JPS63216746A - Method for controlling supply amount of ink in printing press - Google Patents

Abstract

PURPOSE:To allow an open amount of ink fountain key to be set large to facilitate a control, by a method wherein, a maximum area is obtained from picture pattern areas per zone, a feed amount of ink is determined, a factor is determined according to the maximum area, a corrected picture pattern area is obtained, an open amount of ink fountain key per zone is obtained, and a supply amount of ink is controlled by the feed amount of ink and the open amount of key. CONSTITUTION:A video signal from a camera 1 photographing a pressplate surface is converted to a digital signal by an analog-digital converter 3 containing a sample and hold circuit to be a measured value after being subjected to the correction of the value of wave height in a waveform correcting part 2, thereafter being stored in an RAM 4. The contents of the RAM 4 is read by a CPU 5, and the CPU 5 executes a predetermined operation to obtain a maximum area from picture pattern areas per zone obtained by dividing a pressplate surface. According to the maximum area, a feed amount of ink by an ink supply roller is determined and a factor is also determined, and a corrected picture pattern area is obtained by multiplying the picture pattern area per zone by the factor. According to the each corrected picture pattern area, an open amount of ink fountain key per zone is obtained, and a supply amount of ink is controlled by the feed amount of ink and the open amount of key.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Minute Hand] The present invention relates to a method for controlling the ink supply rate of a printing press.

[Conventional technology]

In a printing press, the printing plate surface is divided into multiple zones, and the image area of each zone is measured photoelectrically using a measuring aperture, and the image area of each zone is then mapped to each zone of the inkwell. Determine the key opening amount, and use this to set the facing gap between the ink supply roller and the blade provided in each zone facing the ink supply roller, keep the rotation speed of the ink supply roller constant, and It is designed to control the amount of ink supplied to the printing plate, and for this purpose, "Picture Area Measurement Amount" (Japanese Unexamined Patent Publication No. 58-118) was separately filed by the present applicant.
-201008) etc. are used.

[Problem that the invention seeks to solve]

However, in the past, the rotational speed of the ink supply roller was set at, for example, 50% of the maximum speed, and this remained unchanged, and only the opening amount of the ink fountain key was varied. If the supply amount is small, the key opening amount will decrease, and further adjusting the key opening amount based on this will require detailed adjustment, which will make control difficult.
As the key opening amount decreases, the film thickness of the ink that adheres to the rollers also decreases, and in the ink supply roller group that has a multi-stage configuration,
The film thickness tends to be large on the printing plate side and small on the ink front side, causing reverse trapping in which the ink on the printing plate side is transferred backwards to the ink front side, and the ink in the ink sac is This causes problems such as pollution.

[Means for solving problems]

In order to solve the above-mentioned problem, the present invention is constructed by the following means.

That is, in a printing press ink supply amount control method that measures the pattern area of each zone divided into a plurality of zones on the printing plate surface and controls the ink supply amount for each zone according to the pattern area, the pattern area for each zone is measured. Find the maximum area from among the areas, determine the ink feed amount by the ink supply roller according to this maximum area, and determine the coefficient according to the maximum area,
The corrected pattern area is determined by multiplying the pattern area for each zone by a coefficient, and the ink fountain key opening amount for each zone is determined according to each corrected pattern area.The ink supply amount is calculated from these ink feed amount and key opening amount. The first invention is to perform control of the following.

Further, on the same premise as the first invention, the corresponding ink fountain key opening amount is determined for each zone from the picture area of each zone, and the maximum key opening amount is determined from among the ink fountain key opening amounts. , determine the ink supply amount by the ink supply roller according to the maximum key opening amount, determine a coefficient according to the maximum key opening amount, and correct the ink fountain key opening amount for each zone by multiplying it by the coefficient. A second aspect of the present invention provides that the key opening amount is determined for each zone, and the ink supply amount is controlled by the ink feeding amount and the corrected key opening amount.

[Effect]

Therefore, in each invention, the rotational speed of the ink supply roller is constant tb according to the maximum area among the pattern areas of each zone, and the opening amount of the ink fountain key is determined correspondingly, so the pattern area increases or decreases. Regardless of K, the key opening amount is determined to be large.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to figures showing examples.

FIG. 2 is a block diagram showing an electrical circuit for measuring the pattern area, and shows a camera (hereinafter referred to as CAM) 1 that captures an image of the printing plate surface.
The video signal from 2000 is subjected to wave height correction in a waveform correction unit (WR) 2, and then sent to an analog-to-digital converter (ADC) including a sampling and holding circuit.
3, the measurement value is converted into a digital signal and stored in a variable memory (hereinafter referred to as RAM) 4.

Further, the contents of the RAM 4 are read out by a processor (hereinafter referred to as CPU) 5 such as a microprocessor connected by a data bus DB and an address bus AB, and based on this, the CPU 5 executes a predetermined operation. After determining the area of each image in each zone by dividing the printing plate surface vertically and determining the corresponding ink supply amount for each zone, a magnetic card mechanism (hereinafter referred to as I/F) is sent via an interface (hereinafter referred to as I/F) 6 , MC) 7, a printer (hereinafter referred to as PT) 8, and a cathode ray tube (hereinafter referred to as CRT) 9.

However, CAMI is a control signal generator (hereinafter referred to as CG) 1
The ADC 3 operates based on the synchronization signal from 0, and performs sampling hold and conversion operations based on the same sampling pulse, and the RAM 4 has the following information:
A similar addressing signal (AD) is applied, thereby sequentially storing the output of the ADC3.

Note that the CPU 5 executes predetermined calculations and control operations according to instructions stored in a fixed memory (hereinafter referred to as ROM) It, but it also performs predetermined calculations and control operations according to instructions stored in a fixed memory (hereinafter referred to as ROM) It.
W) 12 and a keyboard (hereinafter referred to as KB) 13, the lamp group (hereinafter referred to as PL) 14 blinks via I/F 6 to display the operating status.

In addition, a start signal is given from the CPU 5 to the CG 10, and when CAM1 finishes the imaging operation for one printing plate, an end signal is given from the CG 10 to the CPU 5, and the CPU 5 starts calculation in response to this. It becomes.

Therefore, in the end, the ink supply amount depends on the rotation speed of the ink supply roller in the printing machine,
The opening amount of the ink fountain key for each zone is determined and recorded on the magnetic card by the MC7.
Printout by PT8 and display by CBr4 are performed.

The imaging situation of the printing plate surface by the CAM1, the details of each part such as the WR2, and the details of the 16X calculation processing by the CPU 5 are as disclosed in the above-mentioned fP Publication No. 58-201008.

However, when determining the ink feed amount and ink fountain key opening, the CPU 5 in FIG. 2 performs the correction process shown in the flowchart in FIG. 1, and the results obtained are recorded on the magnetic card. ing.

That is, once the picture area for each zone is stored in the RAM 4, ``Perform SI ~ 8n Read J 101 and calculate the large size picture area r8max from among these'' 102, and then the solid part of the picture is set to Zoo%. As the area ratio, “O≦Smax≦zo(%)?Jttt, r20(
Smax≦40(%)? J 112, r 40 (
Smax≦60(%)? ”113, r60 (Sma
x≦so <th>? J 114 is sequentially determined, and depending on these Y (YES), the ink feed amount F and the coefficient M are respectively rF=10%・M=a J
121, rF=20 coefficient・M=bJ122, rF=30 coefficient・M-e J 123, "F=40%・M=dJ12
On the other hand, if all of the steps 111 to 114 are N (No), rF=50%・M=I
Established as J 125.

Next, the counter configured in the CPU 5 for counting the zone number is set to rt=t''tat, and r Si
'=Si・Ml According to 132) Picture area Sl of zone i
is multiplied by the coefficient M to obtain the corrected pattern area 81', and using this, convert 81' to Ki 133, zone 1
In addition to finding the ink fountain key opening amount Ki corresponding to
=n+1? Check J 141, and while it is N, register p counter by t = i + t J 142,
Step 132 and subsequent steps are repeated.

In the case of multicolor printing, the process shown in FIG. 1 is performed for each printing plate of each color, and the ink feed amount F1 for each color and the key opening amount Kl to Kn for each zone are recorded in the magnetic card. By inserting this into the ink supply amount control opening connected to the printing machine, the rotation speed of the ink supply roller is determined for each color unit, and the key opening amount for each zone is determined. The amount of ink supplied is automatically controlled.

Further, the coefficient M is selected, for example, as follows, depending on the relationship between the ink feed amount, the key opening amount, and the ink consumption amount on the printing plate surface.

a (5, b<5/z, c (5/3, d<5/4) Figure 4 shows the key opening amount Kmax determined by the conventional method in correspondence with the maximum picture area Smax, and Figure 1 The solid line shows the relationship between the key opening amount determined by the process of ``max'', and ``max'' is large compared to Kmax at a low opening amount, and the blade opening amount is large even in a small pattern area. For,
Setting and control based on this becomes easy.

Further, as the blade opening S becomes larger, the thickness of the ink film adhering to the ink supply roller also becomes larger, and the above-mentioned reverse trapping does not occur.

FIG. 4 shows a flowchart similar to FIG. 1, which corresponds to the second invention, and is similar to FIG. 1 except for the following parts.

That is, the counter for counting the zone number is r i
= IJ 202 and convert rsi to Kl 203 to find the ink fountain key opening amount Kl according to the picture area S1, and then F-i = n+1? j 20
4, and while this is N, ri=1+1j205
After registering the υ counter and repeating step 203 and subsequent steps, if step 204 is Y, each key opening amount is set to 1 to 1.
Perform the maximum key opening amount "determine Kmax" 206 from among Kn, and according to this, r o≦Kmax≦10 (%)
'i' J 211~r 30 (Kmax≦40(%
)? 214 is sequentially determined, and when the same <r i = 1 j 231 as in step 202 is performed, rKi'=Ki・M J 232 Except that the correction key opening amount KL' is immediately determined from K, the first This is similar to the figure, and by selecting the coefficient M, results equivalent to those in FIGS. 1 and 3 can be obtained.

However, the process shown in FIG. 1 or 4 may be performed not only in the pattern area measurement aperture, but also in the ink supply amount control aperture in which the magnetic card is inserted, and in steps 111 to 114 and 211 to 224. To select each determination situation and the corresponding ink feed amount F and the coefficient M, each numerical value may be determined according to the conditions.

Note that various modifications are possible, such as determining the ink feed amount F and the coefficient M by calculating the following equations and changing them continuously.

However, f: ink feed amount before correction [effect of the invention] As is clear from the above explanation, according to the present invention, even if the image area of the printing plate is small, the ink fountain key opening amount can be set generally. In addition to making it easier to control this, the thickness of the ink film that adheres to the ink supply roller is also increased, so reverse trapping does not occur, and the maximum pattern area in each zone can be Since it is used as a standard, the settings of each type can be set with high fidelity, and a significant effect can be obtained in controlling the ink supply amount of various printing machines.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is a flowchart of a correction process, Fig. 2 is a block diagram showing an electric circuit for pattern area measurement opening, and Fig. 3 is a diagram showing changes in the blade opening. FIG. 4 is a flowchart of correction processing corresponding to the second invention. 1----- CAM (camera), 3----- ADC (
analog/digital converter), 4...RAM (variable memory), 5...CPU (processor), 7...
...MC (magnetic card mechanism), 11. urn - ROM (fixed memory).

Claims (2)

[Claims] (1) In the ink supply amount control method for a printing press, the ink supply amount control method for a printing press measures the picture area of each zone divided into a plurality of zones on a printing plate surface, and controls the ink supply amount for each zone according to the respective picture area. The maximum area is determined from the pattern area of each zone, the ink feed amount by the ink supply roller is determined according to the maximum area, and a coefficient is determined according to the maximum area, and the pattern area of each zone is calculated. A corrected pattern area is determined by multiplying by a coefficient, an ink fountain key opening amount for each zone is determined according to each corrected pattern area, and the ink supply amount is controlled by the ink feeding amount and key opening amount. A method for controlling the amount of ink supplied to a printing press. (2) In the ink supply amount control method for a printing press, the method includes measuring the picture area of each of a plurality of zones on a printing plate surface, and controlling the ink supply amount for each zone according to the picture area. The corresponding ink fountain key opening amount is determined for each zone from the pattern area of each zone, and the maximum key opening amount is determined from among the ink fountain key opening amounts, and ink is supplied according to the maximum key opening amount. determining the amount of ink supplied by the roller, determining a coefficient according to the maximum key opening amount, and multiplying the ink fountain key opening amount for each zone by the coefficient to obtain a corrected key opening amount for each zone; A method for controlling an ink supply amount of a printing press, characterized in that the ink supply amount is controlled by the ink feed amount and the correction key opening amount.