JP3434177B2 - Method and apparatus for early stabilization of color tone - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color tone early stabilizing method and apparatus for stabilizing the color tone of a printed matter in a sheet-fed printing press at an early stage. The present invention relates to an ink density control method and a control device.

[0002]

2. Description of the Related Art Conventionally, the color tone of a printed matter in a sheet-fed printing press has been adjusted by adjusting an ink feeding amount at an ink supplier. When the image line is large (image line ratio is 30% or more), the work of adjusting the color tone according to the ink feeding amount is 150 to 150 times until the proper color tone is obtained.
It took about 300 proofs. Further, in the case where the image line is small (image line ratio is less than 30%), it is necessary to perform a trial printing of about 300 to 1000 sheets before obtaining an appropriate color tone.

The above-mentioned difference in the drawing rate causes a difference in the paper loss (when the drawing rate is lower than when the drawing rate is high,
Paper loss increases) due to different changes in the ink response of the printing press. That is, when the image area ratio is high, the amount of ink transferred to the test printing paper surface is large and it is possible to quickly respond to the change in the ink density at the ink source, whereas when the image area ratio is low, Since the amount of ink transferred to the proof printing paper surface is smaller than that in the case where the image area ratio is high, the excess ink on the ink roller is consumed and the ink density at the ink source is reflected on the paper surface. This is because more test printing is required than in the case of a high streak rate.

Therefore, in order to reduce the number of sheets of paper required for the above-mentioned test printing in the case of a low image area ratio, conventionally, when the ink density is insufficient, a spatula 32 is used for the ink roller 31 shown in FIG. When the ink density is too high, the ink roller (inking roller) 3 shown in FIG. 8 is supplied.
The paper 34 was wrapped around the sheet No. 3, and the excess ink was removed from the inking roller 33 by this paper 34. Such color mixing is performed every time the printing work is started, and even when the image area ratio of the plate after the plate change is different from the image area ratio of the plate before the plate change, the color mixture as described above is performed. I was trying to do. In FIG. 8, 35 is an ink fountain,
Reference numeral 36 is an ink key, and 37 is a plate cylinder.

[0005]

However, as described above, the work of supplying the ink to the ink roller 31 with the spatula 32 or winding the paper 34 around the ink roller 33 to remove the excess ink requires a great deal of labor. At the same time, since the amount of ink supplied by the spatula 32 and the amount of ink removed by the paper 34 depend solely on the operator's intuition and experience (skill), the time required to obtain an appropriate color tone varies greatly depending on the operator. The actual situation is that it also causes inconvenience.

The present invention has been made in view of such circumstances, and its object is printing for color tone adjustment.
The number of paper losses in the initial stage (paper loss at the time of initial printing) can be reduced, and it is possible to significantly reduce the paper loss, and always perform good color tone adjustment regardless of the skill of the operator. It is an object of the present invention to provide a method and apparatus for stabilizing a color tone early so that the time required for color tone adjustment can be shortened.

[0007]

To achieve the above object, according to the solution to ## in the present invention, the color tone early for stabilizing the color I line Do adjust the ink amount at the time of the initial printing out the printing press stability in method, the printed surface of the printed matter the initial printing out lines Tsu Na measured by the spectrometer, thereby obtains a difference between the reference value set in advance and the measured values obtained, the difference from the ink supply amount or the ink The adjustment control parameter is calculated from the correlation with the scraping amount, and based on the adjustment parameter of the calculation result , under the idling state where printing on the printing paper is not performed.
Then, the ink is supplied and / or the ink is scraped to stabilize the color tone early.

Also, in a preferred embodiment of the present invention
The printing machine is set to idle at a low speed during the color tone adjustment control based on the adjustment control parameter so that the printing paper is not printed.

Further, according to the present invention, in the color tone early stabilizing device for stabilizing the color tone by adjusting the ink amount at the initial printing of the printing machine, (a) measuring the print density on the printing paper surface A print density measuring device; (b) a color tone management device for obtaining a density difference between the print density measured by the measuring device and a reference density; and (c) a correlation between the density difference and an ink supply amount or an ink scraping amount. Based on the relationship, a computing device that computes adjustment control parameters relating to the ink key opening, the ink source roller rotation speed, the ink calling speed, etc., and (d) operation control based on the adjustment control parameters computed by the computing device. an ink adjustment device constituted by an ink supply system and ink scraping device is a provided respectively, the adjusting system from the computing device
Operate the ink adjustment device based on the control parameters
By doing so , the color tone is stabilized early .

Further, according to the present invention, a spectrometer is used as a printing density measuring device on a printing paper surface.

Further, according to the present invention, an ink scraping doctor is provided on the inking roller which contacts the plate cylinder of the printing machine or the ink roller next to this roller.

Further, according to the present invention, the ink doctors for scraping the ink are installed at a plurality of positions corresponding to the ink rollers.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a sheet-fed printing press 2 equipped with a color tone early stabilizing device 1 according to a first embodiment of the present invention, which device 1 implements the color tone early stabilizing method of the present invention. To do.

As shown in FIG. 1, the early color tone stabilizing device 1 of the present embodiment is obtained by a spectrometer 4 for measuring the ink density on the surface of the printing paper 3 and the measurement of this spectrometer 4. Color tone management device 5 for obtaining an ink density difference δD (= printed paper surface density-referenced density) between a measured solid density (printed paper surface density) and a preset reference density which is obtained by proof printing or the like, and this ink density A computing device 6 for computing the adjustment control parameter based on the difference δD, and this computing device 6
And an ink adjusting device 7 to which adjustment control parameters sent from the device are input. Further, the above-described ink adjusting device 7 includes the ink supply device 11 for controlling the opening degree of the ink key 8, the rotation speed (rotation speed) of the ink source roller 9, the number of times of ink call, and the ink doctor 12.
An ink scraping device 13 is provided for controlling the amount of scraping ink. Ink supply device 1
1, it is not necessary to change all the controlling mechanisms, and any one of them may be selected and controlled.

FIG. 2 shows the correlation between the ink density difference δD and the ink scraping amount and the ink supply amount. As can be seen from FIG. 2, as the ink density difference δD becomes larger, the amount of ink scraped, that is, the number of rotations of the ink roller for scraping ink is increased, and as the ink density difference δD becomes negative, the amount of ink supplied. I am trying to increase.

The specific operation will be described below with reference to the flowchart of an example of the control shown in FIG. First, the spectrometer 4 measures the density of the printing paper surface obtained by printing with the ink key opening set based on the measurement value by the separately provided printing screen area ratio meter. The measurement value obtained in this way is compared with a reference density (reference value) obtained from a proof printing or the like preset in the color tone management device 5, and the ink density difference δD is obtained from the comparison result. When the ink density difference δD is within the allowable set value, it is determined that the ink density is appropriate, the adjustment / control by the early color tone stabilization device 1 is completed, and normal printing is performed.

On the other hand, when the ink density difference δD deviates from the permissible set value, the printing press 2 is set in the idling state (a state in which printing is not performed), and the adjustment / control mode is set by the color tone early stabilizing device 1. It In the adjustment / control at this time, the control operation is divided depending on whether the density difference is positive or negative. That is, when the ink density difference δD is positive, the ink density is too high, so the ink key 8
Is set to a small opening, and the ink roller 14 (see FIG.
Excess ink that has arrived at (see) is scraped off by the ink doctor 12. Ink supply (ink call) is started after a delay of the calculated time, and idling is stopped when the ink film thickness on the ink roller group reaches the number of revolutions corresponding to the changed ink key opening.

When the ink density difference δD is negative, the ink density is too low. Therefore, the ink supply amount related to the opening degree of the ink key 8, the ink feeding speed, the rotation speed of the ink source roller 9 and the like. 2 is obtained from the correlation of FIG. 2, ink is called at the required ink key opening, the ink source roller 9 is rotated to supply the insufficient amount of ink to the ink roller group, and then the ink doctor 12 also scrapes the ink. The printing machine 2 is operated to finish the idling of the printing machine 2 and the actual printing is performed. The printing paper obtained here is subjected to ink density measurement by the spectrometer 4, and the above control is repeated until the ink density difference δD falls within the allowable set value. As described above, by idling the printing machine 2 while performing the color tone adjustment control, it is possible to eliminate the waste paper that was conventionally required during that time, and to significantly reduce the waste paper.

Further, by adjusting the ink key opening so that the ink density difference δD falls within the allowable set value, the adjustment of the color tone can be made constant regardless of the skill of the operator. it can.

Further, the ink amount is adjusted and controlled based on the number of times of ink call-up or the number of times of ink scraping with the ink density difference δD as a parameter, so that the change of the ink amount according to the ink key opening can be performed quickly. Plate cylinder 1
5 (see FIG. 1) will be reflected in the ink density. Therefore, it is possible to significantly reduce the time required for color mixing, and when the drawing rate is low (low drawing).
The accuracy of color mixing in can be improved.

By the way, as the print density measuring device, a densitometer may be used in the case of targeting only colors of which the colors are Sumi (ink), Eye (indigo), Red (red) and Ki (yellow). When printing spot colors, it is preferable to use a spectrometer that can measure all colors with high accuracy.

FIG. 4 shows a sheet-fed printing press 17 equipped with a color tone early stabilization device 16 according to a second embodiment of the present invention. Note that, in FIG. 4, the same parts as those in FIG.

As shown in FIG. 4, in the early color tone stabilizing device 16 of this embodiment, the ink doctor 12 is arranged so that the ink doctor 12 is closer to the plate cylinder 15 than the case of the first embodiment. It is arranged so as to correspond to the next ink roller adjacent to the inking roller 19).

As shown in FIG. 5, the ink film thickness on the ink roller 18 gradually decreases from the ink source roller 9 to the plate cylinder 15 by the transfer of ink between the ink rollers, and is uniform and proper. Ink film thickness is formed on the plate cylinder 15. However, in the conventional color tone early stabilization method, ink is supplied onto the ink source roller 9 after roller cleaning, the sheet-fed printing machine 16 is idled, and then printing is started through printing paper. As for the thickness, the ink remaining on the ink roller group is not consumed (and of course is not supplied), and the ink rollers idle, so that the ink film thickness on all rollers is the same, as shown in FIG. From the start of printing to the target value, that is, the target ink film thickness,
It is necessary to change the ink film thickness indicated by hatching α in FIG.

In view of this, in the present embodiment, the ink doctor 12 is installed on the ink roller 18 as close as possible to the plate cylinder 15 (the ink roller on the upstream side of the inking roller 19 that contacts the plate cylinder 15) and the roller is cleaned. After that, while supplying the calculated target ink amount, the ink scraping device 13
When the ink is scraped off with, the ink film thickness becomes as shown by the solid line β in FIG.

Under this condition, when printing is started through the printing paper, a predetermined target ink film thickness is obtained along with a change in ink film thickness as shown by hatching γ in FIG. 5, which is much larger than that of the conventional one. It can be seen that there is a difference in the amount of change. This difference is the difference in the amount of waste paper and the difference in the print preparation time. That is, in the case of the present embodiment, the number of damaged sheets is reduced and the print preparation time is shortened as compared with the conventional case due to the difference described above.

More specifically, conventionally, the ink film thickness on the ink roller immediately after the end of the trial printing is as shown by "A" in FIG. 5, and the ink density is too high, and the next target "B" is reached. When you do, the idle after the trial printing and the idle before the next printing before inserting into the cylinder continue idle without ink consumption,
The ink film thickness on the ink roller is equalized and becomes like "C" in FIG. When printing starts, the ink film thickness on the plate cylinder 15 is thick, and printing is performed too darkly until “D” shown in FIG. 5 is resolved, resulting in paper loss. On the other hand, in the case of the second embodiment of the present invention, when the ink of the next target density is supplied while scraping with the ink doctor 12 to the ink film thickness "A" immediately after the trial printing, the ink is discharged at the ink doctor 12 part. Since ink is supplied from the ink source roller 9 with a new ink key opening while consuming, the ink film thickness on the ink roller is as shown by β in FIG. The ink film thickness “E” indicated by β differs from the new target ink film thickness “F” by only the γ part indicated by hatching in FIG. The paper loss is greatly reduced.

FIG. 6 shows a sheet-fed printing press 21 provided with a color tone early stabilizing device 20 according to a third embodiment of the present invention. In FIG. 6, the same parts as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 6, the color tone early stabilizing device 20 of this embodiment is the device 16 of the second embodiment.
In addition to the above configuration, the ink doctor 23 is installed on the ink roller 22 near the ink source.

In this color tone early stabilizing device 20,
As shown in Fig. 7, when too much ink is used during proof printing,
That is, when the ink density difference δD is extremely large, the ink film thickness can be consumed quickly by scraping the ink to reach the target ink film thickness at a plurality of locations, and the horizontal line P in FIG. , Q clearly shows that the convergence to the target ink film thickness is much faster.

Explaining in more detail, the difference between the third embodiment of the present example and the above-described second embodiment is that an ink doctor 23 for scraping ink is added, and this ink doctor 23 is added. The effects are as follows.
That is, when the ink film thickness is too large, in order to speed up the idling and the state of "c" in FIG. 7, the doctor blade is calculated based on the excessive ink amount on the ink roller. Determine the scraping time with 23. As a result, the state of "c" becomes faster. The effect after the state of "c" is the same as in the case of the above-described second embodiment.

Although the embodiments of the present invention have been described, the present invention is not limited to these embodiments, and various modifications and changes can be made based on the technical idea of the present invention. For example, the ink roller for scraping the ink with the ink doctor is not limited to the ink rollers 14, 18, and 22 in the case of the above-described embodiment, and other ink rollers such as the inking roller 19 may be used as necessary. Ink doctors may be arranged correspondingly to scrape the ink. Further, the number of ink rollers for scraping the ink with the ink doctor can be changed as necessary.

[0034]

As above, according to the present invention, the color tone early stabilization method according to the present invention as set forth in claim 1, the printed surface of the printed matter the initial printing out lines Tsu Na measured by the spectrometer, is obtained by this Obtain the difference between the measured value and the preset reference value, calculate the adjustment control parameter from the correlation between this difference and the ink supply amount or the ink scraping amount, and based on the adjustment control parameter of the calculation result , print paper Empty without printing on
Since the ink is supplied and / or the ink is scraped under the rolled state, the time required for the ink film thickness on the ink roller to reach the target ink film thickness can be shortened. Therefore, it is possible to reduce the number of printing sheets required for color tone adjustment (color tone adjustment) at the time of initial printing and reduce the amount of waste paper.

Further, according to the present invention as set forth in claim 1 , the color tone is obtained under the idling state in which the printing on the printing paper is not performed.
Since to perform the combined, in other words, while based on the adjustment control parameters are performed tone adjustment control (i.e., while performing scraping ink supply or ink for color tone adjustment) printing press Is set to idle state and printing is not performed on the printing paper.
(That is, by controlling the color tone without printing.
Therefore , it is possible to completely eliminate the wasted paper that was required in the past, and thus it is possible to greatly reduce the wasted paper.

According to the early color tone stabilizing device of the present invention as defined in claim 2 , the following operational effects can be obtained. That is, it is possible to adjust the ink key opening so that the density difference (ink density difference) between the print density measured by the measuring instrument and the reference density falls within the allowable set value. By adopting, the color tone adjustment work can always be performed satisfactorily regardless of the skill level of the operator. Further, by adjusting and controlling the ink amount by calculating the number of times the ink is called up or the number of times the ink is scraped with the density difference as a parameter, the change in the ink amount due to the ink key opening causes the ink density on the plate cylinder to change. It is possible to significantly reduce the time required for color tone adjustment. In addition, when the drawing rate is low (when the drawing is low)
It is also possible to improve the accuracy of color instruction matching in.

Further, according to the color tone early stabilizing device of the present invention as defined in claim 3 , since a spectrometer is used as a printing density measuring device on the surface of the printing paper, all colors can be accurately measured. It is possible to measure, and it is possible to perform color tone adjustment for all colors with high accuracy.

Further, according to the color tone early stabilizing device of the present invention as defined in claim 4 , the inking roller contacting the plate cylinder of the printing machine or the ink roller next to this roller (the ink roller close to the plate cylinder) ) Is equipped with an ink doctor for scraping ink, and ink is scraped by the ink scraping device while supplying the calculated target ink amount, so the ink film thickness on the ink roller is similar to the operating state. . Therefore, when printing is started, the ink film thickness on the plate cylinder reaches the target ink film thickness at an early point. Therefore, it is advantageous to reduce waste paper and shorten the color tone adjustment time (print preparation time).

Further, according to the color tone early stabilizing device of the present invention as defined in claim 5 , since the ink doctors for scraping the ink are installed respectively corresponding to the ink rollers at a plurality of positions, the difference in the ink density is particularly large. When it is extremely large, the ink film thickness can be consumed quickly, and the ink film thickness can be converged to the target ink film thickness in a short time.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a sheet-fed printing press including a color tone early stabilizing device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a correlation between an ink density difference, the number of times ink is called, and the number of times ink is scraped.

FIG. 3 is a flowchart showing a control flow of a color tone early stabilization method executed by the color tone early stabilization device according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram of a sheet-fed printing press provided with a color tone early stabilizing device according to a second embodiment of the present invention.

FIG. 5 is a schematic diagram showing a change in the ink film thickness on the conventional ink roller and a change in the ink film thickness on the ink roller in the second embodiment of the present invention.

FIG. 6 is a configuration diagram of a sheet-fed printing press including a color tone early stabilizing device according to a third embodiment of the present invention.

FIG. 7 is a schematic diagram showing a change in the ink film thickness on the conventional ink roller and a change in the ink film thickness on the ink roller in the third embodiment of the present invention.

FIG. 8 is a configuration diagram of a sheet-fed printing press provided with a conventional color tone early stabilization device.

[Explanation of symbols]

1,16,20 Color Stabilizer 2,17,21 sheet-fed printing press 3 printing paper 4 spectrometer 5 color tone management device 6 arithmetic circuit 7 Ink adjustment device 8 ink keys 9 Ink source roller 10 Ink calling roller 11 Ink supply device 12,23 Ink doctor 13 Ink scraping device 14, 18, 22 Ink rollers 15 plate cylinder 19 Inking roller δD Ink density difference

Continuation of front page (56) Reference JP-A-7-246698 (JP, A) JP-A-62-68760 (JP, A) JP-A-5-96709 (JP, A) JP-A-2-286244 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41F 31/02

Claims (5)

(57) [Claims] 1. A color early stabilization method for stabilizing the color tone adjustment of the quantity of ink lines Do I during the initial printing out of the printing machine, the printed surface of the printed matter the initial printing out lines Tsu Na Measure with a spectrometer, find the difference between the measurement value obtained by this and a preset reference value, calculate the adjustment control parameter from the correlation between this difference and the ink supply amount or ink scraping amount, and then calculate Based on the resulting adjustment parameters, under idle conditions without printing on the printing paper,
An early color tone stabilization method, which comprises stabilizing the color tone early by supplying ink and / or scraping the ink. 2. A color tone early stabilization device for stabilizing the color tone adjustment of the quantity of ink lines Do I during the initial printing out of the printing press, the printing of measuring the print density of the (a) printing paper surface A density measuring device; (b) a color tone management device for obtaining a density difference between the print density measured by the measuring device and a reference density; and (c) a correlation between the density difference and an ink supply amount or an ink scraping amount. From (a) to (d) an arithmetic unit for calculating adjustment control parameters relating to the ink key opening, the ink source roller rotation speed, the ink feeding speed, etc., and (d) operation control based on the adjustment control parameters calculated by the arithmetic unit. that an ink adjustment device constituted by an ink supply system and ink scraping device, the provided respectively, on the basis of the adjustment control parameters from the computing device, the printing paper Do not perform printing
A color tone early stabilizing device , wherein the color tone is stabilized early by operating the ink adjusting device under a free running condition . 3. The early color tone stabilizing device according to claim 2 , wherein the printing density measuring device on the printing paper surface is a spectrometer. 4. A claim, characterized in that a Inkidokuta for scraping ink following ink roller inking roller or the roller contacts the plate cylinder of the printing machine 2
Alternatively, the color tone early stabilizing device according to item 3 . 5. A tone early stabilization device according to any one of claims 2 to 4, characterized in that corresponding to respectively installed on the ink roller of the plurality of positions of the ink scraping doctor.