JP2006248032A - Offset press - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an offset press enabling quick and precise adjustment of tone and density as to a printing plate cylinder having different pattern area ratios. <P>SOLUTION: The offset press 10 is equipped with an ink arrangement 24 comprising an ink roller 25 and many ink supply blades 16, the printing plate cylinder 30 connected to the ink arrangement 24 through the intermediary of an ink transfer roller group 27, and a blanket cylinder 31. The printing plate cylinder 30 has different pattern area ratios along the width direction, while a key opening degree of each ink supply blade 16 is adjusted by a control part 20 through the intermediary of a driving mechanism 16a. The control part 20 has an ink supply control amount per a unit tone adjustment instructive amount built in for each ink supply blade 16. This ink supply control amount per the unit tone adjustment instructive amount is determined beforehand by using the pattern area ratios of the printing plate cylinder 30. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an offset printing machine having an ink roller, a large number of ink supply blades, and a printing plate cylinder, and more particularly to an offset printing machine capable of adjusting the color tone in consideration of the pattern area ratio of the printing plate cylinder.

  As a conventional printing system such as an offset printing machine, a technique is known in which an ink supply device partitioned in the width direction is preset using a pattern area ratio in order to adjust the color tone of a printed matter (for example, Patent Document 1). For color tone management after the start of printing, individual ink supply amounts are automatically determined based on the pattern area ratio of the corresponding section by measuring the control strip (see Patent Document 2), measuring the color tone of the pattern (see Patent Document 3), etc. Corrected.

  However, when the control strip is used, the printing space is limited, and the introduction of the measuring strip and the control system are expensive, so that there are few results. For this reason, at present, the operator compares the printed matter actually printed out with the color tone sample, individually controls the ink supply devices partitioned in the width direction, and adjusts the color tone of the printed matter according to the sample.

In addition, an achromatic plate making technique having a different plate making process (pattern area ratio) is known (see Patent Document 4).
JP 58-166055 A JP-A-11-240137 Japanese Patent Laid-Open No. 10-16198 Japanese Patent Laid-Open No. 10-142775

  In a conventional printing system, in order to adjust the color tone of a printed material, when individually controlling the ink supply devices divided in the width direction of the printing plate cylinder, the operator controls these ink supply devices on the control panel. . In this case, the ink supply amount controlled by one scale controlled on the control panel is constant.

  On the other hand, the ink supply amount required to increase the color tone density by 0.1 varies depending on the pattern area ratio. For example, in order to increase the same color density, one scale may be necessary when the pattern area ratio is 10%, and three scales may be necessary when the pattern area ratio is 30%. In fact, if the pattern area ratio is large, the color tone density may not actually increase as expected, or conversely if the pattern area ratio is low, the color tone density may be too high.

  A skilled printing operator can predict the pattern area ratio from the pattern and can control the scale of the scale to be adjusted sensuously, but it is difficult for an operator with little experience to predict the pattern area ratio. Further, when the plate making process (pattern area ratio) is different from the conventional one in achromatic plate making or the like, it is difficult to predict from experience values. Further, when the color tone density is adjusted by a sense based on experience as described above, a large amount of web must be consumed and time is required until the color tone density is stabilized at the target density.

  The present invention has been made in consideration of such points, and an object of the present invention is to provide a printing system capable of easily and easily adjusting the color tone even by an operator with little experience.

  The present invention has an ink roller and a large number of ink supply blades arranged along the width direction of the ink roller, and is connected to the ink supply device and the ink supply device via an ink transmission roller group. Ink supply comprising: a printing plate cylinder to which ink from an ink supply device is supplied and having a different pattern area ratio in the width direction; and a blanket cylinder to which ink is transferred from the printing plate cylinder to perform printing on the web Each ink supply blade of the apparatus is individually driven by the drive control unit to adjust the key opening degree with the ink roller, and the drive control unit corresponds to each ink supply blade per unit color tone adjustment amount. The offset printing machine includes a key opening, and controls the key opening of each ink supply blade based on an input color tone adjustment amount.

  In the present invention, the key opening per unit color tone adjustment amount corresponding to each ink supply blade incorporated in the drive control unit is determined in advance using the relationship between the pattern area ratio, the key opening, and the color tone density. The offset printing machine is characterized in that it is determined based on the pattern area ratio in the width direction of the plate cylinder.

  In the present invention, the key opening per unit color tone adjustment amount corresponding to each ink supply blade incorporated in the drive control unit is determined in advance using the relationship between the pattern area ratio, the key opening, and the color tone density. The offset printing machine is defined based on the obtained image data.

  The present invention is an offset printing machine, wherein the offset printing machine is a rotary offset printing machine.

  The present invention is an offset printing machine, wherein the offset printing machine is a sheet-fed offset printing machine.

  As described above, according to the present invention, it is possible to quickly and accurately adjust the color tone density using an offset printing machine having printing plate cylinders having different pattern area ratios without depending on experience.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 are diagrams showing an embodiment of an offset printing machine according to the present invention.

  First, an outline of an offset printing machine according to the present invention will be described with reference to FIGS. 1 and 7A and 7B. Here, FIG. 7A is a schematic view of an offset printing machine, and FIG. 7B is an enlarged view showing an ink supply blade.

  As shown in FIGS. 1 and 2, the offset printing machine 10 is a rotary offset printing machine, and the offset printing machine 10 includes an ink roller 25 and a plurality of ink supplies arranged along the width direction of the ink roller 25. An ink supply device 24 having a blade (ink supply unit) 16 for supplying ink, and a printing plate cylinder connected to the ink supply device 24 via an ink transmission roller group 27 and supplied with ink from the ink supply device 24 30 and a blanket cylinder 31 on which ink is transferred from the printing plate cylinder 30 and printing is performed on the web W. Further, water is supplied to the printing plate cylinder 30 from a water supply device 32.

  The ink supply device 24 composed of the ink roller 25 and the ink supply blade 16, the ink transmission roller group 27, the printing plate cylinder 30, the blanket cylinder 31, and the water supply device 32 are provided in pairs above and below the web W, respectively. Printing is performed on the upper and lower surfaces of the web W by a pair of blanket cylinders 31.

  Further, a large number of ink supply blades 16 provided along the width direction of the ink roller 25 are driven by the corresponding drive mechanism 16a so as to be detachable from the ink roller 25 in the arrangement direction of the blade 16, and each drive mechanism 16a is driven. It is controlled by the control unit 20. Among these, a drive control unit is configured by the drive mechanism 16 a and the control unit 20 corresponding to each blade 16.

  As described above, the blades 16 are separated from and in contact with the ink roller 25 by the drive mechanism 16a, and the gap amount (key opening) between the blade 16 and the ink roller 25 is adjusted. In this case, when the key opening degree of each blade 16 increases, the ink supply amount from the blade 16 increases, and when the key opening degree decreases, the ink supply amount from the blade 16 decreases. The ink roller 25 and the blade 16 constitute an ink fountain, and the ink 23 is filled between the ink roller 25 and the blade 16.

  In this way, each ink supply blade 16 is driven and controlled by the control unit 20 via the corresponding drive mechanism 16 a, and for this reason, the ink supplied from each ink supply blade 16 to the printing plate cylinder 30 via the ink transmission roller group 27. The supply amount is individually controlled by the control unit 20. As will be described later, the printing plate cylinder 30 has a different pattern area ratio along the width direction, and the ink supply blades 16 are arranged along the width direction. It will have an area ratio.

  Incidentally, the control unit 20 incorporates an ink supply control amount per unit color tone adjustment amount corresponding to each ink supply blade 16. The control unit 20 drives the ink supply blade 16 via the drive mechanism 16 a based on the color tone adjustment instruction amount input from the outside to adjust the key opening degree of each ink supply blade 16. The ink supply amount is controlled.

  In addition, the ink supply control amount per unit color tone adjustment amount corresponding to each ink supply blade 16 is determined in advance by using a relationship between the pattern area ratio, the key opening, and the color tone density as described later. It is determined based on the pattern area ratio in the width direction of the trunk 30. In this case, instead of the predetermined pattern area ratio in the width direction of the printing plate cylinder 30, the ink supply control amount per unit color tone adjustment amount corresponding to each ink supply blade 16 can be obtained using image data. .

  Next, the operation of the present embodiment having such a configuration will be described.

  First, the ink 23 in the ink fountain composed of the ink roller 25 and the ink supply blade 16 is supplied from the ink roller 25, and the ink 23 supplied from the ink roller 25 passes through the ink transmission roller group 27 to the printing plate cylinder 30. Sent to. The printing plate cylinder 30 has a printing plate on its surface, and ink on the printing plate of the printing plate cylinder 30 is transferred to a blanket cylinder 31. At this time, the continuous web W is supplied to the blanket cylinder 31, and printing is performed on the web W with the ink transferred to the blanket cylinder 31. In the offset printing press shown in FIGS. 7A and 7B, printing is performed on the upper and lower surfaces of the continuous web W supplied between the pair of blanket cylinders 31. Thus, a printed matter is produced by printing on the upper surface and the lower surface of the web W.

  During this time, each ink supply blade 16 is driven by the control unit 20 via the corresponding drive mechanism 16a, and the key opening degree of each ink supply blade 16 is adjusted. By adjusting the key opening degree of each ink supply blade 16 in this way, the amount of ink supplied from each ink supply blade 16 is controlled.

  Next, a control method in the control unit 20 when adjusting the color tone density (color tone adjustment) of the printed matter (web) W will be described.

  First, the basic principle of the color tone adjustment control method will be described.

  FIG. 2 shows the relationship between the key opening degree of the ink supply blade 16 that determines the ink supply amount and the color tone density of the printed matter for each of the sizes of the pattern area ratios. When it is desired to adjust the color tone density of the printed matter by a, the key opening degree adjustment amount increases as the pattern area ratio increases (c> b). Also, when the key opening is adjusted by the same amount, the larger the pattern area ratio, the smaller the change in color tone density of the printed material (the inclination is small e <d).

  FIG. 3 shows the relationship (conversion function) between the pattern area ratio and the gradient of the color tone density of the printed matter with respect to the key opening corresponding to the ink supply amount. Based on this conversion function, for each ink supply blade 16 arranged in the width direction of the printing plate cylinder 30, the inclination corresponding to the pattern area corresponding to each ink supply blade 16 is obtained. Here, the ink supply control amount is the density / gradient of one scale to be controlled by the operator on the control panel.

  Next, a specific color tone adjustment control method will be described.

  FIG. 4 shows an example of the relationship between the key opening corresponding to the actual ink supply amount to the printing plate cylinder and the color tone density of the printed matter. The inclinations of the approximate straight lines when the pattern area ratio was 12%, 35%, and 57% were 0.0268, 0.0197, and 0.0129, respectively. FIG. 5 shows the relationship between the pattern area ratio and the inclination. It is presumed that the characteristics differ for each printing plate cylinder, but for this printing plate cylinder, the inclination with respect to the pattern area ratio changed almost linearly. According to the approximate curve, the conversion function to be obtained was y = −0.0003x + 0.0305.

  A control block diagram is shown in FIG. As described above, each ink supply blade 16 corresponds to a position in the width direction of the printing plate cylinder 30 having a different pattern area ratio in the width direction. That is, each blade 16 corresponds to a different pattern area ratio of the plate cylinder 30. At the start of operation, based on the read pattern area ratio of each item, the relationship between the pattern area ratio in the width direction of the printing plate cylinder 30 and the gradient of the color tone density of the printed matter with respect to the key opening corresponding to the ink supply amount (conversion) Function) is used to determine the ink supply control amount per unit color tone change amount for each ink supply blade 16, and this value is stored in the memory.

  For example, when the pattern area ratio in the width direction of the printing plate cylinder is 12%, 35%, and 57%, the ink supply control amount per unit tone change amount for each ink supply blade 16 obtained using the above conversion function is 3.7, 5.0, and 7.5.

  When the operator wants to increase the color tone density of the pattern by an equal amount, for example, one scale (corresponding to 0.1 of the color tone density of the printed material), the operator gives a color adjustment instruction amount for one scale to the control panel of the controller 20 .

At this time, the control unit 20 determines the amount of ink supplied from each ink supply blade 16.
Ink supply control amount per unit color change amount × color tone adjustment instruction amount (one scale) = + 3.7, +5.0, +7.0.

  Next, the control unit 20 controls each ink supply blade 16 via each drive mechanism 16 a based on the ink supply amount from each ink supply blade 16 to adjust the key opening of the blade 16.

  As described above, according to the present embodiment, it is possible to quickly and accurately adjust the color tone density using an offset printing press having a printing plate cylinder having different pattern area ratios in the width direction.

  Note that the above-described numerical values of the pattern area ratios of 12%, 35%, and 57% and the numerical values of the inclinations of the approximate lines of 0.0268, 0.0197, and 0.0129 are merely examples, and take other numerical values. You can also.

  Next, a modification of the present invention will be described with reference to FIGS. 7A and 7B, the ink supply blade 16 is driven by the drive mechanism 16a so as to be detachable in the arrangement direction of the blade 16 (direction parallel to the blade 16) with respect to the ink roller 25. Although the example in which the gap (key opening) between the blade 16 and the blade 16 is adjusted is shown, the present invention is not limited to this, and the key opening can be adjusted by driving the ink supply blade 16 in a direction orthogonal to the blade 16. Good (FIG. 8A).

  FIGS. 7A and 7B show an example in which the ink supply blade 16 is driven by the drive mechanism 16a so as to be detachable from the ink roller 25 in the arrangement direction of the blade 16. The key opening degree may be adjusted by swinging around the swing shaft 16b by an eccentric roller 35 having 35a (FIG. 8B).

  Furthermore, the offset printing machine 10 is not limited to a rotary offset printing machine, and a sheet-fed offset printing machine as shown in FIG. 9 may be used.

  As shown in FIG. 9, the offset printing machine 10 is of a sheet-fed type, and the offset printing machine 10 includes an ink roller 25 and a plurality of ink supply blades 16 arranged along the width direction of the ink roller 25. An ink supply device 24 for supplying ink, a printing plate cylinder 30 connected to the ink supply device 24 via an ink transmission roller group 27 and supplied with ink from the ink supply device 24, and an ink from the printing plate cylinder 30 And a blanket cylinder 31 for printing on the web W.

  Further, water is supplied to the printing plate cylinder 30 from a water supply device 32. Further, the impression cylinder 40 abuts on the blanket cylinder 31, and printing is performed on the sheet web W between the impression cylinder 40, the blanket cylinder 31, and the impression cylinder 40.

  In the sheet-fed offset printing machine shown in FIG. 9, each ink supply blade 16 of the ink supply device 24 is similar to the offset printing machine shown in FIGS. 7 (a) and 7 (b) via the drive mechanism 16a. The drive is controlled by.

  In this case, each ink supply blade 16 of the sheet-fed offset printing press 10 shown in FIG. 9 is driven and controlled by the control unit 20 shown in FIGS. 7A and 7B based on the same control method as described above. The

FIG. 3 is an enlarged perspective view of an ink roller and an ink supply blade in an embodiment of an offset printing machine according to the present invention. The figure which shows the relationship between key opening degree and printed matter density. The figure which shows the relationship between a pattern area, a key opening degree, and printed matter density | concentration. The figure which shows the relationship between key opening degree and printed matter density. The figure which shows the relationship between a pattern area, the key opening degree, and the inclination of printed matter density. The figure which shows the control method of the offset printing press by this invention. The figure which shows one Embodiment of the offset printing machine by this invention. The figure which shows the modification of the offset printing machine by this invention. The figure which shows the modification of the offset printing machine by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Offset printing machine 16 Ink supply blade 16a Drive mechanism 23 Ink 24 Ink supply apparatus 25 Ink roller 27 Ink transmission roller group 30 Printing plate cylinder 31 Blanket cylinder 32 Water supply apparatus 40 Impression cylinder

Claims (5)

An ink supply device having an ink roller and a plurality of ink supply blades arranged along the width direction of the ink roller, and supplying ink;
A printing plate cylinder connected to the ink supply device via a group of ink transmission rollers, to which ink from the ink supply device is supplied and having a different pattern area ratio in the width direction;
Ink is transferred from the printing plate cylinder, and includes a blanket cylinder for printing on the web,
Each ink supply blade of the ink supply device is individually driven by the drive control unit to adjust the key opening with the ink roller,
The drive control unit has a key opening per unit color tone adjustment amount corresponding to each ink supply blade, and controls the key opening of each ink supply blade based on the input color tone adjustment amount. Features an offset printing machine.   The key opening per unit color tone adjustment amount corresponding to each ink supply blade incorporated in the drive control unit is determined in advance using a relationship between the pattern area ratio, the key opening, and the color tone density. 2. The offset printing machine according to claim 1, wherein the offset printing machine is determined based on a pattern area ratio in the width direction.   The key opening per unit color tone adjustment amount corresponding to each ink supply blade incorporated in the drive control unit is predetermined image data using the relationship between the pattern area ratio, the key opening, and the color tone density. The offset printing machine according to claim 1, wherein the offset printing machine is defined based on   The offset printing machine according to claim 1, wherein the offset printing machine is a rotary offset printing machine.   2. The offset printing machine according to claim 1, wherein the offset printing machine is a sheet-fed offset printing machine.

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