JP4020107B2 - Gravure printing plate - Google Patents

Description

  The present invention relates to a gravure printing plate suitable for suppressing variation in printing quality in long run printing.

  Conventionally, for gravure printing, any of conventional gravure printing method, direct gravure printing method, and engraving gravure printing method has been adopted, and in these three plate types, the basic shape of the cell that is a recess formed on the plate surface is For example, as shown in FIGS. 15, 16, and 17, the volume of the cell is increased in the order of the light cell, medium cell, and shadow cell to increase the amount of ink transferred to the paper.

  However, the conventional method of gradually increasing the cell volume from the center of the cell to increase the cell volume makes the printed product appear grainy and in long-run printing where a single plate is printed. However, there were two problems of varying print quality.

  That is, after the ink is transferred from the cell to the paper, an ink film is formed on the paper. At this time, the ink film has the thickest substantially the center and, conversely, the thinnest periphery. Thus, the ink film formed on paper by the ink transferred from one cell has a difference in thickness. The difference between the ink films increases as the cell volume increases, so that the thick part of the film appears dark, and conversely, the thin part of the film appears thin. As a result, only the dark areas are emphasized and visible to the human eye.

  In long run printing, the viscosity of the ink decreases during printing, and the ink transferred to the paper tends to spread. Therefore, in the case of using a plate in which gradually enlarged cells are formed from the center of the cell, the area of the ink film formed on the paper becomes larger than the area at the beginning of printing, and the color looks dark. In this case, a difference occurs in the finished printed matter between when printing starts and when it is just finished, and the quality is degraded.

Therefore, Cited Document 1 discloses a cell shape that does not vary in quality in long-run printing. That is, the cited document 1 discloses a donut-shaped cell in which a region where no cell is formed is provided at the approximate center of a cell that has been circular in the past. In this way, by forming the cells in a donut shape, the ink transferred to the paper also becomes a donut shape. Therefore, when the viscosity of the ink decreases during long run printing, it spreads inside the ink film transferred to the donut shape. As a result, it is possible to prevent the area of the ink film from being larger than the area at the beginning of printing.
Japanese Patent Laid-Open No. 10-157273

  However, such conventional gravure printing has the following problems.

  That is, even the donut-shaped cell disclosed in the cited document 1 as described above cannot suppress the roughness. That is, in the donut-shaped cell disclosed in the cited document 1, the more the shadow becomes, the thicker the donut portion and the larger the volume. The area around the donut-shaped ink film becomes thinner. Therefore, only the thick central portion of the ink film is emphasized and looks dark to the human eye, and the user feels rough.

  In addition, since the cell currently disclosed by the cited reference 1 is donut shape, the area | region which cannot form a cell exists in the center. However, since the area where the cells are not formed is a very small area, it cannot be identified by the human eye after being transferred to paper. Therefore, even in a donut-shaped cell, the central part of the ink film transferred to the paper looks dark like the cell according to the prior art, and only the dark central part is emphasized and feels rough. End up.

The present invention has been made in view of such circumstances, even long-run printing, aims to provide a gravure printing plate capable of suppressing the roughness of the printed matter, and to prevent variations in print quality And

  In order to achieve the above object, the present invention takes the following measures.

That is, the present invention relates to a gravure printing plate in which a collection of substantially rectangular cells forming an image line portion is formed on a plate surface. Each cell forms a cell outer frame and does not hold ink. A first ink holding portion that is arranged inscribed in the outer frame portion and holds ink, an ink non-holding portion that is arranged inside the first ink holding portion and does not hold ink, And a second ink holding unit arranged to be surrounded by the holding unit and holding ink.

  By taking the above measures, there are two ink holding areas in one cell, that is, the first ink holding part and the second ink holding part. Can be dispersed. As a result, the amount of ink transferred can be reduced as compared with the prior art, and thus the center of each ink film formed by transferring from the first ink holding portion and the second ink holding portion. The thickness can be reduced compared to the prior art.

  As a result, it is possible to suppress the contrast generated between the white of the paper and suppress the roughness. In addition, since the first ink holding portion has a donut shape, it is possible to prevent the quality from varying even in the long run printing.

In the present invention, when the area ratio of the ink holding portion in each cell is further increased, the area of the second ink holding portion is increased while holding the area of the first ink holding portion.

  By taking the above-described means, the first ink holding part and the second ink holding part can be performed independently even when the halftone dot is increased. As in the case of the gravure printing plate of the invention of item 1, the amount of ink transferred can be reduced as compared with the prior art, and thus transferred from the first ink holding part and the second ink holding part. The center thickness of each formed ink film can be made thinner than in the prior art.

The present invention further includes at least one cell, the second while maintaining the area of the ink holding portion, at least one of the position and shape of the second ink holding portion, of the adjacent cells second It is different from that of the ink holding part.

  By taking the above-described means, it is possible to prevent moire of the gravure printed matter printed by this gravure printing plate without changing the size of the halftone dots.

In the present invention , at least one cell is made different from the shape of the outer frame portion of the adjacent cell by changing a part of the shape of the outer frame portion.

  In this way, it is possible to realize a gravure print that does not cause moire by printing using a gravure printing plate in which the shape of adjacent cells is changed.

  According to the gravure printing plate of the present invention, even in long run printing, it is possible to suppress roughness of the printed material and to prevent variations in print quality.

  Therefore, by printing using this gravure printing plate, it is possible to realize gravure prints and booklets that suppress roughness and have no quality variation even in long-run printing.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  Fig.1 (a) is a top view which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention. Moreover, FIG.1 (b) is the figure which arranged two sectional drawings along the AA line in Fig.1 (a).

  That is, the gravure printing plate according to the embodiment of the present invention has an assembly of substantially rectangular cells 10 as shown in FIG. The cell 10 is formed by a rectangular mass of 20 × 20 = 400 as an example, and has an outer frame portion 12, a first ink holding portion 14, a second ink holding portion 18, and no ink holding. It is divided into a part 16.

  The outer frame portion 12 functions as a so-called bank that forms the outer frame of the cell 10 and does not retain ink. The first ink holding portion 14 is inscribed in the outer frame portion 12 and is disposed so as to surround the periphery of the ink non-holding portion 16 and, as shown in FIG. It is a frame-like recessed region surrounded by the portion 16, and ink is held in the recessed portion.

  The ink non-holding portion 16 is disposed inside the first ink holding portion 14 and has the same cross-sectional height as the outer frame portion 12 as shown in FIG. Similarly, no ink is retained. The second ink holding part 18 is a recessed area provided in the central part of the cell 10 so as to be surrounded by the ink non-holding part 16, and holds the ink in the recessed part.

  In order to increase the halftone dot in the gravure print, the area ratio of the second ink holding unit 18 in the cell 10 is increased (that is, the total area of the first ink holding unit 14 and the second ink holding unit 18 is increased). However, in the gravure printing plate according to the embodiment, the area of the first ink holding unit 14 is held, while the area of the second ink holding unit 18 is increased. . 2 to 10 show examples of the cell 10 showing this.

  That is, the area ratio of the ink holding portion in the cell 10 is gradually increased from FIG. 2 to FIG. In this case, it should be noted that the area of the second ink holding part 18 is increased without changing the area of the first ink holding part 14.

  The cells shown in FIGS. 2 to 10 are formed by 20 × 20 = 400 cells. Then, 128 squares of the second and third layers from the outermost periphery are used as the first ink holding unit 14. Therefore, as shown in the plan view of FIG. 2A, when the area of the second ink holding portion 18 is zero, the area ratio of the ink holding portion in the cell 10 is 32% (128/400). FIG. 2B is a diagram in which two cell cross-sectional views along the line BB shown in FIG. The drawing shown in FIG. 2B shows a state where the first ink holding unit 14 does not hold ink yet. FIG. 2C is an elevation conceptual diagram showing a state where the ink 20 is transferred to the paper surface 22 by the printing plate having the cross-sectional cell 10 shown in FIG.

  As shown in the plan view of FIG. 3A, the ink holding portion area ratio is set to 33% (132/400) by using the four squares at the center of the cell 10 as the second ink holding portion 18. Can do. FIG. 3B is a diagram in which two cell cross-sectional views along line CC shown in FIG. The diagram shown in FIG. 3B shows a state in which the ink is not yet held in the first ink holding portions 14 and 18. FIG. 3C is an elevation conceptual diagram showing a state in which the ink 20 is transferred to the paper surface 22 by the printing plate having the cross-sectional cells 10 shown in FIG.

  FIG. 4 shows an example of the cell 10 in which the area of the second ink holding portion 18 is further increased by 4 squares from the state shown in FIG. 3 and the ink holding portion area ratio is 34% (136/400). As shown in FIG. 4, the planar shape of the second ink holding unit 18 is not necessarily a completely symmetric shape such as a square, and may be a partially asymmetric shape such as a rectangle.

  FIG. 5 shows an example in which the area ratio of the ink holding part is 40% (160/400) by forming the second ink holding part 18 by 32 cells on the center side of the cell 10. FIG. 6 shows an example in which the ink holding portion area ratio is 50% (200/400) by forming the second ink holding portion 18 with 72 cells on the center side of the cell 10. The plan view of FIG. 7A shows an example in which the area ratio of the ink holding part is 60% (240/400) by forming the second ink holding part 18 by 112 cells on the center side of the cell 10. ing. FIG. 7B is a diagram in which two cell cross-sectional views along the line DD shown in FIG. The diagram shown in FIG. 7B shows a state in which the first ink holding unit 14 and the second ink holding unit 18 do not hold ink yet. FIG. 7C is an elevation conceptual diagram showing a state in which the ink 20 is transferred to the paper surface 22 by the printing plate having the cross-sectional cells 10 shown in FIG. 7B.

  FIG. 8 shows an example in which the area ratio of the ink holding portion is set to 70% (280/400) by forming the second ink holding portion 18 with 152 squares on the center side of the cell 10. In order to further increase the area ratio of the ink holding part after the area ratio has increased to some extent, the first ink holding part 14 and the second ink holding part 18 are made continuous as shown in FIG.

  FIG. 9 shows an example in which the area ratio of the ink holding part is set to 80% (320/400) by forming the second ink holding part 18 by the 192 cell on the center side of the cell 10. In the state shown in FIG. 9, the first ink holding portion 14 and the second ink holding portion 18 are substantially the same, and the ink non-holding portion 16 has only four squares farthest from the center of the cell 10. Shows the state.

  FIG. 10A shows a state in which the ink holding portion area ratio in the cell 10 is maximized. That is, the ink non-holding portion 16 no longer exists, and all the cells other than the outer frame portion 12 become ink holding portions. In this case, the ink holding area ratio is 81% (324/400). FIG. 10B is a diagram in which two cell cross-sectional views along the line EE shown in FIG. The diagram shown in FIG. 10B shows a state where the ink is not yet held in the first ink holding unit 14 and the second ink holding unit 18. FIG. 10C is an elevation conceptual diagram showing a state in which the ink 20 is transferred to the paper surface 22 by the printing plate having the cross-sectional cell 10 shown in FIG.

  Thus, when raising the ink holding | maintenance part area ratio, it carries out by enlarging the 2nd ink holding | maintenance part 18 toward the outer side from the center side of the cell 10. FIG. In this case, the second ink holding unit 18 is formed by increasing the number of squares. Therefore, by providing the mass finely, the ink holding portion area ratio can be finely adjusted. Further, since the second ink holding unit 18 is configured by combining rectangular masses in this way, the second ink holding unit 18 is not necessarily limited to a polygonal shape, but has a complicated outer shape that is not smooth as shown in FIGS. It may have a shape.

  Next, the operation of the gravure printing plate according to the embodiment of the present invention configured as described above will be described.

  That is, in the gravure printing plate according to the embodiment of the present invention, two ink holding portions, that is, the first ink holding portion 14 and the second ink holding portion 18 are provided in the cell 10. Thereby, since the ink is dispersed, the thickness of the ink film when transferred to paper can be reduced.

  That is, the cell 60 of the gravure printing plate according to the prior art is provided with the ink holding portion 62 on the center side of the cell 60 as shown in the plan view of FIG. FIG. 11B is a diagram in which two cell cross-sectional views along the line FF shown in FIG. The diagram shown in FIG. 11B shows a state where the ink holder 62 does not hold ink yet. FIG. 11C is a vertical sectional view showing a state in which the ink 20 is transferred to the paper surface 22 by the printing plate having the cross-sectional cell 60 shown in FIG.

  The area ratio of the ink holding part 62 of the cell 60 as shown in the plan view of FIG. 11A is 33%. A cell 10 of a gravure printing plate according to an embodiment of the present invention having the same ink holding area ratio corresponds to FIG. Compared to the film thickness t ′ of the ink 20 transferred to the paper surface 22 by the cell 10 of the gravure printing plate according to the prior art, as shown in FIG. As shown in (c), the film thickness t of the ink 20 transferred to the paper surface 22 by the cell 10 of the gravure printing plate according to the embodiment of the present invention becomes thin.

  This effect becomes more prominent as the ink holding area ratio increases. For example, the area ratio of the ink holding part 62 of the cell 60 according to the prior art as shown in the plan view of FIG. 12A is 60%. FIG. 12B is a diagram in which two cell cross-sectional views along the line GG shown in FIG. The diagram shown in FIG. 12B shows a state where the ink holding unit 62 has not yet held ink. FIG. 12C is an elevational sectional view showing a state in which the ink 20 is transferred to the paper surface 22 by the printing plate having the cell 60 having the sectional shape shown in FIG. As can be seen by comparing FIG. 11 (c) and FIG. 12 (c), in the case of the prior art, the film thickness of the ink 20 transferred to the paper surface 22 is increased by the same area ratio from 30% to 60%. It can also be seen that the thickness increases from t ′ to t ″.

  That is, in the conventional technique, when the area ratio of the ink holding portion in the cell 60 is increased, the volume of the ink holding portion 62 must be increased. Therefore, when the ink 20 is transferred to the paper surface 22, a large amount of the ink holding portion 62 is required. The ink 20 is transferred to the paper surface 22. As a result, as shown in FIG. 11C or FIG. 12C, a film of the ink 20 having a thick center and a thin periphery is formed on the paper surface 22. Further, since the cell 60 is determined by the number of lines of the printed matter, the distance between the ink holding portions 62 in the cells 60 adjacent to each other can be formed by forming only one ink holding portion 62 in one cell 60. d becomes longer. For this reason, when the ink 20 is transferred to the paper surface 22, there is paper between the ink 20 transferred from the ink holding portion 62 in each cell 60 and the ink 20. Since the paper is generally white, when the ink 20 is transferred to the paper surface 22, the white of the paper makes the contrast between the central portion of the ink 20 having a thick film and the paper clear. Only the thick central part is emphasized and looks dark, and it looks rough.

  On the other hand, when attention is paid to FIG. 7 which is an embodiment of the present invention having the same ink holding portion area ratio as FIG. 12, as can be seen by comparing FIG. 12 (c) and FIG. 7 (c), FIG. The film thickness t of the ink 20 transferred to the paper surface 22 by the cell 10 of the gravure printing plate according to the embodiment of the present invention shown in (c) is thinner than in the case of FIG. In addition, according to the embodiment of the present invention, as shown in FIG. 3 (c) and FIG. 7 (c), even if the ink holding area ratio increases from 33% to 60%, The film thickness t of the ink 20 transferred to 22 does not increase so much.

  This is because, in the embodiment of the present invention, one cell 10 includes two ink holding portions 14 and 18. As described above, since the two ink holding portions 14 and 18 exist in one cell 10, it is possible to disperse the amount of the ink 20 transferred to the paper surface 22. As a result, the film thickness t formed by the ink 20 transferred to the paper surface 22 can be made thinner than the gravure printing plate according to the prior art having the same cell holding portion area ratio.

  Furthermore, in the prior art, as shown in FIG. 11 (a) and FIG. 12 (a), since one large ink holding portion 62 is provided in the cell 60, a large amount of ink 20 is obtained at one time. When the ink d is transferred to the paper surface 22 and the distance d between the ink holding portions 62 in the cells 60 adjacent to each other is relatively long. As a result, the contrast of the ink transferred from each ink holding portion 62 became clear, and the printed matter varied.

  However, in the embodiment of the present invention, since one cell 60 includes the two ink holding portions 14 and 18, the ink 20 transferred from the first ink holding portion 14 to the paper surface 22, and the second The ink 20 transferred from the ink holding unit 18 to the paper surface 22 can be formed more adjacently. As a result, the ink film having a thin film thickness at the center portion is arranged closer to each other, and the contrast between the ink 20 and the white of the paper surface 22 is suppressed, thereby providing a gravure print with reduced roughness. It becomes possible.

  That is, in the gravure printing plate according to the embodiment of the present invention, since the ink is dispersed, the distance between the inks is shortened, and as a result, the contrast of paper white can be suppressed. Furthermore, since the first ink holding unit 14 can form a thin ink film, the paper white contrast can be further suppressed. That is, since the first ink holding part 14 is provided in contact with the outer frame part 12 and the shape thereof is a donut shape, the first ink holding part 14 is maximized in one cell 10. It is a donut shape provided. Therefore, the ink transferred from the first ink holding unit 14 is transferred into a donut shape on the paper, and then thinly stretches back and forth and right and left. Therefore, it is possible to form a thin ink film on the paper by the first ink holding unit 14, and it is possible to further suppress the contrast of paper white.

  Therefore, even in long-run printing, it is possible to prevent variations in the quality of gravure prints. Further, even when a booklet formed by binding such a gravure print is produced, it is possible to realize a booklet of excellent quality free from roughness and variation.

  In addition, in the gravure printed matter printed by the gravure printing plate in which the completely same cells 10 are continuously arranged, there is a possibility that moire occurs. In order to avoid this, the shape of the outer frame portion 12, the first ink holding portion 14, and the second ink holding portion 18 is the same as that of the adjacent cell 10 even when the ink holding portion area ratio is the same. Alternatively, the position of the second ink holding unit 18 may be different from that of the adjacent cell 10.

  For example, in the case of a gravure printing plate in which cells 10 having an ink holding area ratio of 34% as shown in FIG. 4 are continuously arranged, a part thereof is replaced with a planar cell 11 as shown in FIG. Deploy. The cell 11 shown in FIG. 13 has an outer frame portion by reducing the mass of the first ink holding portion 14 of the cell 10 shown in FIG. 4 by 4 and increasing the mass of the second ink holding portion 18 instead. 12, the shape of the first ink holding part 14 and the second ink holding part 18 are changed, but the ink holding part area ratio is 34% as in FIG. FIG. 14 is an example in which the position of the second ink holding portion 18 is different from that of the adjacent cell 10, and the position of the second ink holding portion 18 is changed from the center of the cell 11. It is shifted by 1 square to the left in the figure.

  The best mode for carrying out the present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to such a configuration. Within the scope of the invented technical idea of the scope of claims, a person skilled in the art can conceive of various changes and modifications. The technical scope of the present invention is also applicable to these changes and modifications. It is understood that it belongs to.

The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention. The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention, and the elevation conceptual diagram (ink holding part area ratio 32%) of the paper surface by which the ink was transferred by the gravure printing plate. The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention, and the elevation conceptual diagram (ink holding part area ratio 33%) of the paper surface by which the ink was transferred by the gravure printing plate. The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention (34% of ink holding | maintenance area ratio). The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention (40% of ink holding | maintenance area ratio). The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention (ink holding part area ratio 50%). The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention, and the elevation conceptual diagram (ink holding part area ratio 60%) of the paper surface by which the ink was transferred by the gravure printing plate. The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention (70% of ink holding | maintenance area ratio). The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention (80% of ink holding | maintenance area ratio). The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention, and the elevation conceptual diagram (ink holding part area ratio 81%) of the paper surface by which the ink was transferred by the gravure printing plate. The figure which shows the structural example of the cell of the gravure printing plate by a prior art, and the elevation conceptual diagram (ink holding part area ratio 33%) of the paper surface by which the ink was transcribe | transferred by the gravure printing plate. The figure which shows the structural example of the cell of the gravure printing plate by a prior art, and the elevation conceptual diagram (ink holding part area ratio 60%) of the paper surface by which the ink was transcribe | transferred by the gravure printing plate. The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention which changed the shape of the ink holding part in order to prevent moire. The figure which shows the structural example of the cell of the gravure printing plate which concerns on embodiment of this invention which changed the position of the ink holding part in order to prevent moire. The figure which shows the change method of the cell volume in the conventional gravure printing method. The figure which shows the change method of the cell volume in the direct gravure printing method. The figure which shows the change method of the cell volume in the engraving gravure printing method.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,11 ... Cell, 12 ... Outer frame part, 14 ... 1st ink holding part, 16 ... Ink non-holding part, 18 ... 2nd ink holding part, 20 ... Ink, 22 ... Paper surface, 60 ... Cell, 62 ... Ink holder

Claims (4)

In a gravure printing plate in which an assembly of substantially rectangular cells forming an image line portion is formed on a plate surface,
Each cell is
Forming a cell outer frame, and a frame-shaped outer frame portion that does not retain ink;
A frame-shaped first ink holding portion that is arranged inscribed in the outer frame portion and holds ink;
An ink non-holding portion that is disposed inside the first ink holding portion and does not hold ink;
A second ink holding part that is disposed so as to be surrounded by the ink non-holding part and holds ink ;
The gravure printing plate in which at least one cell is made different from the shape of the outer frame portion of an adjacent cell by changing a part of the shape of the outer frame portion . In the gravure printing plate according to claim 1,
At least one cell maintains at least one of the position and shape of the second ink holding part while maintaining the area of the second ink holding part, and the second ink holding part of the adjacent cell. A gravure printing plate that is different from the one. In a gravure printing plate in which an assembly of substantially rectangular cells forming an image line portion is formed on a plate surface,
Each cell is
Forming a cell outer frame, and a frame-shaped outer frame portion that does not retain ink;
A frame-shaped first ink holding portion that is arranged inscribed in the outer frame portion and holds ink;
An ink non-holding portion that is disposed inside the first ink holding portion and does not hold ink;
A second ink holding part that is disposed so as to be surrounded by the ink non-holding part and holds ink;
While at least one cell maintains the area of the second ink holding portion, at least one of the position and shape of the second ink holding portion is changed to the second ink holding portion of the adjacent cell. A gravure printing plate that is different from the one. In the gravure printing plate according to any one of claims 1 to 3,
When increasing the area ratio of the ink holding part in each cell, a gravure printing plate is formed by increasing the area of the second ink holding part while holding the area of the first ink holding part.

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