JPS5834458A - Production of screen - Google Patents

Abstract

PURPOSE:To eliminate a moire to be generated on a gravure screen, by using an irregular polygon pattern formed by shifting irregularly the position of each intersection of each segment of line forming an irregular polygon within a prescribed range, as an original pattern of (opaque) transparent segments of lines of the screen. CONSTITUTION:The intersections (A-I) of segments of lines forming an irregular polygon such as a rectangle (dotted lines) are shifted at random (e.g., horizontal and vertical displacement limited to + or -X/2 and + or -Y/2 respectively). The obtained points A'-F' are connected in correspondence to the original rectangle forming segments of lines. Thus a pattern (solid lines) is formed with an irregular rectangle. This irregular polygonal pattern is used to an original pattern of transparent or opaque segments of lines of a gravure screen. The screen causes no moire since the transparent or opaque segments of lines have an irregular change.

Description

Detailed Description of the Invention: ° The present invention relates to a screen, and more specifically, the present invention relates to a screen, and more particularly, to the moiré θ between gravure screens, between a gravure screen and a regular pattern of positive images, or between a gravure screen and a net positive. ) It relates to a gravure screen that can prevent the occurrence of θ).

In order to carry out gravure printing, a so-called pin 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 can be used to form such minute four parts. A gravure screen generally has a large number of opaque independent minute dots regularly arranged. When printing with two or more colors σ) using such a gravure screen, moiré becomes noticeable.

Recently, there has also been a method of performing gravure printing using halftone positive for planography or letterpress printing. In such a method, moiré may occur between the net positive chip, the gravure screen, and the gravure screen. Prevents moiré from occurring with d: ′f
Conventionally, various methods have been considered for this purpose. For example, a method is known in which a gravure screen is not formed from the light area to the intermediate tone area. However, with this method, the old gravure screen
．． 1'J requires a negative tip - When burning the net positive tip, make sure to align it with the negative tip.''1 '/, use clean method also US special d1/2
．． tll 96.79 A Disclosed in the same specification (・
Ru. Shikajinaka L-)ko0) Sand grain screen is usually 10
0 e/ j j+ c h +'+i) 庚0) flll
However, in addition to the inconvenient effect of giving a feeling of roughness in practical use, it also has the disadvantage of being prone to unevenness due to large differences in the area of individual selfies.

In addition, the gravure screen for preventing the occurrence of moiré that may occur between the fz net positive and the gravure screen θ) is π1″ No. 974,884′ in the UK.
;';Details 1! , disclosed in . If you use the gravure screen disclosed here, you will be able to use the gravure screen.
This is thought to be preferable because it prevents this, and there is no large difference in the area (r) of the individual cassettes. However, this clean tube turn consists of θ) pattern σ) repetition':) kl~ in a certain unit.

The present invention aims to provide a gravure screen that prevents the occurrence of moiré (θ) and (1) (I σ) gravure screen with all thorns (different 0) and a new vue gravure screen. be.

−・Generally, gravure screens are negative fins Q) a)
θ) and Bonn type θ) are also known as σ).

Bon type θ) The gravure screen is a continuous transparent I! i! A negative type gravure screen consists of a continuous opaque line segment and an opaque part surrounded by the opaque line segment. It consists of.

According to the present invention, both bon type and negative type gravure screens such as θ) can be provided.

In addition, a typical gravure gravure screen has a transparent part and an opaque part formed on a substrate such as a glass plate or a synthetic resin film. The gravure screen of the present invention requires the above-mentioned α11 substrate to be suitably selected as the substrate.

The most common gravure screen α) that has been used in the past consists of a large number of vertical transparent or opaque line segments (1), as shown in Figure 1. There are various patterns in which a large number of transparent or opaque line segments (2) in the direction of horizontal force intersect.

In the case of a Bon-type gravure screen σ), the line segment 1-1 in the vertical direction and the l'71'i direction θ) in Fig. 1 is transparent, and the point of its open force cell portion (3) is opaque and the line segment is transparent. )vinegar,
In the case of a negative type gravure screen σ), the relationship between transparency and opacity is reversed.3 The gravure screen obtained by the present invention has a completely irregular pattern rather than a regular pattern as in the case θ). are doing.

That is, in the gravure screen obtained according to the present invention, all the points of the cell part are made of polygons with the same angle number θ), and the length of the transparent or opaque straight line formed by forming this polygon is within a predetermined range σ). It changes irregularly within.

With the screen for gravure according to the present invention .theta.), it is possible to provide good marks 11 and 11 without causing moiré.

The gravure screen obtained by the inventor of the present invention is self-contained.
The 119th minute has a square pattern, or the cell part has a triangular or hexagonal pattern θ) θ)
(hO) I like patterns in which the shape of polygons changes irregularly.

The present invention attempts to manufacture a gravure screen such as the one shown in the figure below based on a group of polygonal patterns that are not regular polygons. The polygon pattern groups that are not regular polygons are often made by (a) making a plurality of groups of parallel lines orthogonal or diagonal.

Figures 2 and 3 show parallel lines in the horizontal direction and vertical direction θ)ゞ(
′ A rectangular pattern obtained by orthogonally intersecting the group of lines Yθ
) run in column f.

21' Line segment θ) distance ff111 and the distance between vertical line segments are not equal 1° 6th [゛ in 10) In the case of direction 0) to 11, they form a group of parallel lines. Each line segment σ) distance is uniform ( soil (, vertical direction O
) The distance uiIl between each line segment θ) constituting the group of parallel lines is also uniform and not equal.

Figure 4 is an example of the Kuhn group where the 2-11 line group is ♦ (111, u, ta polygon), and Figure 5 is an example of the Kuhn group of 3 silk parallel lines ++"f that are orthogonal and oblique. polygonal pattern I (work θ
) is an example. .

Patterns other than regular polygons such as θ) above can be obtained by orthogonally or obliquely moving a plurality of parallel line groups, but hexagonal pattern groups may also be considered.

According to the present invention, the gravure screen has such a regular polygon and is manufactured based on the pattern 7ff.

That is, the positional information d1 of each intersection of each line segment constituting the polygonal pattern 11τ as described above is recorded, and each intersection θ is
5.) have irregularities within a predetermined range of θ) centering on each of the positions I and 5. Knee 4 - Determine and record the position of a new point, and create a modified polygon pattern by connecting the new points in correspondence with the line segments forming the polygon based on the position information of the new points. The deformed polygonal pattern is used as an original pattern of transparent or opaque line segments of a gravure screen to manufacture a gravure screen. 4) 1° or less, according to the present invention 2) Parallel line group A case of a polygonal pattern in which two sets of orthogonal patterns are used will be described in more detail as an example.

In the case of non-polygonal patterns such as those shown in FIGS. 2 to 5, π is the distance 1iilC6 between each intersection.
1: For example, if θ is different in the horizontal and vertical directions, and if the intersection point (C) is irregularly displaced, the irregularity will be different from that of a regular polygonal force. It's one day.

For example, in the case of the pattern θ) shown in FIG. 2, the vertical straight line group θ) intervals are all equal distances (χ), the horizontal straight line groups are all equal distances (Y), and and Y
o) The values are different. In such a case, the regularity of the pattern θ) is changed in the horizontal and vertical directions by displacing the position of the intersection of each straight line. That is, the displacement of each intersection point in the horizontal direction and vertical direction is limited to, for example, within -10,000 and ±i, respectively.

Figure 6 shows the controller so that the displacements in the 1° and vertical directions are within ±Y and 2, respectively. Randomly generate values of ±06, ±08, and ±10, and displace the positions of the intersections of A, B, and CT by an amount that is multiplied by the generated value Y. A', T3', C',...I'θ)
This is an example of connecting these points to find the position.

FIG. 7 shows an example of a pattern obtained by modifying the pattern shown in FIG. 2 as shown in FIG.

In the case of the pattern shown in FIG.
) The distance between each straight line is also random, and the horizontal straight line group θ) is also random. Also in this case,
It is sufficient to set a displacement meter randomly within the limit of a displacement of half or less of the interval between each straight line (stop), find the position after displacement, and connect the positions after displacement with a line segment.

FIG. 8 is an example of a pattern in which the position of each intersection point is displaced in this way.

As explained above, it is preferable to add certain restrictions to the displacement meters at each intersection, and the restrictions are as follows, as shown in the general example of FIG.

If the distances from the intersection It) to the adjacent straight lines are respectively (X), (X'), (Y), and (Y) as shown in Figure 9, then
The χ' Y displacement of the intersection fE) is (-1), (--), (X'Y'>
, 2 ゝ 2 2 ゝ 2
21 2X Y' (i, -la) Quadrilateral diagram yf4 obtained by connecting each point
4, which is within the range of 4. Therefore, it is equivalent to specifying arbitrary coordinates within this area irregularly.

Even in the case of polygon σ) of il, it is possible to create a modified polygon pattern by displacing the polygon irregularly with appropriate restrictions.

Although it is preferable to create the deformed polygonal pattern obtained by moving the position of the above-mentioned σ)(ll'l (L, element θ) intersection using a computer in terms of efficiency, it is also possible to create the enlarged pattern manually. It is also possible to create and reduce the size.

In the present invention, the modified polygonal pattern thus obtained is used as an original pattern of transparent or opaque line segments for a gravure screen.

Various means can be used to obtain a gravure screen using the original pattern.

For example, a deformed polygonal pattern is calculated using an electronic computer, and the data from the calculation results is used to control an automatic engraving machine, etc. to scribe a transparent glass plate that has been subjected to the necessary pH treatment. A method of creating a gravure screen can be adopted.

Alternatively, the deformed polygonal pattern can be calculated using a computer, etc., and the data of the calculation results can be used to control the exposure device to form an output on the photosensitive film-1- to form a gravure screen. Wear.

Alternatively, based on the calculation result 0) data, a drafting device is controlled to output and form a deformed polygonal pattern on paper, etc., and this output pattern is formed on a transparent film or glass plate using a photographic method or other means. It can also be used as a gravure screen.

In the present invention, the original pattern may be created with the same dimensions as the final product, but when considering the line width and f19 degrees A and P, the original pattern is enlarged to a certain extent and then reduced and photographed for gravure. It can also be used as a screen.

The memory capacity required to obtain a gravure screen of the required size increases, and the processing time and other loads increase.1
．． If the pattern is too thick, the original pattern may be connected by multiple exposure or the like. In this case, the connection σ) the intersection σ)
Leave the position unchanged, or connect well 1-
All you have to do is move it so that it becomes @.

In the present invention, the modified polygonal pattern part is made transparent and the other parts are made opaque.''If you do this, you will get a gravure screen for Bojikub, and if you do the opposite, you will get a gravure screen for Lee Gataib. Become. Whether to obtain Q) can be appropriately selected depending on the need.

The gravure screen of the present invention is obtained as described above, but most importantly, the points corresponding to 1113 opaque or transparent cells are polygons with the same number of angles.

In the gravure screen according to the present invention, since the transparent or opaque line segments are irregularly changing line segments, moiré does not occur.

Although the explanation has been mainly given to the case of a gravure screen, the present invention can also be applied to a screen for letterpress printing or etching printing in addition to gravure screens.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the pattern of a conventional gravure screen, FIGS. 2 to 5 each show an example of the original pattern for manufacturing the gravure screen of the present invention, and FIG. 6 is a diagram showing the pattern of a conventional gravure screen. FIG. 7 and FIG. 8 each show an example of the original pattern of the gravure screen obtained by the present invention, and FIG.
The figure shows an explanatory diagram of restrictions on the amount of displacement at each intersection. (1)...Vertical transparent or opaque line segment (2)
...Horizontal transparent or opaque line segment (3)...
Cell Part Patent Applicant Toppan Printing Co., Ltd. Representative Kazuo Suzuki Figure 1 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 71 Cover Figure 8 Figure 9

Claims (1)

[Claims] (1) Record the positional information of each intersection of each line segment forming a 7f regular polygon pattern group, and create irregularities within a predetermined range around each of the intersections. The positions of new points corresponding to each of the intersection points are determined and recorded, and the new points are connected in correspondence with the line segments forming the polygon based on the position information of the new points to create a deformed polygon. A method for manufacturing a screen, which comprises forming a polygonal pattern and using the modified polygonal pattern as an original pattern for transparent or opaque line segments of the screen.