JPH0429847A - Control device for multicolor printing machine - Google Patents

Abstract

PURPOSE:To obtain optimum state of printing by a method wherein conformity functions to output state signals are corrected for each of the output state signals in accordance with conformity of input state signals, and the output conformity functions are made on logical sum made by the corrected conformity functions, and quantitative values corresponding to the centroide position of the output conformity functions are outputted as control outputs for adjustment of the state of printing. CONSTITUTION:Density detecting values for inspection marks, the state regarding printing quality, and the state regarding printing machines and materials are outputted, in accordance with preset conformity functions, being converted into qualitative state signals and into conformity D to those state signals. The output R from a conformity function means is inputted, and output state signals to the input state signals are obtained in accordance with preset logical operation rules. Then conformity functions to the output state signals are corrected for each of the output state signals in accordance with conformity of the input state signals, and the output conformity functions are made on logical sum made by the corrected conformity functions. Quantative values corresponding to the centroide position M of the output conformity functions are outputted from MF5 as controlling output for adjustment of the state of the printing.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to the control of a multicolor printing press that adjusts the printing condition by measuring the printing results of inspection marks printed at predetermined positions outside the image range of printed matter. It is related to the device.

[Conventional technology]

Conventionally, in this type of control device, solid marks of each color or other print management marks are printed in strips as inspection marks outside the vertical image range of printed matter, and the density of these inspection marks is detected. By doing so, the density distribution in the left and right direction is read and the settings in the ink supply amount adjusting devices arranged in the left and right directions of the printed matter are corrected to obtain the optimum printing condition.

[Problem to be solved by the invention]

However, although such a control device is capable of automatically adjusting the concentration using a concentration detection signal, it is not practical and is rarely used in practice.

The reasons for this are: (a) In order to print good prints, operators need to check not only density but also contrast, trapping, tont gain,
Comprehensive judgment of conditions such as grayness and due error,
Furthermore, the ink and water are adjusted by comprehensively determining the water supply status, type of printed matter, type of ink paper, etc. For this reason, controlling the concentration alone is not sufficient.

(b) Since the ink passes through many rolls before reaching the paper surface, it is necessary to print a considerable number of sheets until the density becomes stable, making it difficult to perform optimal control.

Causes include:

[Means to solve the problem]

The present invention has been proposed to solve these problems, and the present invention calculates the detected density value of the inspection mark, the status related to print quality, and the status of the printing press and equipment according to a preset fitness function. A fitness function means converts and outputs a qualitative state signal corresponding to a state and a degree of suitability for the state signal, and the output of this suitability function means is input, and the input state signal is converted according to predetermined logical operation rules. Find the output state signal for each output state signal, modify the fitness function for each output state signal according to the suitability of the input state signal, take the logical sum of these modified fitness functions to obtain the output fitness function, and and control means for sending out a quantitative value corresponding to the center of gravity position of the output fitness function as a control output for adjusting the printing state.

[Effect]

Therefore, according to the present invention, not only the density of the inspection mark but also the conditions related to printing quality and the condition of the printing press (including those for which quantitative rules are difficult to determine and those for which quantitative detection is difficult) are taken into consideration. , it becomes possible to obtain the optimum printing condition.

〔Example〕

Hereinafter, a control device for a multicolor printing press according to the present invention will be explained in detail.

FIG. 1 is a block diagram showing one embodiment of a control device for this multicolor printing press. In the figure, 1 manually detects the density signal from the inspection mark on each sample paper given at regular time intervals, and calculates and outputs the density change rate by taking the difference between the density signal value and the previous density signal value. The arithmetic unit 2-1) receives the concentration signal as a branch input to the arithmetic unit 1, and calculates it according to the preset fitness function of the qualitative state signal to the quantitative signal (the fitness function shown in the second peak). , a qualitative state signal according to the concentration signal value and the degree of adaptation D (NL, NM) to the state signal.

A fitness function unit (hereinafter referred to as MFI) that converts and outputs the fitness values (NS, ZR, PS, PM, PL, and each)
, 2-12 inputs the concentration change rate output from the arithmetic device 1, and generates a qualitative state according to the concentration change rate according to a preset fitness function (the fitness function shown in 2nd (a)). The goodness of fit ΔD (NM
, NS, ZR, PS, PM, and their respective degrees of conformity) and output them. 2-21 to 2-20 input quantifiable information such as print quality as a sensor signal and are set in advance. MFI outputs a qualitative state signal according to the sensor signal value and the degree of suitability for that state signal according to the suitability function, and 2-31 to 2-3m input information such as printing quality that is difficult to quantify as a manual operation signal. MFIs 3-1 to 3-m output a qualitative state signal according to the manual operation signal value and the degree of suitability for that state signal according to a preset fitness function; A quantification device that converts the signal into an electric signal proportional to the time or input operation amount and uses it as a manual operation signal to MFI 2-31 to 2-3m, 4 is a predetermined logic operation rule that takes the output of MFI 2 as input. Perform logical operations according to
Arithmetic unit (hereinafter referred to as FUC) that obtains an output state signal for an input state signal, 5-1. 5-2゜5-3 is F
The output state signal obtained by UC4 is input, and the fitness function for each output state signal is modified according to the fitness of the input state signal. For example, for each output state signal, the fitness function for it is modified based on the related input Modify the fitness function by truncating or compressing it with the maximum confidence of the state signal, and take the logical sum of these modified fitness functions to obtain the output fitness function, which corresponds to the center of gravity of this output fitness function. This is a fitness function function device (hereinafter referred to as MF) that sends out a quantitative signal (control output).

In the control device configured as described above, concentration control, which is the basis of the control device, will first be explained. When sample paper is taken out at regular time intervals and the density signal detected from the inspection mark on the sample paper is given to the computing device 1, the computing device 1 calculates the difference between the density signal value and the previous density signal value. The concentration change rate is calculated and output. on the other hand,
The concentration signal detected from the above inspection mark is MFI2-1
), and in this MFI2-1), Figure 2 (
According to the fitness function shown in b), it is converted into a qualitative state signal corresponding to the concentration signal value and the fitness degree for that state signal, and is given to the FUC4. The rate of change in concentration output from the arithmetic unit 1 is given to the MFI 2-12, which generates a qualitative state signal according to the rate of change in concentration according to the fitness function shown in FIG. 2 (8). FU
Given to C4.

Here, 27 logical operation rules shown in the table below are defined in the FUC4 (see FIG. 3), and the output R is logically operated according to these logical operation rules. For example, assume that D is point b in Figure 4 (a in al, ΔD is the same figure price). In this case, D is compatible with both NS and NM states. The goodness of fit is dl for NS and d2 for NM. Similarly, for ΔD, NS and NM fit, and the goodness of fit is d,,d.

The logical operation rules that correspond to this are ■IF D
=NS ANDΔD=NS THEN R=PS■I
F D=NS ANDΔD=NM THEN R=
PM■IF D=NM ANDΔD=NS THE
N R=PM■IF D=NM ANDΔD=NM
THEN R=PL is applied.

Therefore, the output status signals are PS and PM.

PL is output. These degrees of conformity are determined as follows.

First, regarding rule ■, the fitness of D=NS is dl,
The suitability of ΔD=NS is d3, and the suitability of this AND condition is the smaller of d and d3, that is, d1 in this case. Next, regarding rule ■, the fitness of D=NS is dl
, ΔD=NM, the degree of conformity is d4, and the degree of conformity of this AND condition is the smaller of dl and d4, that is, d in this case. Similarly, for rule (2), the degree of conformity for D=NM is d2, the degree of conformity for ΔD=NS is d3, and the degree of conformity for this AND condition is d2. Similarly, for rule (2), the suitability of D=NM is d2, the suitability of 80=NM is d4, and the suitability of this AND condition is d4.

Rule ■ and rule ■ are both the conclusion of R = PM,
The degree of fitness is the larger of dl and d2, that is, d2. Therefore, by truncating the fitness function for each output state signal and taking the logical sum using the fitness obtained in this way, the output fitness function as shown in Fig. 5 is obtained, and this output fitness A quantitative signal corresponding to the center of gravity position M of the function is sent out from the MF 5 as a control output for adjusting the printing state. In the applicant's experiments, it was demonstrated that by controlling not only the concentration but also the rate of change in concentration in this way, extremely stable corrections could be made in a short time. In other words, the flow of ink in a printing press passes through many rolls, and several of these rolls swing from side to side to mix the ink. For this reason, it is difficult to accurately determine the transfer function up to the density change on the printed surface.
The best printing condition cannot be obtained with one sampling correction, and in the past, a lot of paper was wasted.

On the other hand, if the density change rate is controlled in addition to the density as in this embodiment, stable corrections can be made in a short time, and the occurrence of paper waste will be extremely reduced. In this embodiment, the density detection and control are performed by sequentially switching over all the ink supply amount adjusting devices dividedly arranged in the horizontal direction of the printed matter.
In the figure, the switching device is omitted and only the control circuit after switching is shown.

However, the printing condition is a matter of contrast.

Density control alone is not sufficient due to the effects of dirt, trapping, dot gain, etc., and the printing results are still unstable.

Therefore, in this embodiment, (a) Quality control data (status related to print quality) nitrous gain, trapping, due error stain, gear mark, grayness, contrast.

(b) Printing press condition: water supply amount, printing press speed.

(c) Initial settings based on printing conditions: content of the image, type of printed matter, type of paper, type of ink, etc.

shall be given to FUC4. Among these, dot gain, trapping, hue error, grayness, and contrast are given as sensor signals to MFI2-2 by using a quality control mark imprinted in a strip along with a density measurement mark, and the water supply amount is , printing press speed, etc. are also sent to MFI2-2 as sensor signals.
is giving to

Conditions that are difficult to detect with electrical signals, such as dirt, gear marks, and special notes regarding print quality (for example, requests for stronger yellow color), can be detected manually by manual operation without forcing the installation of sensors in consideration of economic efficiency. For example, a quantification device 3 such as a variable resistor that can set the degree continuously is used to provide the signal to the MFI 2-3. For the initial settings, enter the values as they are if you can obtain quantitative values, and if it is difficult to obtain quantitative values, enter them as they are.
When the linguistic information is input, it is provided to the MFI 2-3 via the quantification device 3 which converts it into an electrical signal corresponding to it. In this embodiment, the calculation output of FUC4 is three outputs: the supply amount of the ink supply device, the feed amount of the water supply device, and the machine speed, and this calculation output is used as the MF5-1.5-2
．． 5-3, the signal is converted into a quantitative signal and output.

These examples will be explained below. Now, for example, consider trapping. Trapping failure refers to a situation in multi-color printing where the previously printed ink does not dry sufficiently and the later printed ink does not adhere well. This often occurs in thin cases. In this case, it is common practice to reduce the amount of ink used in preprinting or increase the amount of ink used in postprinting. However, for example, if the amount of post-printing ink is increased, the dot gain will increase and the gray balance of the three colors may also be disrupted. Therefore, this time we will analyze the operator's knowledge. ■ If the trapping is somewhat poor, the gray balance is good, and the increase in dot gain of the post-printing ink is small, increase the amount of post-printing ink.

■If the trapping is somewhat poor, the gray balance is good, and the increase in dot gain of the post-print ink is large, leave the post-print ink as is and reduce the amount of pre-print ink.

We created rules such as:

Among these conditions, dot gain, trapping, hue error, grayness, and contrast are detected by placing detection marks in the color strip, and ink tack value 9 and paper quality are entered from preset data, and stains and gear marks are detected. An attempt was made to manually input information such as the following information into the fitness function function device MFI.

In addition, this rule includes not only the ink adjustment device, but also
Outputs for changing the ink roll rotation speed, water supply amount, and printing speed were also input, and each output was output via the fitness function device MF.

Approximately 300 logical operation rules have been selected, which enables printing to be much clearer than when only density control is used, and which is much closer to the operations performed by experienced operators. became.

Note that in this embodiment, an automatic learning method of the fitness function is attempted. That is, to explain the principle, first, the calculation output of FUC4, that is, MF5-1 to MF5-5-
The control output from No. 3 is separated from the printing press, and the apparatus of this embodiment is used merely as a monitoring apparatus. Note that the control output is separated, but the input is not separated. In this state, have a veteran operator actually perform the operation, compare the operation output based on the operator's judgment with the monitoring output (control output) of the monitoring device, and adjust the MFI2 and MF5 so that the two match. Modify the fitness function in .

In reality, data for about one month is collected without correction for each operation by a veteran operator, and the deviations for each logical operation rule are aggregated from that data, and the least squares method is used to determine which Modify the fitness function so that the output deviation for the rule is minimized. When modifying a fitness function, when many fitness functions are involved in a logical operation rule, it is difficult to decide which fitness function to modify and how much. Therefore, in this embodiment, the confidence level of the fitness skin function itself is determined, and when modifying the fitness function, a fitness function with a high confidence level is slightly modified, and a fitness function with a low confidence level is modified significantly. As a result, an operator with about two months' experience can automatically perform operations close to y゜, and the quality of the actual printed matter has also become very good.

As explained above, the control device for a multicolor printing press according to this embodiment can promote the automation of operations based on the operator's intuitive judgment, which was previously thought to be impossible to automate. Even without this, an operator with little experience can ensure the desired print quality. In addition, in this example, the intended purpose was generally achieved except for printed matter with a very special pattern, and the habits of the veteran operator were learned by slightly correcting the fitness function through the teaching of the veteran operator. , it becomes possible to some extent to pass down the know-how of master-class printing engineers, which was previously thought to be impossible.

〔Effect of the invention〕

As explained above, according to the control device for a multicolor printing press according to the present invention, the density detection value of the inspection mark.

a suitability function means for converting a state related to printing quality or a state of the printing press into a qualitative state signal corresponding to the state and a suitability for the state signal according to a preset suitability function; The output of the fitness function means is input, an output state signal for the input state signal is determined according to predetermined logic operation rules, and a fitness function for each output state signal is determined according to the fitness of the input state signal. control means for correcting the corrected fitness functions, taking the logical sum of these corrected fitness functions to obtain an output fitness function, and sending out a quantitative value corresponding to the position of the center of gravity of the output fitness function as a control output for adjusting the printing state; The system takes into account not only the density of the inspection mark, but also the printing quality and printing machine conditions (including those for which it is difficult to determine quantitative rules and those for which quantitative detection is difficult) to determine the optimal This makes it possible to obtain the printing status, promotes automation of operations based on the operator's intuitive judgment, and enables less experienced operators to ensure the desired print quality without the need for experienced operators. become.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a control device for a multicolor printing press according to the present invention, and FIG. 2 is a diagram showing an example of a fitness function set in a fitness function device in this control device. , FIG. 3 is a diagram showing an example of logical operation rules defined in the calculation section of this control device, FIG. 4 is a diagram for explaining an example of logical operation according to this logical operation rule, and FIG.
The figure shows an output fitness function obtained by taking the logical sum of fitness functions modified for each output state signal obtained according to the logical operation rule. 1... Arithmetic device, 2... Fitness function transformer (MFT),
3... Quantification device, 4... Arithmetic unit (FUC), 5
...Fitness function vector (MF). Patent applicant Komori Printing Machinery Co., Ltd.

Claims (5)

[Claims] (1) In a control device for a multicolor printing press that measures the printing result of an inspection mark printed at a predetermined position outside the image range of a printed matter and adjusts the printing condition, Adaptation that converts the condition or the condition of the printing press into a qualitative condition signal according to the condition and the degree of conformance to that condition signal according to a preset fitness function of the qualitative condition signal to the quantitative signal and outputs it. The output of the fitness function means is input, and an output state signal for the input state signal is determined according to a predetermined logic operation rule, and a fitness function for each of the output state signals is applied to the input state signal. is corrected according to the degree of fitness of A control device for a multicolor printing press, comprising a control means for sending out output. (2) The control device for a multicolor printing press according to claim 1, wherein a part of the status regarding print quality is given by manual operation. (3) A control device for a multicolor printing press according to claim 1 or 2, characterized in that initial settings based on printing conditions are added to the input to the fitness function means. (4) The control device for a multicolor printing press according to claim 1, 2, or 3, characterized in that the rate of change in density is added to the input to the fitness function means. (5) Claim 1 or Claim 2 or Claim 3 or Claim 4
A control device for a multicolor printing press, characterized in that the control output sent by the control means is compared with the operation output based on the operator's judgment, and the fitness function is modified so that the two match. .