JP2001088267A - On-press plate making sheet type printing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-press plate making sheet type printing machine which can make inter-color directions coincide easily by making a pattern of each color printed in each printing station correspond to respective fan-outs even when the amount of fan-out is different in respective printing stations of each color. SOLUTION: In an on-press plate making sheet type printing machine, a control means in which the rotating speed of a plate cylinder and the moving speed of a writing device can be controlled by synchronization with the beam output timing of the writing device is provided, the rotating speed of the plate cylinder and the moving speed in the sub-scanning direction of the writing device are controlled so that, with advance from the starting side in the sub-scanning direction to terminal side of the plate cylinder, a relative movement speed to the plate cylinder of the writing device is increased on the plate surface part 13A side and decreased on the non-plate surface part 13B side, the relative movement speed to the plate cylinder of the writing device in each station of each color is changed reverse-proportionally between the plate surface part 13A and the non-plate surface part 13B, and the quantity of the speed change is changed in turn from the upstream side toward downstream side of each station.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-press plate-fed sheet-fed printing press for making a plate wound on a plate cylinder on a printing press, and more particularly to a plate cylinder and a press for each color of ink to be printed. The present invention relates to an on-press plate making sheet-fed printing press having a plurality of printing press main bodies including a cylinder.

[0002]

2. Description of the Related Art Conventionally, a paper feeding device for transferring a stack of printing papers one by one to a printing press body while accelerating the printing papers one by one, and a paper discharging device for stacking and storing printing papers after printing is completed. Cyan is added to the picture portion of the printing plate that is arranged between the paper feeding device and the paper discharging device and is wound around the plate cylinder from the ink supply device.
Sheet-fed printing machines that transfer corresponding inks of magenta, yellow or black and sequentially transfer the inks to printing paper being conveyed on an impression cylinder are known, and such printing machines include cyan, magenta, Station-type printing presses (for example, Japanese Patent Application Laid-Open No. 6-507353) are mainly provided with four printing stations including a plate cylinder and an impression cylinder for each color of yellow and black, and sequentially transferring the colors.

[0003] Among such printing presses, particularly in offset printing presses, since dampening water is used, the printed image of the paper is generally cut off due to the non-uniform moisture content and surface properties of the printing paper. A fan-out phenomenon occurs in which the fan spreads in a fan shape. Of course, in a multi-printing station type printing press, the printing paper supplied from the paper supply unit is transported to the next printing station while passing it to the next printing station via the intermediate cylinder while holding the leading edge of the printing paper with the claws of the impression cylinder. Therefore, the amount of fan-out differs for each station.

[0004] More specifically, the first printing station 13
The trailing edge of the sheet gradually widens as it proceeds to C (for example, cyan), the second printing station 13M (for example, magenta), the third printing station 13Y (for example, yellow), and the fourth printing station 13B (for example, black).
(See FIG. 3B)

On the other hand, the printing plate used in the above-mentioned printing press has conventionally been prepared in a different place, and is attached to the plate cylinder of the printing press. For the purpose of quality improvement, reduction of waste paper, etc., the plate making device placed on the plate cylinder of each printing station facing each other, printing on the unexposed printing material attached to the plate cylinder surface using the plate making device There is an on-press plate making apparatus that exposes and develops a printed pattern on a press.

[0006] Such a plate-making apparatus includes a moving shaft 23.
The image signal is recorded on the plate material by using a beam writing device such as a laser which moves in parallel with the plate cylinder 13 according to the timing of the exposure signal (raster data) output from the writing device 22. Since the exposure writing is performed while performing the synchronous rotation of the plate cylinder 13 (main scanning direction) and the movement of the writing device 21 in the axial direction (sub-scanning direction) by the moving shaft 23, it is wound around the plate cylinder 13. The pattern (bit data) written on the plate 13A is written in a spiral shape in an oblique direction. (See FIG. 3A)

On the other hand, the pattern written on the printing plate has the same scale as that of the original document data since the principle is to reproduce the raster data as faithfully as possible.

[0008]

That is, despite the fact that the fan-out amount differs for each printing station, the printing plate is created at the same scale, so that the pattern of each color printed at each printing station is The result is a misregistration between colors by the amount of each fan-out.

In order to correct such misregistration between colors,
Conventionally, the butt side of the printing plate is stretched by using a fan-out vise so as to match the color registration. However, the butt expansion amount corresponding to the fan-out amount is 900 m in width of the plate cylinder.
In the case of m, the amount of expansion is extremely small at around 200 μm at the maximum, so that skill is required for the adjustment.

The present invention has been made in view of the above technical problem, and even when the fan-out amount differs for each printing station of each color such as cyan, magenta, yellow, and black, a pattern of each color printed at each printing station can be obtained. It is an object of the present invention to provide an on-press printing machine capable of easily matching color registrations in correspondence with each fan-out.

[0011]

In order to solve the above-mentioned problems, the present invention is directed to a plate cylinder having a plate surface portion and a non-plate surface portion on a peripheral surface thereof. In an on-press plate making sheet-fed printing press provided with a plate making beam writing device movable parallel to an axis (sub-scanning direction), the rotational speed of the plate cylinder is synchronized with the beam output timing of the writing device. And a control means configured to control the moving speed of the writing device, respectively, to set each writing start position on the plate surface for each printing cylinder rotation cycle at the same interval, and to set the printing drum from the starting end side in the sub-scanning direction. The rotation speed of the printing cylinder and the writing device are set so that the relative movement speed of the writing device with respect to the printing plate cylinder changes in a substantially inverse proportion between the printing plate portion and the non-printing plate portion as it moves toward the terminal end. The moving speed in the sub-scanning direction is controlled. In this case, the correction amount for controlling the moving speed is performed to correct the physical amount of the fan-out, and is not necessarily approximated by a linear function. The correction amount may be determined using a corresponding table.

More specifically, as described in the second aspect of the present invention, the relative movement speed of the writing device with respect to the plate cylinder increases on the plate surface side and decreases on the non-plate surface side. The rotational speed of the plate cylinder and the moving speed of the writing device in the sub-scanning direction may be controlled, and vice versa. Further, the balance of the speed increase / deceleration of the relative moving speed differs depending on whether the writing device is on the driving side (starting side in the main scanning direction) or the operating end side (end in the main scanning direction) from the center of the plate cylinder. That is, as shown in FIG. 5, when the substantially center position of the plate cylinder is set as the reference speed (average speed Av), the writing device positions are “drive end + 10”, “drive end + 100”, “center”, and “operation end + 10”. "Operation terminal +1
00 ”, the acceleration / deceleration change amount is
On the relative speed side of the printing plate portion, "Av-100", "A
v-10 "," Av ± 0 "," Av + 10 "," Av + 1 "
00 on the other hand, on the non-printing surface portion relative speed side, “Av + 250”, “Av + 215”, “Av ±
0, "Av-215", and "Av-250". According to a third aspect of the present invention, the above point is specified, and the acceleration / deceleration balance of the relative movement speed of the writing device with respect to the plate cylinder is made different from a substantially center position of the plate cylinder as a reference speed. It is characterized by.

According to a fourth aspect of the present invention, the plate making beam writing device is provided for each printing station of each color, and is applied to the on-press plate making sheet-fed multicolor printing machine according to the first aspect. The relative movement speed of the writing device relative to the plate cylinder at each station is changed in inverse proportion between the plate portion and the non-plate portion, and the speed change amount is sequentially changed from the upstream side to the downstream side of each station. It is characterized by being different.

According to a fifth aspect of the present invention, there is provided a specific configuration of an on-press plate making sheet-fed printing press according to the first aspect, wherein a rotation angle detecting means of a plate cylinder and a plate making beam writing device are provided. Moving speed detecting means in the sub-scanning direction, timing detecting means for detecting timing of writing on the printing plate every one rotation cycle of the printing cylinder, and driving of at least one of the printing cylinder or the writing device based on a signal of the timing detecting means A speed control unit for controlling a speed, wherein the speed control unit is switched based on a detection signal of the timing detection unit to reverse a relative moving speed of the writing device with respect to the plate cylinder between the plate portion and the non-plate portion. It is characterized in that the speed is controlled to change proportionally.

According to a sixth aspect of the present invention, the switching timing portion of the invention is embodied. For example, the speed switching from the non-printing surface portion to the printing plate portion is performed by starting writing to the printing plate every rotation cycle of the printing drum. The switching is performed based on a detection signal from timing detection means for detecting timing, and the speed switching from the printing plate portion to the non-printing surface portion is performed based on a detection signal from the rotation angle detection device of the plate cylinder. .
Incidentally, the timing switching of the present invention is not necessarily limited to only the above-described configuration, and the speed switching from the non-printing surface portion to the printing plate portion is also performed based on the detection signal from the rotation angle detecting means of the plate cylinder. Alternatively, the speed switching from the printing plate portion to the non-printing plate portion may be performed based on a detection signal from timing detection means for detecting the end timing of writing on the printing plate every one rotation cycle of the printing drum.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, unless otherwise specified, dimensions, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the invention, but are merely illustrative examples.

FIG. 2 is a schematic configuration diagram of an on-press plate making apparatus according to an embodiment of the present invention, wherein 1 transfers ink to a picture portion of a printing plate 130 wound around a plate cylinder 13 by an ink supply device 11. The printing press body 1 transfers the ink to the printing paper being conveyed on the impression cylinder 14, and outputs cyan, magenta,
Printing station 1 for each color of yellow and black
Are arranged in series, and are configured to perform four-color printing while transporting the printing paper to the next impression cylinder 14 of the printing press main body 1 with the intermediate cylinder interposed therebetween.

The printing press main body 1 for each color of cyan, magenta, yellow and black includes an ink supply device 11 of a corresponding color, a plate cylinder 13 around which a printing plate 130 is wound, and a plate-making machine arranged to face the plate cylinder 13. The ink transferred to the pattern portion of the printing plate 130 from the device 2 and the ink supply device 11 is transferred to the impression cylinder 14 via the blanket cylinder 15, and the supplied printing paper is transferred to the impression cylinder 6.
Printing is performed by receiving ink from the blanket cylinder 5 above. On the other hand, the printing plate 12 is provided with a plate making device
With the use of the plate making device 2, a printing pattern is exposed and developed on the surface of the plate cylinder 13 or the unexposed printing plate 130 attached to the surface of the plate cylinder 13 on a printing press. And a writing device controller 22 for controlling the writing device 21.

The writing device 21 facing the plate cylinder 13 prints a dot pattern corresponding to raster data on the printing plate 130 using a laser, and is composed of a laser exposure device, a developing device, a fixing device, and the like. When exposing the unexposed printing plate 130 in the plate making mode, the synchronous rotation of the plate cylinder 13 and the writing device 21 are performed in accordance with the exposure signal output timing.
The writing device 2 is rotated by the rotation of the moving shaft 23 supporting the writing device 2.
Exposure is performed while moving 1 in the sub-scanning direction (a direction parallel to the direction of the plate cylinder axis 12). At this time, in order to obtain a dot pattern of the printing plate 13A with high precision, the rotation pulse of the printing cylinder 13 and the width direction position pulse of the moving shaft 23 are fetched by the writing device controller 22 and the data server 31 in the control device 3 is read. The data is output to the semiconductor laser transmitter in the writing device 21 while performing the position correction and the output correction in synchronization with the drawing data (raster data) read out more serially.

As shown in FIGS. 1A and 2, the rotation angle pulse (rotation phase angle) of the plate cylinder 13 is provided at the shaft end of a plate cylinder drive motor 25 attached to the plate cylinder shaft 12. The rotation position signal (sub-scanning direction) of the moving shaft 23 is obtained with high accuracy by the rotation angle signal from the plate cylinder encoder 12B, and the end of the moving shaft 23 or the servomotor 24 for driving the moving shaft 23, etc. Encoder 23 provided at the shaft end of
It is obtained with high accuracy based on the rotation speed and the rotation phase angle of B.

Reference numeral 30 denotes a control device main body of the printing press, which controls the ink key opening degree of the ink supply device 11 and the rotation of the impression cylinder 14, the plate cylinder 13, the moving shaft 23, and the like based on the picture information from the drawing data generating section 32. The rotation of the drive motor 25 and the servo motor 24 is performed. More specifically, as shown in FIG. 1A, the control device main body 30
The constant speed control unit 30B, and the moving axis servomotor 24 are constituted by a speed switching control unit 30A that switches the speed between the plate portion and the non-plate portion in response to a signal from the plate cylinder encoder 12B. And the speed switching control unit 30A
Is set by the arithmetic circuit 28 based on a correction signal obtained from a correction map based on the paper type, plate type, and the like.

Returning to FIG. 2, the drawing data generating section 32 takes in image data (development data) of each corresponding color from the customer upstream system and develops it into a bit map to create raster drawing data. I do. Then, the created drawing data is stored in the data server 31. The drawing data written in the data server is serially transmitted to the writing device controller 22 based on the data clock.

Next, a description will be given of a part corresponding to the present invention based on the above configuration with reference to FIG. First, the encoder 12B on the plate cylinder shaft 12 side is used as a rotation angle detecting means of the plate cylinder 13, and a moving shaft 23A in the plate making beam writing device 21.
The encoder 23B is based on a signal from the timing detecting means, and the writing device controller 22 is based on a signal from the timing detecting means. The speed control means for controlling the drive speeds of the plate cylinder and the writing device comprises a control device main body 30, a servomotor 24 and a plate cylinder drive motor 25.

In this embodiment, the plate cylinder 13 is used.
The plate portion 13A (here, the plate portion indicates either the position of the plate 130 wound around the plate cylinder 13 or the plate position at which data is written on the plate 130) and the non-plate portion When switching to, speed switching is performed,
Since the speed switching is performed in accordance with the fan-out amount, basically, the width between lines in the direction (sub-scanning direction) orthogonal to the data drawing line direction (main-scanning direction) may be controlled. And such control in the sub-scanning direction
Since the movement of the writing device 21 in the sub-scanning direction is controlled by the moving shaft 23, the writing based on the moving shaft 23 is performed while maintaining the data output clock from the writing device 21 and the rotation speed of the plate cylinder with high accuracy. It can be understood that the moving speed of the device 21 may be changed.

Then, from the non-printing surface portion 13B to the printing plate portion 13
A, and the switching of the rotational speed of the moving shaft 23 from the plate portion 13A to the non-plate portion 13B is performed by a speed switching control unit 30A in the control device main body 30. This may be performed by a vertical synchronization signal or the like for detecting the start / end timing of writing on the printing plate obtained by the writing controller 22 for each rotation cycle, or may be performed from any of the rotation angle phase pulses of the plate cylinder encoder 12B. In particular, in the present invention, since it is necessary to set each writing start position on the printing plate for each printing cylinder rotation cycle at the same interval, it is preferable to accurately switch the speed to the printing plate portion 13A based on a vertical synchronization signal. Since the speed switching from the printing plate portion 13A to the non-printing surface portion 13B is a speed switching for returning the delay amount (deceleration) delayed by the printing plate portion 13A based on the fan-out amount, no special high precision is required. The speed may be switched by the rotation angle phase pulse of the plate cylinder encoder 12B.

Next, the operation of the embodiment of the present invention will be specifically described with reference to FIGS. That is, in each printing station, as the plate cylinder advances from the start end side in the sub-scanning direction to the end side, the relative moving speed of the writing device 21 with respect to the plate cylinder increases on the plate surface portion 13A side, and the non-plate surface portion 13B The rotation speed of the plate cylinder and the moving speed of the writing device in the sub-scanning direction are controlled so as to decrease on the side. As an example, the writing device 21 that writes data while moving the moving shaft 23 parallel to each plate cylinder axis at a speed of 10 mm / sec (speed in the sub-scanning direction) performs printing for each color of cyan, magenta, yellow, and black. In the case of being arranged in the stations (13C, 13M, 13Y, 13B), the writing device 2 for each station
By changing the relative movement speed with respect to one plate cylinder between the plate portion 13A and the non-plate portion 13B in an inversely proportional manner, and by changing the speed change amount from the upstream side to the downstream side of each station sequentially. The register between colors can be registered without using the fan-out vise.

As shown in FIG. 1B, if the acceleration / deceleration is neglected, the "plate portion 13A" and the "non-plate portion 13"
The moving speed in “B” is “printing portion 13A” = M− (αn / 2) mm / sec “non-printing surface portion 13B” = M + (αn) mm / sec in the sub-scanning direction on the line side in the sub-scanning direction. At the line position, “plate portion 13A” = M mm / sec “non-plate portion 13B” = M mm / sec On the final line side in the sub-scanning direction, “plate portion 13A” = M + (αn / 2) mm / sec “non-plate portion” 13B ”= M− (αn) mm / sec

In this case, the fan-out amount is expected to be different for each printing sheet. Therefore, as shown in FIG. 1A, calculation is performed using the correction data obtained from the correction map 29 containing the correction data for each sheet. The circuit 28 calculates the optimum correction amount from the printing conditions at the time of writing the print data, thereby suppressing the misregistration caused by the fan-out. For example, as shown in FIG. 3 (B), it is assumed that the pattern on the printing plate is drawn in such a manner as to extend in the sub-scanning direction by 50 μm on each of the printing stations (13C, 13M, 13Y, 13B) of the respective colors in addition to the tail side. 5 in the first printing station 13C.
0 μm, 100 μm at the second printing station 13M,
In the third printing station 13Y, the width needs to be increased by 150 μm, and in the fourth printing station 13B, the width needs to be increased by 200 μm.
Each of the stations (13C, 13M, 13Y,
13B) The perimeter of the plate cylinder is 900 mm, of which the plate exists 600 mm, and the plate cylinder rotates once in 300 msec (main scanning direction). The time ratio in the main scanning direction between the “non-plate surface portion 13B” corresponding to a portion where the plate in the plate cylinder does not exist is:
It is assumed that “200 msec / 100 msec” = 2/1.

For example, as shown in FIG.
In the case of 0 mm / sec, α1:
0.25 mm / sec, at the second station α2:
0.5 mm / sec, α3: 0.
75mm / sec, α4: 1mm at 4th station
/ Sec. More specifically, for example, on the line side in the second station in which writing is started in the sub-scanning direction, “plate portion 13A” = 9.5 mm / sec, “non-plate portion 1”
3B ”= 11 mm / sec At the center line position in the sub-scanning direction,“ plate portion 13A ”= 10 mm / sec,“ non-plate portion 13
B ”= 10 mm / sec On the last line side in the sub-scanning direction, the speed control in the sub-scanning direction is gradually performed by 1 so that“ plate portion 13A ”= 10.5 mm / sec and“ non-plate portion 13B ”= 9 mm / sec. Perform each rotation. Accordingly, strict speed and position control can be performed so that the write start position for each rotation of the plate cylinder always keeps the same interval on the plate surface despite the speed change.

As a result, as shown in FIG. 4, the line spacing in the sub-scanning direction for each rotation cycle on the starting side of the plate surface of each printing station in the main scanning direction is set to be constant at m.
On the other hand, the line interval in the sub-scanning direction for each rotation cycle on the end side in the main scanning direction is equal to (n-
α: first station, n−2α: second station,
..), The inclination amount is (n: first station, n: second station,...) In the drawing center line, and the inclination amount is (n + α: first station,
n + 2α: second station,...) m.

In the present system, strictly speaking, the intervals between the dots are partially different between the front side and the rear side, but they are sufficiently small (the width of the plate cylinder is 900 mm wide and the width is 20 mm).
If it is 0 μ, the gap between the drawing patterns for each rotation of the plate cylinder is (20
0 μmm ÷ 10 mm / sec ÷ 300 msec) = 0.
7μ. No problem.

[0032]

As described above, according to the first and second aspects of the present invention, it is possible to obtain a printing plate that can easily match the dot registration in correspondence with the fan-out of printing paper. According to the third and third aspects of the present invention, even when the fanout amount differs for each color printing station, the pattern of each color printed at each printing station can be easily made to correspond to each fanout. Can match the color register.

According to the fifth aspect of the present invention, the above effect can be achieved with higher accuracy.

[Brief description of the drawings]

FIG. 1A is a control block diagram according to a main configuration of the present invention, and FIG. 1B is a time chart thereof.

FIG. 2 is a schematic configuration diagram of an on-press plate making apparatus according to an embodiment of the present invention.

FIG. 3A shows a schematic diagram of a raster data writing device and a writing state thereof. (B) shows the fan-out state of the printing paper for each printing station.

FIG. 4 shows a writing speed on a plate cylinder according to the embodiment of the present invention.

FIG. 5 is a diagram in which, when a substantially central position of the plate cylinder is set as a reference speed (average speed Av), the writing device position is relative to the plate surface relative speed side and the non-plate surface portion relative to each other on the operation end side from the drive end side. Indicates the amount of increase / decrease speed change on the speed side.

[Explanation of symbols]

 12 Plate cylinder shaft 12B Plate cylinder encoder 13 Plate cylinder 13A Plate part 13B Non-plate part 21 Beam making device for plate making 22 Writing device controller 23A Moving shaft 23B Encoder 24 Servo motor 25 Drive motor 30 Control device body

Claims (6)

[Claims] 1. An apparatus comprising a plate making beam writing device capable of moving parallel to the plate cylinder axis (sub-scanning direction) while facing a plate cylinder having a plate surface portion and a non-plate surface portion on a peripheral surface. In the upper plate making sheet-fed printing press, a control unit configured to control a rotation speed of the plate cylinder and a moving speed of the writing device in synchronization with a beam output timing of the writing device is provided, and the plate on the printing plate is provided. Each writing start position for each cylinder rotation cycle is set at the same interval, and as the plate cylinder advances from the start side to the end side in the sub-scanning direction, the relative movement speed of the writing device with respect to the plate cylinder is set to the plate surface. An on-press plate-fed sheet-fed printing machine characterized in that the rotational speed of the plate cylinder and the moving speed of the writing device in the sub-scanning direction are controlled so that the speed changes in a substantially inverse proportion between the non-plate portions. 2. The method according to claim 1, wherein a relative movement speed of the writing device with respect to the plate cylinder is increased on a plate surface side and decreased on a non-plate surface side.
2. The on-press plate making sheet-fed printing press according to claim 1, wherein the rotational speed of the plate cylinder and the moving speed of the writing device in the sub-scanning direction are controlled. 3. The machine according to claim 2, wherein the balance of the speed of movement of the writing device relative to the plate cylinder is made different from the substantially center position of the plate cylinder as a reference speed. Top plate sheet-fed printing press. 4. The on-press plate making multi-color printing press according to claim 1, wherein said plate making beam writing device is provided for each printing station of each color. Characterized in that the relative movement speed with respect to the printing plate portion is changed in inverse proportion between the printing plate portion and the non-printing plate portion, and the speed change amount is sequentially changed from the upstream side to the downstream side of each station. Plate making sheet-fed printing press. 5. The on-press plate-making sheet-fed printing press according to claim 1, wherein the rotation angle detecting means of the plate cylinder, the moving speed detecting means in the sub-scanning direction in the plate making beam writing device, and one rotation of the plate cylinder. Timing detecting means for detecting writing timing on the printing plate for each cycle; and speed controlling means for controlling a driving speed of at least one of the plate cylinder or the writing device based on a signal from the timing detecting means, wherein the timing detecting means Based on the detection signal, the speed control means is switched to control the relative movement speed of the writing device with respect to the plate cylinder so that the speed changes in inverse proportion between the plate portion and the non-plate portion. On-press plate making sheet-fed printing press. 6. The speed switching from the non-plate portion to the plate portion, and the speed switching from the plate portion to the non-plate portion,
5. The method according to claim 4, wherein the detection is performed based on a detection signal from a timing detection unit for detecting a start / end timing of writing on the printing plate for each rotation of the plate cylinder or a detection signal from a rotation angle detection unit of the plate cylinder. The on-press plate-making sheet-fed printing press described in the above.