JPH08207256A - Dampening controller for offset printer - Google Patents

Abstract

PURPOSE: To enable a dampening unit with multiple supply systems to select an optimal supply system automatically. CONSTITUTION: A dampening unit having multiple dampening systems, which is made to select an optimal supply system automatically which dampens a plate 9 by a dampening roller, depending on an image area of the plate and the type of ink on the basis of a previously obtained knowledge database.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a humidity control device for an offset printing machine.

[0002]

2. Description of the Related Art FIG. 2 shows a multimode dampener (Mul).
Japanese Patent Application Laid-Open No. 6-
A moisturizing device and a moisturizing method for an offset printing machine described in Japanese Patent No. 286098 are shown. 2, 1 is a dampening water tank, 2 is a dampening source roller, 3 is a metering roller, 4 is a dampening roller, 5 is an ink receiving roller, 6 is an ink passing roller,
Reference numeral 7 is an inking roller, 8 is an ink oscillating roller, 9 is a printing plate, and 10 is a plate cylinder on which the printing plate 9 is mounted. Printing plate 9
Ink is applied to the image area (design) of the ink through the ink oscillating roller 8 and the ink depositing roller 7 of the inking device (partly shown), and dampening water is applied to the non-image area to prevent ink transfer. Supplied. The dampening water taken out from the dampening water tank 1 by the dampening source roller 2 is supplied to the dampening roller 4 via the metering roller 3, but the dampening water supplied to the dampening roller 4 is the printed matter. It is supplied to the printing plate 9 through a moisturizing and supplying system that allows the optimum printing quality to be obtained depending on the design and ink. The optimum humidification supply system is selected by the operator, and the push button of the control device corresponding to this selection is pressed to switch the supply system of the humidification device. As shown in FIG. 2, these supply systems include a linear printing plate 9, a path of ink receiving roller 5 → inking roller 7, ink receiving roller 5 → ink transfer roller 6 → ink oscillating roller 8 → inking roller. An ITD system for supplying dampening water together with ink to the printing plate 9 through three paths of the roller 7, and supplying dampening water to the printing plate 9 directly from the dampening roller 4 as shown in FIG.
D system, SAD system for supplying dampening water together with ink to the printing plate 9 through the route of directly supplying to the printing plate 9 as shown in FIG. 4 and the route of dampening roller 4 → ink receiving roller 5 → inking roller 7. 5, as shown in FIG. 5, a direct printing plate 9, a dampening roller 4, an ink receiving roller 5, an ink passing roller 6, an ink oscillating roller 8 and an inking roller 7, and a moisturizing supply system. Therefore, the positions of the ink receiving roller 5 and the ink passing roller 6 are switched so as to form this supply system. The reason why the moisturizing and supplying system is switched in this way is that it is almost impossible to obtain the highest quality for all kinds of printed materials with a single supplying system.

[0003]

As described above, in order to obtain the best print quality depending on the pattern or ink of the printed matter, the installation of the humidifying device having a plurality of supply systems is an essential condition. However, in a moisturizer having a plurality of supply systems, the operator must judge the operator by looking at the image area of the printing plate mounted on the printing unit and selecting the optimum moisturizing path.
Especially in a multi-color printing press, it is a very brain-intensive task because the printing plate to be mounted for each printing unit of each color is judged. It also requires a fair amount of experience to make a good decision.

The present invention proposes a humidification control device for an offset printing machine which can automatically preset based on a knowledge database previously obtained in the optimum humidification supply system.

[0005]

The present invention relates to a moisturizing device having a plurality of supply systems for moisturizing a printing plate from a dampening roller, depending on the pattern area ratio of the printing plate and the type of ink.
It is characterized in that the optimum supply system for humidifying the printing plate can be automatically selected based on a knowledge database obtained in advance.

[0006]

According to a large amount of past data and experience, it is found that mainly the plate image area ratio (based on the dot area) and the type of ink (mainly color) are the factors to obtain the optimum printing for the image on the printed matter. did. Therefore, when the above two elements are calculated by the control device or input to this control device, the control device selects the optimum humidification supply system based on the knowledge data of the two elements and the optimum humidification supply system that are input in advance, and the humidification Command the device. In response to this command, the humidifier automatically switches the positions of the ink receiving roller and the ink passing roller.

[0007]

FIG. 1 is a block diagram showing an operation procedure of a moisturizing control device for an offset printing machine according to the present invention and a graph of a pattern area ratio vs. print quality for each moisturizing and supplying system.
In FIG. 1, the pattern area ratio A of the printing plate 9 (FIG. 2) is controlled by the control device 11 or the plate image area ratio meter (existing one, not shown).
Calculate or calculate (halftone dot area). On the other hand, the type B of ink used is known. When these specifications A and B are input to the control device 11, the specifications A and B input in advance are input.
Data for displaying the optimum humidifying / supplying system set for each classification classified by B combination by number (Dampener)
Hade Algorism Optimal humidification supply system number)
The optimum humidifying / supplying system number is selected from the memory area 12 storing the data, and the humidifying device 1 is selected from the control desk 13.
Command 4 By this instruction, the ink receiving roller 5 and the ink passing roller 6 of the humidifying device 14 (FIGS. 2 to 5)
The bearing or support arm that rotatably supports is moved by an air cylinder (neither is shown) operated by an electric switching valve designated by the control disk 13, and an optimum humidification supply path is instructed as instructed. Form. As described above, the humidifying device provided for each color printing unit is preset to the optimum humidifying and supplying system.

A graph 15 shows the pattern area ratio vs. print quality for each of the representative humidification supply systems ITD, AD, and SAD shown in FIGS. 2, 3, and 4, which are the sources of data input to the memory 13. In the graph shown, the ITD supply system is used when the AD supply system is large when the pattern area ratio is small, and S is used when the image supply ratio is intermediate.
It shows that the AD supply system is good.

[0009]

With the humidity control device of the offset printing machine according to the present invention, the optimum print quality for the printed matter can be obtained only by inputting the measured pattern area ratio of the printing plate and the known ink type into the control device. A humidifying / supplying system to be selected is selected, and the humidifying path of the humidifying device is automatically switched to the optimum humidifying / supplying system by this selection, so that the optimum humidifying / supplying path can be easily preset regardless of the experience of the operator. And the print quality is improved.

[Brief description of drawings]

FIG. 1 is a block diagram of a work procedure showing an embodiment of the present invention.

FIG. 2 is an example of an ITD system humidifying / supplying system of a humidifying device.

FIG. 3 is an example of an AD type humidification supply system of the humidifier.

FIG. 4 is an example of a SAD-type humidifying / supplying system of the humidifying device.

FIG. 5 is an example of a humidification supply system of the humidification device.

[Explanation of symbols]

 4 Damping Roller 5 Ink Receiving Roller 6 Ink Transfer Roller 7 Inking Roller 8 Ink Swing Roller 9 Plate 11 Controller 14 Moisturizer

Claims (1)

[Claims] 1. An optimum supply for humidifying the printing plate according to a pattern area ratio of the printing plate and a kind of ink, to a humidifying device having a plurality of supply systems for humidifying the printing plate from a dampening roller. A humidification control device for an offset printing machine, wherein a system can be automatically selected based on a knowledge database obtained in advance.