JPS61118249A - Register device for printer - Google Patents

Abstract

PURPOSE:To permit a printer to be automatically registered according to results of measurement by a method in which position coordinates of each color pattern are input by a coordinate input unit and register errors between colors are turned out from each color position coordinate and magnification of image to measure register errors of printing exactly. CONSTITUTION:By a camera 101 with a stroboscopic illuminator 106, patterns on a printing paper moving at high speeds are photographed in a standstill state. Images are displayed with a magnification of ten times on a displayer 4 by a magnifying lens 105 with an intermediate ring. The position of patterns is calculated from the turning angles of plate. By input of positions and coordinates on the plate on the surface side of patterns to be photographed by keys on an operating keyboard 3, the position of patterns seeable through the camera is calculated and on the instance the coordinates of patterns to be photographed coincide, photographic operation is made. By operating the keyboard 3, the coordinate input is calculated in CPU and register errors as results of calculation are further calculated into corrected position of plate cylinder and then given to a monitor drive circuit through an interface. A motor M is operated to adjust the position of the plate cylinder.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a registration device for a multicolor printing press.

[Background technology and its problems]

For example, in the case of an offset printing machine, a printing plate with a pattern formed on it is wrapped around the printing plate, the ink stored in the ink tray is transferred to the printing plate via a group of ink rollers, and the ink transferred to the printing plate is transferred to the printing plate. The printing paper is transferred to a blanket plate (rubber plate) that rotates while being pressed against it, and printing is performed by passing the printing paper between the blanket cylinder and the impression cylinder. To perform multicolor printing, the plate cylinder, blanket cylinder, and impression cylinder described above are arranged as a unit for each color. Printing is completed by passing the printing paper through each unit in turn.

By the way, in such multi-color offset printing, if the printing plates wrapped around the plate cylinders of each printing unit are not in the proper positional relationship and are misaligned, the printed matter that has been placed on top of the plate may be printed vertically. (traveling method), misregistration in the left-right direction or in the twisting direction will occur.

Conventionally, an operator performs trial printing, observes the printed material with a magnifying glass, visually measures the amount of misregistration, and adjusts the position of the plate cylinder in accordance with the measurement results. This operation is repeated until the registration error disappears.

However, with this method, the operator is required to be skilled because the operator measures the amount of misregistration by eye and adjusts the position of the plate cylinder based on this measurement result, and the measurement error is large, making it impossible to eliminate misregistration. It takes a lot of time and wasted paper because it goes through trial and error over and over again.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and it is possible to accurately measure the amount of registration error of printed matter by performing simple operations, and automatically adjust the registration of the printing press according to the measurement results. The purpose is to provide a device that performs the following steps.

[Summary of the invention]

To achieve this objective, in the present invention, a picture of a printed matter is photographed and input on a printing machine, this picture is enlarged and displayed on a display, and each color picture is inputted using coordinate input means for a predetermined element in this enlarged display image. Input the position coordinates of , calculate the amount of registration error between each color based on the position coordinates of each color and the magnification rate of the image, calculate the amount of plate cylinder position adjustment based on this registration error a, and adjust the printing press according to the calculation result. A device for performing registration is provided.

〔Example〕

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1(a) and 1(b) show an example of a configuration for implementing the present invention. FIG. 1(a) shows an overview, and FIG. 1(b) shows a block diagram. In the figure, reference numeral 101 denotes two high-speed color video cameras, which are installed at positions where they can photograph the paper surface from the front and front sides, respectively, after gold printing has been completed.

The camera 101 is equipped with a strobe 106, and by emitting light from the strobe 106 in a very short period of time, it is possible to produce an R shadow of a pattern on a printing paper that is moving at high speed while it remains stationary. The formed image is enlarged several tens of times and displayed on the display 4 using a magnifying lens 105 with an intermediate ring.

The photographed image is once recorded in the video recorder 104 in the main body 150 by a control signal from the CPU 6, and either image is selected by the display button "front side display" or "back side display" button on the keyboard 3.
The image is reproduced as a still image and displayed on the color CRT 4 via the superimposer 5. Photographing is performed for only one screen when the "photography" button on the panel 3 is pressed. Note 1: The camera is mounted on a rail 1 that is perpendicular to the printing flow direction.
02 and can be moved to any position on the rail by the motor 103, R shadows can be cast at any position in the left and right direction. Regarding the printing flow direction, it is possible to photograph any position using the method described below. A rotary encoder 107 is attached to the printing plate cylinder shaft, and the rotation angle of the plate can be determined from its signal.

For example, in the case of an offset rotary press, if the paper path from the plate to the bottom of the camera is known, the image position in the machine direction that is in the camera's field of view can be determined from the rotation angle of the plate.

can be calculated. In this embodiment, the operation keyboard 3
By inputting the position and coordinates of the front side of the image you want to photograph on the printing plate using the upper numeric keypad, when the "Shoot" button on the keyboard 3 is pressed, the rotary encoder 1
The position of the picture in the field of view of the camera is calculated from the signal 07, and at the moment when the coordinates match the coordinates of the picture to be photographed, a control signal is sent to the strobe light emitting circuit 109 to cause the strobe 106 to fire! ! There is a system in place to reward students. Further, movement of the camera in the left-right direction is automatically performed by sending a control signal from the CPU 6 to the motor drive circuit 108 to rotate the camera movement motor 103 in accordance with the positional coordinates of the picture desired to be photographed manually entered using the numeric keypad.

Instead of the strobe light 106, a mechanical or electric shutter may be used to enable instantaneous exposure, and if the speed of the paper is slow enough, an ordinary video camera may be used instead of the high-speed video camera 101. It's okay.

Also, instead of the VTR 104, a frame memory may be used. Furthermore, if the printing press is stopped at the position where the R shadow is desired and the image is input, a device for still photographing and recording images, such as a VTR 104 or a strobe light 106, becomes unnecessary.

In another example, images are taken continuously with a camera without using an image recording device such as a VTR 104, and a strobe light or a shutter is used to record images. By blinking or opening and opening in synchronization with the rotation, still images can be displayed intermittently on the CRT 4, making it appear as if the still images are continuously displayed to the naked eye.

Note that in rotary offset printing, etc., it is necessary to match the register marks on the front and back sides, so in this embodiment, the camera is also installed on the back side of the paper, and is moved to the same position facing the front camera across the paper. The front and back sides can be photographed at the same time, making it possible to simultaneously photograph the front and back sides of any desired location on a printed matter. Select "Front side display J rl side display" on the keyboard 3 to determine whether the image from the front camera or the back camera is displayed on the display 4.
You can select it using one of the buttons.

The portion of the printed matter to be photographed is preferably a portion where misregistration is clearly visible, such as a portion of registration marks or other patterns where misregistration is clearly visible.

An image provided from the CPU 6 via the superimposer 5, such as a cross-shaped cursor, is superimposed on the pattern of the printed material displayed on the display 4. This cross-shaped cursor is moved by a joystick 1 connected to the CPU 6 via an interface 2. After performing cursor operation using joystick 1, keyboard 3
gives an input command. Each color position coordinate input command button on the keyboard 3 is "calculation", rBJ, rCJ, rM
J, rYJ, the coordinate input by operating the joystick 1 to move the cursor to the picture position on the display 4 of the picture input by the camera and operating the operation keyboard 3, is calculated by the CPU 6, and the registration error that is the calculation result is roughly The amount of correction of the plate cylinder position is then applied to the motor drive circuit 11 via the interface, and the motor M is actuated to adjust the plate cylinder position.

FIG. 2 shows the connection relationship between each motor M and each plate cylinder.

One printing unit includes an upper blanket l1120 and a lower blanket I cavity 21 that are in pressure contact with each other, and are composed of an upper plate field J22 that is in pressure contact with the upper blanket cylinder 20, and a lower plate llA23 that is in pressure contact with the lower blanket cylinder 21, Helical gear 20 installed
By interlocking a, 21a, 22a, and 23a, the winter clothes are made to rotate synchronously. The shaft 24 of the lower blanket cylinder 21 is connected to a driving shaft 30 rotated by a drive motor 29 via bevel gears 25, 26 and helical gears 27.28.

Further, a vertical error WJ adjusting motor 32, a left/right error adjusting motor 33, and a twist error adjusting motor 34 are connected to the shaft 31 of the upper plate cylinder 22, and similarly, a vertical error adjusting motor 36, a vertical error adjusting motor 36, A left and right error adjustment motor 37 and a twist error adjustment motor 38 are connected.

By applying an output from a motor drive circuit 11 (FIG. 1(b)) to each motor incorporated in this apparatus, the position of the plate cylinder is automatically corrected.

FIGS. 3(a) to 3(d) show images appearing on the display 4 in FIG. 1, and FIG. 3(a) is a misregister mark called a register mark printed on a printed matter. , four marks for each of the four colors cyan, magenta, yellow, and black are located on the drive side of the plate cylinder.
Attached to each operating side. FIG. 5B is an example in which an appropriate part of the pattern is used instead of the register mark, and it is preferable to use an appropriate part of the pattern as shown in the figure, where the degree of deviation of the pattern of each color can be clearly seen.

Figure (C) shows a cross-shaped cursor 111 that is displayed superimposed on the picture shown in Figure (a) or Figure (b), and this cursor can be moved on the screen of the display 4 by operating the joystick 1. can be moved to any position. FIG. 3(d) shows a point 112 on the picture to which the cursor should be positioned. The shape of the register mark is generally a cross, and by inputting the intersection of this cross, the position coordinates in the vertical and horizontal directions are simultaneously input.

However, there are register marks that have only horizontal lines or vertical lines other than the cross shape.

In this case, only position coordinates in one of the vertical and horizontal directions are input. The input method is to input any one point on the horizontal line or vertical line. However, in this case, the calculation is only for the top, bottom, or left and right, so there are buttons on the operation panel for ``Calculate only the top and bottom'' and ``Calculate only the left and right.'' will be established.

The signal flow and device operation will be explained below using FIG. 1(1)) and FIG. 5. In step 1, first, the position of the image to be photographed on the printing plate is input using the keyboard 3. In this embodiment, in order to photograph the front and back sides of two locations on the operation side and the drive side, first, the drive side registration mark position is input. keyboard 3
is connected to data bus 130 via interface 120. In step S2, when the CPU 6 confirms the signal from the keyboard, it sends a signal to the motor drive circuit 108 to rotate the camera movement motor 103 to move the camera. In step 83.84, the camera position is signaled by the position detector 122 and the interface 123
The horizontal positioning of the camera is completed by stopping the camera when it is determined that the camera has reached the desired position.

In step S5, the pulse count of the rotary encoder corresponding to the input position to be photographed is calculated. Step S6 indicates that the printing press has started trial printing. During test printing, press the "shoot" button (step S7). A rotary encoder 107 is attached to the plate cylinder shaft, and the rotation pulse is counted by a counter (step 88), and the counter 123 is cleared with a reference signal for each rotation, and the pulse calculated in step S5 is When the CPU 6 determines that the count and the pulse count of the rotary encoder have become the same (step S9)
First, the CPU 6 sends a signal to the VTR controller 124 to start recording on both VTR1 and VTR-2 (step 510). Next, a signal is sent to the strobe light emitting circuit 109 (step 511), causing the strobe 106 to emit light and stopping the VTR when recording for one screen is completed.

In step S12, on the keyboard 3 ("Front display",
If the CPU 6 determines the input of the button ("display on the back side"), the CPU 6 determines the button input.Step $13) Sends a switching signal to the VTR controller 124, activates the signal switching device 125, and selects VTR1 or VTR2. Next, in step S14, the CPtJ6 outputs a still image reproduction signal to the VTR selected by the VTR controller 124, and transfers the desired image to the superimposer 5.
The image is displayed on the CRT4 via the . Steps 815-31
At step 8, the joystick is operated on the displayed image to move the cursor to each predetermined position.

Joystick 1 is connected via interface 2 to data bus 130. video interface 12 at a position corresponding to the joystick position.
5. A cursor is synthesized on the CRT 4 through the superimposer 5.

When the cross cursor reaches the desired position (step 81)
8) The coordinate position is memorized by pressing the capo button on the panel 3 (steps 819 and 320). Repeat steps 815 to 820 for each color, and when the gold color is input (step 521), the coordinate position is memorized (step 819.320>. Steps 812 to 521) are input for each image, and steps 81 to S21 are similarly performed for each registration mark on the operating side.

When all the inputs are completed, the calculation button is pressed (step 523), and the CPU 6 calculates the amount of registration error and the direction in which the plate cylinder should be moved according to the contents described later (step 524). Through the data bus 121, each motor is driven. The signal is sent to the circuit 11 to operate each register adjustment motor 32 to 34 (step 525). The movement of each motor is monitored by the CPU via an interface 129 using potentiometers 126 to 128, and is stopped when the motor reaches a target position. In addition, in order to perform calculation control by CPU6, 80M1
51 and RAM 152 are connected to the data bus 130.

The amount of misregistration is calculated as follows.

When the calculation button is pressed, the CPU 6 calculates the amount of plate cylinder position correction for each color according to the following procedure, and sends a signal to the motor drive circuit 11.

(1) Matching of 0 front and back coordinate systems Since the front and back images were taken at the same position and at the same moment, if only the sign of the X coordinate (horizontal direction) of the back side coordinates is reversed, It can be handled using the same coordinate system, that is, it is sufficient to match the position coordinates of each color on the front and back sides.

(2) Calculation of twist amount Figure 4 (a>, (b) is an example of the registration mark on the operation side and drive side on the front side. In this case, B (shade) is toward the top side with respect to C (eye). ((j −41) −(fh)) xm where m is a constant determined by the printing machine and the input registration mark position interval of the photographing unit.

In this way, the amount of twisting movement is determined for each color based on a certain color, for example, C (eye), and the amount of twisting for each color is determined by subtracting the average value of the maximum amount of twisting from the amount of twisting of each color. The amount of plate cylinder correction in the twisting direction is determined from the twisting amount and the enlargement ratio. In addition, the constant m is input on the operating side using the numeric keypad,
The registration mark interval is calculated and determined from the registration mark position on the driving side.

(3) Calculation of the vertical and horizontal directions and plate cylinder correction amount (1) shows that the front and back coordinates are expressed by the same coordinates, so the next step is to superimpose these register marks using simple calculations similar to twisting. The amount of movement in the vertical and horizontal directions is calculated.

The method of calculating this movement value is as follows: - As an example, the movement amount is calculated by adjusting the vertical and horizontal directions of all the registration marks to the average position, but excluding the registration marks that are extremely deviated, the average position You may ask for it. From this movement amount and magnification rate, the amount of correction of the plate cylinder position in the vertical and horizontal directions can be determined.

[Other variations]

In the above embodiment, an offset printing machine was explained, but the present invention can also be applied to a gravure printing machine, a letterpress printing machine, and a flexo printing machine.

[Effects of the Invention] As described above, the present invention enlarges and displays the image of a running printed matter on a display stationary during photographing, and uses coordinate input means to input the image of each color for a predetermined element in this enlarged display image. Input the position information, determine the amount of registration error between each color based on the position coordinates of each color and the magnification rate of the image, calculate the amount of plate cylinder position adjustment based on this registration error m, and adjust the registration of the printing press according to the calculation result. Since alignment is performed, the plate cylinder position is automatically adjusted by a simple operation that does not require any skill.
Registration can be done by making multiple test prints, which greatly reduces registration work time and waste paper.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are explanatory diagrams showing the configuration of an embodiment of the present invention, FIG. 2 is a diagram showing the mechanical relationship between the plate cylinder of the printing press and the plate cylinder adjustment motor, and FIG. Figures (a) to (d) are diagrams showing examples of images appearing on the display screen of the device shown in Figure 1, and Figures 4 (a) and (b) are one of the calculations of the device shown in Figure 1. An explanatory diagram of the twist amount calculation, FIG. 5(a)
. (b) is a flowchart showing the operation of the apparatus of FIG. 1; 1... Joystick, 3... Keyboard, 4...
・・Display, 20.21・・Blanket body,
22.23...plate cylinder, 32,33.34.38...
Error adjustment motor, 111...Cursor, 112...
Points to be aligned. Applicant's agent Setsu Ino Figure 1 (α) −−−−−＋＋＋＋＋＋ −−W Figure 3A-1 (b (C) Figure 4 (α) (b) Figure 5 (α)

Claims (1)

[Scope of Claims] 1. A display for enlarging and displaying a pattern of printed matter as a pattern input means for inputting the pattern on a printing machine;
means for extracting the positional coordinates of a predetermined element for each color in an enlarged display image on the display, determining the amount of misregistration between each color from the image enlargement rate of the display and the positional coordinates of the predetermined element; A registration device for a printing press, comprising means for calculating a plate cylinder position adjustment amount based on the calculation means, and means for registering the printing press according to the calculation result of the calculation means. 2. In the registration device according to claim 1, a video camera or high-speed video camera is used as the pattern input means, and an image recording device such as a VTR or frame memory is provided to record the pattern instantaneously. A registration device with a mechanism. 3. In the registration device according to claim 1, the input means for inputting the positional coordinates of a specific pattern portion on the printing plate to be inputted as a pattern input means, the means for moving the input camera on the machine, and the printing device. A registration device that has a rotational phase detection means that detects the rotational state of the printing plate cylinder, and allows input of any part of the printed material. 4. In the registration device according to claim 1, a video camera or a high-speed video camera and a shutter of a strobe light emitter, etc. are used as the pattern input means to enable instantaneous exposure, so that still images can be intermittently captured. A registration device characterized in that a still image is displayed on a display so that it appears as if a still image is continuously displayed.