JP2003001799A - Ink supplier for printing press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink supplier for a printing press which is capable of forming an ink film coping with the fluctuation of printing condition, such as the characteristics of ink or the like, upon previously forming the ink film on an ink roller before starting printing. SOLUTION: The ink supplier is provided with a number of calling times memory unit for storing the number of calling times, an ink shifting roller control unit for controlling the ink shifting roller based on the number of calling times stored in the number of calling times memory unit, and a number of calling times operating unit for operating the number of calling times based on the value of ink density of a printed sample inputted after starting the printing. The number of calling times memory unit renews the stored number of calling times into the number of calling times operated by the number of calling times operating unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink supply device for a printing machine, and more particularly to a device for forming a predetermined ink film on an ink roller in advance before starting printing.

[0002]

2. Description of the Related Art Generally, a plate cylinder used in a printing machine has
A printing plate is wrapped around the outer peripheral surface, and ink and dampening water are supplied to the printing plate for printing. FIG. 6 schematically shows the ink supply device of the printing machine. Explaining the configuration of the apparatus, the printing machine is an offset sheet-fed printing machine, and includes a plate cylinder 1 around which a printing plate 4 is wound and a blanket cylinder 2
It is printed on a printing sheet such as a sheet of paper passing between the impression cylinder 3 and the blanket cylinder 2 via the (blanket cylinder).

An ink supply device 5 for supplying ink to the plate 4 of the plate cylinder 1 and a water supply device 6 for supplying water to the plate 4 are provided for each plate cylinder 1. The ink supply device 5 comprises an ink fountain 7 composed of an ink fountain roller 8 and a blade 9, and the ink 10 stored in the ink fountain 7 flows out from a gap G between the ink fountain roller 8 and the blade 9. Then, the ink is supplied to the outer peripheral surface of the rotating ink fountain roller 8.
The gap G can be adjusted by opening and closing the blade 9. When the opening degree of the blade 9 is increased, the gap G is expanded and the amount of ink flowing out of the ink fountain 7 is increased. If the opening degree is made smaller, the gap G becomes narrower and the amount of ink coming out becomes smaller. Further, the blade 9 is composed of a plurality of ink fountain keys arranged in parallel along the axial direction of the ink fountain roller 8 (width direction of the printing paper), and the degree of opening of each ink fountain key can be adjusted individually. Has become. Then, the opening degree of each ink fountain key is adjusted according to the pattern area ratio of the printing plate 4.

The ink flowing from the ink fountain 7 onto the ink fountain roller 8 is supplied to the printing plate 4 via an ink roller group 11 composed of a large number of ink rollers 17. The ink roller 17 is provided in parallel with the ink fountain roller 8 and the plate cylinder 1 and is provided so as to be in contact with each other so that the ink is sequentially transferred from the upstream side to the downstream side. Incidentally, the inking roller 12 located at the most downstream,
13, 14, 15 are configured to be able to come into contact with and separate from the plate cylinder 1. The ink roller 17 located at the most upstream side
An ink transfer roller 16 is positioned between the ink fountain roller 8 and the ink fountain roller 8 so as to be swingable between the rollers. The ink transfer roller 16 performs a calling operation that reciprocates between the rollers in the directions of arrows 91 and 92, and by this calling operation, the ink attached to the outer peripheral surface of the ink fountain roller 8 is transferred to the ink roller 17. In this way, the ink 10 of the ink fountain 7
Moves from the ink fountain roller 8 to the ink transfer roller 16 and the ink roller 17, and the inking rollers 12, 13,
The plates 14 and 15 are supplied to the plate 4 by coming into contact with the plate 4.

By the way, it is necessary to attach to each ink roller 17 the minimum basic ink film required during printing. The basic ink film 10 is shown in FIG.
It shows the ink roller 17 to which a is attached, and the basic ink film 10a has a uniform thickness along the axial direction of the ink roller 17. Then, an image ink film 10b corresponding to the design of the printing plate 4 is superposed on the basic ink film 10a. The thickness of the image ink film 10b changes along the axial direction of the ink roller 17. For example, when the ink film thickness distribution as shown in FIG. 7 (b) is required, the degree of opening of each ink fountain key is adjusted according to the measured pattern area ratio, and the ink corresponding to the pattern is printed from the ink fountain 7. Is sent to the ink roller 17, and the image ink film 10b is superposed on the basic ink film 10a having a uniform thickness to form an ink film thickness distribution in the axial direction on the ink roller 17.

The ink adhering to each ink roller 17 is transferred from the upstream ink roller 17 to the downstream ink roller 1.
It gradually becomes thinner toward 7. Therefore, the basic ink film 10
As shown in FIG. 7D, a is gradually thinned from the upstream side to the downstream side, and the image ink film 10b superimposed thereon is gradually thinned as shown in FIGS. 7E and 7F. Incidentally, FIG.
Ink amounts corresponding to the lines L1 and L2 in (c) are shown in FIGS. 7 (e) and 7 (f), respectively.

The greater the opening of the blade 9, the greater the number of revolutions of the ink fountain roller 8 and the greater the number of times the ink transfer roller 16 is called, the greater the amount of ink supplied becomes. The ink film formed on the roller 17 also becomes thicker, so the density of the printed image also becomes thicker.

On the other hand, in recent years, in order to obtain a good printing state early after printing is started and to reduce wasted paper, a predetermined ink film is preliminarily formed on each ink roller 17 before printing is started. Has been done. For example, when the printing operation is started in a state where the ink is not attached to the ink roller 17, first, all the ink fountain keys have the same degree of opening, and the ink transfer roller 16 is called a predetermined number of times to move the ink roller 17 to the ink roller 17. After forming the basic ink film 10a,
The opening degree of each ink fountain key and the rotation speed of the ink fountain roller 8 are preset according to the pattern of the printing plate 4 to be printed,
The ink transfer roller 16 is called a predetermined number of times to superimpose the image ink film 10b on the basic ink film 10a of the ink roller 17. As described above, by forming the ink film thickness distribution in the axial direction according to the pattern of the printing plate 4 on the ink roller 17 in advance before starting printing, a good printing state can be obtained early after starting printing, It is possible to reduce the waste paper generated up to that point.

[0009]

However, the ink characteristics are not always constant but fluctuate day by day, whereas in the conventional ink film formation before the start of printing, only a constant operation can be performed. , It was not possible to deal with the fluctuation of ink characteristics. As described above, in the ink supply device of the conventional printing machine, it is difficult to form an ink film before printing starts by adapting to changes in printing conditions such as ink characteristics.

Therefore, the present invention has been made in view of the above conventional problems, and when an ink film is formed in advance on an ink roller before printing is started, an ink film corresponding to a change in printing conditions such as ink characteristics is changed. It is an object of the present invention to provide an ink supply device for a printing machine that can form the ink.

[0011]

The present invention has been made to solve the above problems, and an ink supply device of a printing machine according to the present invention comprises an ink fountain composed of an ink fountain roller and a blade. Printing in which ink is transferred from the ink fountain roller to the ink roller by the calling operation of the ink transfer roller and ink is supplied to the printing plate through the ink roller, and an ink film is formed in advance on the ink roller before printing is started. In the ink supply device of the machine, the ink density value of the print sample after printing is input, and based on the input ink density value, the ink transfer roller is called when the ink film is formed on the ink roller before printing is started. It is characterized by controlling the number of times.

In this structure, when the ink density value of the print sample after the start of printing is input, when the ink film is formed on the ink roller before the start of the printing of the next printing work of the printing sample. , The number of times the ink transfer roller is called is controlled based on the input ink density value, and the ink amount corresponding to the number of calls is transferred from the ink fountain to the ink roller via the ink transfer roller to form an ink film. .

In this case, the input ink density value is an ink density value at a plurality of positions along the width direction of the paper, and an average value is calculated from the ink density values at the plurality of positions, and the calculated ink density average is calculated. Based on the value, it is preferable to control the number of times the ink transfer roller is called when forming an ink film on the ink roller before starting printing. By using the average value of the ink density values at a plurality of positions along the width direction of the paper, it is possible to more accurately grasp the change in printing conditions such as ink characteristics.

In the ink supply device of the printing machine according to the present invention, the ink fountain is composed of the ink fountain roller and the blade, and the ink is transferred from the ink fountain roller to the ink roller by the calling operation of the ink transfer roller. It is configured to supply ink to the printing plate via an ink roller,
In an ink supply device of a printing machine that forms an ink film in advance on an ink roller before starting printing, a calling number storage unit that stores the number of times the ink transfer roller is called when forming an ink film on the ink roller before starting printing, An ink transfer roller control unit for controlling the ink transfer roller based on the number of calls stored in the number-of-calls storage unit;
The ink density value of the print sample after printing is entered,
A calling number calculation unit that calculates the number of times the ink transfer roller is called when an ink film is formed on the ink roller before printing is started based on the input ink density value. The number of calls is updated to the number of calls calculated by the number-of-calls calculation unit.

With this configuration, when the ink density value of the print sample after the start of printing is input, the ink transfer roller is called when the ink film is formed on the ink roller before the start of printing based on the ink density value. The number of calls is calculated, and the stored number of calls is updated to the calculated number of calls. In this way, since the number of times of calling is calculated and updated each time the printing conditions such as the ink characteristics are changed, the number of calling times is dealt with. At the time of forming, the ink transfer roller can be called by a new number of times of calling corresponding to a change in printing conditions.

In this case, the calling frequency calculation unit does not calculate the calling frequency when the input ink density value is within the allowable range, and calculates the calling frequency when the input ink density value is outside the allowable range. Preferably. In this way, by defining a certain range and calculating the number of calls only when the ink density value is outside the allowable range, it is possible to avoid complicated calculation of the number of calls and to improve the quality when the printing conditions do not change. It is possible to surely maintain such a state.

Further, the input ink density value is an ink density value at a plurality of points along the width direction of the paper, and the calling number calculation unit calculates an average value from the input ink density values at the plurality of points. In addition, it is preferable to calculate the number of times the ink transfer roller is called when the ink film is formed on the ink roller before the start of printing, based on the calculated average ink density value. By using the average value of the ink density values at a plurality of positions along the width direction of the paper, it is possible to more accurately grasp the change in printing conditions such as ink characteristics.

Further, the blade is composed of a plurality of ink fountain keys arranged in parallel along the axial direction of the ink fountain roller.
The input ink density value is preferably an ink density value for each zone corresponding to each ink fountain key. By using the ink density value for each zone corresponding to each ink fountain key, it is possible to accurately and easily grasp the change in the printing conditions from the entire print sample.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an ink supply device for a printing machine according to the present invention will be described below with reference to the drawings. FIG. 1 is a hardware configuration diagram of a main part of the ink supply device according to the present embodiment. C on the bus line 24
PU21, ROM22, RAM23 are connected.
The CPU 21 controls each unit according to the program stored in the ROM 22. The machine control unit 25 and the paper feed control unit 26 are connected to the bus line 24 via an I / O interface 38. The machine control unit 25 controls the rotation of each cylinder and each roller of the printing machine, and the paper feed control unit 26 controls the feeder unit to feed paper.

Further, on the bus line 24, an ink fountain key control unit 31, an ink fountain roller control unit 32, an ink transfer roller control unit 33, via an I / O interface 38,
Inking roller control unit 34, floppy (registered trademark)
The disk drive 35 and the communication interface 36 are connected. The inking roller control unit 34 controls the inking rollers 12, 13, 14, 1 of the ink roller group 11.
The contact and non-contact of the plate cylinder 5 with the plate cylinder 1 are controlled. The ink fountain key control unit 31 controls movement of each ink fountain key of the ink fountain 7 to control the degree of opening. The ink fountain roller control unit 32 controls the rotation speed of the ink fountain roller 8. The ink transfer roller control unit 33 controls stop and drive of the calling operation of the ink transfer roller 16.

Further, a paper type selection input section 27, a start pattern input section 28, a machine start input section 29, and an inking start input section 30 are connected to the bus line 24 via an I / O interface 38. The operator selects and inputs the paper type through the paper type selection input unit 27, and the inking content, that is, the inking content through the start pattern input unit 28.
Select either start inking or preset inking and enter. The CPU 21 recognizes this input and executes control according to the input. When the operator makes an input through the machine start input unit 29, the CPU 21 recognizes this input and controls the machine control unit 25 described above.
When the operator makes an input through the inking start input unit 30, the CPU 21 recognizes the input and controls the ink fountain key control unit 31, the ink fountain roller control unit 32, the ink transfer roller control unit 33, and the like to perform the inking. To execute.

On the other hand, FIG. 2 is a functional block diagram of the ink supply unit in this embodiment. Call count storage unit 40
Is printed on the ink roller 17 before the start of printing.
When forming b (hereinafter referred to as image ink film formation)
The reference number of times the ink transfer roller 16 is called (hereinafter referred to as the reference number of times when the image ink film is formed) is stored, and the ink transfer roller control unit 33
The calling operation of the ink transfer roller 16 at the time of image ink film formation is controlled based on the reference number of calls at the time of image ink film formation stored in the call number storage unit 40.
In the present embodiment, the ink transfer roller control unit 33 multiplies the reference number of calls when the image ink film is formed, which is stored in the number-of-calls storage unit 40, by the paper coefficient corresponding to the paper type, and according to the number of adjustment calls. When the image ink film is formed, the ink transfer roller 16 is called and operated. The RAM 23 is the call count storage unit 40 in this embodiment. Further, the number-of-calls calculation unit 41 receives the ink density value of the print sample S after the printing is started via the communication interface 36, and calculates the standard number of times of calling when the image ink film is formed based on the input ink density value. To do. In the present embodiment, the CPU 21 functions as the call count calculation unit 41.

Further, in the present embodiment, the density difference data for each zone is input as the ink density value. When printing is started, a print image 50 is printed on the print paper as shown in FIG.
Along with this, the color bar 51 is also printed along the horizontal direction of the printing paper. The printing paper is composed of zones Z along the lateral direction according to the width of each ink fountain key. That is, if there are 21 ink fountain keys, the printing paper will have 21 zones Z1,
Z2, ..., Z21. Therefore, the color bar 51 also has a patch portion P corresponding to each ink fountain key.
1, P2, ..., P21, and each patch portion P
Contains solid patches. Then, one print sheet taken out from the print sheet after the start of printing is set as the print sample S, and the color bar 5 in the print sample S is
The density of the solid patch of 1 is the densitometer 3 such as a color reflection densitometer
7, and the density difference from the reference printed matter is calculated.
This density difference is obtained for each zone Z (for each patch portion P), and the density difference data for each zone Z is sent from the densitometer 37 to the printing machine via the communication interface 36, and is sent to the calling number calculation unit 41. Is entered. For example, if the number of zones is 21, 21 pieces of density difference data are sent.

As shown in FIG. 2, the call count calculation unit 41 includes an average density difference calculation unit 42 for calculating an average value from the inputted density difference data for each zone Z and an average density difference calculation unit 42. An average density difference discriminating unit 43 for discriminating whether or not the calculated average density difference (ink density average value) is within a preset allowable range; and the average density difference is not within the allowable range.
That is, when the average density difference determination unit 43 determines that the average density difference exceeds the allowable range, the number-of-calls calculation unit that executes the calculation of the reference number of calls when the image ink film is formed based on the average density difference. 44 are provided. When the number-of-calls calculation unit 44 executes the calculation, the current number of reference calls at the time of image ink film formation stored in the number-of-calls storage unit 40 is read, and when a new image ink film is formed from the reference number of calls and the average density difference. Calculate the reference number of calls of. The calling number storage unit 40 updates the stored reference calling number when forming the image ink film to the reference calling number calculated by the calling number calculation unit.

Next, the contents of the first program stored in the ROM 22 will be described with reference to the flow charts of FIGS. First, the CPU 21 determines whether or not the paper type of the printing paper is selected and input through the paper type selection input unit 27 (step S2). The paper type selection input unit 27 is provided as a button for each paper type on the operation panel, and the operator presses the button corresponding to the paper type of the printing paper used for the current printing. The CPU 21 recognizes through the I / O interface 38 that the operator has pressed the button corresponding to the paper type, and stores the selected paper type in the RAM 23 (step S4).

Next, the CPU 21 fetches image information (step S6). The image information is information about the amount of ink required according to the content of the image on the printing plate 4, and is read from the floppy disk set in the floppy disk drive 24. When the image area ratio data is stored as image information on the floppy disk,
In a later step, this pattern area ratio data is converted into the ink fountain key opening degree of the ink fountain 7. In addition, the communication interface 36
It is also possible to directly take in the pattern area ratio data via. In the case of reprinting, the image area ratio data has already been converted into ink fountain key opening degree data in the previous printing operation, and each ink fountain key opening degree data is already stored in the floppy disk. Therefore, in this case, data conversion is not performed in the subsequent step.

After capturing the image information in step S6,
The CPU 21 determines whether or not the start pattern is input through the start pattern input unit 28 (step S8).
There are two types of start patterns, start inking and preset inking, and the operator inputs either pattern through the selection button. The start inking is performed by the ink roller 17 such as when starting work in the morning.
The preset inking is selected when the ink is not adhered to the ink roller 17, and the ink is applied to the ink roller 17 when the printing plate 4 is replaced and a new printing is performed after the previous printing is completed. Is selected when is already attached. When the operator inputs the start pattern to the start pattern input unit 28, the CPU 21 recognizes the input start pattern through the I / O interface 38,
It is stored in the RAM 23 (step S10).

When the operator operates the machine start input section 29 to instruct to start the machine, the CPU 21 gives a signal to the machine control section 25 to start the machine (steps S12 and S14), and the operator performs inking. When the start input unit 30 is operated to instruct the inking start, the start pattern stored in step S10 is determined (steps 16 and 18).

When the start pattern is start inking, the CPU 21 gives a signal to the ink fountain key controller 31 through the I / O interface 38 to open all the ink fountain keys in parallel according to a preset initial opening degree. Along with (step S20), a signal is given to the ink fountain roller controller 32 to rotate the ink fountain roller 8 in accordance with a preset reference rotational speed (step S2).
2). The initial opening degree is, for example, 10%,
For example, 40% is set as the reference rotation speed.
The degree of opening is expressed as a percentage with the maximum open state of the ink fountain key set as 100%.
The number of rotations of is represented by a percentage with 100% of the rotation at the maximum speed.

Subsequently, the CPU 21 sends a signal to the ink transfer roller control unit 33 through the I / O interface 38 to operate the ink transfer roller 16 and perform a preset number of calling operations, for example, 80 calling operations. (Step S24, step S26). The above steps S20 to S26 are the basic ink film forming step, whereby the basic ink film 10a is formed on each ink roller 17.

When preset inking is selected as the start pattern in step S10, the ink roller 17 is idled until it reaches a preset idling number, for example, 50 times (step S28), and each ink roller. The amount of ink between 17 is made uniform.

Next, the CPU 21 determines that the image information stored in step S6 is "pattern area ratio data".
Is determined (step S30), and if the pattern area ratio data is stored, the process proceeds to step S32 to convert the pattern area ratio data into ink fountain key opening degree data of each ink fountain key, A signal is given to the ink fountain key control unit 31 to control each ink fountain key according to the ink fountain key opening degree data.

Then, in step S34, the reference rotation speed (40%) of the ink fountain roller 8 is multiplied by the paper coefficient corresponding to the paper type stored in step S4 to obtain the adjusted rotation speed. The paper coefficient of each paper type is stored in the ROM 22, and the paper coefficients of coated paper, matte coated paper, and non-coated paper are "1", "1.1", and
It is “1.2”. For example, if uncoated paper is stored in step S4, the reference rotation speed of 40% is set to "1.
2 "is multiplied to obtain the adjusted rotation speed of 48%. If ink fountain key opening degree data is stored as image information in step S6, the process proceeds from step S30 to step S30.
Proceeding to 42, the CPU 21 gives a signal to the ink fountain key controller 31 to control and open each ink fountain key according to the ink fountain key opening degree data. Then, in step S44, the ink fountain roller 8 is rotated at the reference rotation speed without multiplying the reference rotation speed by the sheet coefficient.

Next, the RAM 23 (call count storage unit 4
0), the reference number of calls at the time of forming the image ink film is read (step S36), and the reference number of calls is multiplied by the sheet coefficient corresponding to the stored sheet type to obtain the number of adjustment calls (step S38). For example, RAM23
When the reference number of times of calling when the image ink film is read is 10 and the stored paper type is uncoated paper, the sheet coefficient “1. Multiply 2 "to get 12 adjustment calls.

Then, the ink transfer roller 16 is reciprocated by the number of adjustment calls, and the ink is transferred from the ink fountain roller 8 to the ink roller 17 so that the ink roller 1
7 to form the image ink film 10b (step S4).
0). When this image ink film forming process is completed, the CPU
Reference numeral 21 gives signals to the ink form roller control section 34 and the paper feed control section 26 so that the ink form rollers 12, 13, 14, 1
5 is brought into contact with the printing plate 4, and paper feeding from the feeder section is started (step S46).

Subsequently, the number of printed sheets is input, and the input number of printed sheets is stored in the RAM 23 (step S48,
S50), printing is started. After printing the preset number of sheets just before setting, the CPU 21 gives a signal to the ink transfer roller control unit 33 to stop the operation of the ink transfer roller 16 (steps S52 and S54), and thereafter, the ink is attached to the ink roller 17. Printing is continued with the ink that has been used, and when the number of printed sheets reaches the number stored in step S50, the printing ends (step S56).

Next, the contents of the second program stored in the ROM 22 will be described with reference to the flowchart of FIG. When printing is started from step 50, the operator extracts a printing sheet after printing a predetermined number of sheets from the printing start as a printing sample S, sets the printing sample S in the densitometer 37, and prints the ink of the color bar 51. Measure the density value. The ink density value is measured from the solid patch of the color bar 51 and is measured for each patch portion P.
When the ink density value of the patch portion P corresponding to each zone Z is measured, the density difference between the measured ink density value and the reference printed material is automatically calculated, and the calculated density difference data for each zone Z is calculated. Are sent via the communication interface 36 to the printing press during the printing operation. After the start of printing, the print sample S is extracted every time a predetermined number of sheets are printed, the ink density value is measured each time, and the calculated density difference data is sent to the printing machine. The CPU 21 reads the density difference data for each zone Z, and calculates the average density difference from the data (Step S60, Step S).
62). For example, each zone Z1, Z2, ..., Z21
When 21 pieces of density difference data obtained from the solid patches respectively included in the patch portions P1, P2, ..., P21 are sent, the average value of the entire 21 pieces of density difference data is obtained. The density difference data is "0.01" or "0.0".
4 ”or“ 0.17 ”, the smaller the absolute value of the density difference, the smaller the density difference with the reference printed material, and conversely, the larger the absolute value of the density difference data, the density with the reference printed material. It means that the difference is large. Further, when the density difference is positive, it means that the printed matter is printed darker than the reference printed matter, and when the density difference is negative, it means that the printed matter is lighter than the reference printed matter.
The first print sample S is, for example, the 20th to 50th sheets after the start of printing.

Then, in step S64, the CPU 2
1 determines whether the calculated average density difference is within the allowable range. This allowable range is set in advance and is ± 0.05 in this embodiment. If the average density difference exceeds ± 0.05, the process proceeds to step S66, and the CPU 21 uses the RAM 23 as the reference number of times of current image ink film formation.
Read from. As described above, the reference calling number is 10 in the present embodiment, and in the image ink film forming process performed before the start of printing of the printing operation currently in progress, the reference calling number serves as a reference and the sheet coefficient The call operation is performed for the number of adjustment calls multiplied by.

Then, in step S68, the CPU
Reference numeral 21 calculates the standard number of times of calling when a new image ink film is formed from a standard number of times of calling when the current image ink film is formed and the average density difference according to a predetermined formula. Specifically, the average density difference of 0.05 is set as one call.
That is, the calculated average density difference is divided by 0.05, and the value rounded down to the right of the decimal point is used as the correction number and subtracted from the current reference calling number at the time of forming the image ink film. For example, when the average density difference is +0.1, the number of corrections is changed from 2 to 10
Subtract from the times to get a new reference call count of 8. The large average density difference of +0.1 means that the image ink film 10b formed before the start of printing was thick, and the reference number of calls, which was the reference before multiplying the paper coefficient, was 10 as a result. is doing. This means that, until now, the image ink film 10b having the optimum thickness could be formed on the basis of the standard number of times of calling 10 times. This means that it is no longer possible to form the optimum image ink film 10b. Therefore, when the image ink film is formed next time before the start of printing, considering the change in the printing condition, the number of times of calling is set to be eight times, which is smaller than that of the previous time. Conversely, the average density difference is −
If it is 0.17, -3 is subtracted as the correction number to obtain 13 as the new reference invocation number. In this case, since the reference number of times of calling the image ink film in the printing operation for the print sample S was small as a result, the number of times is set to be 13 more times next time.

When the reference number of times of calling when forming a new image ink film is calculated in this way, the process proceeds to step S70, where the CPU 21 sends an update signal to the RAM 23,
The RAM 23 updates the stored reference number of calls when forming the image ink film to the calculated reference number of times when the new image ink film is formed. If the printing conditions change from the conventional one, such as when the ink characteristics change due to temperature, humidity, etc., the optimum number of calls until now is not necessarily the optimum, and the result is the density of the print sample S. Appears as a difference. Therefore, by obtaining the average value from all the density differences for each zone Z, the change in the printing conditions can be accurately grasped, and based on the average density difference, the image ink film formation in the next printing operation can be performed. By calculating the standard number of calls and updating the stored number of standard calls to a new one, it was possible to adapt to changes in printing conditions during image ink film formation in the next printing operation after the printing operation related to this print sample. A new reference number of calls can be used, and the image ink film 10b having an appropriate thickness can be formed in response to a change in printing conditions.

On the other hand, if the average density difference is within ± 0.05 in step S64, the call count calculation process is terminated without calculating the call count. In this case, it means that the image ink film 10b formed before the start of printing due to the current printing operation had a good thickness as in the previous time. That is, this means that the printing conditions have not changed from before, and therefore, next time, the ink can be transferred from the ink fountain roller 8 to the ink roller 17 on the basis of the same reference calling number as that time.

In this way, it is judged from the density difference of the first print sample S after the start of printing whether or not there is a change in the printing conditions such as ink characteristics. By feeding back to the reference number of times of calling at the time of formation, the image ink film 10 corresponding to the printing conditions is obtained.
b can be formed. In particular, the provision of the allowable range has the advantage that the measurement error of the densitometer 37 and the like can be absorbed, and complicated calculation and update can be avoided. The state can be reliably retained. Further, by using the average density value, it is possible to accurately grasp the change in printing conditions such as ink characteristics from the entire print sample S without being influenced by the design.

Although the average value is calculated from all the density difference data of each zone Z, the average value may be calculated using only the typical density difference data of the zones Z at several places. The reference number of calls may be calculated from the density difference data of one zone Z instead of the average value. However, by using the average value, it is possible to more accurately grasp the variation in the printing conditions. Further, although the density difference from the reference printed material is used as the ink density value, it is not limited to the density difference, and the measured ink density value data may be directly used. The average number of ink densities may be obtained and the reference number of calls may be calculated therefrom, or it may be calculated from the ink concentration values at one representative place.

Further, in the above embodiment, the printing machine side, that is, C
The PU 21 is provided with the average density difference calculation unit 42, but the average density difference calculation unit 42 is provided in a device other than the printing machine, for example, the densitometer 37 or the like to obtain an average density value, and the average density value is the number of times of calling calculation unit 41. It may be configured to be input to.
The ink density value may be input via a floppy disk instead of being input via the communication interface 36.

Further, in the above embodiment, the structure for calculating the reference number of times of calling when the image ink film is formed during printing has been described, but the calculation timing is not limited to this.
For example, the input ink density value or the average ink density value is temporarily stored in the RAM 23 or the like, and when the image ink film is formed before the next printing is started, the stored data is used as the reference number of times when the image ink film is formed. And calculate
The number of adjustment calls may be obtained by proceeding to step S40. The same applies to the timing at which the ink density value is input. In any case, the print sample S after the start of printing is printed.
The ink density value of the ink is input, and based on the input ink density value, the ink transfer roller 16 is used when the image ink film is formed.
May be configured to control the calling operation of the.

When the ink density value such as the average density value exceeds a predetermined value, the ink transfer roller 1 is printed until a predetermined number (for example, 10 to 20 sheets) of printing is completed after the start of printing.
If the calling operation of No. 6 is stopped, it is possible to reduce the waste paper generated after the start of printing.

Further, in the above embodiment, the number of adjustment calls taking into consideration the paper type was obtained from the reference number of calls at the time of forming the image ink film, but the reference number of calls is used as it is without multiplying the paper coefficient and ink transfer is performed. The roller 16 may be called and operated. Further, the ink transfer roller 16 may be called by multiplying the reference calling number at the time of forming the image ink film by a coefficient other than the paper coefficient.

[0048]

As described above, by controlling the number of times the ink transfer roller is called when the ink film is formed on the ink roller before the next printing is started based on the ink density value of the print sample after the start of printing. Even when printing conditions such as ink characteristics change, it is possible to form an ink film corresponding to the change.

[Brief description of drawings]

FIG. 1 is a hardware configuration diagram of an ink supply device of a printing machine according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of the ink supply device.

3 is a flowchart of a first program stored in the ROM of FIG.

FIG. 4 is the same flowchart.

5 is a flowchart of a second program stored in the ROM of FIG.

FIG. 6 is a schematic side view of an ink supply device.

7A and 7C are schematic diagrams showing the amount of ink attached to an ink roller. (B) is a graph showing an example of the required amount of ink according to the image on the printing plate. (D) and (e) and (f) are schematic diagrams showing the ink amount in the ink roller group.

FIG. 8 is a schematic diagram showing a print sample.

[Explanation of symbols]

1 ... plate cylinder, 2 ... rubber cylinder, 3 ... impression cylinder, 4 ... printing plate, 5 ... ink supply device, 7 ... ink fountain, 8 ... ink fountain roller, 9 ...
Blade, 10 ... Ink, 10a ... Basic ink film, 10
b ... Image ink film, 11 ... Ink roller group, 12, 1
3, 14, 15 ... Inking roller, 16 ... Ink transfer roller, 17 ... Ink roller, 33 ... Ink transfer roller control unit, 40 ... Call number storage unit, 41 ... Call number calculation unit, 42 ... Average density difference calculation unit , 43 ... Average density difference determination unit, 44 ... Call number calculation unit, 50 ... Print image,
51 ... Color bar, G ... Gap, P ... Patch part, S
… Printed sample, Z… Zone

Claims (6)

[Claims] 1. Ink fountain roller (8) and blade (9)
And the ink fountain (7) is composed of the ink fountain roller (8) and the ink transfer roller (16).
The ink is transferred from the ink roller to the ink roller (17), and the ink is supplied to the printing plate (4) through the ink roller (17), and an ink film is formed in advance on the ink roller (17) before starting printing. In the ink supply device of the printing machine, the ink concentration value of the print sample (S) after the start of printing is input, and an ink film is formed on the ink roller (17) before the start of printing based on the input ink concentration value. An ink supply device for a printing press, characterized in that the number of times the ink transfer roller (16) is called up is controlled. 2. Ink fountain roller (8) and blade (9)
And the ink fountain (7) is composed of the ink fountain roller (8) and the ink transfer roller (16).
The ink is transferred from the ink roller to the ink roller (17), and the ink is supplied to the printing plate (4) through the ink roller (17), and an ink film is formed in advance on the ink roller (17) before starting printing. In an ink supply device for a printing machine, a calling number storage unit (40) that stores the number of times the ink transfer roller is called when an ink film is formed on the ink roller (17) before starting printing, and the calling number storage unit (40). 40), the ink transfer roller control unit (33) for controlling the ink transfer roller (16) based on the number of calls stored, and the ink density value of the print sample (S) after the start of printing are input, and the input ink is input. A call for calculating the number of times the ink transfer roller (16) is called when an ink film is formed on the ink roller (17) before printing is started based on the density value. An ink supply of a printing press, comprising: a calling number calculation unit (41), wherein the calling number storage unit (40) updates the stored calling number to the calling number calculated by the calling number calculation unit (41). apparatus. 3. The calling number calculation unit (41) does not calculate the calling number when the input ink density value is within the allowable range, and calls the calling number when the input ink density value is outside the allowable range. The ink supply device for a printing press according to claim 2, wherein 4. The ink density value input is an ink density value at a plurality of locations along the width direction of the paper, and an average value is calculated from the ink density values at the plurality of locations, and the calculated ink density average value is calculated. Based on the ink roller (1
The ink supply device for a printing press according to claim 1, wherein the number of times the ink transfer roller (16) is called when the ink film is formed on 7) is controlled. 5. The ink density value input is an ink density value at a plurality of positions along the width direction of the paper, and the calling number calculation unit (41) calculates the average of the ink density values at the plurality of input positions. The value is calculated, and based on the calculated average value of ink density, the ink transfer roller (1) when forming an ink film on the ink roller (17) before starting printing.
The ink supply device for a printing press according to claim 2, wherein the number of calls of 6) is calculated. 6. The blade (9) is composed of a plurality of ink fountain keys arranged in parallel along the axial direction of the ink fountain roller (8), and the ink density value to be input corresponds to each ink fountain key. The ink density value for each zone (Z).
Or the ink supply device of the printing machine of 5.