JPH091785A - Registering device for printer - Google Patents

Abstract

PURPOSE: To facilitate exertion of automatic registering of a printer by using a register mark. CONSTITUTION: Register marks overlapping each other when a color misregistering is not generated are photographed by color cameras 10, 11. The register marks photographed by the color cameras are separated in color to obtain a register mark image of each printed color by image processing, and a misregistering amount of a comparative register mark image to a standard register mark image is detected. A registering motor of a printing unit is driven according to a signal of the shear amount obtained by the image processing to solve the color shear.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a registration device for eliminating color misregistration of printing colors of a continuous paper printing machine.

[0002]

2. Description of the Related Art As a conventional registration device, there is one disclosed in Japanese Patent Laid-Open No. 63-22651. This is because the registration mark image parts that are intentionally displaced from each other by a predetermined amount are formed on the printing plates of each color that are mounted on each printing unit of the continuous paper printing machine, and the printed image comes out from the printing machine. The continuous paper is scanned by a sensor, and if the registration mark deviation from the sensor detection signal matches the above-mentioned predetermined amount, the printing registration is correct, and if it deviates from the above-mentioned predetermined amount, the deviation is the printing deviation. It was decided to judge. Output to the plate cylinder of the printing machine to eliminate this deviation,
By moving the plate cylinder in its axial direction and in the circumferential direction to eliminate the printing misregistration, it is possible to obtain a proper printed matter.

[0003]

However, in the above-mentioned conventional registration device, the registration mark is printed so that it is displaced from the beginning, and the sensor determines whether or not the deviation amount is appropriate. When the misregistration is such that the positions of the registration marks are exchanged, there arises a problem that it is determined to be proper despite the color misregistration.

Further, in order to form the register mark on the printing plate,
For example, in the case of four-color printing, first, four registration mark image parts positioned relatively to each plate are formed, and then the register mark image parts of other colors are erased from each plate. There is a need. However, since the registration mark image area is generally formed so as not to stand out on the printed matter,
There is a case in which a mistake in work such as erasing an image area to be left or forgetting to erase the image area to be erased may be made. In such a case, it becomes difficult to control the registration.

Conventionally, a register mark is printed so that an operator of a printing machine can determine whether the register is good or bad. According to the conventional register apparatus described above, all colors such as the register mark are printed. Color misregistration cannot be detected with register marks that overlap each other.
The special register mark must be printed separately from the register mark, which makes the plate making process and the plate making process troublesome. Further, there is a problem that the special register mark tends to stand out when it remains on a printed matter as a product.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a registration device for a printing press that can solve the above-mentioned conventional problems.

[0007]

In order to achieve the above object, the invention of claim 1 is a color in which overlapping register marks 6, 7, 8 and 9 are imaged by stroboscopic light emission after completion of printing when color misregistration does not occur. The cameras 10 and 11, and the registration mark 6 imaged by the color cameras 10 and 11
Color separation of 7, 8 and 9 to obtain register mark images of each printing color,
Image processing means for detecting the deviation amount of the comparative registration mark image with respect to the reference registration mark image, and printing units I, II, III, IV so as to eliminate the deviation of the printing color based on the deviation amount signal from the image processing means. The registering motor control means for driving the registering motor is provided, and the image registering means of the invention according to claim 2 is characterized in that: , The center position 9a of the reference register mark 9 and the center positions 6a, 7a, 8a of the comparative register marks 6, 7, 8 are calculated.
Is calculated to calculate the color shift amount of the comparative register marks 6, 7, 8 with respect to the color of the reference register mark 9, and the central positions 6a, 7a, 8a of the comparative register marks 6, 7, 8 cannot be calculated. , The center position 6a of each of the comparative register marks 6, 7, 8 is corrected by correcting the overlapping portion of the comparative register marks 6, 7, 8.
The central positions 6a, 7a, 8a cannot be obtained even by calculating 7a, 8a to calculate the color shift amount of the comparative register marks 6, 7, 8 with respect to the color of the reference register mark 9 and correcting the overlapping portion. In this case, the edge positions of the reference register mark 9 and the comparative register marks 6, 7, 8 are detected to calculate the color shift amount of the comparative register marks 6, 7, 8 with respect to the color of the reference register mark 9. According to a third aspect of the present invention, there is provided a registering device for a printing press, wherein the register marks 6, 7, 8 and 9 are register marks. The configuration of the registration device of the printing machine according to item 1 or 2 is adopted.

[0008]

According to the first aspect of the invention, the color cameras 10 and 11 face the continuous paper 1 discharged from the printing machine, and the register marks 6, 7, 8 and 9 are taken as still images by strobe emission. . Next, the image processing means color-separates the register marks 6, 7, 8, 9 captured by the color cameras 10 and 11 to obtain register mark images of respective print colors, and compares the register mark images with the reference register mark image. The amount of deviation is detected.
If the displacement amount is not detected, the registering device does not operate. However, when the displacement amount is detected between the register marks 6, 7, 8 and 9, the image processing means outputs a signal of this displacement amount to the control means. The control means drives the registration motors of the printing units I, II, III, IV so as to eliminate the deviation amount. As a result, the printing machine can perform proper printing without color misregistration.

According to the second aspect of the present invention, the image processing means calculates the central position 9a of the reference register mark 9 after the color separation and the central position 6 of the comparative register marks 6, 7 and 8.
a, 7a, 8a are calculated to calculate the amount of color shift of the comparative register marks 6, 7, 8 with respect to the color of the reference register mark 9.
Center positions 6a, 7a of the comparative register marks 6, 7, 8
If 8a cannot be calculated, the comparison register marks 6, 7, 8
Of each comparative register mark 6, 7, 8 by correcting the overlapping part of
The center positions 6a, 7a, 8a of the above are calculated to calculate the color shift amount of the comparative register marks 6, 7, 8 with respect to the color of the reference register mark 9. Even if the above-mentioned overlapping portion is corrected, the center position 6
If a, 7a, 8a cannot be obtained, the edge positions of the reference register mark 9 and the comparative register marks 6, 7, 8 are detected to determine the color of the comparative register marks 6, 7, 8 with respect to the color of the reference register mark 9. Calculate the amount of deviation. As described above, since the printing states of the register marks 6, 7, 8, and 9 are examined over three stages, it is possible to properly judge the color misregistration.

According to the invention of claim 3, the register mark 6,
The register marks are used as 7, 8, and 9. Therefore, it is not necessary to prepare a register mark other than the register mark, and the plate making process and the plate making process are simplified.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. The printing machine exemplified as the registration control target in this embodiment is a double-sided rotary printing machine that prints on the continuous paper 1 as shown in FIG. The printing machine is, for example, a four-color printing machine, and four printing units I, I are provided for each color.
I, III, IV are provided. Printing unit I, I
I, III, and IV are, for example, a black (K) ink printing unit, a magenta (M) ink printing unit, a cyan (C) ink printing unit, and a yellow (Y) ink printing in the flow direction of the printing paper. It is a unit. In addition, the printing units I, II, III, and IV have blanket cylinders 2 and 3 facing each other, and blanket cylinders 2 and 3, respectively.
And the plate cylinders 4 and 5 corresponding to the plate No. 3. When printing, the continuous paper 1 is impressed with printing pressure by the blanket cylinders 2 and 3 while passing through the printing units I, II, III, and IV to imprint an image of each color, and when the final printing unit IV exits, multicolor printing is performed. Printing will be completed.

In such multicolor printing, each color Y, M,
If the C and K are misaligned, the print quality is deteriorated. Therefore, a printing plate (not shown) wound around the plate cylinders 4 and 5 to detect the color misalignment is called a register mark in advance. Image areas for printing the register marks 6, 7, 8, 9 as shown in FIG. This registration mark 6, 7,
When all colors Y, M, C, and K are normally printed without deviation, all of the colors 8 and 9 are printed in an overlapping manner as shown in FIG. If there is a deviation, the printing is shifted as shown in FIGS. In this embodiment, the registration marks 6, 7,
Marks 8 and 9 that are conventionally used for printing generally are used. It is desirable that the register marks have the same size for each color.

As the register mark, a register mark having another shape may be printed in addition to the register mark. Also, the shape of the register mark is not limited to the cross shape,
It can be set in various shapes such as one-letter shape, T-shape, L-shape, square, triangle, and circle.

As shown in FIG. 1 and FIG. 2, this registering device is a color camera 10 for picking up the overlapping register marks 6, 7, 8, 9 by stroboscopic light emission after completion of printing when color misregistration does not occur. , 11, and the registration marks 6, 7, imaged by the color cameras 10, 11.
8 and 9 are color-separated to obtain a register mark image of each print color, and an image processing means for detecting a positional deviation of the comparative register mark image with respect to the reference register mark image, and a printing color based on the positional deviation signal from the image processing means. It has a registration motor control means for outputting to the registration motors of the printing units I, II, III, IV so as to eliminate the misregistration.

The color cameras 10 and 11 are, for example, C
It is a CD color camera, which is prepared corresponding to the upper and lower sides of the continuous paper 1 so that the register marks 6, 7, 8 and 9 of the continuous paper 1 printed out from the printing machine face the places to pass through. It is fixed to the press frame. Each color camera 10 and 11 includes a strobe light source and a strobe power supply unit 1.
2 and 13 have a register mark 6 by stroboscopic light emission.
Color cameras 10, 11 as 7, 8, 9 still images
I'm supposed to shoot at. The timing at which the strobe emits light is set by the encoder 14, the position counter 15, and the CPU 17. The encoder 14 is a main shaft 16 for driving the printing press.
Is output to the position counter 15, and the CPU 17 operates the strobe power supply units 12 and 13 based on the output from the position counter 15 so that the strobe light source can detect the registration marks 6 and 7. ，
Each time 8 and 9 arrive, it will emit light. The registration mark 6, which is taken by the color cameras 10 and 11, respectively.
Images 7, 8 and 9 are alternately switched by the multiplexer 18 and sent to the next image processing means.

The image processing means is an RGB color processor 19
And the register marks 6, 7, 8 captured by the color cameras 10 and 11 by the computer (CPU) 17.
An image composed of 9 RGB signals is color-separated, and each print color Y,
The M, C, and K register mark images are created, and the positional deviation of the comparative register mark image with respect to the reference register mark image is detected. However, in this embodiment, the reference register mark image is black K and the comparative register mark image is yellow Y, magenta M, and cyan C. Of course, a register mark of a color other than the black ink K may be used as a reference and a register mark of another color may be used as the comparative register mark.

An image processing procedure by the image processing means will be described with reference to FIGS. 3 and 4. First, based on the signal from the encoder 14, it is detected when the registration marks 6, 7, 8, 9 of the four colors Y, M, C, K come to the photographing positions of the color cameras 10, 11 (step 1), and the registration is performed. When the marks 6, 7, 8, 9 arrive, strobe light is emitted to capture the color image of the register marks 6, 7, 8, 9 (step 2), and the register marks 6, 7, 8, 9 are detected (step 3). , 4). These four color Y, M, C, K register marks 6,
When printing is normal, 7, 8, and 9 are displayed on the printing paper in a state where they are almost overlapped with each other as shown in FIG. 8, and when each color is printed with a deviation, the registration mark is also displaced by the deviation amount. Is displayed.

Next, the detected registration marks 6, 7,
8 and 9 are color-separated into Y, M, C, and K colors, and the deviation amount of each color Y, M, C, and K is calculated (step 5). More specifically, if the registration marks 6, 7, 8, 9 are photographed in the state as shown in FIG. 5 after the color separation (step 11), the center position 9a of the reference registration mark 9 is calculated. At the same time (step 17), the center positions 6a, 7a, 8a of the comparison register marks 6, 7, 8 are calculated (steps 12, 18, 23), the center positions 6a, 7a, 8a are compared, and the reference register mark 9 is compared. The deviation amounts of the colors Y, M, and C of the comparative register marks 6, 7, and 8 with respect to the color K are calculated (step 28). Two types of misregistration are detected: the amount of misalignment of the registration mark in the vertical direction and the amount of misalignment in the horizontal direction. The amount of deviation in the vertical direction corresponds to the flow direction of the continuous paper, and the amount of deviation in the left-right direction corresponds to the width direction of the continuous paper.

Registration proceeds further than the state shown in FIG.
When the register marks 6, 7, 8 and 9 are in the state as shown in FIG. 6, the center positions 6a, 6a of the comparative register marks 6, 7 and 8 are
There are cases where 7a and 8a cannot be calculated. In such a case, the center portion 6a of each of the comparative register marks 6, 7, 8 is corrected after the overlapping portion between the comparative register marks 6, 7, 8 is corrected.
7a and 8a are calculated (steps 13, 14, 19, 2
0, 24, 25) and the center positions 6a, 7a, 8a are compared to calculate the deviation amount of the colors Y, M, C of the comparative register marks 6, 7, 8 with respect to the color K of the reference register mark 9 (step 28).

Registration proceeds further than the state shown in FIG.
If the registration marks 6, 7, 8, 9 are in the state shown in FIG. 7, the center position may not be obtained even by correcting the overlapping portion. In such a case, the edge positions of the reference register mark 9 and the comparative register marks 6, 7, 8 are detected (steps 17, 15, 16, 21, 22, 22).
6, 27), and the edge positions are compared to calculate the amount of deviation of the color Y, M, C of the comparative register mark from the color K of the reference register mark (step 28). For example, the deviation amount a shown in FIG. 7 is the deviation amount in the width direction of the cyan C with respect to the black ink K, and the deviation amount b is the deviation amount in the up-and-down direction with respect to the black ink K of cyan C.

The center position 9a of the register mark 9 of the black ink K
When the edge position is not obtained, the center positions 6a, 7a, 8a and the edge positions of the register marks 6, 7, 8 of other colors are appropriately selected as the reference position.

Thus, when the deviation amount of each color is obtained, C
Output from the PU 17 to the registration motor control means, and the printing units I, II, III, I in which color misregistration occurs
The V registration motor is driven (step 6).

The motor control means has a motor controller 20, and the motor controller 20 outputs to the registration motors of the printing units I, II, III and IV. Registration motor is plate cylinder 4, 5
There are prepared means (not shown) for displacing the blade in its circumferential direction, and for displacing it in the axial direction. When the CPU 17 outputs the signal indicating the amount of misregistration, the registration motor of the plate cylinder that causes the color misregistration is driven to eliminate the misregistration.

As the register marks, in addition to the register marks for color registration, the register marks for creases,
It is also possible to use a register mark for bookbinding.

[0025]

According to the first aspect of the present invention, there is no problem of the color misregistration detection failure due to the switching of the positions of the registration marks as in the prior art, and the color misregistration in the printing machine can be properly eliminated. It is possible to reduce the amount of waste paper generated when printing is started. Further, in order to form the register mark on the printing plate, it is only necessary to form one register mark image portion at the same position on each printing plate.
The printing plate process is simplified. In addition, it does not require the work of erasing the unnecessary registration mark image area as in the past, so there is no mistake in erasing the image area that should be left or forgetting to erase the image area that should be erased. It does not occur, so that the registration control can be reliably performed. further,
Even if the registration mark remains on the printed matter, it can be formed as a small black dot, so that the deterioration of print quality can be prevented.

According to the invention of claim 2, since the image processing means examines the printing state of the register mark in three steps,
It is possible to properly judge the presence or absence of color misregistration. According to the invention of claim 3, since the register mark is used as the register mark, it is not necessary to prepare a special register mark other than the register mark, and the plate making process and the plate making process can be simplified. Further, since the printed portion of the register mark is cut off from the final printed matter, it is possible to surely prevent the print quality from being deteriorated due to the mark for registering.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a printing machine provided with a registration device according to the present invention.

FIG. 2 is a block diagram showing a configuration of the registration device.

FIG. 3 is a flowchart showing an image processing procedure of the registration device.

FIG. 4 is a flowchart showing details of a part of the flowchart.

FIG. 5 is an explanatory diagram showing a state in which a register mark is printed with a complete deviation.

FIG. 6 is an explanatory diagram showing a state in which register marks are printed with a medium shift.

FIG. 7 is an explanatory diagram showing a state in which register marks are printed with a slight deviation.

FIG. 8 is an explanatory diagram showing a state in which a register mark is printed without displacement.

[Explanation of symbols]

 I, II, III, IV ... Printing unit 6, 7, 8, 9 ... Register mark 6a, 7a, 8a, 9a ... Center position of register mark 10, 11 ... Color camera

Claims (3)

[Claims] 1. A color camera that images overlapping registration marks when no color misregistration occurs after printing is completed by stroboscopic light emission, and color registration is performed on the registration marks captured by the color camera to obtain register mark images for each printing color. , An image processing means for detecting a deviation amount of the comparative registration mark image with respect to the reference registration mark image, and a registration motor of the printing unit so as to eliminate the deviation of the printing color based on the deviation amount signal from the image processing means. A registration device for a printing press, comprising: 2. The image processing means, after color separation, calculates the center position of the reference register mark and the center position of the comparison register mark to calculate a color shift amount of the comparison register mark with respect to the color of the reference register mark. If it is not possible to calculate the center position of the comparative register mark, calculate the center position of each comparative register mark by correcting the overlapping part of the comparative register mark and calculate the color of the comparative register mark with respect to the color of the reference register mark. If the center position cannot be obtained even by calculating the amount of deviation and correcting the overlapping part, the edge positions of the reference register mark and the comparative register mark are detected, and the color of the reference register mark is compared with the color of the reference register mark. The registration device for a printing press according to claim 1, wherein the registration device is configured to calculate a deviation amount. 3. The register device for a printing press according to claim 1, wherein the register mark is a register mark.