JP3404888B2 - High quality printing method and system - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to high quality printing methods and systems.

[0002]

2. Description of the Related Art In recent years, in the plate making process of printing, the process of making a master block has been digitized by a plate data making system using a computer. This system is a system that edits / simulates characters / images / figures on a computer.
P: Characters represented by desktop publishing)
This is an image processing system. With this system, print data such as character data, image data, and graphic data, which is digital data, is edited and simulated page by page, and is multifaceted according to specifications such as the size of the printing machine.

A process of printing a pattern such as characters, images, figures, etc., thus multi-faced using a planographic plate will be described. The lithographic printing plate is suitable for color printing and large area printing.
The surface of the aluminum plate (printing surface) is generally used as the plate material.
A PS (pre-sensitized) plate obtained by coating an emulsion sensitive to ultraviolet rays (UV; ultra violet) is used.

Using this PS plate, a required number of printing plates (practical plates) are produced by a plate making device. The printing plate is usually produced by printing a design on a PS plate using a net positive film. This pattern includes all information to be printed such as characters, images and figures. After that, the plate
Emulsion other than the picture part is removed and wound around the plate cylinder and fixed. The printing surface of the printing plate wound around the plate cylinder comes into contact with the ink forming roller (rotating together with the plate cylinder) having the ink adhered to the peripheral surface thereof, so that the ink adheres to the emulsion portion (picture portion). This ink is transferred to a printing material such as paper, and a pattern is printed.

As described above, in order to perform printing by lithographic printing, it is necessary to attach ink to the peripheral surface of the inking roller. The printing density varies depending on the thickness of the ink deposited here, and in some cases, "blurring" or "bleeding" occurs. Therefore, it is necessary to make the thickness of the ink on the peripheral surface of the inking roller uniform. Here, a mechanism for supplying the ink to the ink applying roller will be described.

As shown in FIG. 8, the ink is stored in an ink fountain 3 composed of a fountain roller 1 rotating counterclockwise in the figure and a plate-shaped blade 2. The blade 2 is rotatably provided around a starting point 2a, and is supported by a tip portion 4b of a lever 4 which is rotatably provided around a fulcrum 4a. The other tip portion 4c of the lever 4 is gently gripped by a gripping tool 6 that slides in the direction A in the figure in accordance with the rotation of the adjusting screw 5. The adjusting screw 5 is rotated by the micromotor 7 or the manual knob 8.

According to such a configuration, the blade 2 moves in accordance with the operation of the micromotor 7 or the manual knob 8.
When it rotates about the fulcrum 2a, the gap t between the pot roller 1 and the tip 2b of the blade 2 changes. When the gap t changes, the thickness of the ink attached to the fountain roller 1 also changes according to the gap t. The fountain roller 1 and the above-mentioned inking roller (not shown) are in contact with each other via some rollers (not shown), and the ink adhering to the fountain roller 1 is smoothed and adheres to the inking roller. In this way, the ink is supplied.

By the way, as shown in FIG. 9, when a pattern on a printing plate is divided into a plurality of regions parallel to the printing direction, the integrated areas of the patterns in each region are usually different. Therefore, it is necessary to change the ink amount according to the integrated area of the pattern (area of the halftone dot) in each area. Therefore,
Usually, the above-described constituent elements 2 to 8 (hereinafter referred to as ink keys) are provided in a plurality of rows for each area (hereinafter referred to as key area) in FIG. 9, and are supplied from each ink key according to the integrated area of each key area. The amount of ink used is varied. The width of each key area is usually several cm (for example, about 3 cm).

Conventionally, the above-mentioned adjustment of the ink amount for each ink key has been carried out by a skilled worker by referring to the design of the printing plate based on his own experience and intuition. Further, there is also a method in which the printing plate is scanned by a scanner that receives reflected light of laser light, the integrated area of each key region is obtained, and the ink key is controlled based on this integrated area.

[0010]

However, due to the intuition and experience of skilled workers, the method of controlling the ink keys has a problem that the number of skilled workers who can control the ink keys with high accuracy is small. Further, even such a skilled person has a problem that the control accuracy may vary depending on the physical condition and the like.

On the other hand, in the method of controlling the ink keys by scanning the printing plate with a scanner and calculating the integrated area, an expensive device such as a scanner using laser light is required. That is, there is a drawback that it invites high cost. Further, the scanner used in this method, as described above, projects the laser light to the printing plate and receives the reflected light thereof, and the reflected light fluctuates according to the state of the printing plate. There is also a problem that the scanning information varies and the ink key cannot be controlled with sufficient accuracy. Further, there is a problem that the processing time including the scanning time by the scanner and the time for obtaining the integrated area from the scanning information becomes an extremely long time of several tens of minutes.

In addition to these problems, even if the ink key control based on the above-mentioned conventional method is performed, the density of a part of the design becomes low depending on the design of the printing plate, or
A ghost sometimes occurs in which the density of some patterns becomes high. Generally, the integrated area is not uniform in one key region. For example, as shown in FIG. 10, even if the integrated area of the pattern in each of the key areas R1 to R3 has one value, in reality, as shown in FIG. The integrated area of each region SR is different from the integrated area of the adjacent minute region SR.

A ghost that the print density of the pattern is too low or too high occurs at a portion where the difference in the integrated area is remarkable. Therefore, in order to prevent the occurrence of ghosts, conventionally, a skilled worker refers to a pattern such as a film and predicts whether or not a ghost will occur due to the pattern. Then, for a design in which a ghost phenomenon may occur, a solid or flat screen design is added to the margin of the printing plate at the time of making the printing plate to balance the design and prevent the ghost. Alternatively, when a skilled worker refers to the ghost that has occurred in the printed matter that has been subjected to the test printing and re-produces the printing plate, the above-described measures are taken.

However, few skilled workers can take such measures, and the effect itself of the measures also depends on the physical condition of the skilled worker. Also, in the latter measure,
Measures are taken after the ghost actually occurs in the printed matter, and there is a drawback that ink, paper, etc. are wasted. The present invention has been made in view of the above circumstances, while preventing the occurrence of ghosts in advance,
An object of the present invention is to provide a high quality printing method and system capable of accurately controlling the amount of ink with high precision.

[0015]

According to a first aspect of the present invention, there is provided a high-quality printing method, wherein a plate making device creates a plate based on plate data created by a plate data creating system, High-quality printing in which a printing plate is wrapped around a plate cylinder, and a plurality of ink keys are used to supply a preset amount of ink to each key area formed by dividing the printing plate in the axial direction of the plate cylinder. In the method

A step of performing page-by-page layout processing from print data containing at least one of character data, image data, and graphic data to create page data; and printing a page represented by the page data. A step of creating imposition data for imposition processing on the plate,
The page data is expanded into a bit map to be converted into binary data, and based on the binary data and the imposition data, the print target data is set for each of a plurality of minute areas continuous in a direction orthogonal to the printing direction. And a step of calculating the area of the pattern shown in FIG. 4, and detecting the portion where the area remarkably changes in the axial direction of the plate cylinder based on the area of each of the minute areas, and the page data and the imposition data. In the printing plate data consisting of, a step of adding ghost prevention image data for reducing a difference from a peripheral portion to a portion where the area is remarkably small,

Based on the area of each of the minute areas, the area of each of the key areas is obtained, and based on the obtained area distribution, control data for controlling the ink amount supplied by the plurality of ink keys is set. And a step of supplying the plate data to which the ghost prevention image data is added to the plate making apparatus and supplying the control data to the printing machine, and a pattern corresponding to the ghost prevention image data. Is transferred to the margin portion of the printing plate.

The high-quality printing system according to claim 2 is
A printing machine comprising a plate cylinder around which a printing plate is wound, and a plurality of ink keys for supplying a preset ink amount to each key region formed by dividing the printing plate in the axial direction of the plate cylinder; In a high quality printing system comprising a plate making device for transferring plate data to a plate and a plate data creating system for creating the plate data,

The printing plate data creation system includes an editing means for creating page data by performing layout processing in page units from print data containing at least one of character data, image data, and graphic data, and the page. Imposition means for creating imposition data for imposing a page represented by data on the printing plate; and bitmap conversion of the page data to convert it into binary data, and the binary data and Based on the imposition data, an integrated area calculating unit that calculates the area of the pattern represented in the print target data for each of a plurality of minute areas that are continuous in the direction orthogonal to the printing direction, and for each of the minute areas. Based on the area, the area where the area significantly changes in the axial direction of the plate cylinder is detected, and from the page data and the imposition data, In the printing plate data that, in the area is considerably small portion, and preventing the image adding means for adding the ghost preventing image data for a small difference with the surrounding parts,

The area of each of the key areas is obtained based on the area of each of the minute areas, and control data for controlling the ink amount supplied by the plurality of ink keys is set based on the obtained area distribution. The ghost prevention image. The ink amount setting means for controlling the ghost prevention image and the ghost prevention image data are supplied to the plate making device and the control data is supplied to the printing machine. It is characterized in that the pattern corresponding to the data is transferred to the margin portion of the printing plate.

[0021]

According to the high quality printing method or high quality printing system of the present invention, character data, image data, and
The page data is created by performing layout processing in page units from the print target data including at least one of the graphic data. Then, imposition data for imposing the page represented by the page data on the printing plate is created. Next, the page data is expanded into a bit map and converted into binary data, and based on the binary data and the imposition data, for each of a plurality of minute regions continuous in a direction orthogonal to the printing direction, The area of the pattern represented in the print data is calculated.

Next, based on the area of each of the minute areas, a portion in which the area remarkably changes in the axial direction of the plate cylinder is detected, and in the printing plate data including the page data and the imposition data, Ghost prevention image data for reducing the difference from the surrounding area is added to the area where the area is extremely small. Next, the area of each of the key areas is obtained based on the area of each of the minute areas, and the control data for controlling the ink amount supplied by the plurality of ink keys is obtained based on the obtained area distribution. Is set. Then, the printing plate data to which the ghost prevention image data is added is supplied to the plate making apparatus, and the control data is supplied to the printing machine.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. A high-quality printing system according to an embodiment of the present invention comprises a printing machine having a plurality of ink keys, a plate making device for transferring printing plate data to a printing plate, and a printing plate data creating system for creating the printing plate data. Become. Since the printing machine and the plate making apparatus are the same as the conventional ones, the description thereof will be omitted, and here, the plate data creating system of the high quality printing system according to the present embodiment will be described with reference to FIG.

FIG. 1 is a block diagram showing the functional arrangement of a plate data creating system of a high quality printing system according to an embodiment of the present invention. Reference numeral 1 is an input for inputting data such as images, characters and figures. Means 2, edit means for editing the data inputted via the input means 1 on the page, 3
It is a display unit for displaying a page edited by the editing unit 2. On the display means 3, for example, an image as shown in FIG. 2 is displayed. In FIG. 2, 21 is a page, 22,
Reference numeral 23 is an image / character input via the input means 1. Note that, in FIG. 2, the cutting symbols, page numbers, and the like used in the subsequent steps are omitted in order to avoid complicated description.

Referring again to FIG. 1, page 4 is page 21.
Output means 5 for temporarily printing (see FIG. 2), storage means 5 for storing data representing a page (page data; also includes print data such as images, characters and figures), and 6 for storage means 5. The page represented by the stored page data is PS
It is an imposition unit that creates imposition data for imposition processing on a plate. Here, the imposition process is a process of selecting a plurality of pages to be arranged on one PS plate and arranging them in a desired pattern on the PS plate. Hereinafter, the imposition data and the page data impositioned by the data are collectively referred to as plate data.

Reference numeral 7 is an integrated area calculating means, which converts the page data into a bit map and converts it into binary data, and calculates the integrated area for each minute area based on the binary data and the imposition data. As shown in FIG. 3, the integrated area is obtained when a printing plate obtained by imposing pages P1 to P4 on a PS plate is divided into a plurality of minute regions SR, SR, ... Which are continuous in the direction orthogonal to the printing direction. In each area SR, SR, ...
The area of halftone dots existing in.

The width of each of the key areas R1 to R7 corresponding to the pitch of the ink key is obtained by multiplying the width of each of the minute areas SR, SR, ... Again in FIG. 1, 8 is an ink amount setting means, which is an integrated area of each of the key areas R1 to R7 obtained by adding the integrated areas of the minute areas SR, SR, ... Calculated by the integrated area calculating means 7. Based on the above, control data for controlling the amount of ink supplied from each ink key is output.

Reference numeral 9 denotes a preventive image adding means for preventing the generation of ghosts, which prevents the generation of ghosts based on the integrated areas of the respective minute regions SR, SR, ... Calculated by the integrated area calculating means 7. Image data such as solid or flat screen (hereinafter referred to as ghost prevention image data)
Is generated and added to the plate data. At this time, the ghost prevention image data is added so that the pattern represented by the data is transferred to the margin portion in the actual printing plate.

The ghost is generated between the adjacent minute regions SR.
It tends to occur when the integrated area fluctuates significantly. here,
Small areas SR and S of pages P1 and P2 shown in FIG.
The distribution of the integrated areas of R, ... Is shown in FIG. In this example, as shown in FIGS. 3 and 4, the integrated areas are remarkably changed in the B and C portions, and ghosts are likely to occur in these portions. Specifically, in the pattern H of FIG. 3, the print density of the region H2 located behind the pattern G and the print densities of the regions H1 and H3 adjacent to the region H2 are different. That is,
The print density of the area H2 becomes significantly lower than the print density of the areas H1 and H3.

In order to prevent the generation of this ghost, the prevention image adding means 9 has a remarkably large integrated area as compared with the adjacent small areas SR so as to reduce the fluctuation of the integrated area between the adjacent small areas SR. In the small area SR that is small,
Solid or flat screen ghost prevention image data is added to a portion corresponding to a blank portion of the printing plate. The data added here is solid (100 if the fluctuation range of the integrated area is large).
% Flat mesh), and if the fluctuation range is small, it is set as thin flat mesh (several% flat mesh) according to the fluctuation range.

Reference numeral 10 denotes a transmitting means for transmitting the control data of each ink key set by the ink amount setting means 8 to a printing machine (not shown) and adding the ghost prevention image data by the prevention image adding means 9. The printing plate data thus created is transmitted to a plate making apparatus (not shown) for making a printing plate.

The plate data creating system having the above-described functional configuration is actually realized as a computer system as shown in FIG. In this figure, reference numeral 11 is an external storage device such as a floppy disk drive or magneto-optical disk drive, and 12 is an internal storage device such as a hard disk, which stores an OS (operating system) and application software.

Reference numeral 13 denotes a CPU, ROM, RAM, not shown.
It is a computer including various I / O interfaces and executes an OS and application software stored in the external storage device 11 or the internal storage device 12. Reference numeral 14 is a display device such as a CRT (cathode ray tube), 15 is an output device such as a color copying machine or a film output device, 16 is a communication device such as a modem, 17, 1
8 and 19 are an image input device, a character input device, and
It is a figure input device.

Each of the devices 11, 12, 14 to 19 is connected to the computer 13 and stored in the internal storage device 12.
It is controlled by a computer 13 running S and application software to provide the functionality shown in FIG. The specific configuration of each of the above-described devices 11 to 19 is the same as that used in a system generally called CEPS or DTP, and therefore description thereof will be omitted.

The operation of the high quality printing system having such a configuration will be described with reference to FIG. FIG. 6 is a process diagram showing the flow of plate making and printing steps by the high quality printing system. When the power of the computer 13 of FIG. 5 is turned on, the computer 13 reads the OS and application software from the external storage device 11 or the internal storage device 12 and executes them. As a result, the function shown in FIG. 1 can be provided. Then, the process of step S1 of FIG. 6 is performed.

In step S1, the input means 1 inputs character data to the editing means 2. Subsequent Step S
In steps 2 and S3, the graphic data and the image data are input to the editing means 2 as in step S1. of course,
The data input to the editing means 2 does not have to be all the character / graphic / image data, but may be only character data or graphic data in some cases.
Each data entered in this way is arranged on the page,
It is displayed on the display means 3.

Next, in step S4, it is determined whether or not the data input to the editing means 2 is appropriate. This determination process is performed by the operator who refers to the display means 3. If this determination result is “Yes”, it means that unsuitable data has been input, and thus the process proceeds to step S1.
Returning to, the input process is performed again. On the contrary, if the determination result is “No”, the process proceeds to step S5.

In step S5, the editing means 2 which operates in response to an instruction from the operator forms the characters and figures based on the character data and the figure data. next,
In step S6, the editing unit 2 performs image trimming processing based on the image data. Next, in step S7, the editing unit 2 performs an overall editing operation of the page, and raster data, which is bitmap data, is created based on the completed page data.

Then, in step S8, it is determined whether or not the editing made by the editing means 2 is sufficient.
This determination process is performed by the operator who refers to the display unit 3 (or the color comp obtained by outputting the raster data from the output unit 4). This judgment result is "Ye
If “s”, the editing process is incomplete, and the process returns to step S1. Alternatively, as shown by the dotted line in the figure, the process returns to any of steps S5 to S7. On the contrary, if the determination result is “No”, the process proceeds to step S9.

In step S9, the storage means 5 first stores the page data edited in steps S5 to S7. Then, the imposition unit 6 creates imposition data for imposing pages corresponding to the page data stored in the storage unit 5 as shown in FIG. 3 in consideration of efficiency improvement. Next, step S1 in FIG.
At 0, the integrated area calculation means 7 obtains the integrated area for each of the minute regions SR, SR, ... Based on the plate data including the raster data and the imposition data.

Next, in step S11, the ink amount setting means 8 calculates the integrated areas of the key areas R1 to R7 corresponding to the respective ink keys based on the integrated areas of the minute areas SR, SR ,. The control data of each ink key is set based on each integrated area thus obtained. For example, if the integrated areas corresponding to the key areas R1 to R7 have a distribution as shown in FIG. 10, the ink amount supplied from the ink keys corresponding to the key areas R1 and R3 is small, and the key area R2 is small.
The control data is set to increase the amount of ink supplied from the ink key corresponding to. Further, in this step, the preventive image adding means 9 generates image data for preventing the occurrence of ghost and adds it to the printing plate data.

Next, in step S12, the transmitting means 10
Thus, the control data and the printing plate data created in step S11 are supplied to the printing machine and the plate making device. Here, the data supply to the printing machine is performed by the communication device 1 shown in FIG.
6 or a medium such as a floppy disk inserted in the external storage device 11. FIG. 7 shows an example of a printing plate created based on the data thus supplied. In the example shown in this figure, since ghosts may occur in the B, C, D, and E portions, the patterns M1, M2, and M3 represented in the ghost prevention image data are displayed in the margin portion of the printing plate.
Has been transcribed.

The printing machine controls the micromotor 7 shown in FIG. 8 according to the control data to rotate the blade 2 for adjusting the ink amount to control the gap t. As a result, the key areas R1 to R7 of the printing plate wound around the plate cylinder
To the appropriate amount of ink from multiple ink keys. Therefore, ghosts are prevented and high quality printed matter can be obtained. Of course, the blank portion of the printed matter is cut later, and the design of the blank portion (the design represented in the ghost prevention image data) is removed. In this way, the plate making and printing steps are performed.

As described above, according to the embodiment of the present invention, the raster data created at this time is created based on the current situation that the pre-printing processes such as design, plate making, and plate making are rapidly digitized. By using this, it is possible to prevent ghosts that affect the quality of the final printed matter.
In addition, the ink amount can be set quickly and with high accuracy.

In the above embodiment, the key areas are R1 to R7, but the invention is not limited to this.
It goes without saying that it can be set arbitrarily. Further, although an example in which four pages are impositioned on one printing plate has been shown, the present invention is not limited to this, and it is possible to support all types of imposition processing.

[0046]

As described above, according to the present invention,
A pattern corresponding to the ghost prevention image data is transferred to the margin portion of the printing plate created by the plate making device, and an amount of ink corresponding to the control data is transferred from each of the ink keys.
It is supplied to each key area of the printing plate. As a result, there is an effect that the amount of ink supplied to each key area can be accurately controlled. In addition, the transfer ink amount in each key area corresponding to each ink key becomes substantially uniform due to the ghost prevention image data, and it is possible to prevent the occurrence of ghosts and to accurately control the ink amount with high accuracy. There is.

[Brief description of drawings]

FIG. 1 is a block diagram showing a functional configuration of a plate data creating system of a high quality printing system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a page.

FIG. 3 is a diagram showing an example of a printing plate.

FIG. 4 is a diagram showing a distribution of integrated areas of respective minute regions SR, SR, ...

FIG. 5 is a block diagram showing a physical schematic configuration of a printing plate data creation system of a high quality printing system according to an embodiment of the present invention.

FIG. 6 is a processing diagram showing a flow of plate making and printing steps by the printing system.

FIG. 7 is a diagram showing an example of a printing plate obtained by the printing system.

FIG. 8 is a diagram showing a structure of a general ink key.

FIG. 9 is a diagram for explaining the operation of each ink key.

FIG. 10 is a diagram showing an example of an integrated area distribution for each key area.

FIG. 11 is a diagram illustrating an example of an integrated area distribution for each minute area.

[Explanation of symbols]

2 Editing means 6 imposition means 7 Integrated area calculation means 8 Ink amount setting means 9 Preventive image addition means 10 Transmission means

Continuation of the front page (56) Reference JP-A-4-201260 (JP, A) JP-A-4-125155 (JP, A) JP-A-3-27944 (JP, A) JP-A-53-134510 (JP , A) JP 63-216745 (JP, A) JP 60-25759 (JP, A) JP 56-72997 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) B41F 31/00-31/02 B41M 1/00 G03F 1/00 B41C 1/00 G01B 11/28

Claims (2)

(57) [Claims] 1. A plate making apparatus creates a plate based on the plate data created by a plate data creating system, the printing machine winds the plate around a plate cylinder, and a plurality of ink keys are used to print the plate. In a high-quality printing method in which a preset ink amount is supplied to each key region formed by dividing in the axial direction of the plate cylinder to perform printing, at least one of character data, image data, and graphic data is used. A step of creating page data by performing a page-by-page layout process from the print data consisting of two pages; and a step of creating imposition data for imposing a page represented by the page data on the printing plate. , Converting the page data into a binary data by expanding the bitmap, and based on the binary data and the imposition data, in a direction orthogonal to the printing direction. A step of calculating the area of the pattern represented in the print target data for each of a plurality of continuous micro areas, and a portion where the area remarkably changes in the axial direction of the plate cylinder based on the area of each of the micro areas In addition to detecting, in the printing plate data consisting of the page data and imposition data, in the portion where the area is significantly small,
A step of adding ghost prevention image data for reducing the difference from the surrounding portion, based on the area of each of the minute areas, the area of each of the key areas is obtained, and based on the obtained area distribution. A step of setting control data for controlling the amount of ink supplied by the plurality of ink keys, supplying the plate data to which the ghost prevention image data is added to the plate making device, and the control data And a step of supplying the image to the printing press, the pattern corresponding to the ghost prevention image data being transferred to a margin portion of the printing plate. 2. A plate cylinder around which a printing plate is wound, and a plurality of ink keys for supplying a preset ink amount to each key region formed by dividing the printing plate in the axial direction of the plate cylinder. In a high-quality printing system comprising a printing press, a plate making device that transfers printing plate data to the printing plate, and a printing plate data creating system that creates the printing plate data, wherein the printing plate data creating system is character data, Editing means for creating page data by performing layout processing in page units from print data including at least one of image data and graphic data, and imposition processing of pages represented by the page data on the printing plate Imposition means for creating imposition data for converting the page data into a binary data by expanding the bitmap into the binary data and the imposition data. Based on the data, for each of a plurality of micro areas that are continuous in the direction orthogonal to the printing direction, an integrated area calculation unit that calculates the area of the pattern represented in the print target data, and based on the area of each of the micro areas. And detecting a portion where the area remarkably changes in the axial direction of the plate cylinder, and in the printing plate data including the page data and imposition data, a portion where the area remarkably decreases,
Preventive image adding means for adding ghost preventive image data for reducing the difference from the surrounding area, and the area distribution for each key area, based on the area for each micro area Based on the ink amount setting means for setting control data for controlling the ink amount supplied by the plurality of ink keys, and supplying the plate data to which the ghost prevention image data is added to the plate making device. A high-quality printing system, comprising: a transmission unit that supplies the control data to the printing machine, wherein a pattern corresponding to the ghost prevention image data is transferred to a blank portion of the printing plate.