JPS5834453A - Screen and its preparation - Google Patents

Abstract

PURPOSE:To form a gravure screen causing no Moire pattern, by joining each intersection point of figures consisting of groups of irregular polygons except a straight line segment corresponding to a side in a prescribed direction, and using a pattern consisting of a large number of obtained irregular broken lines. CONSTITUTION:Each intersection point, such as A-F, of a pattern shown in dotted lines, obtained by connecting squares 2-dimensionally is randomly moved as follows: Average movement distance is about 1/4 the length of one side of the square; its standard deviation is about 1/8 the length of one side of the square; and the movement direction is optional direction around the intersection point. The obtained points A'-F' are connected except lateral line segments corresponding to the initial lateral line segments joining the points, resulting in forming line segments consisting only of substantially vertical line segments. A screen is formed by using a pattern consisting of the obtained irregular broken lines.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a screen, and more particularly, the present invention relates to a screen, and more specifically, a screen for gravure, between a gravure screen and a positive pattern θ), or between a gravure screen and a net positive. Preventing failure 1-
Concerning gravure screens that can be used in a variety of ways.

In order to perform gravure printing, a so-called concave is generally required to form independent minute depressions on the surface of the gravure plate to hold the ink). It is well known that a gravure screen is used to form such microscopic points. Gravure screens are generally used to form opaque independent microscopic points. In the case of printing on a two-color layer using such a gravure Nuclean (C), recently, gravure printing has been performed using a halftone positive for planography or letterpress printing. In such a method, moiré may occur between the net positive and the gravure screen.In order to prevent the occurrence of moiré, conventional methods (the method of For example, there is a method to prevent gravure screens from being formed from the light area to the halftone area, such as f:11 etc.
te℃・ro. However, in this method, when printing the gravure screen, it is necessary to use a positive tip, and when printing the gravure screen, the net positive tip must be aligned with the negative tip.11. There is no 7x.

A method of using a sand screen instead of a gravure screen is also disclosed in US Pat. No. 2,096,794 Y: Specification. Although it is 1~, this sand loss screen usually costs 100 edicts/i +1 c: hi? 1st degree (
However, in practical use, it has the disadvantage that it feels rough, and it also has the disadvantage that unevenness tends to occur because there is a large difference in the area of the individual cells.

Further, a gravure screen for preventing the occurrence of moiré that may occur between a net positive and a gravure screen is disclosed in British Patent No. 974,884. By using the gravure screen disclosed herein, it is possible to prevent the occurrence of moiré, and
;) 7) In addition, there is no large difference in the area of individual cells, so it is considered to be unsound. However, this pattern is made up of repetitions of turns in units of k).

The present invention aims to provide a new gravure screen that is completely different from the above-mentioned gravure screens as a gravure screen that prevents the occurrence of moire.

Generally speaking, gravure screens come in negative type and positive type.

A positive type gravure screen consists of a continuous transparent line segment and an opaque area surrounded by the transparent line segment. It consists of a transparent part surrounded by line segments and a force.

The present invention can provide both such positive type and positive type gravure screens.

Generally, a gravure screen has a transparent portion and a non-transparent portion formed on a substrate such as a glass plate or a synthetic resin film. For the gravure screen of the present invention, the above-mentioned substrates may be appropriately selected and used as the substrate.

As shown in Figure 1, the most common type of gravure screen used in the past consists of a large number of transparent or opaque line segments (1) in the vertical direction and a large number of horizontal lines. It has a pattern in which the transparent or opaque line segments (2) intersect with each other.

In the case of a positive type gravure screen, the vertical and lateral force direction σ) line segments in Fig. 1 are transparent, and the cell portion (3) between them is opaque; In some cases, the relationship between transparency and opacity is reversed.

The gravure screen of the present invention does not have such a regular pattern but a completely irregular pattern.

The gravure screen of the present invention can provide good mortar prints without causing moiré.

The gravure screen of the present invention is shown in FIG. The cell part (3) has a repeating pattern of regular squares, or the cell part has a repeating pattern of regular triangles or regular hexagons, but the shape of each regular polygon is irregularly changed. It can be made based on a), but it can also be made in I- based on a collection pattern such as a rectangle or diamond.

The gravure screen invented by Jzo and Sewer will be explained in more detail by taking the case of a square pattern as an example.

When obtaining the gravure (I'l) screen of the present invention, each intersection of line segments forming a polygonal set pattern (I'l,
'Record information 1-:ta <. Figure 2 is an enlarged part of Figure 1, but in this case, each A
) of (C) 1 City + (Pi is the intersection point.

Next, create irregularities within a predetermined range around one row of such intersections to correspond to each of the intersections;
'f point (Af (11') (Cr(Of (El'
(Ff position tgt wo decision L note Q 'fru.

Based on the position information of this new point, the line segment 00) (l n (12) f2 (1)
(21), (22), and (23), a deformed rectangular pattern is formed by connecting the random points. FIG. 3 shows a rectangular pattern transformed in this way.

By moving the other intersection points in this manner, form a pattern in which a regular quadrilateral is irregularly deformed.

FIG. 4 shows a rectangular pattern which is irregularly deformed by moving the positions of the intersections of the regular rectangles shown in FIG. 1 in this way.

The lengths of the line segments forming each side of the first rectangle thus deformed vary irregularly, and the irregularity depends on the irregularity in moving the intersection point.

When moving the intersection point, it is done within a specified range, but
The first reason is based on the requirement that it is preferable that the area of the cells be as uniform as possible. Like this 1. In order to satisfy the c requirement, for example, move the intersection point.The average moving distance is about 1/4 of the length of one side of the regular polygon, and the standard deviation is 8 minutes of the length of one side of the regular polygon. The direction of movement is 0° from the original intersection.
It is possible to employ means for uniformly taking directions up to 360 degrees.

In the case of Fig. 4, by setting the moving distance of each intersection to a random variable whose maximum value is 071 times the original pattern σ) - side, the area of the square of the original pattern is 0 to 40.
This corresponds to the example IJ-shaped pattern σ) with an area of 0%.

In the pattern of the 41st line 1, when connecting the positions of the points after the displacement, they are all made to completely correspond to the points before the displacement. On the other hand, when connecting the points after the pattern G''-1 displacement shown in FIG.
) corresponds to the claw of a particular line segment, a vertical line segment. In the present invention, a pattern such as the first one shown in FIG. 5 is used as the original pattern of the gravure screen. FIG. 6 shows an example of a gravure screen made from this original pattern.

By the way, as shown in Fig. 4, in order to further equalize the area of the cells of the 11-square pattern, for example, the distance to which the intersection point is moved is ``= up'' 1-6 (, y; length of one side of the regular polygon). The direction of movement of the intersection point is set to θ°, 15°, 30°, ... 330° in 15° increments, and the deviation of each intersection is set within this limit. I'm really good at thinking of no-laws that move the rules. In such a case, the area of the cell after the change changes from 1/2 to twice the area of the original cell.

However, in this method, if an attempt is made to reduce the roughness by making the area of the cells more uniform, the irregularity will be sacrificed to some extent. On the other hand, if one tries to achieve sufficient irregularity, the area of the cells becomes insufficiently uniform.

In order to eliminate such inconveniences, the following measures can be adopted.

That is, after forming the deformed rectangular pattern as described above, find the area of each deformed rectangle. Any method may be used to find the area of this modified rectangle, for example,
In the case of the deformed quadrilateral K TJM Nυ) as shown in the figure, the respective coordinates are K(x+, y+), [, (X2.V2),
If M(xself, y5) and N(X4.y4) are 1, the area S can be calculated using the following formula.

S = 1max (XI, X2, X5, X4
)-min (XI, X2, xg, xJl-1, m
ay(y+,)12,Y3,y4)-min(
y+ ,yz,ys,y4)1-↓(lx+-X41Y+-Y41+1x2-x+1-y2.7+l+I X
3-X21・Iy3-y＞l+1x4-xsl・+y
4-y3+] If the area of the irregular polygon calculated in this way exceeds a predetermined range, for example, if the area of the regular polygon is 1 to D, it is larger than the predetermined range, or If the range is "smaller than S", perform the dividing or merging process of irregular polygons. This division processing and merging processing means the work of connecting non-adjacent vertices of the irregular polygon and the work of erasing the nIJ irregular polygon θ) - sides, each of which means +1, but the n1 Point selection and edge selection are performed under the condition that the area of the new irregular polygon generated after performing the work is within a constant range.1. Nagerabana ``]/.C.

Figure 8 shows a pattern in which the area is restricted in this way. It is a group of irregular polygons with .

If only the original quadrilateral is transformed, as is clear from the 41st picture, all the patterns are quadrangular even after the transformation. In other words, the number of angles of the redundant polygon f and the transformed θ) polygon are the same. This is the same for triangular and hexagonal patterns, D) ro.

As is clear from FIG. 8, the deformation pattern after applying the above-mentioned area restriction to the dough includes polygons with a divine number of angles. The shape of this polygon with the number of angles σ] is completely in accordance with JJI's law, and the area of this polygon is within a predetermined range θ) and 7'.

In the present invention, a pattern is formed in which lines corresponding to specific line segments of the line segments forming the polygon before deformation of the pattern shown in FIG. 8 are erased. FIG. 9 shows a pattern obtained by erasing the line segments corresponding to the 4'l''+1 direction from among the line segments forming the rectangular pattern before deformation from the pattern of FIG. 8.

In the present invention, such a pattern is used as the original pattern for the gravure screen σ. The 101st Swamp is a gravure screen J created using this original pattern]
Please give an example).

The gravure screen shown in FIG. 10 has improved irregularity tL compared to the gravure screen shown in FIG. 6.

You can use divine means to obtain a gravure screen using the original pattern.

For example, a modified polygonal pattern is calculated using an electronic computer, and the data from the calculation results is used to control an automatic engraving machine to scribe a transparent glass plate that has undergone the necessary processing, and then scribes it using the usual method. The method of creating a gravure screen can be adopted.

Alternatively, the deformed polygonal pattern can be calculated using a computer or the like, and the data of the IL calculation result can be used to control an exposure device to form an output on a photosensitive film, which can be used as a gravure screen.

Alternatively, based on the data of the calculation results, a 1il1 drawing device is controlled to output and form a deformed polygonal pattern on paper or the like,
This output pattern is formed on a transparent film or glass plate by photographing or other means. : Can also be used as a gravure screen depending on the filter.

In the present invention, the original pattern may be created with the same dimensions as the final product, but if the line width, accuracy, etc. are -41, σ, the original pattern is enlarged to a certain extent, then reduced and photographed for gravure use. It can also be used as a screen.

If the required size of the gravure screen is too large, the memory capacity is too large, and the load during processing 11.1 is too large. In this case, (intersection point σ of 1 connection part) 16 may be left unchanged, or 4:t
, '+Move it to a position where it connects well λ], that's fine.

According to the fourth invention, the line segment portions of the modified polygonal pattern are made transparent Lvj, and the other portions are made opaque. Ni-J'-, 17, positive type σ] Grapiano moon screen and vice versa? If so, it will become a gravure screen for Oh Gataib. It doesn't matter which one you get, it's earth d-i, basically L6Z, so you just have to choose accordingly.

The gravure screen of the present invention starts from a rectangular cell shape.It is not limited to 1-a), but it may also be triangular. [O] Good. Furthermore, hexagonal cell shapes can also be manufactured in the same manner).

The gravure screen of the present invention has transparent or opaque line segments that change irregularly, so there is no moiré, and the area of the cell part θ is within the range of θ. , it has the effect that it is less likely to cause 414 No. Uya Zaratsu.

Generally, it is said that in order to perform gravure printing, it is necessary to form cells with shapes such as squares, rectangles, hexagons, and semicircles. However, the 6th
In the case of the gravure screen of the present invention having a pattern as shown in FIG. 1 or FIG. 10, complete cells as described above are not formed, but printed matter without ink flow can be obtained.

As shown in FIG. 6 or 10, irregularly bent line segments are arranged in one direction. In the case of the gravure screen of the present invention (in fact, for example, in the case of a positive type screen, if the thickness of the transparent lines is taken into account, the vertical lines may be close to each other or touch each other). , the state of adding the first one at a certain interval is repeated irregularly.

When a gravure plate is created using such a gravure screen, even if the concentration of positive is the same, if the distance between the transparent lines is close to each other, the erosive liquid will be absorbed during corrosion. Therefore, the corrosion depth in that part becomes shallow. In the area where the transparent line is in contact, there is no corrosion. In this way, in the area where the transparent line is close to or in contact, Compared to the area where the lines are far apart, the area is shallower than the area where the lines are far apart. The attack is prevented
do. In this way, according to the gravure screen of the present invention, as shown in FIG. 6 or FIG.
Even if there is only a transparent line in the direction, a printed matter with no ink flow can be produced (11).

Since the gravure screen according to the present invention is composed of patterns arranged in one direction, the area of the edge of the gravure printing plate is reduced.

Therefore, since the amount of ink retained on the printing plate increases accordingly, the depth of corrosion can be reduced.

For this reason, it is possible to shorten the corrosion time, and there is less zide etching, so the line width of the gravure screen can be narrowed.

Such a thin line gravure screen! It is effective in the gravure plate making process when used together with a mesh board for planography or letterpress printing.

In other words, the expression of gradation by halftone dots for lithography or letterpress printing is obstructed by the gravure screen.
Therefore, it is desirable that the gravure screen WJIII;l: fine °C. However, according to the conventional effective screen, the line of the gravure screen is distorted due to the large amount of zide enoching θ].11. θ) and 4) were not able to be used as thin objects. According to the invention, the above drawbacks are overcome.

Up to now, we have mainly explained the case of a gravure screen, but it can also be applied to letterpress or planographic θ] screens in addition to gravure screens.

[Brief explanation of the drawing]

Figure 1 shows the conventional gravure screen i (d Shikoku, 2
The figure is a partially enlarged explanatory view of the gravure screen in Figure 1, Figure 3 is a Goboda pattern modified from the line segments in Figure 2, and the fourth
The figure shows a pattern that combines all the points after displacement, and Figure 5 shows the pattern in Figure 4, which corresponds to the vertical line segment of the rectangle before displacement, followed by 1. Pattern, No. 6 [
'& I is an explanatory diagram of a gravure screen manufactured based on the pattern in Figure 5, Figure 7 is an explanatory diagram of a deformed rectangle, and Figure 8 is an area restriction process applied to the pattern in Figure 4. Pattern, Fig. 9 (1 Among the patterns in Fig. 8, the pattern in which the line segments corresponding to the horizontal line segments of the rectangle before displacement are deleted, Fig. 10 is manufactured based on the pattern in Fig. 9. Also, here is an explanatory diagram of the gravure screen.
[. (1)...vertical transparent or opaque line (2)...
...Transparent or opaque line (3) in the horizontal direction...Cell portion Patent applicant 19- Fig. 1 Fig. 2 Fig. 3 Fig. F' 334- Fig. 4 Fig. 5

Claims (2)

[Claims] (1) The first screen consists of a large number of transparent or opaque line segments and opaque or transparent parts outside the line segments. The line segments are irregularly bent, and the positions of the bent portions form a predetermined multi-frJ-shaped set pattern. , Furthermore, for each bent part, at least a line that responds to a force on the side of each side of the set pattern of the predetermined polygons in the direction of the fixed polygon. A screen featuring the absence of minutes. (2) Line segment σ that forms a set pattern of many polygons]
Record the location jj/7 information of the point of intersection, and use the center as the center of the location of the intersection.
1! : Determine and record the position of a new point corresponding to each father point, and use the position information of the new point to determine the position of a specific line segment among the line segments forming the polygon. A method for manufacturing a screen, characterized in that a pattern is formed by connecting the new points, and the pattern is used as an original pattern of transparent or opaque line segments of the screen. , (3) record the positional information of each intersection of line segments forming a set pattern of a large number of polygons, and create irregularities within a predetermined range around each of the positions of the intersections so that each of the intersections determine and record the position of a new point corresponding to the new point, and form a modified polygon pattern by connecting the new point in correspondence with the line segment forming the polygon based on the position information of the new point. Then, the area of each of the modified polygons is determined, and if the area exceeds a predetermined range, the line segment connecting the new points is erased according to a predetermined format and/or the new point is An irregular deformed polygon pattern is formed in which the area of all the deformed polygons is within a predetermined range by connecting according to the pattern of 1) 4I of the irregular deformed polygon pattern before deformation. A method for manufacturing an Iro screen, characterized in that a pattern is formed by erasing those corresponding to specific line segments among the formed line segments, and the non-turns are used as the original pattern of the screen. .