JP2015066857A - Plate making method, plate making apparatus, printing apparatus, and printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate making method, a plate making apparatus, a printing apparatus, and a printing plate which enable determination of relief pattern data with printing pressure distribution conditions and printing conditions taken into account so as to reproduce favorable images on a print medium.SOLUTION: Relief pattern data is determined (S12-S14) on the basis of a step of acquiring printing pressure distribution conditions indicating the printing pressure distribution on a printing plate pressed against a print medium (S10), and a step of acquiring printing conditions indicating the characteristics of at least one of the printing plate, the print medium, and an ink (S11). A relief is formed on the printing plate on the basis of the relief pattern data thus determined to thereby enable reproduction of favorable images with the printing pressure distribution conditions and the printing conditions taken into account.

Description

  The present invention relates to a plate making method, a plate making apparatus, a printing apparatus, and a printing plate, and more particularly, to a printing plate produced by laser engraving a flexographic printing plate material.

  Letterpress for printing is widely used in the printing field such as flexographic printing, and in recent years, flexographic printing has attracted attention as an environmentally friendly printing method. In flexographic printing, a flexible and elastic plate material and ink (water-based ink, UV ink, etc.) are used. The plate material used in flexographic printing is deformed according to the printing pressure (push-in amount) due to its elasticity, and also follows up and adheres appropriately to a printing medium such as corrugated cardboard having irregularities on the surface, and is excellent. Transfer printing can be performed.

  Patent Document 1 discloses a printing relief plate used in flexographic printing. In the flat halftone area of this printing relief plate, multiple types of halftone dot main projections with different printing surface heights are provided, avoiding local thickening of halftone dots, non-printing defects near the solid part And the instability of printing pressure due to the lowering of some dot projections.

  Patent Document 2 discloses a printing plate for preventing a transfer region formed on the surface of a transfer target from being transferred into a trapezoidal shape that extends beyond the pattern region by transferring the pattern region of the printing plate. Disclose. This printing plate is provided with a pattern area that is smaller than the pattern area data, and the reduction ratio of the portion of the pattern area that is present on the leading end side in the rotation direction of the plate cylinder and that is first printed and transferred is the trailing edge. It is smaller than the reduction ratio of the portion that is present on the side and is printed and transferred later.

JP 2011-224878 A JP 2012-074281 A

  The ideal plate deformation characteristics of printing plates used in flexographic printing, etc., are not deformed near the surface of the printing plate (the part related to ink transfer) due to the printing pressure during printing, but only sink in the height direction. It is desirable that the printing plate (relief part) be deformed so as to be embedded. However, in actual printing, deformation occurs from the vicinity of the surface of the printing plate.

  Such deformation of the printing plate varies depending on the magnitude of the printing pressure generated between the printing plate and the printing medium. The printing pressure between the printing plate and the printing medium varies depending on the relief shape of the printing plate, and varies depending on the contact area between the two. That is, pressure is more concentrated in an area having a relatively small contact area (for example, a halftone dot (isolated point) formation area) than in an area having a relatively large contact area (for example, a solid formation area). The printing pressure tends to increase. Therefore, an area having a relatively small contact area tends to have a larger plate deformation and a printed image on the printing medium becomes thicker than an area having a relatively large contact area.

  The bias in printing pressure is influenced not only by the size of the contact area of the area of interest (relief shape) but also by the sum of the contact areas in the peripheral area including the area of interest (relief shape). The printing pressure in the area of interest (the amount of pressing of the printing plate) varies depending on the screen percentage, halftone dots, white spots, etc.

  Therefore, areas with small contact areas (isolated points, etc.) differ in how the printed image is thickened on the print medium depending on whether there is an area (solid, etc.) with a large contact area nearby or not. . Therefore, even in a halftone dot formation area with the same contact area ratio, the image density reproduced on the printing medium differs depending on the type of relief in the peripheral area, and various image quality degradations such as isolated dots and thin lines become thicker. May occur in different areas of the image. As described above, in the conventional flexographic printing technique, halftone dots and fine lines become thicker or thinner than expected, and it is difficult to guarantee uniform print reproducibility in an image.

  Even when there is variation in the thickness of the printing plate, the reproduction accuracy of the printed image on the printing medium is not constant. When there is a thickness distribution in the printing plate itself due to a manufacturing error or the like, the position (height) of the top of the relief differs between a thick plate portion and a thin plate portion even if the plate has the same relief (engraving structure). That is, the position of the relief top at the portion where the plate thickness is thick becomes relatively high, and the position of the relief top at the portion where the plate thickness is thin becomes relatively low. Therefore, in a printing plate having variations in thickness, the printing pressure changes according to the thickness distribution, and the image reproduced on the printing medium varies in thickness depending on the plate thickness.

  Furthermore, the degree of image quality degradation also varies depending on the characteristics of the printing plate (printing machine), ink, and printing medium. In a printing technique in which ink is transferred to a printing medium by pressing the relief of the printing plate against the printing medium, how the ink spreads on the printing medium (behavior) depending on the characteristics of the printing plate, printing medium, and ink ) Changes and the dot size changes. The behavior of ink on such a printing medium varies depending on printing conditions such as plate hardness, ink type, printing medium material, and the like, and the image reproducibility on the printing medium depends on these printing conditions. . Therefore, it is preferable from the viewpoint of image reproducibility to individually optimize the relief (engraving shape) of the printing plate according to the printing conditions.

  The present invention has been made in view of the above-mentioned circumstances, and can determine the relief (relief pattern data) of the printing plate in consideration of the printing pressure distribution condition and the printing condition, and can reproduce a good image on the printing medium. The purpose is to provide technology.

  One aspect of the present invention is a plate making method for forming a relief on a printing plate based on relief pattern data, the printing pressure distribution condition indicating the printing pressure distribution of the printing plate pressed against the printing medium, and the printing plate The present invention relates to a plate making method in which relief pattern data is determined on the basis of printing conditions indicating characteristics of at least one of ink to adhere to a printing medium and a relief of a printing plate.

  According to this aspect, the relief can be formed on the printing plate based on the relief pattern data reflecting the printing pressure distribution condition and the printing condition. Therefore, relief pattern data can be determined by taking into account plate deformation according to the printing pressure distribution and ink spreading behavior according to the printing conditions, and relief capable of printing and reproducing images with good image quality on the printing medium. Can be formed into a printing plate.

  It should be noted that the “printing pressure distribution condition” can be derived by comprehensively considering the attention position in the relief of the printing plate and the state of the relief around it. “Printing conditions” are not particularly limited, but are preferably based on characteristics that can affect the spreading behavior of the ink transferred from the relief of the printing plate to the printing medium, among the printing plate, printing medium, and ink characteristics. .

  “Relief pattern data” may include pattern data of an arbitrary relief. For example, a relief for halftone dot printing, a relief for convex fine line printing, a relief for solid printing, and a relief for printing of other shapes can be included in the relief pattern data.

  Desirably, the printing pressure distribution condition is acquired based on image data and plate thickness distribution data indicating the plate thickness distribution of the printing plate.

  According to this aspect, the printing pressure distribution condition can be accurately obtained from the image data and the plate thickness distribution data.

  Desirably, the printing pressure distribution condition is estimated based on the area ratio of the portion of the printing plate that contacts the printing medium.

  The printing pressure varies according to the ratio of the contact area (contact area) between the printing plate and the printing medium. Therefore, according to this aspect, the printing pressure distribution condition can be estimated with high accuracy.

  Desirably, the relief pattern data is determined based on a printing diameter condition indicating a range of ink transferred onto the printing medium by the relief of the printing plate pressed against the printing medium.

  Desirably, the printing diameter condition is estimated based on the printing condition.

  According to these aspects, the relief pattern data can be accurately determined based on the ink range (printing diameter condition) on the printing medium. The spreading behavior of the ink on the printing medium may vary depending on the printing conditions. However, according to these embodiments, it is possible to form an appropriate relief that takes into account the spreading behavior of the ink.

  Desirably, the printing conditions include information on at least one of the composition and hardness of the printing plate.

  The composition and hardness of the printing plate are factors that can affect the behavior (spreading range) of the ink transferred onto the printing medium by the relief of the printing plate. Therefore, according to this aspect, it is possible to derive relief pattern data that accurately reflects the behavior of ink on the printing medium.

  Preferably, the plate making method includes a step of calculating relief pattern data based on image data, a step of acquiring printing pressure distribution conditions, a step of acquiring printing conditions, and a printing condition and printing pressure distribution conditions. A step of calculating a correction amount of the relief pattern data based on the correction amount; and a step of correcting the relief pattern data based on the correction amount.

  According to this aspect, the relief pattern data can be accurately corrected and determined based on the correction amount calculated from the printing condition and the printing pressure distribution condition.

  Preferably, the relief includes a plurality of convex portions, the relief pattern data includes data on the height of the plurality of convex portions and data on the shape, and the correction amount of the relief pattern data is the height of the plurality of convex portions. It relates to at least one of data and shape data.

  According to this aspect, the relief pattern data can be corrected based on at least one of the height and shape of the convex portion.

  Desirably, the plurality of convex portions have a base portion and a tip portion provided on the base portion and pressed against the printing medium, and the shape data of the plurality of convex portions is at least the data of the shape of the tip portion. including.

  According to this aspect, the relief pattern data can be corrected based on the shape data of the tip of the convex portion. The “tip portion of the convex portion” means an end portion including a portion (surface) that is pressed against the printing medium during printing.

  Desirably, the data of the shape of the front-end | tip part of a some convex part contains the data of the part which contact | connects a to-be-printed medium at the time of printing among front-end | tip parts.

  According to this aspect, the relief pattern data can be corrected based on data of a portion (surface) in contact with the printing medium during printing at the tip of the convex portion.

  Desirably, the plurality of convex portions include a base portion and a tip portion provided on the base portion and pressed against the printing medium, and the height data of the plurality of convex portions includes the height of the tip portion, The present invention relates to at least one of the height of the base and the overall height of the tip and the base.

  According to this aspect, the relief pattern data can be corrected based on at least one of the height of the tip portion of the convex portion, the height of the base portion, and the overall height of the tip portion and the base portion.

  Desirably, the relief includes a plurality of convex portions, the relief pattern data includes volume data of the plurality of convex portions, and the correction amount of the relief pattern data relates to volume data of the plurality of convex portions.

  According to this aspect, the relief pattern data can be corrected based on the volume data of the convex portion.

  Note that the relief pattern data and the correction amount of the relief pattern data may directly target the volume data of the convex portion, or “determine the volume of the convex portion, which can indirectly express the volume data of the convex portion. “Elements (cross-sectional size, cross-sectional area, height, etc.)” may be targeted.

  Preferably, the plate making method includes a step of forming a relief on the printing plate based on the corrected relief pattern data.

  According to this aspect, an image with good image quality is printed by a printing plate on which relief pattern data is corrected and relief is formed in consideration of plate deformation according to printing pressure distribution and ink behavior according to printing conditions. Printing can be reproduced on the medium.

  Preferably, the relief is formed on the printing plate by an exposure process for the printing plate, and the exposure characteristics in the thickness direction of the printing plate are derived based on the plate thickness distribution data, and the relief process is performed by taking the exposure characteristics into consideration. Is formed on the printing plate.

  According to this aspect, since the relief is formed by the exposure process that takes into account the “exposure characteristics in the thickness direction of the printing plate” derived based on the plate thickness distribution data, the relief formation with high accuracy according to the exposure characteristics is performed. Is possible. Therefore, even when the plate thickness of the printing plate is not constant, it is possible to accurately form a relief capable of reproducing a desired image on the printing plate.

  Here, the “exposure characteristics” are characteristics that can vary in the thickness direction of the printing plate, and can include various factors such as exposure conditions that can affect the exposure process. For example, the “exposure beam diameter” used for the exposure process can be adopted as the exposure characteristic.

  Preferably, the plate making method includes a step of forming, on the printing plate, a printing condition identification unit indicating printing conditions.

  According to this aspect, the user can easily grasp the correspondence between the printing condition and the printing plate from the printing condition identification unit formed on the printing plate. The form of the printing condition identification unit is not particularly limited. For example, the printing condition is preferably configured by a relief that can print the printing condition on the printing medium, but the printing condition is printed by a device such as an IC chip that does not print on the printing medium. A condition identifying unit may be configured.

  Another aspect of the present invention is a plate making apparatus for forming a relief on the printing plate based on the relief pattern data, the printing pressure distribution condition indicating the printing pressure distribution of the printing plate pressed against the printing medium, and the printing plate The present invention relates to a plate making apparatus including a relief determining unit that determines relief pattern data based on printing conditions indicating characteristics of at least one of ink to adhere to a printing medium and a relief of a printing plate.

  Preferably, the plate making apparatus further includes a printing condition input unit for inputting printing conditions.

  According to this aspect, an accurate printing condition is input by the user via the printing condition input unit, and relief pattern data can be determined based on the accurate printing condition.

  Preferably, the plate making apparatus further includes a condition identification forming unit that forms a printing condition identification unit indicating a printing condition on the printing plate.

  Another aspect of the present invention relates to a printing apparatus including the plate making apparatus and a printing unit that presses a printing plate on which a relief is formed by the plate making apparatus against a printing medium.

  Another aspect of the present invention is a printing plate on which a relief is formed, the printing pressure distribution condition indicating the printing pressure distribution of the printing plate pressed against the printing medium, the printing plate, the printing medium, and the printing plate. The present invention relates to a printing plate in which a relief is determined based on a printing condition showing a characteristic of at least one of the inks adhering to the relief.

  Desirably, the printing plate is provided with a printing condition identifying unit indicating printing conditions.

  According to the present invention, a relief capable of accurately printing and reproducing a desired image on a printing medium is formed on a printing plate based on relief pattern data reflecting printing pressure distribution conditions and printing conditions.

It is a figure which shows the example of a principal part structure of a flexographic printing machine. It is an enlarged view of the contact location of a flexographic printing plate and a to-be-printed medium. It is a top view which shows an example of the laser engraving machine which forms a relief in a flexographic printing plate. It is a top view which shows the example of a relief formed in a part of flexographic printing plate. FIG. 5 is a diagram illustrating an example of a relationship between a flexographic printing plate area illustrated in FIG. 4 and a pressing amount during printing. FIG. 5 is a diagram illustrating a relationship example between a flexographic printing plate area illustrated in FIG. 4 and a printing pressure during printing. FIG. 5 is a plan view of a printing medium on which an actual print image is shown when normal printing is performed by the flexographic printing plate shown in FIG. 4, and in particular, it is assumed that the plate thickness of the flexographic printing plate is constant throughout. The printed image (printed medium) obtained in this case is shown. It is a figure which shows plate | board thickness distribution of the flexographic printing plate which concerns on FIGS. FIG. 5 is a plan view of a printing medium on which a target print image is shown when ideal printing is performed by the flexographic printing plate shown in FIG. 4. FIG. 5 is a plan view of a printing medium on which an actual print image is shown when normal printing is performed by the flexographic printing plate shown in FIG. 4. 1 is a block diagram illustrating a configuration of a flexographic printing system according to an embodiment of the present invention. It is a functional block diagram which shows the example of 1 structure of the exposure amount data generation part of FIG. It is a functional block diagram which shows the example of 1 structure of the engraving shape data correction part of FIG. It is an external view which shows an example of the printing surface of a flexographic printing plate. It is a block diagram which shows the example of arrangement | positioning of a condition identification formation part. It is a flowchart which shows the flow of a process in an engraving shape data correction | amendment part and an exposure amount data conversion part, and shows the example which estimates printing pressure distribution based on the image data and plate | board thickness distribution data before converting into engraving shape data. It is a figure which shows the laser diameter at the time of the laser exposure in a laser engraving machine. It is a flowchart which shows the flow of a process in an engraving shape data conversion part, an engraving shape data correction part, and an exposure amount data conversion part, and shows the example which estimates printing pressure distribution based on engraving shape data and plate thickness distribution data. An example of a process for calculating an indentation amount (printing pressure distribution) based on image data (engraving shape data) and a plate thickness distribution and calculating a correction amount based on the indentation amount (printing pressure distribution) according to printing conditions will be described. It is a flowchart to do. It is a figure which shows the example of an image for demonstrating ROI. It is a figure which shows an example of the correspondence of the contact area ratio in ROI, and the pushing amount. It is a figure which shows an example of the correspondence of "the pushing amount in an attention position (attention pixel)" and "the correction amount of the engraving shape data of an attention position". An example of the exposure table which implement | achieves shape correction is shown. An example of an exposure conversion table for realizing shape correction corresponding to the laser beam diameter is shown. It is a figure which shows an example of the image data (1 bit image data) before conversion into engraving shape data. It is a figure which shows an example of the engraving shape data calculated | required from the image data of FIG. It is a figure which shows the example of a relationship between the location where the front-end | tip of a relief contacts with a to-be-printed medium, and the spreading of the ink on a to-be-printed medium. It is a figure which illustrates "engraved shape data after correction" obtained by correcting engraving shape data based on printing pressure distribution conditions and printing conditions, and "engraved shape data" is corrected so as to be thick overall An example of a print image is shown. It is a figure which illustrates "engraved shape data after correction" obtained by correcting engraving shape data based on printing pressure distribution conditions and printing conditions, and "engraved shape data" is corrected so as to be thin as a whole An example of a print image is shown. It is an external perspective view showing an example of a relief formed on a part of a flexographic printing plate, and engraved on the flexographic printing plate based on engraving shape data that is not corrected according to the printing pressure distribution condition and the printing condition An example of the created relief (convex part) is shown. It is an external perspective view showing an example of a relief formed on a part of a flexographic printing plate. Engraving is created on a flexographic printing plate based on engraving shape data corrected according to printing pressure distribution conditions and printing conditions. An example of the relief (convex part) made is shown. It is an external view of the convex part for demonstrating the example which correct | amends the sculpture shape (tip part shape) of the small dot in a halftone dot according to printing pressure distribution conditions and printing conditions, (a) is larger than a standard. The convex portions of “when the printing pressure is applied” and “when the ink spreading behavior on the printing medium is larger than the standard” are shown, and (b) is “when the standard printing pressure is applied” and “the printing target” (C) shows a convex portion of “when the ink spreading behavior on the medium is standard”, and (c) shows “when the printing pressure smaller than the standard acts” and “the ink spreading behavior on the printing medium is lower than the standard”. The convex part of “when small” is shown. It is an external view of the convex part (relief) for demonstrating the example which correct | amends the sculpture shape (convex part height) of the small dot in a halftone dot according to printing pressure distribution conditions and printing conditions, (a) is " The convex portions of “when a printing pressure larger than the standard is applied” and “when the ink spreading behavior on the printing medium is larger than the standard” are shown, and (b) is “when the standard printing pressure is applied”. And the convex part of “when the ink spreading behavior on the printing medium is standard”, and (c) shows the “when the printing pressure smaller than the standard acts” and “the ink spreading behavior on the printing medium” The convex part of “when is smaller than the standard”. It is an external view of the convex part (relief) for demonstrating the example which correct | amends the sculpture shape (the convex part tip part volume) of the small dot in a halftone dot according to printing pressure distribution conditions and printing conditions, (a) The convex portions of “when a printing pressure larger than the standard acts” and “when the ink spreading behavior on the printing medium is larger than the standard” are shown, and (b) shows “when the standard printing pressure acts” ”And“ when the ink spreading behavior on the printing medium is standard ”, and (c) shows the“ when printing pressure smaller than the standard acts ”and“ spreading of ink on the printing medium ” The convex part is shown when the behavior is smaller than the standard. It is an external view of the convex part for demonstrating the example which correct | amends the relief engraving shape (tip part shape) for convex fine line printing according to printing pressure distribution conditions and printing conditions, (a) is the convex for convex fine line printing. FIG. 4B is a cross-sectional view of the convex portion of “when a printing pressure larger than the standard acts” and “when the ink spreading behavior on the printing medium is larger than the standard”. , (C) is a cross-sectional view of the convex portion when “standard printing pressure is applied” and “when the spreading behavior of the ink on the printing medium is standard”, and (d) is “more than standard” Sectional views of the convex portions of “when a small printing pressure is applied” and “when the ink spreading behavior on the printing medium is smaller than the standard” are shown. It is an external view of the convex part (relief) for demonstrating the example which correct | amends the relief engraving shape (tip part volume) for convex fine line printing according to printing pressure distribution conditions and printing conditions, (a) is convex fine line printing. FIG. 2B is a perspective view of the appearance of the convex portion for use, and (b) is a cross section of the convex portion when “a printing pressure larger than the standard is applied” and “when the ink spreading behavior on the printing medium is larger than the standard”. (C) shows a cross-sectional view of the convex portion when “standard printing pressure acts” and “when the ink spreading behavior on the printing medium is standard”, and (d) shows “ Sectional views of the convex portions of “when a printing pressure smaller than the standard acts” and “when the ink spreading behavior on the printing medium is smaller than the standard” are shown. It is a functional block diagram showing a modification of the engraving shape data correction unit.

  Embodiments of the present invention will be described with reference to the accompanying drawings. Hereinafter, an example in which the present invention is applied to “flexographic printing” will be described. However, the present invention is not limited to this, and can be widely applied to a printing technique using a printing plate on which a relief is formed. is there.

  FIG. 1 is a diagram illustrating a configuration example of a main part of a flexographic printing machine 10. FIG. 2 is an enlarged view of a contact portion between the flexographic printing plate 1 and the printing medium 3 during printing.

  A flexographic printing machine (printing unit) 10 includes a flexographic printing plate 1, a plate cylinder 4 to which the flexographic printing plate 1 is attached via a cushion tape 2 such as a double-sided tape, and an anilox roller 8 to which ink is supplied by a doctor chamber 6. And an impression cylinder 9 installed opposite to the plate cylinder 4.

  Ink is transferred from the anilox roller 8 to the top (printing surface) of the relief 50 of the flexographic printing plate 1. The flexographic printing plate 1 (the top of the relief 50) is pressed against the printing medium 3 while the printing medium 3 passes between the plate cylinder 4 and the impression cylinder 9 to which the flexographic printing plate 1 is attached. As a result, the ink adhering to the top of the relief of the flexographic printing plate 1 is transferred to the printing medium 3, and a desired image is printed on the printing medium 3.

  FIG. 3 is a plan view showing an example of the laser engraving machine 20 that forms the relief 50 on the flexographic printing plate 1.

  The laser engraving machine 20 includes a drum 22 and an exposure head 28 for exposing and engraving a flexographic plate material (printing plate) F held on the drum 22. The exposure head 28 is mounted on a stage 30 and can be moved by a focus position changing mechanism 32 and an intermittent feed mechanism 38.

  The focus position changing mechanism 32 includes a motor 34 and a ball screw 36 for moving the exposure head 28 back and forth with respect to the drum 22 to which the flexographic printing material F is attached. The movement of the exposure head 28 in the main scanning direction is controlled by the motor 34 and the ball screw 36, and the focus position of the exposure engraving process is adjusted.

  The intermittent feed mechanism 38 includes a ball screw 40 and a sub-scanning motor 42 that rotates the ball screw 40. The movement of the exposure head 28 (stage 30) in the sub-scanning direction is controlled by the ball screw 40 and the sub-scanning motor 42, and the exposure head 28 is intermittently fed in the direction of the axis 24 (sub-scanning direction) of the drum 22. The flexographic printing material F on the drum 22 is chucked by the chuck member 26, and the holding position on the drum 22 is fixed. The portion of the flexographic printing material F that is chucked by the chuck member 26 is in a region where exposure by the exposure head 28 is not performed.

  A desired relief 50 is formed on the surface of the flexographic printing plate F by irradiating the flexographic printing plate F with a laser beam from the exposure head 28 while rotating the drum 22. While the chuck member 26 passes in front of the exposure head 28 by the rotation of the drum 22, the exposure head 28 (stage 30) is intermittently fed in the sub-scanning direction, and then laser engraving of the next line is performed.

  The exposure scanning position is controlled by combining the above-mentioned “feeding of the flexographic printing plate F in the main scanning direction by rotation of the drum 22” and “intermittent feeding of the exposure head 28 in the subscanning direction”. Further, by controlling the intensity and on / off of the laser beam based on the exposure data (depth data) for each exposure scanning position, the relief 50 having a desired shape is engraved on the flexographic printing material F, and the flexographic printing plate 1 ( 1 and 2) are formed.

<Relationship between printing pressure distribution and printing results>
The flexographic printing plate 1 (particularly the relief 50) is formed by a flexible member rich in elasticity, and deforms according to the printing pressure. Accordingly, the amount of deformation of the relief 50 varies depending on the magnitude of the applied printing pressure, and the print image formed on the print medium 3 also changes. The printing pressure applied to the flexographic printing plate 1 fluctuates not only according to the type of relief 50 at the target position (such as white, halftone dot, convex fine line, solid, etc.) but also depending on the type of the surrounding relief 50.

  FIG. 4 is a plan view showing an example of a relief formed on a part of the flexographic printing plate 1. The relief 50 of the flexographic printing plate 1 shown in FIG. 4 is based on 1-bit image data.

  In the flexographic printing plate 1 shown in FIG. 4, a “white area” for white printing is sandwiched between “a halftone area” in which reliefs 50 for printing halftone dots having a uniform halftone dot density (area ratio) are formed. There is a “blank area” (left side in FIG. 4) and a “solid area” (right side in FIG. 4) for solid printing. When the flexographic printing plate 1 has such a plurality of types of areas (relief 50), the printing pressure applied to each area during printing varies depending on the type of the adjacent area. That is, while the halftone dot area receives a relatively strong printing pressure on the side close to the white area (see “strong printing pressure area” in FIG. 4), the halftone dot area on the side close to the solid area is compared. A weak printing pressure is received (see “weak printing pressure region” in FIG. 4).

  FIG. 5 is a diagram showing an example of the relationship between the area of the flexographic printing plate 1 shown in FIG. 4 (position in the direction of arrow A in FIG. 4) and the amount of pressing during printing. FIG. 6 is a diagram showing an example of the relationship between the region of the flexographic printing plate 1 shown in FIG. 4 (position in the direction of arrow A in FIG. 4) and the printing pressure during printing. FIGS. 5 and 6 show the case where a load of the same magnitude is uniformly applied to each of the “white area”, “halftone area”, and “solid area” of the flexographic printing plate 1 shown in FIG. The relationship is shown. FIGS. 5 and 6 also show changes in “pressing amount” and “printing pressure” along the cross-sectional lines indicated by “upper”, “center”, and “lower” in FIG. Yes.

  There is no flexographic printing plate 1 that does not contact the printing medium and does not obstruct printing movement in the pressing direction during printing. Compared to the “halftone area” and “solid area”, the amount of pressing down during printing tends to increase (see FIG. 5). In addition, since the “white area” does not contact the printing medium, the printing pressure generated between the “white area” and the printing medium is basically zero (see FIG. 6).

  On the other hand, the “solid area” of the flexographic printing plate 1 is in full contact with the printing medium at the time of printing, and the push-down movement is obstructed. Therefore, compared with the “white area” and “halftone area”, The amount of pushing down itself becomes small (see FIG. 5). Further, when the applied load is the same, the larger the ratio of the contact area with the printing medium, the smaller the pressure per unit area. Therefore, in the “solid region” of the flexographic printing plate 1 that is in contact with the entire surface of the printing medium. The printing pressure is smaller than that of the “halftone dot region” that partially contacts the printing medium (see FIG. 6).

  On the other hand, the “halftone dot region” of the flexographic printing plate 1 is partially in contact with the printing medium at the time of printing, and the push-down movement is hindered. Therefore, the push-down amount at the time of printing is smaller than the “white region”. However, the pressing amount during printing is larger than that of the “solid region” (see FIG. 5). Further, the printing pressure in the “halftone dot area” of the flexographic printing plate 1 is larger than the “white area” that does not contact the printing medium, and the contact area ratio (number of black pixels) with the printing medium is large. It becomes larger than the “solid area”.

  As described above, the pressing amount and the printing pressure during printing of the flexographic printing plate 1 are affected by the characteristics (relief 50, contact area) of each area itself, but are also affected by the type and characteristics of the adjacent area.

  For example, in the example shown in FIG. 4, the “halftone area” closer to the “white area” is affected by the press-down amount of the white area, a relatively strong printing pressure is applied, and the press-down quantity is also relatively large. (Refer to “strong printing pressure region” in FIGS. 5 and 6). On the other hand, on the side close to the “solid region” in the “halftone dot region”, a relatively weak printing pressure is applied due to the effect of the amount of depression of the solid region, and the amount of depression is relatively small (see FIGS. 5 and 6). Refer to “Weak printing pressure area”). As described above, the relief (small dots) in the halftone dot region in which the degree of deformation varies depending on the printing pressure is affected by the type of surrounding relief, and the printing state may change depending on the position.

  FIG. 7 is a plan view of the printing medium 3 on which an actual print image is shown when normal printing is performed by the flexographic printing plate 1 shown in FIG. A print image (printed medium 3) obtained when it is assumed to be constant throughout is shown.

  In actual printing, printing pressure is biased due to the influence of the relief type of the peripheral area (see FIG. 6), and the printing state on the printing medium 3 is affected by such printing pressure bias. Therefore, in actual printing, as shown in FIG. 7, unevenness occurs in the printing state of the “strong printing pressure area” close to the white area and the “weak printing pressure area” close to the solid area in the halftone dot area.

  Further, the pressing amount and printing pressure of the flexographic printing plate 1 during image printing are also affected by the plate thickness that the flexographic printing plate 1 inherently has. That is, in the portion of the flexographic printing plate 1 (flexographic printing plate material F) where the plate thickness is thick, the “pressing amount” and the “printing pressure” are larger than in the portion where the plate thickness is thin.

  FIG. 8 is a diagram showing the plate thickness distribution of the flexographic printing plate 1 according to FIGS. In FIG. 8, the darker portion indicates that the plate thickness is thinner, and the portion closer to white (blank) indicates that the plate thickness is thicker. In the examples shown in FIGS. 4 to 6 and 8, the plate thickness is changed from a thick part to a thin part in the order of “upper part”, “central part”, and “lower part”. Shows values from large to small in the order of "upper part", "central part", and "lower part". That is, since the plate thickness at the upper part of the plate is relatively large and the plate thickness at the lower part of the plate is relatively small, the printing pressure at the upper part of the plate is relatively large and the printing pressure at the lower part of the plate is relatively small. In this way, the plate thickness affects the magnitude of the printing pressure, and in the halftone dot area and the convex thin line area, the print image of the thick plate thickness (see “upper part” in FIG. 4 and FIG. 8) is dark (thick). Thus, the printed image of the thin part (see “lower part” in FIG. 4 and FIG. 8) becomes thin (thin).

  FIG. 9 is a plan view of the printing medium 3 showing an ideal print image as a target when ideal printing is performed by the flexographic printing plate 1 shown in FIG. FIG. 10 is a plan view of the printing medium 3 on which an actual print image is shown when normal printing is performed by the flexographic printing plate 1 shown in FIG.

  As shown in FIG. 9, when printing is performed in an ideal state, printing in which the relief 50 of the flexographic printing plate 1 is appropriately reflected is performed, and the “white area”, “halftone area”, and “solid area” are printed. "Is also clear, and the printing state in each region is uniform.

  However, in actual printing, as shown in FIG. 10, the influence of the relief type of the peripheral area (see FIG. 7) and the influence of the plate thickness distribution (plate height distribution) of the flexographic printing plate 1 (flexographic printing plate F) (FIG. 8). See). That is, the printing state on the printing medium 3 is marked because the degree of deformation of the small dots in the halftone dot region differs depending on the relief type of the peripheral region, and the plate surface height varies depending on the plate thickness variation. Influenced by pressure bias. As described above, since the printing state of the attention area depends on the engraving shape distribution (relief type) and the plate thickness distribution in the peripheral area, the normal flexographic printing may not obtain a printing result as intended by the user. is there.

  Further, the printing result on the printing medium 3 may vary depending on the types of the flexographic printing plate 1, the ink, and the printing medium 3. In other words, if the ink transferred from the flexographic printing plate 1 (relief 50) to the printing medium 3 is too wide or larger than expected on the printing medium 3, the printing result on the printing medium 3 is The image quality deteriorates. The degree of ink expansion (the size of the dot diameter) on the printing medium 3 depends on the characteristics (printing conditions) of the flexographic printing plate 1, ink, and printing medium 3. It fluctuates according to printing conditions such as the surface roughness of the print medium 3 and the ink viscosity.

  Thus, the degree of image quality degradation of the image (print) reproduced on the printing medium 3 is not only the “printing pressure distribution condition” based on the image data and the plate thickness distribution of the flexographic printing plate 1 but also the flexographic printing plate 1. , And the “printing condition” based on the combination of the ink and the printing medium 3.

  The present inventor pays attention to the relationship between “printing pressure distribution condition and printing condition” and “printing state”, and predicts the reproduction of the printed image from the plate deformation according to the printing pressure distribution and the ink behavior according to the printing condition. Thus, the inventors have newly found a technique that can determine relief pattern data and satisfactorily reproduce a desired image on a printing medium. That is, the image data and the plate thickness distribution to be printed are analyzed to estimate the printing pressure distribution applied to the flexographic printing plate 1, while the types of the flexographic printing plate 1, ink, and printing medium 3 to be actually used are used. From the above, the behavior (spreading) of the ink on the printing medium 3 during printing is estimated. By determining (correcting) the engraving shape in consideration of the “deformation of the flexographic printing plate 1” based on the estimated printing pressure distribution and the estimated “spreading of ink on the printing medium 3”, a desired image is obtained. It becomes possible to reproduce the print accurately on the printing medium.

  Hereinafter, an example of a printing apparatus that performs engraving shape correction based on such printing pressure distribution conditions and printing conditions will be described.

<Configuration example of printing device>
FIG. 11 is a block diagram showing the configuration of a flexographic printing system (printing relief printing system (printing apparatus)) 60 according to an embodiment of the present invention.

  The flexographic printing system 60 includes a RIP (Raster Image Processor) device 61 and a printing plate manufacturing device 62. The RIP device 61 and the printing plate manufacturing device 62 constitute a plate making device (plate making method) for forming a relief 50 (relief pattern) based on image data (relief pattern data) on the flexographic plate material F (flexographic printing plate 1). Has been.

  The RIP device 61 includes a RIP processing unit 66, a screening processing unit (binary image data generation unit) 68, and an exposure amount data generation unit 70.

  The RIP processing unit 66 outputs page description language (PDF) data such as PDF (Portable Document Format) data and PS (PostScript (registered trademark)) data representing a vector image of a printed document edited using a computer or the like. And raster image data.

  Each pixel data constituting the raster image data can take 8 bits, that is, 256 (0 to 255) gradations for each channel in four channels of CMYK, for example, as gradation values. Such a gradation can be converted into a corresponding halftone dot area ratio (halftone dot density). For example, when the halftone dot area ratio takes a value from 0 to 100, a solid portion is formed when the halftone dot area ratio is 100, and a halftone dot projection (for halftone dot printing) when the halftone dot area ratio is zero. The protrusions or simply the protrusions may not be formed.

  The screening processing unit 68 screens the raster image data under conditions such as a predetermined network (AM halftone dot, FM halftone dot, etc.), angle, screen line number, etc., and converts the raster image data into binary image data. For example, if the number of screen lines is 175 lines / inch and the gradation that can be expressed by one halftone dot is 256 (= 16 × 16) gradation, the screening processing unit 68 has a resolution of 2800 (= 175 × 16) dpi. Binary bitmap data can be generated.

  The exposure amount data generation unit 70 converts the binary image data into exposure amount data that can be expressed by 16 bits (65536 gradations) or the like. Details of the exposure amount data generation unit 70 will be described later (see FIG. 12).

  On the other hand, the printing plate manufacturing apparatus 62 has an engraving-type CTP (Computer To Plate) drawing machine 72, and the CTP drawing machine 72 includes the laser engraving machine 20 (see FIG. 3). In the printing plate manufacturing apparatus 62, the laser engraving process (exposure process) by the CTP drawing machine 72 is performed based on the exposure amount data supplied from the RIP device 61 (exposure amount data generation unit 70). , Elastic materials such as rubber). Thereby, the relief 50 reflecting the image to be printed is engraved on the flexographic printing material F (flexographic printing plate 1). Although details will be described later, the printing plate manufacturing apparatus 62 (CTP drawing machine 72) of this example is based on relief pattern data (engraving shape data, exposure amount data) corrected according to the printing pressure distribution condition and the printing condition. A relief is formed on the flexographic printing material F (flexographic printing plate 1) (relief forming step).

  The flexographic printing plate 1 manufactured in this way is used in a flexographic printing machine 10 (see FIGS. 1 and 2) provided in a subsequent stage, and is used to transfer and print a desired image on a printing medium 3.

  FIG. 12 is a functional block diagram showing a configuration example of the exposure amount data generation unit 70 in FIG.

  The exposure amount data generation unit 70 includes a projection height data conversion unit 74, an engraving shape data conversion unit 76, a plate thickness distribution acquisition unit 77, an engraving shape data correction unit 78, a printing condition acquisition unit 79, and an exposure amount data conversion unit 80. including.

  The projection height data conversion unit 74 converts the binary image data from the screening processing unit 68 into projection height data representing a two-dimensional distribution of the height of the relief 50 (projection height).

  The engraving shape data conversion unit 76 converts the protrusion height data supplied from the protrusion height data conversion unit 74 into higher-resolution engraving shape data (relief pattern data). This engraving shape data is data obtained by two-dimensional interpolation of the projection height data in order to reproduce the three-dimensional shape of the projection, and the depth indicating the distance in the depth direction of the flexographic printing plate F It can also be data.

  As described above, in this example, the projection height data conversion unit 74 and the engraving shape data conversion unit 76 constitute a “relief calculation unit that calculates relief pattern data based on image data”.

  The plate thickness distribution acquisition unit 77 acquires plate thickness distribution data indicating the plate thickness distribution of the flexographic printing material F (flexographic printing plate 1). In the example shown in FIG. 12, the thickness (plate thickness distribution) of the flexographic printing material F to be relief engraved is measured by the plate thickness distribution measuring device 43 provided separately from the exposure amount data generating unit 70 (RIP device 61). The measurement result is stored in the plate thickness distribution storage unit 44. The plate thickness distribution acquisition unit 77 reads the thickness of the flexographic printing material F (plate thickness distribution data) stored in the plate thickness distribution storage unit 44 and supplies it to the engraving shape data correction unit 78. From the viewpoint of performing plate making quickly and smoothly, the flexo plate material F after the plate thickness distribution measurement is automatically obtained by performing the measurement by the plate thickness distribution measuring device 43 in the preceding stage of the exposure amount data generating unit 70 (RIP device 61). In particular, it is preferably set in the printing plate manufacturing apparatus 62 (CTP drawing machine 72). Further, the plate thickness distribution data measured and acquired by the plate thickness distribution measuring device 43 may be sent directly to the plate thickness distribution acquisition unit 77.

  The printing condition acquisition unit 79 acquires a printing condition indicating the characteristics of at least one of the ink attached to the flexographic printing plate 1 (flexographic printing material F), the printing medium 3 and the relief 50 of the flexographic printing plate 1.

  The printing conditions here can include various conditions that can affect the behavior of the ink on the printing medium 3 during printing in a broad sense, and the flexographic printing plate 1 and the printing medium 3 that are used. And based on the type (characteristic) of the ink. More specific printing conditions include, for example, “composition, hardness, surface characteristics (surface roughness (smoothness), surface energy, etc.), and other characteristics (viscoelasticity, etc.)” of the flexographic printing plate 1 and the printing medium 3. And one or more information (conditions) of “composition, viscosity, and other characteristics (surface tension, etc.)” of the ink. Note that the printing conditions may be indirectly represented by attribute information (lot, code (model number, etc.)) representing the types and characteristics of the flexographic printing plate 1, the printing medium 3, and the ink.

  The acquisition (conditioning) of printing conditions may be based on manual input by the user, or the measurement result of automatically measuring the type / characteristics of the flexographic printing plate 1, printing medium 3 and ink to be used by any method. May be based on automatic input using. In the example shown in FIG. 12, the user inputs printing conditions (printing condition data) to the printing condition input unit 46, and the inputted printing condition data is stored in the printing condition storage unit 47. The printing condition acquisition unit 79 reads out the printing condition data (the characteristics of the flexographic printing plate 1, the printing medium 3, and ink) stored in the printing condition storage unit 47 and supplies it to the engraving shape data correction unit 78. Note that the printing condition data input to the printing condition input unit 46 may be sent directly to the printing condition acquisition unit 79.

  The printing condition storage unit 47 and the printing condition input unit 46 of this example are provided as a part of the RIP device 61 (see FIG. 11), but may be provided separately from the RIP device 61, respectively. If the printing conditions are determined in advance, the determined printing conditions (printing condition data) may be stored in the printing condition storage unit 47 and the printing condition input unit 46 may be omitted. The printing conditions (printing condition data) are stored in the printing condition storage unit 47 in advance, and are stored in the printing condition storage unit 47 only when printing is performed under a printing condition different from the stored printing conditions. The print condition may be corrected via the print condition input unit 46.

  The engraving shape data correction unit 78 is based on the printing pressure distribution conditions (engraving shape data, plate thickness distribution data) indicating the printing pressure distribution of the flexographic printing plate 1 pressed against the printing medium 3, and the printing conditions. It functions as a relief determining unit that corrects engraving shape data (relief pattern data) to determine relief pattern data. Details of the engraving shape data correction unit 78 will be described later (see FIG. 13).

  The exposure amount data conversion unit 80 converts the engraving shape data (relief pattern data) corrected and determined by the engraving shape data correction unit 78 into exposure amount data corresponding to the amount of exposure light for the flexographic printing plate F. The exposure amount data conversion unit 80 (exposure amount data generation unit 70) of this example is provided as a part of the RIP device 61 (see FIG. 11), but may be provided on the printing plate manufacturing device 62 side.

  In this way, the exposure amount data is calculated from the corrected engraving shape data (relief pattern data). Based on the calculated exposure amount data, the printing plate manufacturing apparatus 62 (see FIG. 11) uses the flexographic printing material F (flexographic plate material F). A relief 50 is formed on the printing plate 1).

  The data correction based on the printing pressure distribution condition and the printing condition of the flexographic printing plate 1 can be performed based on various methods, and the data correction amount calculated based on the printing pressure distribution condition and the printing condition is used as the engraving shape data. It may be reflected in the exposure amount data. When the data correction amount is reflected in the engraving shape data, the engraving shape data including the correction amount is converted into exposure amount data, and an exposure process is performed using the converted exposure amount data. On the other hand, when the data correction amount is reflected in the exposure amount data, “exposure amount data based on engraving shape data (not reflecting the data correction amount)” and “exposure amount data based on the data correction amount itself” are calculated. From both, “exposure amount data reflecting the data correction amount” is calculated. In the example shown in FIG. 13 below, a case where the data correction amount is reflected in the engraving shape data will be described.

  FIG. 13 is a functional block diagram illustrating a configuration example of the engraving shape data correction unit 78 of FIG.

  The engraving shape data correction unit 78 includes a printing pressure distribution estimation unit 82, a correction amount calculation unit 84, a data correction unit 86, and a condition identification mark determination unit 87.

  The printing pressure distribution estimation unit 82 presses against the printing medium 3 during printing based on the engraving shape data (image data) from the engraving shape data conversion unit 76 and the plate thickness distribution data from the plate thickness distribution acquisition unit 77. The printing pressure distribution (printing pressure distribution condition) of the obtained flexographic printing plate 1 is estimated and acquired. The printing pressure distribution estimation unit 82 may estimate the printing pressure distribution based on the image data before being converted into the engraving shape data, or may estimate the printing pressure distribution based on the engraving shape data. When the printing pressure distribution is calculated more precisely, or when the relief shape cannot be engraved according to the 1-bit image due to the characteristics of the engraving device (printing plate manufacturing device 62), the engraving shape data representing the shape actually engraved It is preferable that the printing pressure distribution is estimated based on this.

  The correction amount calculation unit 84 calculates the correction amount of the engraving shape data (relief pattern data) based on the printing pressure distribution condition acquired by the printing pressure distribution estimation unit 82 and the printing condition acquired by the printing condition acquisition unit 79. Then, final engraving shape data (relief pattern data) is determined. A specific calculation example of the correction amount will be described later (see FIG. 19).

  The data correction unit 86 corrects the engraving shape data (relief pattern data) obtained by the engraving shape data conversion unit 76 based on the correction amount calculated by the correction amount calculation unit 84.

  In the flexographic printing plate 1 of this example, a “printing condition identification unit” indicating printing conditions is formed by exposure together with a relief 50 based on image data. A specific shape or the like of the printing condition identification unit is determined based on the printing condition data by the condition identification mark determination unit 87 of the engraving shape data correction unit 78.

  FIG. 14 is an external view of the printing surface of the flexographic printing plate 1, and illustrates the flat flexographic printing plate 1 for easy understanding. The flexographic printing plate 1 of this example has an image relief region (image line portion) 12 provided at the central portion of the plate and a plurality of printing condition control regions 14 provided at the end portions of the plate. The image relief area 12 is an area where the relief 50 based on the image data is engraved, and the printing condition control area 14 is used for alignment for cutting the printing medium 3 to a finished size and for registering multicolor printing. This is a region for a mark (Registration Guide). In this example, the printing condition control areas 14 are provided in a total of eight places at the four corners and the center of each side of the flexographic printing plate 1, and one or a plurality of areas (upper left in FIG. 14) of those printing condition control areas 14 are provided. A printing condition identification unit 16 is provided in the corner printing condition control area 14).

  The printing condition identification unit 16 is a part that prints information about printing conditions (printing condition information) on the printing medium 3, and a desired image based on image data when the flexographic printing plate 1 is pressed against the printing medium 3. At the same time, the printing condition information is transferred and printed on the printing medium 3. The printing condition information printed on the printing medium 3 by the printing condition identification unit 16 may be such that the flexographic printing plate 1, the printing medium 3, and the ink characteristics and types are directly represented by characters or the like. (1D barcode, 2D barcode (QR code (registered trademark), etc.)) or the like may be used indirectly. The user can know the printing conditions for using the flexographic printing plate 1 by checking the printing condition identification unit 16 provided on the flexographic printing plate 1. Can effectively prevent the “correspondence between printing and printing conditions”. Further, the user can easily recognize the characteristics and types of the flexographic printing plate 1, the printing medium 3 and the ink used by confirming the printing condition information printed on the printing medium 3.

  Therefore, the condition identification mark determination unit 87 shown in FIG. 13 determines the shape, position, and the like of the printing condition identification unit 16 based on the printing conditions from the printing condition acquisition unit 79, and determines the data (printing) of the determined printing condition identification unit 16 Condition identification data) is sent to the correction amount calculation unit 84. The correction amount calculation unit 84 includes the correction amount of engraving shape data based on the printing pressure distribution condition and the printing condition, and the correction amount of engraving shape data based on the printing condition identification data (engraving shape data for engraving the printing condition identification unit 16 ) Is calculated. The data correction unit 86 of this example corrects the engraving shape data so that the printing condition identification unit 16 is engraved on the flexographic printing plate F together with the relief (image relief region 12) for printing and reproducing the image data. .

  Note that the shape, position, and the like of the printing condition identification unit 16 provided on the flexographic printing plate 1 are not particularly limited, and the specific printing method of the printing condition information on the printing medium 3 is not particularly limited. For example, printing condition information may be printed using a substance other than ink (such as a watermark liquid), or printing condition information may be printed by marking by pressing of the printing condition identification unit 16.

  FIG. 15 is a block diagram illustrating an arrangement example of the condition identification forming unit. In the above example, printing is performed by the condition identification forming unit 64a (condition identification mark determining unit 87) provided in the image relief forming unit 63 (RIP device 61, printing plate manufacturing device 62) that forms the relief 50 on the flexographic printing plate F. A condition identification unit 16 is formed on the flexographic printing plate 1. However, the timing for forming the printing condition identification unit 16 on the flexographic printing plate 1 (flexographic printing material F) is not particularly limited. For example, even if the printing condition identifying unit 16 is formed on the flexographic printing plate 1 (flexographic printing material F) by the condition identifying forming unit 64b provided at the subsequent stage of the image relief forming unit 63 or the condition identifying forming unit 64c provided at the preceding stage. Good.

  In this example, printing condition information is recorded on the printing medium 3 by the printing condition identification unit 16 provided on the flexographic printing plate 1, but the printing condition information is not recorded on the printing medium 3. The condition identification unit 16 may be used. For example, an information recording medium such as an IC chip capable of recording printing conditions may be used as the printing condition identification unit 16, and the user reads the printing condition information recorded in the printing condition identification unit 16 using a dedicated reader. Thus, it is possible to grasp the correspondence between the flexographic printing plate 1 and the printing conditions. The recording method and specific configuration of the printing condition identification unit 16 that electrically holds printing conditions are not particularly limited, and the reading method may be a contact type or a non-contact type (RFID (Radio Frequency IDentification) or the like). It may be.

  FIG. 16 is a flowchart showing the flow of processing in the engraving shape data correction unit 78 and the exposure amount data conversion unit 80. The printing pressure distribution is estimated based on the image data and plate thickness distribution data before conversion into engraving shape data. An example is shown. In the example shown in FIG. 16, the printing pressure distribution is calculated based on the image and the plate height distribution, and the engraving shape is corrected according to the printing pressure distribution and printing conditions (ink behavior on the printing medium 3). Furthermore, since the exposure beam diameter varies depending on the plate height, the relief 50 having a sculpture shape that takes into account the printing pressure distribution and printing conditions in advance is created by performing exposure correction and exposure conversion so as to obtain a target sculpture shape.

  That is, in this example, the printing pressure distribution estimation unit 82 (see FIG. 13) uses flexographic data based on image data before conversion into engraving shape data (see 1-bit image data example shown in FIG. 25 described later) and plate thickness distribution data. The printing pressure distribution of the printing plate 1 is calculated, and the printing pressure distribution condition is acquired (S10 in FIG. 16). The printing pressure distribution estimation unit 82 can acquire image data before conversion into engraving shape data via the engraving shape data conversion unit 76, and can acquire plate thickness distribution data via the plate thickness distribution acquisition unit 77. It is.

  On the other hand, the printing condition acquisition unit 79 (see FIG. 12) acquires printing conditions that can affect the behavior of ink on the printing medium 3 (thickness of ink based on printing conditions: dot spread) (S11).

  Based on these printing pressure distribution conditions and printing conditions, the correction amount of the engraving shape data (relief pattern data) is calculated by the correction amount calculation unit 84 (see FIG. 13). The data correction unit 86 corrects the engraving shape data (relief pattern data) calculated by the projection height data conversion unit 74 and the engraving shape data conversion unit 76 based on the image data based on the calculated correction amount. (S12). The correction amount calculation unit 84 and the data correction unit 86 of this example use the flexographic printing material F (flexographic printing plate 1) as a printing condition identification unit 16 (see FIG. 14) in addition to the relief 50 for printing and reproducing image data. The correction amount calculation and data correction for engraving are performed.

  Then, in the exposure amount data converter 80, exposure correction based on the plate thickness distribution data is added to the engraving shape data (S13), and the engraving shape data after the exposure correction is further converted into exposure amount data (S14). Note that the data correction amount based on the printing pressure distribution condition and the printing condition may be reflected in any of the data before conversion into exposure amount data and the data after conversion. Accordingly, as described above, the engraving shape data before conversion into exposure amount data may be corrected based on the calculated correction amount, or the converted exposure amount data may be corrected based on the calculated correction amount.

  FIG. 17 is a diagram showing a laser diameter at the time of laser exposure of the laser engraving machine 20. The beam diameter of the laser L used in the exposure process for forming the relief 50 on the flexographic plate material F (flexographic printing plate 1) changes in the traveling direction (plate thickness direction) C.

That laser L, the beam diameter d0 is minimum at the focus position f _0, based the focus position f _0, the beam diameter increases with distance from the focus position f ₀ (relative height). For example, in the example shown in FIG. 17, with respect to the plate thickness direction C, “the beam diameter dp at the focus position fp (the distance from the reference focus position f ₀ is Tp)” and “the focus position fq (the distance from the reference focus position f ₀ is The beam diameter dq ”at Tq) is“ dq> dp ”when“ Tq> Tp ”. The beam diameter of the laser L, based on the focus position f _0, with symmetry with respect to its traveling direction (plate thickness direction) C. Thus, across the reference focus position _{f 0} relates focus position fm and fn located opposite to the above-mentioned focus position fp and fq, the distance Tm from the reference focus position _{f 0} of the focus position fm is "Tm = Tp" When satisfying, the beam diameter dm at the focus position fm satisfies the relationship “dm = dp”. Similarly, if the distance Tn from the reference focus position _{f 0} of the focus position fn is "Tn> Tm ', the beam diameter dn of the focus position fn satisfies the relationship of"dn>dm'.

  Since the beam diameter of the laser L is an element that affects the irradiation range and irradiation intensity of the laser L, the exposure processing using the laser L is characteristic exposure characteristics in the thickness direction of the flexographic printing material F (flexographic printing plate 1). (Beam diameter, irradiation intensity, etc.). Therefore, it is preferable that the relief 50 is formed on the flexographic printing material F (flexographic printing plate 1) by an exposure process in which the exposure characteristics of the laser L are added. In particular, when the thickness of the flexographic printing material F (flexographic printing plate 1) is not constant, the engraving accuracy of the relief 50 can be improved by adding the exposure characteristics of the laser L in the plate thickness direction. Therefore, the exposure amount data conversion unit 80 derives the exposure characteristics regarding the plate thickness direction of the laser L (thickness direction of the flexographic printing plate 1) based on the plate thickness distribution data, and the exposure characteristics are converted into engraving shape data / exposure amount data. It is reflected (S13 in FIG. 16). The exposure amount data conversion unit 80 may acquire the plate thickness distribution data directly from the printing condition acquisition unit 79, or indirectly acquire the plate thickness distribution data via the engraving shape data correction unit 78. Also good.

  The engraving shape data subjected to the above-described “engraving shape data correction” (S12) and “exposure correction” (S13) is converted into exposure amount data by the exposure amount data conversion unit 80 (S14). It is sent to the printing plate manufacturing apparatus 62 (see FIG. 11). The “exposure correction based on the plate thickness distribution data (S13)” may be performed together with the “exposure amount data conversion (S14)”. That is, correction based on exposure characteristics may be added at the stage of engraving shape data or at the stage of exposure amount data so as to cancel manufacturing errors based on exposure characteristics that vary depending on the plate thickness of the flexographic printing plate F. May be.

  Through the above-described series of processes (S10 to S14), the relief 50 having the engraving shape based on the printing pressure distribution condition and the printing condition is applied to the flexographic printing material F (flexographic printing plate 1) by the exposure process in which the exposure characteristics are added. Therefore, it is possible to calculate exposure amount data for forming with high accuracy.

  FIG. 18 is a flowchart showing the flow of processing in the engraving shape data conversion unit 76, the engraving shape data correction unit 78, and the exposure amount data conversion unit 80. The printing pressure distribution is estimated based on the engraving shape data and the plate thickness distribution data. An example is shown. Of the processing steps in FIG. 18, the description of steps common to FIG. 16 is omitted.

  When the projection height data (relief pattern data) is obtained by the projection height data conversion unit 74 (see FIG. 12), the engraving shape data conversion unit 76 converts the engraving shape data from the projection height data (image data). Conversion is calculated (S20 in FIG. 18).

  Based on the obtained engraving shape data and plate thickness distribution data, a printing pressure distribution (printing pressure distribution condition) of the flexographic printing plate 1 is calculated in the printing pressure distribution estimation unit 82 (S21). In addition, the printing condition acquisition unit 79 acquires printing conditions that can affect the behavior (dot spread) of ink on the printing medium 3 (S22). Then, calculation of the correction amount of the engraving shape data based on the printing pressure distribution condition and the printing condition and execution of the correction are performed in the correction amount calculation unit 84 and the data correction unit 86 (S23), and exposure correction based on the plate thickness distribution data (S23). S24) and conversion into exposure data (S25) are performed in the exposure data converter 80 (see FIG. 12).

  Next, an example of calculating the correction amount of engraving shape data based on the printing pressure distribution condition and the printing condition will be described.

  FIG. 19 shows a process of calculating the pressing amount (printing pressure distribution) based on the image data (engraving shape data) and the plate thickness distribution, and calculating the correction amount based on the pressing amount (printing pressure distribution) according to the printing conditions. It is a flowchart explaining an example. Each process in the flow of FIG. 19 is mainly performed in the correction amount calculation unit 84 (see FIG. 13) of the sculpture shape data correction unit 78, but even if a part of the process is performed by other units as necessary. Good.

  The range of influence of the printing pressure distribution of the flexographic printing plate 1 varies depending on “plate hardness of the flexographic printing plate 1 (Shore A)” and “viscoelasticity of the flexographic printing plate 1”. Therefore, the size of ROI (Region of Interest) which is “printing pressure distribution range (predetermined range) for calculating the correction amount of engraving shape data” is determined based on the plate hardness and viscoelasticity of the flexographic printing plate 1. It is desirable. Therefore, first, the ROI (printing pressure distribution range) is determined based on the plate hardness and viscoelasticity of the flexographic printing plate 1 that is obtained in advance and stored in a memory or the like (S30 in FIG. 19). In addition, when the information regarding the plate hardness and viscoelasticity of the flexographic printing plate 1 is included in the above-described printing conditions, the ROI may be determined based on the printing conditions acquired by the printing condition acquisition unit 79.

  FIG. 20 is a diagram illustrating an example of an image for explaining the ROI. The ROI is composed of a predetermined area centered on the target position (target pixel) in the image, and the correction amount of the relief sculpture (sculpture shape data) at the target position is calculated based on the printing pressure distribution in the ROI. The Accordingly, the ROI is set for each position in the image, and “calculation of the amount of correction of the relief sculpture at the position of interest based on the printing pressure distribution in the ROI” described later is performed while sequentially changing the position of interest in the image. For example, when the plate hardness (Shore A) of the flexographic printing plate 1 is 79 ° and the viscoelasticity is about 15 MPa and the circular ROI shown in FIG. 20 is applied, the ROI size (diameter) is 500 μm to 3000 μm. A range may be set. In the example shown in FIG. 20, a circular ROI centered on the position of interest is set, but the size and shape of the ROI are not particularly limited.

  Next, the contact area ratio (contact area ratio) of the flexographic printing plate 1 with respect to the printing medium 3 in the ROI range is calculated (S31 in FIG. 19).

  That is, the area (contact area) of the relief portion that is in contact with the printing medium 3 in the ROI during printing and corresponds to the support of the flexographic printing plate 1 with respect to the printing medium 3 with respect to the “area of the entire ROI” ”(The contact area ratio in the ROI) R is calculated. For example, if the entire area in the ROI is a white area, the flexographic printing plate 1 (relief 50) and the printing medium 3 are not in contact with each other, so the area ratio is 0% and R is zero (R = 0). On the other hand, if the entire area within the ROI is a solid area, the flexographic printing plate 1 (relief 50) and the printing medium 3 are in contact with each other within the entire area within the ROI, so that the area ratio is 100%. Becomes 1 (R = 1). Therefore, R approaches zero if there are many white areas in the ROI, and R approaches one if there are many solid areas in the ROI.

  Next, the type of relief at the target position (target pixel) is determined. First, it is determined whether or not the target position is an area corresponding to a halftone dot (S32 in FIG. 19). This determination is made for each target position (target pixel) based on the image data (engraving shape data).

  When the target position is an area corresponding to a halftone dot (YES in S32), the amount of pressing of the target position corresponding to the area ratio (ground contact area ratio, halftone dot area ratio, halftone dot density) R of the halftone dot area is obtained. (S33).

  FIG. 21 is a diagram illustrating an example of a correspondence relationship between the contact area ratio (%) and the push-in amount in the ROI.

  As shown in FIG. 21, when the same load is applied, the push amount decreases as the ground contact area ratio in the ROI increases, and the push amount increases as the ground contact area ratio in the ROI decreases. This is because the smaller the contact area is, the larger the force (printing pressure) applied per unit area is, and the push-in amount increases as the printing pressure increases. This “correspondence between the contact area ratio in the ROI and the push amount” is measured in advance, stored in a memory or the like (not shown), and read out as necessary. Then, based on the read “correspondence between the contact area ratio in the ROI and the push amount”, the push amount of the target position corresponding to the area ratio R of the halftone dot region is obtained.

  Thus, in this example, the “push-in amount” related to the “printing pressure distribution” is used as a parameter. By using this “push-in amount” parameter, the printing plate pressed against the printing medium is used. The printing pressure distribution is indirectly estimated based on the image data. Note that “printing pressure (printing pressure distribution)” may be used as a use parameter. However, from the viewpoint of performing correction based on plate thickness distribution data described later, it is easier to use “push-in amount” as a parameter. It is.

  The pushing amount of the target position obtained in this way is corrected based on the height distribution (plate thickness distribution) of the flexographic printing material F (flexographic printing plate 1) (S34 in FIG. 19). That is, the pushing amount of the target position is corrected so as to cancel the variation in printing pressure caused by the variation in the plate thickness of the flexographic printing material F. The plate thickness distribution can be based on the lowest position height (reference height) in the solid area, that is, the contact position of the thinnest part in the solid area, based on the correspondence with the image. When the relief tip position (relief contact position) of the target position (target pixel) is relatively high with respect to this reference height, the amount of pushing at the target position increases, and when the position is relatively low, The pushing amount data at the position of interest is corrected so that the amount of pushing at the position of interest is reduced.

  Then, the correction amount of the engraving shape data is obtained based on the corrected “pushing amount data at the target position” (S35). In this example, the correction amount of the engraving shape data is calculated according to the printing conditions.

  FIG. 22 is a diagram illustrating an example of a correspondence relationship between the “push amount at the target position (target pixel)” and the “correction amount of the engraving shape data at the target position”. Note that the “reference value” in FIG. 22 corresponds to a pressing amount corresponding to a predetermined standard printing pressure.

  As shown in FIG. 22, the correction amount increases as the push amount increases, and the correction amount decreases as the push amount decreases. This is because the force (printing pressure) applied per unit area increases as the push-in amount increases, and the amount of deviation from the original printed image tends to increase as the printing pressure increases.

  This “correspondence between the push amount and the data correction amount” is measured in advance, stored in a memory (not shown), and read out as necessary. The data of “correspondence between the push amount and the data correction amount” is measured in advance for each printing condition and stored in a memory (not shown). From among the plurality of “correspondence relationship between push-in amount and data correction amount” data stored in the memory, data “correspondence relationship between push-in amount and data correction amount” corresponding to the printing condition is appropriately read out. Then, based on the read “correspondence between the push amount and the data correction amount”, the correction amount of the engraving shape data corresponding to the corrected “push amount data at the target position” is obtained.

  The data of “correspondence between indentation amount and data correction amount” for each printing condition can be obtained experimentally, changing one or both of “printing condition” and “indentation amount (printing pressure)”. However, it is desirable to obtain the required data correction amount and store it in the memory. The data correction amount can be determined based on, for example, the shape of the relief (diameter, height, volume, etc.).

  As described above, the pressing amount and the data correction amount are calculated based on the image data, the plate thickness distribution data, and the printing conditions. This is because the printing pressure distribution conditions are estimated based on the image data and the plate thickness distribution data. This is equivalent to calculating the correction amount of the relief pattern data based on the printing pressure distribution condition and the printing condition.

  The data shown in FIG. 21 and the data shown in FIG. 22 vary depending on the printing conditions and the engraving characteristics (relief forming characteristics) of the laser engraving machine 20, so that the data shown in FIG. 21 depends on the system used (flexographic printing system 60). Determined. Therefore, the data of “correspondence relationship between the contact area ratio in the ROI and the push amount” and the “push amount and the data correction amount at the target position (target pixel)” obtained in advance for each type of relief according to the printing conditions. The “correspondence relationship” data is stored in a predetermined memory (not shown), and is appropriately read and used when calculating the “engraving shape data correction amount”.

  When the target position is a halftone dot, the characteristic of “correspondence between the contact area ratio in the ROI and the pushing amount” according to the halftone dot area ratio (halftone dot density: halftone dot percentage) (see FIG. 21). Further, it is desirable that the characteristic (see FIG. 22) of “correspondence relationship between the push amount and the data correction amount at the target position (target pixel)” is changed and determined. In the case of a halftone dot having a high halftone dot percentage (particularly a halftone dot having a halftone dot area ratio of 50% or more), the deformation of the relief 50 of the flexographic printing plate 1 during printing is relatively small. This is because the deformation of the relief 50 of the flexographic printing plate 1 during printing is relatively large when the halftone dot is low.

  In this way, the “engraving shape data correction amount” when the target position is a halftone dot is calculated. On the other hand, when the position of interest is a convex fine line, the “correction amount of engraving shape data” is calculated in the same manner.

  That is, when it is determined that the target position is not a halftone dot (NO in S32 in FIG. 19) and is a region corresponding to a convex fine line (YES in S36), the area ratio (ground contact area ratio) R of the convex fine line region is set. The corresponding push amount of the target position is obtained (S37, see FIG. 21). Then, on the basis of the plate thickness distribution data of the flexographic printing plate material F, the indentation amount data at the target position is corrected (S38), and on the basis of the corrected “indentation amount data at the target position”, the printing condition is determined. The correction amount of the engraving shape data is obtained (S39, see FIG. 22).

  In this case, the characteristic of “correspondence between the contact area ratio in the ROI and the push amount” for calculating the correction amount of the engraving shape data and the correspondence between the push amount and the data correction amount at the target position (target pixel) The characteristic of “relation” is the characteristic when the target position is a convex thin line, and is basically different from the characteristic when the target position is a halftone dot (see FIGS. 21 and 22).

  On the other hand, when it is determined that the position of interest is not a convex thin line (NO in S36) and is an area corresponding to a solid (YES in S40), the correction amount is not calculated and the data correction unit 86 (see FIG. 13). The sculpture shape data is not corrected and is skipped. This is because in the solid area, the flexographic printing plate 1 and the printing medium 3 are in contact with each other, so that the engraving shape data need not be corrected.

  If it is determined that the position of interest is not a halftone dot, a convex thin line, or a solid (NO in S40), the amount of pushing of the position of interest corresponding to the area ratio (contact area ratio) R of other regions (S41, see FIG. 21). Then, based on the plate thickness distribution data of the flexographic printing plate F, the data of the pressing amount at the target position is corrected (S42), and based on the corrected “data of the pressing amount at the target position”, according to the printing conditions. A correction amount of the engraving shape data is obtained (S43, see FIG. 22).

  In this case, the characteristic of “correspondence between the contact area ratio in the ROI and the push amount” for calculating the correction amount of the engraving shape data and the correspondence between the push amount and the data correction amount at the target position (target pixel) The characteristic of “relation” is basically different from the characteristic in the case where the target position is a halftone dot (see FIGS. 21 and 22) and the characteristic in the case of a convex fine line.

  The characteristics of the “correspondence between the contact area ratio in the ROI and the push amount” used at the time of calculating the correction amount of the engraving shape data (see S30 to S43 in FIG. 19) and “at the target position (target pixel)” The characteristic of “correspondence relationship between indentation amount and data correction amount” is the same as the ROI size, regardless of whether the position of interest is a halftone dot, a convex fine line, or any other case. The printing condition (flexographic printing plate 1 (flexographic printing plate 1 It is desirable to determine it according to the plate hardness and viscoelasticity of the material F).

  When the correction amount of the engraving shape data is determined as described above, the data correction unit 86 (see FIG. 13) of the engraving shape data correction unit 78 corrects the engraving shape data based on the determined correction amount.

  The data correction unit 86 may be provided integrally with the exposure amount data conversion unit 80, and the “data correction amount” obtained based on the printing pressure distribution condition and the printing condition is directly applied to the engraving shape data. You may make it reflect with respect to exposure amount data instead of reflecting.

  FIG. 23 is a table (conversion table) showing an example of an exposure table for realizing shape correction. In FIG. 23, “exposure table (“ halftone dot ”,“ halftone ”,“ halftone ”,“ correction amount 1 ”to“ correction amount 5 ”)” and “relief type of target position (target pixel)”. "Exposure table 1" to "exposure table 5") "in" convex thin line "and" others "are associated.

  When the data correction unit 86 is provided integrally with the exposure amount data conversion unit 80, it corresponds to each of the determined “engraving shape data correction amounts” (see “correction amount 1” to “correction amount 5” in FIG. 23). The exposure amount data may be predetermined for each of “halftone dot”, “convex thin line”, and “other” (“exposure table 1” to “exposure table 5”). In this case, the exposure amount data conversion unit 80 generates exposure amount data in which the correction amount is reflected for each of the cases where the target position is a halftone dot, a convex fine line, a solid, or the like based on the conversion table as shown in FIG. It can be calculated.

  In this case, exposure correction (see “S13” in FIG. 16 and “S24” in FIG. 18) based on the plate thickness distribution data may also be performed by the exposure amount data conversion unit 80.

FIG. 24 is a table showing an exposure conversion table for realizing shape correction corresponding to the laser beam diameter. In FIG. 24, “focus position f ₀ ” represents the position (reference focus position) where the beam diameter is minimum (see FIG. 17), and “+” and “−” are the opposite sides across the reference focus position f _0. The unit of height is based on micrometers (μm). Therefore, the “focus position f ₊₁ ” and “focus position f ₊₂ ” and “focus position f ₋₁ ” and “focus position f ₋₂ ” shown in FIG. 24 are positioned on the opposite side across the reference focus position f _0. (Refer to “fp” and “fq” and “fm” and “fn” in FIG. 17). Regarding the distance from the reference focus position f ₀ , “focus position f ₊₁ ” and “focus position f ₋₁ ” are equal, and “focus position f ₊₂ ” and “focus position f ₋₂ ” are equal.

As shown in FIG. 24, exposure amount data corresponding to the relief height may be stored in a memory (not shown) as an exposure table. The laser engraving machine 20 (see FIG. 3) adjusts the focal position of the laser L so that the predetermined position of the flexographic printing plate F becomes the focus position (“f ₀ ” in FIG. 17) by the autofocus mechanism. The “height” (focus position) in the table of FIG. 24 is based on the reference focus position f ₀ , and the plate height (plate thickness) variation is represented by the distance (relative height) with respect to the focus position f ₀ . .

The exposure amount data conversion unit 80 can correct exposure amount data (exposure correction) based on the correction amount determined for each target position by referring to the exposure conversion table shown in FIG. Note that the exposure table for each focus position shown in FIG. 24 includes the correction amount (“correction amount 1” to “correction amount 5”) and the relief type (“halftone dot”, “convex thin line”, and “other” shown in FIG. ) Are assigned to each of the exposure tables (“Exposure Table 1” to “Exposure Table 5”) determined by Therefore, the exposure amount data conversion unit 80 calculates the relief type (“halftone dot”, “convex thin line”, and “other”) of the target position (target pixel) and the calculated data correction amount (“correction amount 1” to “correction amount”). 5 "), the corresponding exposure table (FIG. 23) is determined. On the other hand, the exposure amount data converter 80 calculates the plate height (plate thickness) with respect to the reference focus position f ₀ of the target position. Then, the exposure amount data conversion unit 80 corresponds to the plate height (plate thickness) at the target position in the “exposure table for each focus position shown in FIG. 24” assigned to the determined exposure table (FIG. 23). Determine the table. The exposure amount data is determined based on the exposure table determined in this way.

  Based on the “exposure amount data reflecting the correction amount” calculated in this way, the printing plate manufacturing apparatus 62 can perform appropriate relief engraving on the flexographic printing plate 1. It should be noted that, in the conversion calculation process of exposure amount data based on the engraving algorithm corresponding to the engraving apparatus (print plate manufacturing apparatus 62), numerical values (correction reflected values: exposure table) stored in the conversion tables as shown in FIGS. ) May be multiplied by exposure amount data before correction (exposure amount data derived from engraving shape data before correction) to calculate “exposure amount data reflecting the correction amount”.

<Example of relief correction>
By correcting the engraving shape data / exposure amount data as described above, it is possible to perform relief correction in consideration of printing pressure distribution conditions and printing conditions.

  FIG. 25 is a diagram illustrating an example of image data (1-bit image data) before conversion into engraving shape data, and FIG. 26 is a diagram illustrating an example of engraving shape data obtained from the image data in FIG. Each of FIGS. 25 and 26 shows a print image 90 reproduced on the printing medium 3 by image data / engraving shape data. Further, FIG. 27 shows a location where the tip of the relief 50 comes into contact with the printing medium 3 (relief tip shape 92) and the spread of the ink transferred from the tip of the relief 50 to the printing medium 3 (printed image 90). It is a figure which shows the example of a relationship.

  In the above example, the printing pressure distribution condition is estimated based on the area ratio (the number of black pixels) of the portion in contact with the printing medium 3 in the predetermined range of the flexographic printing plate 1. It may be estimated based on “image data before conversion into shape data” or may be estimated based on “engraving shape data” as shown in FIG. Further, the ink transferred from the flexographic printing plate 1 (relief 50) to the printing medium 3 exhibits spreading behavior according to the printing conditions, and the relief tip shape 92 and the printed image 90 do not necessarily match.

  28 and 29 are diagrams illustrating “engraved engraving shape data” obtained by correcting the engraving shape data shown in FIG. 26 based on the printing pressure distribution condition and the printing condition. In each of FIGS. 28 and 29, normal flexo printing (transfer printing) is performed on the basis of “engraved shape data after correction” in a state where the influence of the surrounding printing pressure distribution is ignored. An example of the printed image 90 reproduced above is shown.

  Compared with the “engraved shape data before correction” shown in FIG. 26, in the example shown in FIG. 28, the “engraved shape data” is corrected so that the print image 90 is thick overall, and in the example shown in FIG. The “engraving shape data” is corrected so that the image is thin as a whole. Therefore, for example, when the printing pressure applied to the target position becomes smaller than normal due to the surrounding state, the print data is corrected to “engraved shape data for thickening the print image 90” as shown in FIG. Thereby, even if the applied printing pressure is smaller than normal, as a result, it is possible to reproduce the same print image 90 on the printing medium 3 as when normal printing pressure is applied. On the other hand, when the printing pressure applied to the target position becomes larger than usual due to the surrounding state, the printing pressure applied is corrected by correcting to “sculpture shape data for thinning the print image 90” as shown in FIG. Even if it is larger than normal, as a result, the same print image 90 as when normal printing pressure is applied can be reproduced on the printing medium 3. Similarly, for example, in the case of a printing condition in which the degree of ink spread on the printing medium 3 is smaller than usual, correction is made to “engraved shape data for thickening the print image 90” as shown in FIG. As a result, it is possible to reproduce the same print image 90 on the printing medium 3 as in the case of the printing conditions showing the normal ink spreading behavior. On the other hand, in the case of a printing condition in which the degree of ink spread on the printing medium 3 is larger than usual, by correcting to “engraving shape data for narrowing the print image 90” as shown in FIG. It is possible to reproduce the same print image 90 on the printing medium 3 as in the case of the printing conditions showing the normal ink spreading behavior.

  FIG. 30 is an external perspective view showing an example of a relief 50 formed on a part of the flexographic printing plate 1, based on engraving shape data that is not corrected according to the printing pressure distribution condition and the printing condition. An example of a relief 50 (convex portion 51) engraved on the flexographic printing plate 1 is shown. FIG. 31 is an external perspective view showing an example of the relief 50 formed on a part of the flexographic printing plate 1, and based on the engraving shape data corrected according to the printing pressure distribution condition and the printing condition. An example of the relief 50 (convex portion 51) engraved on the printing plate 1 is shown.

The relief pattern formed on the flexographic printing plate 1 includes a plurality of convex portions 51, and each convex portion has a base portion and a tip portion provided on the base portion and pressed against the printing medium 3. The quality of the printed image 90 to be reproduced onto the print medium 3 in flexographic printing as greatly affects elements, the height of the convex portion 51 (see "T _A" in FIG. 30), the print medium of the convex portion 51 3 (the diameter: see “D _A ” in FIG. 30).

  Therefore, the engraving shape data (relief pattern data) preferably includes height data and shape data of the plurality of convex portions 51 included in the relief pattern. The correction amount of the engraving shape data based on the printing pressure distribution is preferably related to at least one of the height data and the shape data of these convex portions 51. In particular, it is preferable that the shape data of the convex portion 51 includes at least data on the shape of the tip portion. The data on the shape of the tip portion is data on a portion (surface) of the tip portion that is in contact with the printing medium during printing. It is preferable to contain. The height data of the plurality of convex portions is preferably related to at least one of the height of the tip portion, the height of the base portion, and the overall height of the tip portion and the base portion. It is preferable to relate to the overall height and the height of the tip.

The correction based on the printing pressure distribution conditions and printing conditions Therefore, (see "T _{B (=} T _A -ΔT)" in FIG. 31) the height of the convex portion 51 formed on the flexographic plate 1 (relief 50) and tip It is preferable to adjust the shape of the part (diameter: see “D _B ” in FIG. 31).

  FIG. 32 is an external view of the convex portion 51 for explaining an example of correcting the engraving shape (tip portion shape) of a small dot in a halftone dot according to the printing pressure distribution condition and the printing condition. In FIG. 32, (a) shows the convex portions 51 of “when a printing pressure larger than the standard acts” and “when the spreading behavior of the ink on the printing medium 3 is larger than the standard”, and (b) shows The convex portions 51 of “when a standard printing pressure is applied” and “when the ink spreading behavior on the printing medium 3 is standard” are shown, and (c) is “a printing pressure smaller than the standard is applied. The case 51 and the convex portion 51 of “when the ink spreading behavior on the printing medium 3 is smaller than the standard” are shown.

  Each of the convex portions 51 has a truncated cone-shaped base portion 52 and a columnar tip portion 53 provided on the base portion 52, and the tip portion 53 has the same cross-sectional diameter as the top portion of the base portion 52. have. In the example shown in FIG. 32, “the data of the shape of the plurality of convex portions 51” of the engraving shape data includes at least the data of the shape of the tip portion 53, and this “data of the shape of the tip portion 53” Including the data of the portion in contact with the printing medium 3 during printing, the shape (diameter) of the tip 53 of the convex portion 51 is corrected and adjusted according to the printing pressure distribution condition and the printing condition.

  In other words, when the influence from the periphery is small and the printing pressure applied to the target position is within the expected standard range, “the portion in contact with the printing medium 3 (grounding portion)” of the tip portion 53 of the convex portion 51. Is also set to a standard size (see “D2” in FIG. 32B). On the other hand, when the printing pressure applied to the target position is larger than the expected standard size due to the influence from the surroundings (when it is excessive), the convex pressure is higher than the standard printing pressure (FIG. 32B). The diameter of the tip end portion 53 of the portion 51 is reduced to reduce the tip end cross-sectional area (see “D1” in FIG. 32A). Accordingly, it is possible to perform prediction correction that reduces the “thickness of the ground contact portion and the printed image 90” that may be caused by the deformation of the convex portion 51 (the tip portion 53). Further, when the printing pressure applied to the target position is smaller than an expected standard size due to the influence from the surroundings (when it is too small), the convex portion is compared with the case of the standard printing pressure (FIG. 32B). The diameter of the ground contact portion of the tip portion 53 of 51 is increased to increase the cross-sectional area of the tip portion (see “D3” in FIG. 32C). Accordingly, prediction correction is performed to reduce the influence of “smoothing of the ground contact portion and the printed image 90” that may be caused by insufficient deformation of the convex portion 51 (tip portion 53) or insufficient ink spread due to a printing pressure smaller than expected. be able to.

  Further, in this example, the ink spreading behavior on the printing medium 3 based on the printing conditions is further added, and when the ink spreading behavior is standard, the “printing medium” of the tip 53 of the convex portion 51 is selected. The diameter of the portion in contact with 3 (grounding portion) ”is also set to a standard size (see“ D2 ”in FIG. 32B). On the other hand, when the spread of the ink on the printing medium 3 is larger than the standard (excessive), the diameter of the tip 53 of the convex portion 51 is larger than that in the standard ink behavior (FIG. 32B). Is reduced to reduce the cross-sectional area of the tip (see “D1” in FIG. 32A). As a result, it is possible to perform prediction correction that reduces the “thickness of the printed image 90” that may be caused by the ink behavior on the printing medium 3. In addition, when the spread of ink on the printing medium 3 is smaller than the standard (too small), the diameter of the tip 53 of the convex portion 51 is larger than that in the standard ink behavior (FIG. 32B). Is reduced to reduce the cross-sectional area of the tip (see “D3” in FIG. 32C). As a result, it is possible to perform predictive correction that reduces the “thinness of the print image 90” that may be caused by the ink behavior on the print medium 3.

  As described above, in this example, the shape of the convex portion 51 (the shape of the relief 50) is determined by comprehensively considering the printing pressure distribution and the printing condition (ink behavior), and the sectional diameter of the tip portion 53 is controlled. Therefore, unintended printing image 90 can be prevented from being thickened or thinned, and high-quality flexographic printing can be performed.

  FIG. 33 is an external view of a convex portion 51 (relief 50) for explaining an example of correcting the engraving shape (convex height) of a small dot in a halftone dot according to the printing pressure distribution condition and the printing condition. . In FIG. 33, (a) shows the convex portions 51 of “when a printing pressure larger than the standard acts” and “when the spreading behavior of the ink on the printing medium 3 is larger than the standard”, and (b) shows The convex portions 51 of “when a standard printing pressure is applied” and “when the ink spreading behavior on the printing medium 3 is standard” are shown, and (c) is “a printing pressure smaller than the standard is applied. The case 51 and the convex portion 51 of “when the ink spreading behavior on the printing medium 3 is smaller than the standard” are shown.

  In the example shown in FIG. 32, the “diameter of the tip 53 of the convex portion 51 (relief 50)” is adjusted to correct the engraving shape data based on the printing pressure distribution condition and the printing condition. Such correction may be performed by adjusting (height / lowering) the “height”. That is, by adjusting the height of the ground contact portion of the tip portion 53 of the convex portion 51, the magnitude of the printing pressure applied to the target position is controlled, and unintended deformation of the convex portion 51 and ink behavior during printing are prevented. It is possible.

  The adjustment of the “height of the convex portion 51” herein refers to adjustment of the relative relief height in the relief forming area of the flexographic printing plate 1 (see the image relief area 12 in FIG. 14). is there. For example, by adjusting the relative position (relative height) with respect to the position (height) of the top of the relief of the solid portion printing region (see “solid region” in FIG. 4), the height of the convex portion 51 is adjusted. Is adjustable.

  Depending on the characteristics of the engraving device, the grounding surface (minimum grounding surface) of the relief 50 (projection 51) used for halftone dot printing having the minimum diameter is limited. By adjusting the “height of the convex portion 51”, it is possible to control the relative distance from the printing medium 3 and to reduce the print small dot diameter.

  For example, when the printing pressure applied to the target position is within the expected standard range, or when the ink spreading behavior on the printing medium 3 is standard, the tip 53 of the convex portion 51 The “height of the convex portion 51” is also set to a standard height (see “T2” in FIG. 33B). On the other hand, when the printing pressure applied to the target position is larger than an expected standard size, or when the ink spread on the printing medium 3 is larger than the standard, the standard printing pressure (FIG. 33 (b) )) Is made smaller (see “T1” in FIG. 33A). Accordingly, it is possible to perform prediction correction that reduces the “thickness of the ground contact portion and the printed image 90” that may be caused by the deformation of the convex portion 51 (tip portion 53) or the spreading behavior of the ink. Further, when the printing pressure applied to the target position is smaller than an expected standard size, or when the ink spread on the printing medium 3 is smaller than the standard, the standard printing pressure (FIG. 33 (b) )) Is increased (see “T3” in FIG. 33C). Accordingly, prediction correction is performed to reduce the influence of “smoothing of the ground contact portion and the printed image 90” that may be caused by insufficient deformation of the convex portion 51 (tip portion 53) or insufficient ink spread due to a printing pressure smaller than expected. be able to.

  FIG. 34 is an external view of the convex portion 51 (relief 50) for explaining an example of correcting the engraving shape (convex tip portion volume) of the small dot in the halftone dot according to the printing pressure distribution condition and the printing condition. is there. In FIG. 34, (a) shows the convex portions 51 of “when a printing pressure larger than the standard acts” and “when the spreading behavior of the ink on the printing medium 3 is larger than the standard”, and (b) shows The convex portions 51 of “when a standard printing pressure is applied” and “when the ink spreading behavior on the printing medium 3 is standard” are shown, and (c) is “a printing pressure smaller than the standard is applied. The case 51 and the convex portion 51 of “when the ink spreading behavior on the printing medium 3 is smaller than the standard” are shown.

  In the example shown in FIGS. 32 and 33, the sculpture shape data is corrected based on the printing pressure distribution by adjusting the size (tip end diameter, convex height) of the convex portion 51 (relief 50) in the one-dimensional direction. Although it is performed, the engraving shape data correction based on the printing pressure distribution may be performed from a three-dimensional viewpoint. That is, the engraving shape data directly or indirectly includes volume data of the plurality of convex portions 51 included in the relief pattern, and the correction amount of the engraving shape data based on the printing pressure distribution condition and the printing condition is It is preferably related to data. By controlling the volume of the convex portion 51 (particularly, the volume of the tip portion 53), it is possible to adjust the magnitude of the printing pressure applied to the target position and prevent unintentional deformation of the convex portion 51 and ink behavior during printing. Is possible. The “volume data of the convex portion 51” referred to here is an indirect “represented by the data of the cross-sectional shape (cross-sectional diameter, etc.) and the height data of the convex portion 51 (the base portion 52 and the tip portion 53). It may be “volume data”.

  In the example shown in FIG. 34, each convex portion 51 is provided integrally so that the bottom of the truncated cone-shaped tip portion 53 is positioned on the top of the truncated cone-shaped base portion 52. And the bottom cross-sectional diameter of the tip end portion 53 do not necessarily coincide with each other, and there is a relationship of “cross-sectional diameter of the top portion of the base portion 52”> “cross-sectional diameter of the bottom portion of the front end portion 53”. In this configuration, it is possible to control the print small dot diameter by adjusting the “volume of the tip 53 of the convex portion 51”.

  For example, when the printing pressure applied to the target position is within an expected standard range, or when the ink spreading behavior on the printing medium 3 is standard, the volume of the tip 53 of the convex portion 51 is determined. The diameter and height of the distal end portion 53 are determined so as to be a standard size (see “D2” and “TH2” in FIG. 34B). On the other hand, when the printing pressure applied to the target position is larger than an expected standard size, or when the ink spread on the printing medium 3 is larger than the standard, the standard printing pressure (FIG. 34 (b)). )), The diameter and height of the tip portion 53 are determined so that the volume of the tip portion 53 of the convex portion 51 is reduced (see “D1” and “TH1” in FIG. 34A). Accordingly, it is possible to perform prediction correction that reduces the “thickness of the ground contact portion and the printed image 90” that may be caused by the deformation of the convex portion 51 (tip portion 53) or the spreading behavior of the ink. Further, when the printing pressure applied to the target position is smaller than an expected standard size, or when the ink spread on the printing medium 3 is smaller than the standard, the standard printing pressure (FIG. 34 (b)). )), The diameter and height of the tip portion 53 are determined so that the volume of the tip portion 53 of the convex portion 51 is larger (see “D3” and “TH3” in FIG. 34C). Accordingly, prediction correction is performed to reduce the influence of “smoothing of the ground contact portion and the printed image 90” that may be caused by insufficient deformation of the convex portion 51 (tip portion 53) or insufficient ink spread due to a printing pressure smaller than expected. be able to.

  In addition to the tip portion 53 of the convex portion 51 (or in place of the tip portion 53 of the convex portion 51), the volume of the base portion 52 may be adjusted. That is, when the printing pressure larger than the standard is applied or the degree of ink spreading on the printing medium 3 is large so as to reduce the influence of the surroundings on the printing pressure and the influence of the ink behavior, The diameter of the base portion 52 is increased so that the volume of the base portion 52 is increased when the printing pressure is smaller than the standard or when the degree of ink spreading on the printing medium 3 is small. The height may also be determined (see “DB1” to “DB3” and “TL1” to “TL3” in FIGS. 34A to 34C). However, since the volume of the tip portion 53 usually has a greater influence on the printing pressure than the base portion 52, it is often better to preferentially control the volume (diameter, height) of the tip portion 53.

  The engraving shape (engraving shape data) of the relief 50 for the halftone dots (convex portion 51) of the flexographic printing plate 1 may be adjusted by a method other than the above. Further, by combining the methods shown in FIGS. 32 to 34 described above, the diameter and height of the tip portion 53 of the convex portion 51, the diameter and height of the base portion 52, and the size between the tip portion 53 and the base portion 52 are combined. The ratio (volume ratio) and the like may be adjusted as appropriate.

  In the above description, the engraving shape correction for halftone printing has been described, but other engraving shape corrections can be performed in the same manner.

  FIG. 35 is an external view of the convex portion 51 for explaining an example of correcting the relief engraving shape (tip portion shape) for convex fine line printing according to the printing pressure distribution condition and the printing condition. In FIG. 35, (a) is an external perspective view of the convex portion 51 for printing fine convex lines, and (b) is “when printing pressure larger than the standard acts” and “spread of ink on the printing medium 3”. The sectional view of the convex portion 51 when the behavior is larger than the standard is shown, and (c) shows the case where the standard printing pressure acts and the case where the ink spreading behavior on the printing medium 3 is standard. 4D is a cross-sectional view of the convex portion 51, and (d) shows the convex portion 51 of “when a printing pressure smaller than the standard acts” and “when the ink spreading behavior on the printing medium 3 is smaller than the standard”. FIG.

  The convex portion 51 for printing convex fine lines in this example has a base portion 52 and a tip portion 53 provided on the top surface of the base portion 52, and the base portion 52 has a quadrangular prism shape with a trapezoidal side surface. The distal end portion 53 has a quadrangular prism shape with a rectangular side surface.

  For example, when the printing pressure applied to the target position is within the expected standard range, or when the ink spreading behavior on the printing medium 3 is standard, the tip 53 of the convex portion 51 The size (width) of the “top portion (grounding portion) in contact with the printing medium 3” is also set to a standard size (see “D2” in FIG. 35C). On the other hand, when the printing pressure applied to the target position is larger than an expected standard size or when the ink spread on the printing medium 3 is larger than the standard, the standard printing pressure (FIG. 35 (c) )), The size (width) of the tip 53 of the convex portion 51 is reduced to reduce the tip cross-sectional area (see “D1” in FIG. 35B). As a result, it is possible to perform prediction correction that reduces the “thickness of the ground contact portion and the printed image 90” that can be caused by deformation of the convex portion 51 (tip portion 53) or ink spreading behavior. Further, when the printing pressure applied to the target position is smaller than an expected standard size, or when the ink spread on the printing medium 3 is smaller than the standard, the standard printing pressure (FIG. 35 (c) )), The size (width) of the tip 53 of the convex portion 51 is increased to increase the tip cross-sectional area (see “D3” in FIG. 35D). Accordingly, prediction correction is performed to reduce the influence of “smoothing of the ground contact portion and the printed image 90” that may be caused by insufficient deformation of the convex portion 51 (tip portion 53) or insufficient ink spread due to a printing pressure smaller than expected. be able to.

  Further, the sculpture shape data may be corrected from a three-dimensional viewpoint. By controlling the volume of the convex portion 51 (particularly, the volume of the tip portion 53), the magnitude of the printing pressure applied to the target position is adjusted. It is possible to prevent unintended deformation of the convex portion 51 and ink behavior during printing.

  FIG. 36 is an external view of the convex portion 51 (relief 50) for explaining an example in which the relief engraving shape (tip end volume) for convex fine line printing is corrected according to the printing pressure distribution condition and the printing condition. 36 (a) is an external perspective view of the convex portion 51 for printing convex fine lines, and FIG. 36 (b) is a case where “printing pressure larger than the standard acts” and “spread of ink on the printing medium 3”. The sectional view of the convex portion 51 when the behavior is larger than the standard is shown, and (c) shows the case where the standard printing pressure acts and the case where the ink spreading behavior on the printing medium 3 is standard. 4D is a cross-sectional view of the convex portion 51, and (d) shows the convex portion 51 of “when a printing pressure smaller than the standard acts” and “when the ink spreading behavior on the printing medium 3 is smaller than the standard”. FIG.

  The base portion 52 of the convex portion 51 for printing convex fine lines in this example has a trapezoidal square columnar shape on the side surface as in the convex portion 51 of FIG. 35, and the tip portion 53 also has a trapezoidal rectangular columnar shape on the side surface. Have

  For example, when the printing pressure applied to the target position is within an expected standard range, or when the ink spreading behavior on the printing medium 3 is standard, the volume of the tip 53 of the convex portion 51 is determined. The size (width) of the “top portion (grounding portion) in contact with the printing medium 3” in the front end portion 53 is also set to a standard size (FIG. 36C). (See “D2”). On the other hand, when the printing pressure applied to the target position is larger than an expected standard size, or when the ink spread on the printing medium 3 is larger than the standard, the standard printing pressure (FIG. 36 (c) )), The size (width) of the ground contact portion in contact with the print medium 3 in the front end portion 53 is determined so that the volume of the front end portion 53 of the convex portion 51 is reduced (“D1” in FIG. 36B). "reference). Accordingly, it is possible to perform prediction correction that reduces the “thickness of the ground contact portion and the printed image 90” that may be caused by the deformation of the convex portion 51 (tip portion 53) or the spreading behavior of the ink. Further, when the printing pressure applied to the target position is smaller than an expected standard size, or when the ink spread on the printing medium 3 is smaller than the standard, the standard printing pressure (FIG. 36 (c) )), The size (width) of the ground contact portion in contact with the print medium 3 in the front end portion 53 is determined so that the volume of the front end portion 53 of the convex portion 51 is larger (“D3” in FIG. 36D). "reference). Accordingly, the prediction correction that reduces the influence of “smoothing of the grounding portion and the printed image 90” that may be caused by insufficient deformation of the convex portion 51 (tip portion 53) or insufficient ink spreading due to a printing pressure smaller than expected. It can be carried out.

  The engraving shape (engraving shape data) of the relief 50 (convex portion 51) for the convex fine line of the flexographic printing plate 1 may be adjusted by a method other than the above. Further, by combining the methods shown in FIGS. 35 to 36, the width and height of the tip 53 of the convex portion 51, the width and height of the base 52, and the size between the tip 53 and the base 52 are combined. The ratio (volume ratio) and the like may be adjusted as appropriate.

  As described above, according to the above-described embodiment, the printing pressure distribution is estimated based on the plate thickness distribution of the flexographic printing material F (flexographic printing plate 1) and the image data, and the estimated printing pressure distribution (indentation) The correction amount for the relief pattern data based on the amount) is determined for each printing condition. Thereby, a desired printed matter can be stably obtained regardless of printing conditions and image contents (image data).

  It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described example, the example in which the relief pattern data is directly determined from the printing pressure distribution condition and the printing condition has been described. However, the relief pattern data may be indirectly determined from the printing pressure distribution condition and the printing condition.

  FIG. 37 is a functional block diagram showing a modification of the engraving shape data correction unit 78. As shown in FIG. The engraving shape data correction unit 78 of this modification has an ink behavior estimation unit 83. Based on the printing conditions supplied from the printing condition acquisition unit 79, the ink behavior estimation unit 83 determines the amount of ink transferred onto the printing medium 3 by the relief 50 of the flexographic printing plate 1 pressed against the printing medium 3. A print diameter condition indicating the range is estimated. The printing diameter condition here is an index indicating the range (spreading behavior) of the ink on the printing medium 3 at the time of transfer. For example, a simple index that classifies the degree of the range of the ink into a plurality of stages can be used. . The correction amount calculation unit 84 corrects relief pattern data (engraving shape data) based on the printing pressure distribution condition supplied from the printing pressure distribution estimation unit 82 and the print diameter condition supplied from the ink behavior estimation unit 83. The amount is calculated and final relief pattern data is determined. By using the “parameter indicating the spreading behavior of the ink (printing diameter condition)” corresponding to the printing condition in this way, even if the printing condition includes a plurality of parameters, the correction amount calculation unit can be relatively easily performed. At 84, relief pattern data can be determined.

  DESCRIPTION OF SYMBOLS 1 ... Flexographic printing plate, 2 ... Cushion tape, 3 ... Printing medium, 4 ... Plate cylinder, 6 ... Doctor chamber, 8 ... Anilox roller, 9 ... Impression cylinder, 10 ... Flexographic printing machine, 12 ... Image relief area, 14 ... Printing condition control area, 16 ... Printing condition identification unit, 20 ... Laser engraving machine, 22 ... Drum, 24 ... Axis, 26 ... Chuck member, 28 ... Exposure head, 30 ... Stage, 32 ... Focus position changing mechanism, 34 ... Motor: 36 ... Ball screw, 38 ... Mechanism, 40 ... Ball screw, 42 ... Sub-scanning motor, 43 ... Plate thickness distribution measuring device, 44 ... Plate thickness distribution storage unit, 46 ... Printing condition input unit, 47 ... Printing condition storage unit, DESCRIPTION OF SYMBOLS 50 ... Relief, 51 ... Convex part, 52 ... Base part, 53 ... Tip part, 60 ... Flexographic printing system, 61 ... RIP apparatus, 62 ... Printing plate manufacturing apparatus, 63 ... Image relief Forming unit, 64 ... condition identification forming unit, 66 ... RIP processing unit, 68 ... screening processing unit, 70 ... exposure amount data generation unit, 72 ... CTP drawing machine, 74 ... projection height data conversion unit, 76 ... engraving shape Data conversion unit, 77 ... plate thickness distribution acquisition unit, 78 ... engraving shape data correction unit, 79 ... printing condition acquisition unit, 80 ... exposure amount data conversion unit, 82 ... printing pressure distribution estimation unit, 83 ... ink behavior estimation unit, 84: Correction amount calculation unit, 86: Data correction unit, 87 ... Condition identification mark determination unit, 90 ... Print image, 92 ... Relief tip shape

Claims (21)

A plate making method for forming a relief on a printing plate based on relief pattern data,
A printing pressure distribution condition indicating a printing pressure distribution of the printing plate pressed against the printing medium, and at least one characteristic of the printing plate, the printing medium, and ink adhering to the relief of the printing plate A plate making method in which the relief pattern data is determined on the basis of a printing condition indicating the above.   The plate making method according to claim 1, wherein the printing pressure distribution condition is acquired based on image data and plate thickness distribution data indicating a plate thickness distribution of the printing plate.   The plate making method according to claim 1, wherein the printing pressure distribution condition is estimated based on an area ratio of a portion of the printing plate that contacts the printing medium.   The relief pattern data is determined based on a printing diameter condition indicating a range of the ink transferred onto the printing medium by the relief of the printing plate pressed against the printing medium. 4. The plate making method according to any one of 3 above.   The plate making method according to claim 4, wherein the printing diameter condition is estimated based on the printing condition.   The plate making method according to any one of claims 1 to 5, wherein the printing conditions include information on at least one of the composition and hardness of the printing plate. Calculating the relief pattern data based on the image data;
Obtaining the printing pressure distribution condition;
Obtaining the printing conditions;
A step of calculating a correction amount of the relief pattern data based on the printing condition and the printing pressure distribution condition;
The plate making method according to claim 2, further comprising: correcting the relief pattern data based on the correction amount. The relief includes a plurality of convex portions,
The relief pattern data includes height data and shape data of the plurality of convex portions,
The plate making method according to claim 7, wherein the correction amount of the relief pattern data relates to at least one of height data and shape data of the plurality of convex portions. The plurality of convex portions have a base portion and a tip portion provided on the base portion and pressed against the printing medium,
The plate making method according to claim 8, wherein the shape data of the plurality of convex portions includes at least data of the shape of the tip portion.   The plate making method according to claim 9, wherein the data of the shape of the tip portion of the plurality of convex portions includes data of a portion of the tip portion that contacts the printing medium during printing. The plurality of convex portions have a base portion and a tip portion provided on the base portion and pressed against the printing medium,
The height data of the plurality of convex portions relates to at least one of the height of the tip portion, the height of the base portion, and the overall height of the tip portion and the base portion. The plate making method according to any one of 10. The relief includes a plurality of convex portions,
The relief pattern data includes volume data of the plurality of convex portions,
The plate making method according to claim 7, wherein the correction amount of the relief pattern data relates to volume data of the plurality of convex portions.   The plate-making method as described in any one of Claims 1-12 including the step which forms the said relief in the said printing plate based on the corrected said relief pattern data. The relief is formed on the printing plate by an exposure process on the printing plate,
Based on the plate thickness distribution data indicating the plate thickness distribution of the printing plate, the exposure characteristics related to the thickness direction of the printing plate are derived,
The plate making method according to any one of claims 1 to 13, wherein the relief is formed on the printing plate by an exposure process in which exposure characteristics are taken into account.   The plate making method as described in any one of Claims 1-14 including the step which forms the printing condition identification part which shows the said printing conditions in the said printing plate. A plate making apparatus for forming a relief on a printing plate based on relief pattern data,
A printing pressure distribution condition indicating a printing pressure distribution of the printing plate pressed against the printing medium, and at least one characteristic of the printing plate, the printing medium, and ink adhering to the relief of the printing plate A plate making apparatus comprising a relief determining unit that determines the relief pattern data on the basis of a printing condition indicating.   The plate making apparatus according to claim 16, further comprising a printing condition input unit to which the printing conditions are input.   The plate making apparatus according to claim 16 or 17, further comprising a condition identification forming unit that forms a printing condition identification unit indicating the printing condition on the printing plate. A plate making apparatus according to any one of claims 16 to 18,
And a printing unit that presses a printing plate on which a relief is formed by the plate making apparatus against a printing medium. A printing plate on which a relief is formed,
A printing pressure distribution condition indicating a printing pressure distribution of the printing plate pressed against the printing medium, and at least one characteristic of the printing plate, the printing medium, and ink adhering to the relief of the printing plate A printing plate on which the relief is determined based on printing conditions indicating   The printing plate according to claim 20, wherein a printing condition identification unit indicating the printing conditions is formed.