JPH0443036A - Automatic preparation system of machine plate - Google Patents

Abstract

PURPOSE:To prepare a machine plate automatically to a plate cylinder directly by providing a control means receiving picture data at every color corresponding to the number of printing colors obtained from a printing original, controlling the operation timing of the plate cylinder and the operation timing of a jet head and preparing a picture by a lipophilic liquid to a plate mounted to the plate cylinder. CONSTITUTION:When a picture data is received, a control means 34 controls the drive system of a plate cylinder 11, the drive system of a jet head 15 and the operation timing of the jet head 15 in order to draw a picture corresponding to the data on a plate 17 by a liquid. The position of liquid injection is calculated because the picture is changed into a network and drawn especially when the operation timing of the jet head 15 is controlled. When a hydrophilic plate and a lipophilic liquid are used, the picture (plate) 11 by the lipophilic liquid is formed on the plate 17 by the jet head 15.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an offset printing press, and more particularly to an automatic printing plate creation system that allows printing plates to be created using a plate cylinder.

(Prior Art) Conventionally, in the field of offset printing machines, when printing,
A printing plate must be created in advance based on the printing manuscript. This printing plate is made from an aluminum plate or the like using a plate making machine or the like.

During printing, it is attached to a plate cylinder and offset printing is performed. In the case of color printing, the above work is usually 4 times depending on the number of colors.
It will be held twice.

(Problems to be Solved by the Invention) Therefore, in the above-described method, it takes time and effort to attach the printing plate to the plate cylinder.

Accordingly, one object of the present invention is to provide an automatic printing plate creation method that allows printing plates to be created using a plate cylinder.

(Means for Solving the Problems) In the automatic printing plate creation method according to the present invention, a hydrophilic or oil-resistant (or oleophilic) flat plate is attached to a plate cylinder and moved along the plate cylinder in the direction of its rotation axis. A jet head for ejecting a lipophilic (or hydrophilic) liquid is provided as possible, and the operation timing of the plate cylinder and the jet head are adjusted based on image data for each color corresponding to the number of printing colors obtained from the printing original. The present invention is characterized by comprising a control means for controlling operation timing to create an image (plate) on the flat plate using the lipophilic (or hydrophilic) liquid.

(Operation) When the control means in this system receives one image data, it controls the drive system of the plate cylinder, the drive system of the jet head, and the operation timing of the jet head in order to draw an image corresponding to the data on a flat plate using liquid. especially.

For jet head operation timing control.

The liquid injection position is calculated in order to halftone and draw the image.

When a hydrophilic flat plate and a lipophilic liquid are used, what is formed on the flat plate by the jet head is an image (plate) made of the lipophilic liquid.

(Example) An example of the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1, a transfer blanket cylinder 12 is arranged so as to be in pressure contact with a first plate cylinder 11.
An impression cylinder 13 for transferring the pattern transferred thereto onto printing paper (not shown) is placed in pressure contact with the printing paper 2. On plate cylinder 11.

A jet head 15 is slidably provided on a guide shaft 14 attached in the direction of the rotation axis.

The jet helad 15 is slidably driven by the rotation of the ball screw 16.

A hydrophilic or curved flat plate 17 is wound around the plate cylinder 11 as a printing plate material.

The jet head 15 is for jetting a lipophilic liquid onto the flat plate 17, and forms a liquid image (plate) of a printing original by an image data calculation control section to be described later. Note that the lipophilic liquid contains a fixing agent for improving fixing properties to the flat plate 17.

The image data calculation control unit (not shown) includes one image scanner,
Magnetic disk device 9 receives image data from an image data transmission device, etc. and performs two-color separation.

The decomposed data is divided into an appropriate number of pixels and gradations, and then a halftone area ratio is calculated in order to halftone the liquid image using the jet head 15 (second Also, determine how much liquid area should be occupied per pixel, as shown in Figure (a). According to a normal jet head, as shown in Fig. 2(b), 16
It can be represented by the number of pixels above, and one pixel can be represented by the number of gradations of 32 or more gradations. The pixel data calculation control section is also connected to the first plate cylinder 11. It also controls the operation timing of the blanket cylinder 12° impression cylinder 13, etc.

It also controls the movement of the jet head 15 and the timing of liquid injection.

The printing plate creation process will be explained below.

First, the flat plate 17 is attached to the plate cylinder 11 as required (in the case of making a printing plate using the flat plate 17).

Image data is supplied from an image scanner, magnetic disk device, etc. to the image data calculation control section. The image data calculation control unit performs color separation according to the input image data and determines the injection position of the lipophilic liquid for each separated data.

The dot area ratio at that position is calculated. These calculation data are stored in the -H buffer. The image data calculation control section rotates the ninth plate cylinder 11 at low speed and drives the ball screw 16 to move the jet head 15 along the plate cylinder 11. Then, while the jet head 15 is moving, the lipophilic liquid is jetted toward the plate cylinder 11 or the flat plate 17 attached to the plate cylinder 11 at the jetting position and dot area ratio obtained by the above calculation. Due to this.

A liquid image is drawn on the plate cylinder 11 (flat plate 17), which is represented in different gradations by halftone dots with different halftone dot area ratios depending on the color shading of the printing original. This behavior is.

This continues until the plate cylinder 11 rotates once, and as a result, the plate cylinder 11 (
On the flat plate 17), a liquid image with the same colors as the printing original is drawn 1
One printing plate is formed directly on the plate cylinder 11 or on a flat plate 17 attached to the plate cylinder 11.

Ink is applied to the plate cylinder 11 (flat plate 17) on which this liquid image is drawn by a known method and transferred onto the blanket cylinder 12 rotating together with the first plate cylinder 11, and then supplied from a printing paper supply section (not shown). Blankerat cylinder 12 and impression cylinder 13
One color is printed by transferring the color onto the printing paper that passes between the two. Similarly, in the case of multicolor printing, the second and subsequent colors are printed.

FIG. 3 is a schematic diagram when the present invention is applied to a color offset printing machine. This printing machine.

It includes an essential printing unit 31A, an indigo printing unit 31B, a regular printing unit 31C, and a yellow printing unit 31D, and each of these printing units 31A to 31D employs the above-described automatic plate creation method.

Regarding the necessary printing unit 31A, the first plate cylinder 11A,
Blanket cylinder 12A, impression cylinder 13A and jet head 1
Contains 5A. 33 is a roller for feeding paper to the next mold printing unit 31B. The data correction device 35A is! Errors such as printing misalignment due to characteristics specific to the printing unit 31A for 1A are stored in advance, and by correcting the data from the image data calculation control unit 34 based on this stored information, automatic registration can be performed. Has a function.

The image data calculation control unit 34 is basically the same as described above, and receives color image data from an image scanner or other device, performs color separation into black, indigo, red, and yellow, and performs calculation processing for each separated color. Do it.

Normally, first, the necessary printing unit 31A is activated to print the black part, then the pattern printing unit 31B is activated to print the indigo part, and then the regular printing unit 31C is activated to print the red part. The yellow portion is printed, and the yellow printing unit 31D is further activated to print the yellow portion.

In the embodiment, the case where the plate cylinder 11 (flat plate 17) is hydrophilic and the ejected liquid is lipophilic has been described, but these relationships may be reversed.

(Effects of the Invention) As explained above, according to the present invention, a printing plate can be automatically created directly on a plate cylinder or a flat plate attached to the plate cylinder without using a separate special device such as a plate making device. 1. It is possible to reduce the time and labor required for the troublesome installation and removal of printing plates, and it is also possible to perform so-called test printing while making test prints. There is no need to adjust the register, so there is no need to waste printing. Furthermore, even when the same plate is used repeatedly, it is sufficient to directly create a printing plate each time it is used, so there are advantages such as no need to store or manage printing plates.

Peng 1 diagram

[Brief explanation of the drawing]

FIG. 1 is a perspective view schematically showing the main parts of the present invention. FIG. 2 is a diagram for explaining dot-like jetting by the jet head according to the present invention, and FIG. 3 is a schematic diagram of the configuration when the present invention is applied to a color offset printing machine. In the figure, 11 is a plate cylinder, 12 is a blanket cylinder, 13 is an impression cylinder, 15 is a jet head, 16 is a ball screw, and 17 is a flat plate.

Claims (1)

[Claims] (1) A hydrophilic or oil-resistant (or oleophilic) flat plate is attached to the plate cylinder, and a jet that injects oleophilic (or hydrophilic) liquid so that it can move along the plate cylinder in the direction of its rotational axis. A flat plate mounted on the plate cylinder or the plate cylinder, which is provided with a head and receives image data for each color according to the number of printing colors obtained from the printing original, and controls the operation timing of the plate cylinder and the operation timing of the jet head. An automatic printing plate production method characterized by comprising a control means for producing an image (plate) using the lipophilic (or hydrophilic) liquid.