Cut out into a "P" shape for use. For the background, a diffraction grating B (FIG. 1B) having a relatively large radius of curvature and a downwardly convex curve group is used except for the character portion “DNP”. When the display pattern body is configured by combining these two as shown in the figure, when the viewpoint is moved from left to right when the light source is located above the front side of the drawing, the character portion “DNP” displays the viewpoint moving direction. The area that appears to shine relatively slowly moves, and the character "DNP" is recognized. On the other hand, in the background, a region that appears to shine in a direction opposite to the viewpoint moving direction moves relatively fast, and the movements of these two are combined to provide excellent display effects and design effects.

In FIG. 3, it is also possible to omit the diffraction grating of either the character portion or the background and express the character "DNP" only by the other diffraction grating. Further, as the diffraction gratings A and B, a diffraction grating consisting of a group of wavy lines as shown in FIG. 2 can be used, or a diffraction grating whose grating pitch changes depending on the place can be used.

By the way, in the diffraction grating composed of the above curve group, a desired curve group is drawn at a predetermined pitch on the resist coated on the substrate by an electron beam drawing apparatus, an ion beam drawing apparatus or a laser drawing apparatus. It can be manufactured by doing. However, even if such a drawing apparatus is used, it takes time and cost to manufacture all curve groups of a diffraction grating having an area by drawing.
On the other hand, if the diffraction grating can be formed by a group of straight lines, it can be easily manufactured by, for example, two-beam interference, which is extremely desirable.

Therefore, it is considered that the diffraction grating composed of the above curve group is approximately constructed by the partial diffraction grating composed of the straight line group. FIG. 4 is a diagram showing an example in which the diffraction grating A of FIG. 1A is composed of partial diffraction gratings A1 to A7,
A portion of the diffraction grating A having the same inclination and the same grating pitch is divided into one unit, and the portion is replaced with linear diffraction gratings A1 to A7 having the inclination and the grating pitch. Therefore, each of the partial diffraction gratings A1 to A7 is composed of a linear diffraction grating, and the inclination and pitch of the diffraction grating sequentially change smoothly between adjacent diffraction gratings. Does not change drastically. In this way, the partial linear diffraction grating group is formed continuously, and the inclination and pitch of the grating of each partial linear diffraction grating sequentially and smoothly change between adjacent partial linear diffraction gratings (the pitch may not be changed. ), Even in the diffraction grating assembly A ′ that does not change drastically, as in the case of the diffraction grating A in FIG. 1A, the brightly shining region smoothly moves as the viewpoint moves. The smaller the divided area, the smoother the movement. The diffraction gratings shown in FIGS. 1B, 2A, and 2B can be similarly configured. The shape of the divided portion is determined by the shape and distribution of the original curve group, but both the diffraction gratings of FIGS. 1 and 2 are divided into vertical parallel stripe regions as shown in FIG. In this case, the widths of the divided stripes do not necessarily have to be evenly spaced.

FIG. 5 shows the display unit of FIG. 3 in the character area "D" by the diffraction grating assembly composed of such partial linear diffraction gratings.
NP ”and its background, and the direction of the diffraction grating provided in each region is indicated by an arc. Both the diffraction grating assemblies A ′ and B ′ are divided into vertical parallel stripe regions as shown in the drawing, and the inclination of the grating in each region is 30 ° and 25 ° from the left in the diffraction grating assembly A ′. ...
10 °, 5 °, 0 °, −5 °, −10 °, ..., −
It changes in steps of 5 ° of 25 ° and -30 °. Further, in the diffraction grating assembly B ′, −39 °, −36
°, -6 °, -3 °, 0 °, 3 °, 6 °, ...
.., 36.degree., 39.degree. Are changed in 3 degree increments.
Regarding the grating pitch, the same pitch is used in each divided area of the diffraction grating assembly A ′, and the same pitch is used in each divided area of the diffraction grating assembly B ′. . In this case as well, the region that looks bright as the viewpoint moves moves smoothly, as in the case of FIG.

In order to manufacture such a display pattern body, a plurality of masks having the contours of the respective areas are prepared,
By exchanging the mask on one photosensitive plate, exposing only each region, and exposing two regions by interfering two light fluxes so that interference fringes depending on the grating pitch and direction of the region are generated. Can be manufactured in a simple manner. However, in the method of manufacturing a diffraction grating assembly by two-beam interference using such a mask, if the image capturing through one mask fails, all the steps up to that point are wasted. is there. Further, if the positioning of a certain mask is incorrect, a region without a grating or an overlapping region will be generated between the partial diffraction gratings of the finally completed diffraction grating assembly, which makes the product unattractive.

Therefore, in the present invention, in order to expose the interference fringes of each region, a substrate is coated with a photosensitive material without using a mask, and the entire surface thereof has the direction and pitch of the first partial region. The light beam interference fringes are exposed to produce the first diffraction grating, and then the diffraction grating is duplicated, the duplicated plate is used as a new substrate, and the photosensitive material is coated again. A two-beam interference fringe having a direction and a pitch is exposed to produce a second diffraction grating, and then a mask is adhered to the region and at least the first partial region other than the second partial region is irradiated with ultraviolet rays or the like. Then, the photosensitive material in the irradiation region of ultraviolet rays or the like is peeled off or removed by the development treatment to form the first diffraction grating in at least the first partial region and the second diffraction grating in the second partial region. , Then, by repeating the same process, each part Can be manufactured diffraction grating assemblies predetermined diffraction grating is formed in each region. In this case, as the photosensitive material, for example, a positive photoresist or a photopolymer that can record as a relief pattern according to the irradiation amount of light and can decompose or dissolve the photosensitive material by irradiation with ultraviolet rays or the like is used.

Hereinafter, the manufacturing process of the present invention will be described in more detail with reference to FIG. First, as shown in FIG. 1A, for example, a positive photoresist 2 is applied to the substrate 1, and the first diffraction region of the first partial region of the diffraction grating assembly to be produced is applied to the entire surface of the resist layer 2. The interference fringes in the direction and pitch corresponding to the grating are exposed by the interference of the two light beams. Then
As shown in FIG. 3B, the exposed resist layer 2 is developed to produce a first diffraction grating. Then, for example, an ultraviolet curable resin is applied and irradiated with ultraviolet rays to produce a first replica 3 in which the first diffraction grating as shown in FIG. Then, a photoresist 4 similar to the above is applied thereon, and interference fringes of a direction and a pitch corresponding to the second diffraction grating of the second partial region of the diffraction grating assembly to be produced are formed on the entire surface of the resist layer 4. Exposure is performed by the interference of two light fluxes. Then, as shown in FIG. 2D, the first diffraction grating is formed on the exposed resist layer 4 by the first diffraction grating.
The first mask 5 that shields the region other than the region is adhered, and ultraviolet rays are irradiated to make the first region of the resist layer 4 soluble in the developing solution and developed, as shown in FIG. , The first diffraction grating is exposed in the first region, and the second diffraction grating is manufactured in the other regions. For example, by applying an ultraviolet curable resin and irradiating it with ultraviolet light, the first resin as shown in FIG.
The first diffraction grating in the area of
A second replica 6 to which the diffraction grating of 1 is transferred is produced. Then, a photoresist 7 similar to the above is applied thereon,
On the entire surface of the resist layer 7, the third diffraction grating assembly to be produced
The interference fringes in the direction and pitch corresponding to the third diffraction grating in the partial region of are exposed by the interference of two light fluxes. Then, as shown in FIG. 3G, a second mask 8 that shields a region other than the first region and the second region is brought into close contact with the resist layer 7 on which the third diffraction grating is exposed, Irradiate with ultraviolet rays,
When the first region and the second region of the resist layer 7 are made soluble in a developing solution and developed, the first diffraction grating is exposed in the first region as shown in FIG. The second diffraction grating is exposed in the region 2 and the third diffraction grating is exposed in the other regions.
The obtained diffraction grating is obtained. By similarly applying an ultraviolet curable resin on this and irradiating it with ultraviolet rays, the first diffraction grating is formed in the first region and the second region is formed in the second region as shown in FIG. The third replica 9 having the diffraction grating of No. 1 and the third diffraction grating transferred to the other region is produced. In this case, the diffraction grating assembly is composed of only the first to third diffraction gratings, and for example, the diffraction grating assembly having the arrangement shown in FIG. However, even when the diffraction grating assembly is composed of four or more diffraction gratings, it can be manufactured by repeating the same steps.

Incidentally, in the case of FIG. 6, the first mask 5 of FIG. 6D shields all regions other than the first region, but this has a shape that shields only the second region. You may In that case, in the replica 8 of FIG. 7I, the height of the third diffraction grating in the third region is the same as the height of the second diffraction grating in the second region, and Only the height of the first diffraction grating is lower than the others. Further, it is possible to configure them in a mixed form. Further, in the process of FIG. 6, the production of each duplicate was considered to be a duplicate that can have the same shape, that is, the duplicate is repeated twice, but it may be one duplicate in which the unevenness is reversed. . in this case,
It is necessary to use the odd-numbered or even-numbered mask with the back side and the front side reversed.

The above description has been made on the premise of the display body using the diffraction grating proposed by the present applicant as the diffraction grating assembly, but the manufacturing method of the present application is described in Japanese Patent Application Laid-Open No. 27322/1990.
Like No. 0, each minute dot is made with a diffraction grating,
A machine which is constructed by arranging these dots two-dimensionally and which is constructed by arranging a plurality of diffraction gratings having different directions or pitches in parallel as in JP-A-3-211096 is also used. It can also be applied to possible information recording media.
Further, it can be applied to various other methods of manufacturing a diffraction grating assembly.

Although the method for producing the diffraction grating assembly of the present invention has been described above based on the embodiments, the present invention is not limited to these embodiments and various modifications can be made.

[0027]

As is apparent from the above description, according to the method of manufacturing a diffraction grating assembly of the present invention, the coating of the photosensitive material, the exposure of the two-beam interference fringes on its entire surface, the duplication, the coating of the photosensitive material, By repeating the exposure of the two-beam interference fringes on the entire surface and the exposure of the diffraction grating under the predetermined portion by light irradiation, a diffraction grating assembly in which a predetermined diffraction grating is formed in each partial region is produced. Even if the imaging of a partial area fails, the process up to that point is not wasted, and even if the positioning is incorrect, there is no grating-existing area or overlapping area between the partial diffraction gratings of the final product. The lattice assembly can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the movement of a brightly appearing region associated with a viewpoint movement of a diffraction grating including a group of curves.

FIG. 2 is a diagram for explaining movement in the case of a diffraction grating including a group of wavy lines.

FIG. 3 is a plan view of an example of a display body.

FIG. 4 is a diagram for explaining the principle of approximately constructing a diffraction grating including a group of curves with a partial diffraction grating including a group of straight lines.

FIG. 5 is a diagram showing an example in which the display body of FIG. 3 is represented by a diffraction grating assembly composed of partial linear diffraction gratings.

FIG. 6 is a process drawing for explaining one example of the method for producing a diffraction grating assembly according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Resist layer 3 ... 1st copy 4 ... Resist layer 5 ... 1st mask 6 ... 2nd copy 7 ... Resist layer 8 ... 2nd mask 9 ... 3rd copy ... 1st part Area ... Second partial area ... Third partial area

Claims (3)

[Claims] 1. A method of manufacturing a diffraction grating assembly, in which a plurality of diffraction gratings having different directions or pitches are arranged in parallel,
The substrate is coated with a photosensitive material, and the entire surface thereof is exposed with two-beam interference fringes having the direction and pitch of the first partial region to expose the first partial region.
Of the two-beam interference fringes having the direction and pitch of the second partial region on the entire surface of the diffraction grating, and then duplicating the diffraction grating, using the duplicate plate as a new substrate, and coating the photosensitive material again. To form a second diffraction grating, and then irradiate light on a region including at least the first partial region other than the second partial region, and the photosensitive material in the light-irradiated region is not peeled off by a developing process. To produce a diffraction grating body having at least a first diffraction grating in a first partial area and a second diffraction grating in a second partial area, and then replicating the diffraction grating body. And producing a diffraction grating assembly having a predetermined diffraction grating formed in each of the partial areas by repeating the same steps for the third partial area and thereafter. Method. 2. The photosensitive material comprises a photosensitive material which can be recorded as a relief pattern in accordance with the irradiation amount of light and which can be decomposed or dissolved by irradiation with ultraviolet rays or the like. 1. The method for producing the diffraction grating assembly according to 1. 3. The diffraction gratings in the partial regions of the diffraction grating assembly are adjacent to each other, and the inclination of the grating gradually changes smoothly, and the grating pitch changes smoothly or almost the same. , When connecting a diffraction grating of each partial area or a straight line parallel to it, it becomes a polygonal line that approximates a smooth curve to a straight line, and each partial area has characters or images depending on its outer contour or inner contour. The method for producing a diffraction grating assembly according to claim 1 or 2, wherein the display patterns are arranged so as to be divided and displayed.