JP3595510B2 - Plate making equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plate making apparatus for creating a printing plate based on digital data of a sample picture, and more particularly to a plate making apparatus for writing a picture on a plate provided on an outer peripheral surface of a drum (so-called external drum method). .
[0002]
[Prior art]
In recent years, digitization of the plate making process has been advanced, and a workflow called CTP (Computer to Plate) for directly creating a printing plate based on digital data (image data) obtained by digitizing a sample pattern has been established. According to a system using this workflow (hereinafter, referred to as a CTP system), there is no need to create a film as an underprint, thereby reducing costs and faithfully reproducing a sample pattern with high positional accuracy. There is.
[0003]
As a plate making apparatus applied to such a CTP system, a so-called external drum type plate making apparatus as shown in FIG. 9A is known. In this plate making apparatus, a writing device 4 such as a laser is arranged on the outer peripheral surface toward a drum 3 on which a raw plate (a plate on which no pattern is written) is mounted, and the drum 3 is moved at a constant speed in one direction. While rotating the writing device 4 at a constant speed in the axial direction of the drum 3 by the traverser 2, the laser beam is emitted from the writing device 4 toward the outer peripheral surface on the drum 3 based on the image data. In this way, a picture is written on the printing plate portion of the drum 3 (writable area of the picture on which the raw plate is mounted).
[0004]
In this plate making apparatus, the rotation direction of the drum 3 is the main scanning direction, and the moving direction of the writing device 4 by the traverser 2 is the sub-scanning direction. As shown in FIG. Is written diagonally in a spiral shape on the printing plate. The pattern written on the plate should reproduce the sample pattern as faithfully as possible To As a rule, the scale is the same as the sample design. In addition, the plate making apparatus of this type includes an on-press plate making press that directly makes a plate on a printing press. In this case, CTP is sometimes read as Computer to Press.
[0005]
[Problems to be solved by the invention]
By the way, in a printing machine, for example, a sheet-fed printing press, it is known that a fan-out phenomenon in which the size of the printing paper is widened due to the non-uniform moisture content and surface properties of the printing paper (sheet paper) due to the use of dampening water occurs. Have been. This fan-out phenomenon is generally remarkable at the edge of the printing paper, and the edge of the printing paper spreads in a fan shape.
[0006]
Moreover, in the multi-printing station type sheet-fed printing press, the printing paper is conveyed sequentially 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. The fan-out amount for each station differs depending on the holding state with the nail. More specifically, as shown in FIG. 10, the trailing edge of the printing paper gradually widens in order as it proceeds to the first station 1C, the second station 2C, the third station 3C, and the fourth station 4C. This is the same for a rotary press for newspapers, and the band-shaped printing paper (newspaper) spreads in the left-right width direction as it goes downstream.
[0007]
As described above, in the plate making apparatus of the conventional CTP system, since the principle is to reproduce the sample pattern as faithfully as possible, the patterns are all the same scale regardless of the fan-out amount for each printing station. Written. For this reason, the pattern of each color printed in each printing station is misregistered by the respective fan-outs.
[0008]
Conventionally, in order to correct such misregistration, the rear side of the printing plate is stretched by using a fan-out vise to adjust the color registration. When the width in the left and right direction is 900 mm, the amount of expansion is extremely small at around 200 μm at the maximum, so that there is a problem that skill is required for the adjustment. On the other hand, there is a type of on-press printing machine in which a plate portion is formed on the outer peripheral surface of the plate cylinder itself and a pattern is written directly on the outer peripheral surface of the plate cylinder. Cannot be used.
[0009]
The present invention has been made in view of such a problem, and has made it possible to obtain a printing plate capable of easily registering colors between colors in correspondence with a fan-out of printing paper in a CTP system. It is intended to provide a plate making device.
[0010]
[Means for Solving the Problems]
To achieve the above objectives, Claim 1 A plate-making apparatus according to the present invention includes a drum having a plate portion on an outer peripheral surface and performing main scanning by rotation, and a pattern arranged on the outer peripheral surface of the drum based on digital data of a sample pattern. A writing device for selectively writing a dot pattern, a moving device for performing sub-scanning by moving the writing device in a direction parallel to the axis of the drum, and a movement of the writing device with respect to a rotation speed of the drum Moving speed control means for controlling the speed according to printing conditions (paper type, printing pressure, position of the corresponding printing station on the printing line, etc.) The moving speed control means switches the moving speed of the writing device between the plate surface portion and a non-plate surface portion excluding the plate surface portion from the outer peripheral surface of the drum. It is characterized by: This makes it possible to arbitrarily deform the pattern drawn on the plate portion in the left-right width direction with respect to the sample pattern in accordance with the fan-out of the printing paper.
[0011]
In this case, as a writing device, a device for writing a pattern pattern by exposing a photosensitive plate surface portion with a light beam such as a laser beam, a device for writing a pattern pattern by attaching a drop of a plate material to the plate surface portion, or the like. Various writing methods are applied depending on the printing plate preparation method. Further, the plate portion is a region where a printing plate is formed by writing a picture, and in addition to fixing a raw plate around the outer peripheral surface of the drum, the plate making device is configured as an on-press plate making press. In this case, the outer peripheral surface of the plate cylinder corresponding to the drum may be used as the plate surface.
[0012]
Preferably, a control pattern of the moving speed of the writing device by the moving speed control means is stored in a database for each printing condition in accordance with a fan-out in a width direction of the printing paper, and is input via the input means. A search unit searches the database for a control pattern corresponding to the printing condition, and controls the moving speed of the writing device based on the searched control pattern. (Claim 8) .
[0014]
Further, in the above-described plate making device, the moving speed control means controls the writing device on the plate portion so that each writing start position for each rotation cycle of the drum on the plate portion is at the same interval. The moving speed of the writing device on a non-plate surface portion of the drum (a part of the outer peripheral surface of the drum other than the plate surface portion) may be controlled in accordance with the moving speed. (Claim 2) . Thus, on the leading end side of the printing plate portion, that is, on the holding head side with less fan-out, it is possible to match the left and right widths of the pattern with the left and right widths of the sample pattern.
[0015]
In this case, it is preferable that the control by the moving speed control means be performed such that the moving speed of the writing device on the plate portion increases as the writing device advances from the axial start end to the end side of the drum. (Claim 3). This makes it possible to draw a trapezoidal pattern on the plate portion, which is enlarged in the left-right width direction toward the buttocks side of the sample pattern. In this case, more preferably, A moving speed deviation of the writing device on the plate portion with respect to a reference speed is set symmetrically at the start end and the end side with respect to the center of the plate. (Claim 4). Thereby, a trapezoidal pattern symmetrical in the left-right width direction from the center of the plate portion is drawn on the plate portion.
On the axial start end side of the drum, the moving speed of the writing device on the plate portion is set lower than the reference speed, and the moving speed of the writing device on the non-plate portion is set higher than the reference speed. (Claim 5).
Furthermore, as the drum moves toward the axial end, the moving speed of the writing device in the plate portion gradually increases, and the moving speed of the writing device in the non-plate portion increases the speed of the writing device in the plate portion. The speed gradually decreases in inverse proportion to the moving speed, and near the axial center of the drum, both the plate portion and the non-plate portion substantially match the reference speed, and the magnitude relationship between the plate portion and the non-plate portion is reversed. It is preferable that the setting is made so as to be performed (claim 6).
Also, the area enclosed by the line indicating the moving speed on the printing plate portion and the reference speed line on the time axis and the area surrounded by the line indicating the moving speed on the non-printing plate portion and the reference speed line are set to be equal. (Claim 7).
Contract Request 9 The plate making apparatus of the present invention described above is a plate making apparatus for making a printing plate for printing a pattern on printing paper, comprising: a drum having a plate surface portion on an outer peripheral surface and performing a main scan by rotation; and A writing device that is disposed toward the outer peripheral surface of the printer and selectively writes a dot pattern of a pattern on the plate based on digital data of a sample pattern, and moves the writing device in a direction parallel to the axis of the drum. And a moving speed control means for controlling a moving speed of the writing device with respect to a rotation speed of the drum in accordance with a printing condition. Increases the moving speed of the writing device from the axial start end to the center of the drum, and decreases the moving speed of the writing device as the writing device advances from the axial center of the drum to the end side. Specially It is set to.
Further, in this case, it is preferable that a speed deviation with respect to the moving speed of the writing device at the axial center of the drum is set symmetrically at the axial start and end sides. 10 ). Further, it is preferable that the moving speed of the writing device near the writing start position and near the writing end position is set so as to substantially coincide with the reference speed. 11 ).
Preferably, a control pattern of the moving speed of the writing device by the moving speed control means is stored in a database for each printing condition in accordance with a fan-out in a width direction of the printing paper, and is input via the input means. A search unit searches the database for a control pattern corresponding to a printing condition, and controls a moving speed of the writing device based on the searched control pattern. 12 ).
[0016]
Claim Thirteen The plate making apparatus of the present invention described above is provided with a drum that has a plate portion on the outer peripheral surface and performs main scanning by rotation, and is provided on the plate portion based on digital data of a sample pattern arranged toward the outer peripheral surface of the drum. A writing device for selectively writing a dot pattern of a picture, a moving device for performing sub-scanning by moving the writing device in a direction parallel to an axis of the drum, and the writing device with respect to a rotation speed of the drum Writing speed control means for controlling the writing speed of the writing device according to printing conditions (paper type, printing pressure, position of the corresponding printing station on the printing line, etc.), and synchronizing with the writing speed of the writing device. Moving speed control means for controlling the moving speed of the writing device with respect to the rotation speed of the drum, the moving speed control means comprising a plate portion and a non-plate surface obtained by removing the plate portion from the outer peripheral surface of the drum. Transfer of the writing device between the It is characterized by performing the switching speed. This makes it possible to arbitrarily deform the pattern drawn on the plate portion in the vertical direction (the circumferential direction of the drum) with respect to the sample pattern in accordance with the fan-out of the printing paper.
[0017]
In addition, the moving speed control means controls the writing speed in accordance with the moving speed of the writing device on the printing plate so that the writing start positions for each rotation cycle of the drum on the printing plate are at the same interval. It is preferable to control the moving speed of the writing device on the plate portion. 14 ).
It is preferable that the moving speed of the writing device on the plate portion is increased as the writing device advances from the axial start end to the terminal end of the drum. Fifteen ).
A moving speed deviation of the writing device on the plate portion with respect to a reference speed is set symmetrically at the start end and the end side with respect to the center of the plate. Is preferable (claim 16 ).
On the axial start end side of the drum, the moving speed of the writing device on the plate portion is set lower than a reference speed, and the moving speed of the writing device on the non-plate portion is set higher than the reference speed. Is preferred (claim 17 ).
As the drum advances toward the axial end, the moving speed of the writing device in the plate portion gradually increases, and the moving speed of the writing device in the non-plate portion increases the moving speed of the writing device in the plate portion. And gradually decreases in inverse proportion to the reference speed near the center of the drum in the axial direction, so that both the plate portion and the non-plate portion substantially match the reference speed, and the magnitude relationship between the plate portion and the non-plate portion is reversed. Is preferably set to (claim 18 ).
On the time axis, the area enclosed by the line indicating the moving speed at the plate portion and the reference speed line is set equal to the area enclosed by the line indicating the moving speed at the non-plate portion and the reference speed line. Is preferable (claim 19 ).
Preferably, a control pattern of the writing speed of the writing device by the writing speed control means is stored in a database for each printing condition in accordance with a fan-out of the printing paper in a vertical direction, and the data is input via the input means. A search unit searches the database for a control pattern corresponding to the input printing condition, and controls the writing speed of the writing device based on the searched control pattern. 20 ).
Contract Request 21 The plate making apparatus of the present invention described above is a plate making apparatus for making a printing plate for printing a pattern on printing paper, comprising: a drum having a plate surface portion on an outer peripheral surface and performing a main scan by rotation; and A writing device that is disposed toward the outer peripheral surface of the printer and selectively writes a dot pattern of a pattern on the plate based on digital data of a sample pattern, and moves the writing device in a direction parallel to the axis of the drum. A moving device for performing sub-scanning, a writing speed control means for controlling a writing speed of the writing device with respect to a rotation speed of the drum in accordance with printing conditions, and a synchronizing operation with the writing speed of the writing device. Moving speed control means for controlling the moving speed of the writing device with respect to the rotation speed of the drum, the moving speed control means controlling the moving speed of the writing device from the axial start end to the center of the drum. Moving speed of writing device Increases, 該書 write apparatus is characterized by reducing the moving speed of the 該書 write device as one proceeds to the end side from the axial center of the drum.
In addition, it is preferable that a speed deviation with respect to a moving speed of the writing device at an axial center of the drum is set symmetrically at an axial start end and an axial end. 22 ).
It is preferable that the moving speed of the writing device in the vicinity of the writing start position and the writing end position is set to substantially match the reference speed. 23 ).
Preferably, a control pattern of the writing speed of the writing device by the writing speed control means is stored in a database for each printing condition in accordance with a fan-out of the printing paper in a vertical direction, and the data is input via the input means. A search unit searches the database for a control pattern corresponding to the input printing condition, and controls the writing speed of the writing device based on the searched control pattern. 24 ).
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, FIGS. 1 to 4 show the present invention. Fruit 1 shows a plate making apparatus according to an embodiment.
As shown in FIG. 1, the plate making apparatus according to the present embodiment is an external drum type plate making apparatus. And a traverser (moving means) 2 for moving the writing device 4 in the axial direction of the drum 3.
[0019]
A drum driving device 9 and a rotary encoder 6 are attached to a rotating shaft of the drum 3. The drum driving device 9 rotates the drum 3 at a high speed at a constant speed in one direction. Further, the rotary encoder 6 outputs a pulse signal in synchronization with the rotation of the drum 3. Among the pulse signals output from the rotary encoder 6, the A and B phase signals are used for detecting the rotation speed (rotation frequency) of the drum 3, and the Z phase signal is used for detecting the zero point. Further, the rotational phase of the drum 3 can be accurately detected from the A, B, and Z phase signals.
[0020]
The traverser 2 includes a screw rod 7 that is disposed parallel to the axis of the drum 3 and that is screwed to the writing device 4, and a traverse drive device 8 that rotates the screw rod 7. The rotation of the screw rod 7 by the traverse driving device 8 realizes the movement of the writing device 4 in the axial direction of the drum 3. The traverse driving device 8 is provided with a rotary encoder (not shown), and the position of the writing device 4 on the screw rod 7 is detected by the rotation speed and the rotation phase angle of the rotary encoder.
[0021]
In addition, the writing device 4 selectively exposes the plate portion (pattern writable area) 3A on the unexposed raw plate 5 by laser irradiation to write a picture pattern (dot pattern constituting the picture). It is configured as a laser writing device of the system. A plurality of semiconductor laser oscillators are provided inside the writing device 4 so that a plurality of dot patterns can be obtained at one time. In the present embodiment, the timing of laser irradiation by the writing device 4 (that is, the timing of writing a picture on the printing plate 3A) and the moving speed of the writing device 4 in the axial direction by the traverse driving device 8 will be described below. It is controlled by the control device 10.
[0022]
The control device 10 includes a print image data generation device 11, an image buffer 12, a laser driver 13, an image start trigger generation device 14, an encoder frequency-drawing frequency conversion device 15, a traverse speed instruction device 16, a search device 17, a database 18, It comprises a conversion coefficient indicating device 19.
First, the control of the laser irradiation timing by the writing device 4 will be described. This control is performed by a printing image data generating device 11, an image buffer 12, a laser driver 13, an image start trigger generating device 14, an encoder frequency-drawing frequency conversion. This is performed using the device 15 and the conversion coefficient indicating device 19.
[0023]
The print image data generation device 11 is a device that generates print image data (sample pattern digital data) from original data of each color taken in from an upstream process. More specifically, here, a RIP (Raster Image Processor) is used as the print image data generation apparatus 11, and the RIP uses this to generate text data (documents for manuscripts) including images, characters, and graphics described in a page description language. Is converted into bit data (image data). The image data generated by the print image data generation device 11 is stored in the image buffer 12.
[0024]
The image data stored in the image buffer 12 is converted into a drawing clock signal by the encoder frequency-drawing frequency converter 15 by using the image start trigger signal from the image start trigger generator 14 as the transmission start timing for each rotation cycle of the drum 3. The data is serially transmitted to the laser driver 13 on the basis of the data. The laser driver 13 outputs a laser output signal to each laser transmitter in the writing device 4 in synchronization with the image data transmitted from the image buffer 12. Then, each laser transmitter in the writing device 4 receives a laser output signal from the laser driver 13 and irradiates a laser toward the raw plate 5.
[0025]
The image start trigger generator 14 detects the zero point of the phase of the drum 3 from the Z-phase signal from the rotary encoder 6 and generates an image start trigger signal. Here, the phase of each writing start position on the drum 3 for each rotation cycle is made to correspond to the zero point. The encoder frequency-drawing frequency converter 15 detects the encoder frequency (rotation frequency of the drum 3) from the A and B phase signals from the rotary encoder 6 and converts the detected encoder frequency to the drawing frequency. The drawing clock signal is generated based on the drawing frequency. The encoder frequency / drawing frequency conversion device 15 is provided with a conversion coefficient designating device 19 that variably designates a conversion coefficient when converting the encoder frequency to the drawing frequency. The conversion coefficient indicating device 19 indicates a conversion coefficient based on a signal from a search device 17 described later. Note that a PLL (Phase-Locked Loop) circuit can be used as the encoder frequency-drawing frequency conversion device 15 and the conversion coefficient instruction device 19.
[0026]
Next, control of the moving speed of the writing device 4 in the axial direction by the traverse driving device 8 will be described. This control is performed using the traverse speed indicating device 16, the search device 17, and the database 18.
The traverse speed indicating device 16 detects the rotation speed of the drum 3 from the A and B phase signals from the rotary encoder 6 and simultaneously detects the rotation phase of the drum 3 from the Z phase signal from the rotary encoder 6. Further, the position of the writing device 4 in the axial direction is detected based on a signal (traverse position signal) from a rotary encoder (not shown) provided in the traverse driving device 8. Then, a signal (traverse speed instruction signal) indicating the moving speed of the writing device 4 in the axial direction is output to the traverse drive device 8 based on the detected information and the control pattern searched by the search device 17.
[0027]
In the present embodiment, the moving speed on the printing plate portion 3A is the reference speed (moving speed when there is no fan-out) as the writing device 4 advances from the axial start end to the end side of the drum 3 in the present embodiment. The writing speed is gradually increased from a lower speed to a speed higher than the reference speed, and the writing start positions of the drum 3 on the plate surface portion 3A in each rotation cycle are set to have the same interval. This setting corresponds to the fan-out of the printing paper, in particular, the fan-out that gradually expands in the left-right width direction from the front side to the rear side like a sheet of paper.
[0028]
FIG. 2 is a time chart illustrating a specific example of the control pattern. As shown in FIG. 2, in the present embodiment, the writing device 4 is disposed between the printing plate portion 3A and the non-printing plate portion (the region where the pattern is not written, excluding the printing plate portion 3A from the outer peripheral surface of the drum 3). Switching of the moving speed. This is to adjust the speed of the non-plate portion 3B according to the delay (increase) with respect to the reference speed in the plate portion 3A so that the reference speed is averaged between the plate portion 3A and the non-plate portion 3B. It was made.
[0029]
Specifically, on the starting end side in the axial direction, the moving speed in the plate portion 3A is set lower than the reference speed, and the moving speed in the non-plate portion 3B is set higher than the reference speed. And, as it moves toward the terminal side in the axial direction, the moving speed in the plate portion 3A gradually increases, and the moving speed in the non-plate portion 3B gradually decreases in inverse proportion to the moving speed in the plate portion 3A. In the vicinity of the center (around the center of the plate), both the plate surface portion 3A and the non-plate surface portion 3B substantially match the reference speed, and the magnitude relationship between the plate surface portions 3A and the non-plate surface portion 3B is reversed. The speed relationship between the printing plate portion 3A and the subsequent non-printing plate portion 3B is such that the distances between the respective writing start positions (positions at which the non-printing plate portion 3B is switched to the printing plate portion 3A) are equal, that is, The area A1 surrounded by the line indicating the moving speed at the plate portion 3A and the reference speed line shown in FIG. 2 and the area A2 surrounded by the line indicating the moving speed at the non-plate portion 3B and the reference speed line are shown in FIG. It is set to be equal.
[0030]
The length (time length) T1 of the plate portion 3A and the length (time length) T2 of the non-plate portion 3B on the time axis in FIG. 2 are the plate portion 3A and the non-plate surface in the circumferential direction of the drum 3. The length is determined by each length of the portion 3B and the rotation cycle of the drum 3. For example, if the circumference of the drum 3 is 900 mm, of which the plate portion 3A is 600 mm and the drum 3 makes one rotation at 300 msec, T1 becomes 200 msec and T2 becomes 100 msec.
[0031]
By the main scanning by the rotation of the drum 3 and the sub-scanning by the movement of the writing device 4, a picture is written in a diagonal direction in a spiral manner on the plate surface portion 3A of the raw plate 5. By controlling the moving speed of the writing device 4 by using, the movement locus (drawing line of the picture) of the writing device 4 on the plate surface portion 3A becomes as shown in FIG. The trajectory indicated by a solid line in the drawing is a drawing line when the moving speed of the writing device 4 is controlled as described above, and the trajectory indicated by a two-dot chain line indicates that the writing device 4 is moved at the reference speed. It is a drawing line when it is. In each line, the angle with respect to the drum rotation direction is exaggerated for easy understanding of the slant.
[0032]
As shown in FIG. 3A, the angle α formed by the drawing line with respect to the main scanning direction (the rotation direction of the drum 3) is smaller than the angle at the time of writing at the reference speed at the axial start end (drawing start side). In the vicinity of the center of the plate, the angle becomes substantially equal to the angle at the time of writing at the reference speed, and at the axial end side (drawing end side), it becomes larger than the angle at the time of writing at the reference speed. As a result, the interval between the drawing lines is equal to that at the writing start position at the time of writing at the reference speed, but gradually widens toward the tail. For this reason, as shown in FIG. 3B, the pattern drawn on the plate portion 3A gradually expands in a trapezoidal shape in the left-right width direction from the gripping head side to the gripping butt side similarly to the fan-out of the printing paper. Will be. The area indicated by the two-dot chain line in the figure indicates the drawing area of the pattern when the writing apparatus 4 is moved at the reference speed, and the area indicated by the solid line indicates the moving speed of the writing apparatus 4 as described above. 3 shows a drawing area of a pattern when is controlled.
[0033]
In the present embodiment, the above control patterns are prepared for each printing condition and stored in the database 18. The printing conditions are paper types, printing pressure, and other conditions that affect the fan-out of printing paper. The position on the printing line of the printing station where the plate is mounted is also included in the printing conditions. For example, since the stretchable paper has a larger fan-out between the stretchable paper and the stretchable paper, the control pattern is set such that the pattern expands in the left-right width direction as the stretchable paper increases. In addition, as for the position of the printing station, the control pattern is such that the more downstream the printing station, the larger the fan-out. Specifically, the speed deviation of the moving speed of the writing device 4 with respect to the reference speed (the speed near the center of the plate) at the axial start end and the axial end end is set to be large.
[0034]
The database 18 also stores the values of the conversion coefficients according to the printing conditions together with the control patterns. The conversion coefficient is a coefficient used for frequency conversion in the encoder frequency-drawing frequency conversion device 15, and the drawing speed by the writing device 4 changes according to the magnitude of the conversion coefficient. For example, as the conversion coefficient becomes smaller, the drawing speed becomes slower, and the drawing line on the raw plate 5 is enlarged in the vertical direction (the circumferential direction of the drum 3) as shown in FIG. The trajectory indicated by the two-dot chain line in the figure is a drawing line when the conversion coefficient is set to the reference value, and the trajectory indicated by the solid line is a drawing line when the conversion coefficient is set smaller than the reference value. .
[0035]
Since the fan-out of the printing paper occurs not only in the left-right width direction but also in the vertical direction, the conversion coefficient is variably set in accordance with the printing conditions as described above, so that the vertical direction as shown in FIG. It becomes possible to deform the picture in correspondence with the fan-out. The area indicated by the two-dot chain line in the figure indicates the pattern drawing area when the conversion coefficient is set to the reference value, and the area indicated by the solid line indicates that the conversion coefficient is set smaller than the reference value as described above. The drawing area of the pattern in the case is shown.
[0036]
When the picture is enlarged in the circumferential direction, the ratio of the plate portion 3A to the non-plate portion 3B in the circumferential direction of the drum 3 changes. Therefore, in the present embodiment, the length T1 of the plate portion 3A and the length T2 of the non-plate portion 3B on the time axis in FIG. 2 are considered in consideration of the change in the ratio between the plate portion 3A and the non-plate portion 3B. Is synchronized with the magnitude of the conversion coefficient. That is, the moving speed of the writing device 4 by the traverser 2 is controlled in synchronization with the writing speed of the writing device 4. More specifically, the plate portion 3A extends in the circumferential direction of the drum 3 as the conversion coefficient decreases, so that T1 is set longer by the extension of the plate portion 3A, and conversely, T2 is set shorter by that amount.
[0037]
The search device 17 searches the database 18 for control patterns and conversion coefficients that match the printing conditions. The searched control pattern is input to the traverse speed indicating device 16, and the conversion coefficient is input to the conversion coefficient indicating device 19. The printing conditions are input via an input device (not shown). The input device may be a device such as a keyboard which is manually input by an operator, or may be a device which is input online from a downstream printing process.
[0038]
As described above, by controlling the timing of laser irradiation by the writing device 4 and the moving speed of the writing device 4 by the traverser 2, the plate making device according to the present embodiment allows the plate surface portion 3A on the drum 3 Thus, it is possible to draw a picture that is gradually enlarged in the left-right width direction in a trapezoidal shape from the mouth side to the mouth side. At the same time, a picture enlarged in the vertical direction can be drawn. These enlarged deformation amounts can be arbitrarily set in accordance with printing conditions by setting control patterns and conversion coefficients.
[0039]
Therefore, according to the plate making apparatus according to the present embodiment, a printing plate that can easily register colors between print papers in correspondence with the fan-out of printing paper can be obtained without using a fan-out vise as in the related art. It becomes possible. In the control method according to the present embodiment, strictly speaking, the intervals between the dots are partially different between the gripping head side and the gripping butt side, but the amount is sufficiently small and does not cause any problem. If the left and right widths are 900 mm and the spread amount is 200 μ, the gap between the drawn patterns for each rotation of the drum 3 is (200 μmm ÷ 10 mm / sec ÷ 300 msec) = 0.7 μ｝.
[0040]
Figure 5, FIG. 6 Shown in The plate making device is shown in FIG. Fruit Since it has the same configuration as the plate making apparatus according to the embodiment, Said Description will be made using the same reference numerals as those in the embodiment. In this device , The method of controlling the moving speed of the writing device 4 by the traverser 2, that is, only the control pattern Shown in FIG. This is different from the embodiment. Here, FIG. , System FIG. 6 is a time chart showing an example of a control pattern, and FIG. 6 is a diagram showing a state of writing a picture by the control pattern of FIG.
[0041]
5 and 6 Does not switch the moving speed of the writing device 4, Shown in FIG. The speed control of the traverser 2 is simplified compared to the embodiment. That is, as shown in FIG. ,book The moving speed of the writing device 4 is set higher than the reference speed, and the writing device 4 is moved at a set speed from the start to the end of drawing without changing the moving speed. The increment of the moving speed of the writing device 4 with respect to the reference speed is set according to the printing conditions as described later. The drawing start position in the axial direction is set in accordance with the moving speed such that the center of the pattern coincides with the center of the plate portion 3A.
[0042]
By controlling the moving speed of the writing device 4 with the control pattern as described above, the movement locus (drawing line of the pattern) of the writing device 4 on the printing plate 3A becomes as shown in FIG. . The trajectory indicated by a solid line in the drawing is a drawing line when the moving speed of the writing device 4 is controlled as described above, and the trajectory indicated by a two-dot chain line indicates that the writing device 4 is moved at the reference speed. It is a drawing line when it is.
[0043]
As shown in FIG. 6A, the angle α formed by the drawing line with respect to the main scanning direction (the rotation direction of the drum 3) is determined by setting the moving speed of the writing device 4 higher than the reference speed. It becomes larger than the angle when writing at the reference speed. Thus, the interval between the drawing lines is wider than when writing at the reference speed. Therefore, the pattern drawn on the plate portion 3A is uniformly enlarged in the left-right width direction as shown in FIG. 6B. The area indicated by the two-dot chain line in the figure indicates the drawing area of the pattern when the writing apparatus 4 is moved at the reference speed, and the area indicated by the solid line indicates the moving speed of the writing apparatus 4 as described above. 3 shows a drawing area of a pattern when is controlled.
[0044]
5 and 6 However, the above-described control patterns are prepared for each printing condition and stored in the database 18. For example, the control pattern corresponding to the printing condition with a large fan-out has an increase in the moving speed with respect to the reference speed such that the enlargement ratio in the left-right width direction is larger than the control pattern corresponding to the printing condition with a small fan-out. It is set large. The drawing start position in the axial direction is also set for each printing condition in accordance with the control pattern so that the center of the picture coincides with the center of the plate portion 3A.
[0045]
further, The aforementioned As in the embodiment, the database 18 also stores, for each printing condition, a value of a conversion coefficient (a coefficient used for frequency conversion from an encoder frequency to a drawing frequency) corresponding to the printing condition, together with the control pattern. In addition to the moving speed of the writing device 4 by the traverser 2, the drawing speed by the writing device 4 is variably controlled according to the magnitude of the conversion coefficient. As the drawing speed becomes slower, the picture is enlarged in the vertical direction (the circumferential direction of the drum 3). 5 and 6 However, the moving speed of the writing device 4 by the traverser 2 is synchronized with the writing speed of the writing device 4 in consideration of the change in the ratio between the plate portion 3A and the non-plate portion 3B due to the circumferential enlargement of the picture. Let it be controlled.
[0046]
As mentioned above, Shown in FIGS. 5 and 6 According to the plate making device, it is possible to draw, on the plate surface portion 3A on the drum 3, a pattern uniformly enlarged in the left-right width direction with respect to the sample pattern. At the same time, a picture enlarged in the vertical direction can be drawn. These enlarged deformation amounts can be arbitrarily set in accordance with printing conditions by setting control patterns and conversion coefficients.
[0047]
Therefore Or Even with such a plate making apparatus, it is possible to obtain a printing plate that can easily register the colors in correspondence with the fan-out of printing paper without using a fan-out vise as in the related art. Also, This example According to The aforementioned There is an advantage that it is possible to respond to the fan-out of the printing paper by a simpler control than in the embodiment. In particular, for fan-outs that deform into a trapezoidal shape from the front to the bottom, like the fan-out of a sheet printed on a sheet-fed printing press, The aforementioned A printing plate made by the control pattern of the embodiment is preferable, but for a fan-out that extends substantially uniformly in the left-right width direction, for example, a fan-out of newsprint printed on a rotary press. , Main system A printing plate made according to a control pattern is preferable.
[0048]
As described above, the present invention Fruit Although the embodiment has been described, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.
According to the configuration of the plate making device according to the above-described embodiment, the moving speed of the writing device 4 can be arbitrarily controlled according to the rotational phase of the drum 3 and the axial position of the writing device 4. Therefore, the control pattern for controlling the moving speed of the writing device 4 is not limited to the above-described embodiments, and an arbitrary control pattern may be set according to the fan-out state of the printing paper. It is possible.
[0049]
As an example, it is possible to control the moving speed of the writing device 4 with a control pattern as shown in FIG. Specifically, the moving speed of the writing device 4 is gradually increased as the writing device 4 advances from the drawing start position at the axial start end of the drum 3 to the vicinity of the center of the plate portion 3A, and the maximum movement is performed at the center of the plate portion 3A. Speed. Then, the moving speed of the writing device 4 is gradually reduced from the center of the plate portion 3A to the drawing end position at the axial end. Here, the velocity distribution in the axial direction is symmetrical with respect to the center of the plate portion 3A on the axial start and end sides, and the moving speeds near the drawing start position and the drawing end position are substantially equal to the reference speed. Are matched. The drawing start position in the axial direction is set such that the center of the pattern coincides with the center of the plate portion 3A.
[0050]
By controlling the moving speed of the writing device 4 with the control pattern as described above, the movement locus (drawing line of the pattern) of the writing device 4 on the printing plate 3A is as shown in FIG. 8A. . The trajectory indicated by a solid line in the drawing is a drawing line when the moving speed of the writing device 4 is controlled as described above, and the trajectory indicated by a two-dot chain line indicates that the writing device 4 is moved at the reference speed. It is a drawing line when it is.
[0051]
As shown in FIG. 8A, the angle α formed by the drawing line with respect to the main scanning direction (the rotation direction of the drum 3) is equal to the angle at the start of the axial direction when writing at the reference speed, and near the center of the plate surface. It becomes the largest and becomes equal to the angle when writing at the reference speed again at the axial end. As a result, the interval between the drawing lines gradually increases from the starting end in the axial direction to the center of the printing plate, and narrows again from the center of the printing plate to the axial end. In this case, the intervals between the drawing lines in the vertical direction of the plate portion 3A (the circumferential direction of the drum 3) are substantially equal.
[0052]
For this reason, the pattern drawn on the plate portion 3A is enlarged in the left-right width direction, particularly in the center portion of the pattern, as shown in FIG. 8B. Also in this case, the moving speed of the writing device 4 is set in accordance with the printing condition, and the enlargement ratio in the left-right width direction is larger for the printing condition with a large fan-out than for the printing condition with a small fan-out. Then, the moving speed near the center of the plate is set high. The area indicated by the two-dot chain line in the figure indicates the drawing area of the pattern when the writing apparatus 4 is moved at the reference speed, and the area indicated by the solid line indicates the moving speed of the writing apparatus 4 as described above. 3 shows a drawing area of a pattern when is controlled.
[0053]
In the plate making apparatus according to the above-described embodiment, the conversion coefficient used when converting the encoder frequency into the drawing frequency is variably set by the conversion coefficient indicating device 19. May be variably set in accordance with. In this case, a conversion coefficient setting pattern (control pattern) corresponding to the axial position of the writing device 4 is set in advance for each printing condition. Preparation The traverse position signal from the rotary encoder of the traverse driving device 8 can be input to the conversion coefficient indicating device 19 while being stored in the database 18. Then, based on the setting pattern and the traverse position signal searched by the search device 17, a set value of the conversion coefficient is obtained and output to the encoder frequency-drawing frequency conversion device 15. This makes it possible to change the drawing speed by the writing device 4 according to the axial position of the drum 3.
[0054]
Further, the A, B, and Z phase signals from the rotary encoder 6 may be input to the conversion coefficient indicating device 19 so that the conversion coefficient can be variably set according to the rotation phase of the drum 3. Also in this case, a setting pattern (control pattern) of the conversion coefficient according to the rotation phase of the drum 3 is previously set for each printing condition. Preparation It is preferable to store the data in the database 18. This makes it possible to change the drawing speed by the writing device 4 according to the rotation phase of the drum 3.
Further, instead of making the drawing speed by the writing device 4 variable as in the above-described embodiment, the rotation speed of the drum 3 may be variably controlled according to printing conditions. This also allows the picture to be deformed in the vertical direction. In this case, the moving speed of the writing device 4 is controlled according to the rotation speed of the drum 3. Further, both the drawing speed of the writing device 4 and the rotation speed of the drum 3 can be variably controlled according to printing conditions.
[0055]
Further, in the above-described embodiment, a case has been described in which the present invention is applied to a dedicated plate making apparatus. However, the present invention can also be applied to an on-machine plate making press incorporating the plate making apparatus as an internal function. . The on-press printing machine has a type in which a plate is mounted on the outer peripheral surface of a plate cylinder (drum) to write a pattern, and a type in which a pattern is written directly on the outer peripheral surface of a plate cylinder. It can be applied to any of them. In addition, the pattern writing method is not limited to the method of writing a pattern pattern by exposing the photosensitive plate surface portion with a light beam such as a laser beam as in the above-described embodiment, and is not limited to a plate surface portion such as an ink jet. Various writing methods can be used in accordance with the printing plate creation method, such as a method of writing a picture pattern by attaching drops of a plate material.
[0056]
【The invention's effect】
As described in detail above, the plate making apparatus of the present invention (claims 1 to 5) 12 According to), by controlling the moving speed of the writing device with respect to the rotation speed of the drum in accordance with the printing conditions, it is possible to draw a pattern which is deformed in the left-right width direction with respect to the sample pattern on the plate portion. Thus, it is possible to obtain a printing plate capable of easily registering colors between colors in correspondence with the fan-out of printing paper.
In particular, a control pattern of the moving speed of the writing device is stored in a database for each printing condition according to the fan-out in the width direction of the printing paper, and the moving speed of the writing device is stored based on the control pattern retrieved from the database. , It is possible to easily obtain a printing plate according to the printing conditions.
[0057]
Further, the plate making apparatus of the present invention (claim Thirteen ~ 24 According to), the writing speed of the writing device with respect to the rotation speed of the drum is controlled in accordance with the printing condition, and the moving speed of the writing device with respect to the rotation speed of the drum is synchronized with the writing speed of the writing device. By controlling, it is possible to draw a pattern that is deformed in the vertical direction with respect to the sample pattern on the plate surface part, so that the printing plate that can easily register the color registration according to the fan-out of the printing paper Can be obtained.
[0058]
In particular, the control pattern of the writing speed of the writing device is stored in a database for each printing condition according to the vertical fan-out of the printing paper, and the writing pattern of the writing device is stored based on the control pattern retrieved from the database. By controlling the loading speed, it is possible to easily obtain a printing plate according to the printing conditions.
[Brief description of the drawings]
FIG. 1 shows the present invention. Fruit It is a functional block diagram showing the composition of the plate making device concerning an embodiment.
FIG. 2 The present invention Fruit 4 is a time chart illustrating a control pattern of an axial movement speed of the writing device according to the embodiment.
3A and 3B are diagrams illustrating a state of writing a pattern according to the control pattern of FIG. 2, wherein FIG. 3A is a diagram illustrating a drawing line on a raw plate, and FIG. 3B is a diagram illustrating a drawing area of the pattern.
4A and 4B are diagrams showing a state of writing a pattern when the writing speed is further changed in FIG. 3, wherein FIG. 4A shows a drawing line on a raw plate, and FIG. FIG.
FIG. 5 book 6 is a time chart illustrating a control pattern of an axial movement speed of the insertion device.
6A and 6B are diagrams showing a state of writing a pattern by the control pattern of FIG. 5; FIG. 6A is a diagram showing a drawing line on a raw plate; FIG.
FIG. 7 is a time chart showing a modification of the control pattern of the writing device in the axial direction.
8A and 8B are diagrams illustrating a state of writing a pattern by the control pattern of FIG. 7, in which FIG. 8A illustrates a drawing line on a raw plate, and FIG. 8B illustrates a drawing area of the pattern.
9A is a diagram showing a schematic configuration of a conventional general external drum type plate making device, and FIG. 9B is a diagram showing a state of writing a picture by the plate making device of FIG. 9A.
FIG. 10 is a diagram illustrating a fan-out state of printing paper for each printing station in a multi-printing station type printing press.

Claims (24)

A plate making device for making a printing plate for printing a pattern on printing paper,
A drum having a plate portion on the outer peripheral surface and performing main scanning by rotation,
A writing device arranged toward the outer peripheral surface of the drum and selectively writing a dot pattern of a pattern on the plate portion based on digital data of a sample pattern;
A moving device for performing sub-scanning by moving the writing device in a direction parallel to the axis of the drum;
Moving speed control means for controlling the moving speed of the writing device with respect to the rotational speed of the drum according to printing conditions,
The moving speed control means,
A plate making apparatus characterized in that the moving speed of the writing device is switched between the plate portion and a non-plate portion excluding the plate portion from the outer peripheral surface of the drum. The moving speed control means,
The writing device on the non-plate portion according to the moving speed of the writing device on the plate portion such that the respective writing start positions for each rotation cycle of the drum on the plate portion are at the same interval. The plate making apparatus according to claim 1, wherein the moving speed of the plate is controlled. 3. A plate making apparatus according to claim 1, wherein the moving speed of the writing device on the plate portion is increased as the writing device advances from the axial start end to the end side of the drum. . The moving speed deviation of the writing device on the printing plate portion with respect to a reference speed is set symmetrically on the starting end side and the ending side with respect to the center of the printing plate. A plate-making apparatus according to any one of the above. On the axial start end side of the drum, the moving speed of the writing device on the plate portion is set lower than a reference speed, and the moving speed of the writing device on the non-plate portion is set higher than the reference speed. The plate making apparatus according to any one of claims 1 to 4, characterized in that: As the drum advances toward the axial end, the moving speed of the writing device in the plate portion gradually increases, and the moving speed of the writing device in the non-plate portion increases the moving speed of the writing device in the plate portion. And gradually decreases in inverse proportion to the reference speed near the center of the drum in the axial direction, so that both the plate portion and the non-plate portion substantially match the reference speed, and the magnitude relationship between the plate portion and the non-plate portion is reversed. The plate making apparatus according to claim 5, wherein the value is set to: On the time axis, the area enclosed by the line indicating the moving speed at the plate portion and the reference speed line is set equal to the area enclosed by the line indicating the moving speed at the non-plate portion and the reference speed line. The plate making apparatus according to any one of claims 1 to 6, wherein: Input means for inputting printing conditions;
A database storing a control pattern of the moving speed of the writing device by the moving speed control means for each printing condition in accordance with a fan-out of the printing paper in a width direction;
Search means for searching the database for a control pattern corresponding to the printing condition input via the input means,
The plate making apparatus according to claim 1, wherein the moving speed control unit controls a moving speed of the writing device based on a control pattern searched by the search unit. A plate making device for making a printing plate for printing a pattern on printing paper,
A drum having a plate portion on the outer peripheral surface and performing main scanning by rotation,
A writing device arranged toward the outer peripheral surface of the drum and selectively writing a dot pattern of a pattern on the plate portion based on digital data of a sample pattern;
A moving device for performing sub-scanning by moving the writing device in a direction parallel to the axis of the drum;
Moving speed control means for controlling the moving speed of the writing device with respect to the rotational speed of the drum according to printing conditions,
The moving speed control means,
As the writing device advances from the axial start to the center of the drum, the moving speed of the writing device increases, and as the writing device advances from the axial center of the drum to the end, the writing device A plate making apparatus characterized by reducing a moving speed. 10. The plate making apparatus according to claim 9 , wherein a speed deviation with respect to a moving speed of the writing device at an axial center of the drum is set symmetrically at an axial start end and an axial end. The plate making apparatus according to claim 10 , wherein the moving speed of the writing device near the writing start position and the writing end position is set to substantially match the reference speed. Input means for inputting printing conditions;
A database storing a control pattern of the moving speed of the writing device by the moving speed control means for each printing condition in accordance with a fan-out of the printing paper in a width direction;
Search means for searching the database for a control pattern corresponding to the printing condition input via the input means,
The plate making apparatus according to any one of claims 9 to 11 , wherein the moving speed control means controls the moving speed of the writing device based on the control pattern searched by the search means. A plate making device for making a printing plate for printing a pattern on printing paper,
A drum having a plate portion on the outer peripheral surface and performing main scanning by rotation,
A writing device arranged toward the outer peripheral surface of the drum and selectively writing a dot pattern of a pattern on the plate portion based on digital data of a sample pattern;
A moving device for performing sub-scanning by moving the writing device in a direction parallel to the axis of the drum;
Writing speed control means for controlling the writing speed of the writing device with respect to the rotation speed of the drum according to printing conditions;
Moving speed control means for controlling the moving speed of the writing device with respect to the rotation speed of the drum in synchronization with the writing speed of the writing device;
The moving speed control means,
A plate making apparatus characterized in that the moving speed of the writing device is switched between the plate portion and a non-plate portion excluding the plate portion from the outer peripheral surface of the drum. The moving speed control means,
The writing device on the non-plate portion according to the moving speed of the writing device on the plate portion such that the respective writing start positions for each rotation cycle of the drum on the plate portion are at the same interval. The plate making apparatus according to claim 13 , wherein the moving speed of the plate is controlled. 該書write device, characterized in that the moving speed of the該書write device on said plate surface as it travels to the end side from the axial direction starting end of the drum is increased, the plate making apparatus of claim 13 or 14, wherein . It characterized <br/> be set symmetrically with starting end and the terminating end moving speed deviation該書write device on said plate surface portion with respect to the plate center with respect to the reference speed, claim 13-15 A plate-making apparatus according to any one of the above. On the axial start end side of the drum, the moving speed of the writing device on the plate portion is set lower than a reference speed, and the moving speed of the writing device on the non-plate portion is set higher than the reference speed. The plate making apparatus according to any one of claims 13 to 16 , characterized in that: As the drum advances toward the axial end, the moving speed of the writing device in the plate portion gradually increases, and the moving speed of the writing device in the non-plate portion increases the moving speed of the writing device in the plate portion. And gradually decreases in inverse proportion to the reference speed near the center of the drum in the axial direction, so that both the plate portion and the non-plate portion substantially match the reference speed, and the magnitude relationship between the plate portion and the non-plate portion is reversed. The plate making apparatus according to claim 17 , wherein the value is set to: On the time axis, the area enclosed by the line indicating the moving speed at the plate portion and the reference speed line is set equal to the area enclosed by the line indicating the moving speed at the non-plate portion and the reference speed line. The plate making apparatus according to any one of claims 13 to 18 , characterized in that: Input means for inputting printing conditions;
A database storing a control pattern of a writing speed of the writing device by the writing speed control means for each printing condition in accordance with a vertical fan-out of the printing paper;
Search means for searching the database for a control pattern corresponding to the printing condition input via the input means,
The prepress according to any one of claims 13 to 19 , wherein the writing speed control means controls the writing speed of the writing device based on the control pattern searched by the search means. apparatus. A plate making device for making a printing plate for printing a pattern on printing paper,
A drum having a plate portion on the outer peripheral surface and performing main scanning by rotation,
A writing device arranged toward the outer peripheral surface of the drum and selectively writing a dot pattern of a pattern on the plate portion based on digital data of a sample pattern;
A moving device for performing sub-scanning by moving the writing device in a direction parallel to the axis of the drum;
Writing speed control means for controlling the writing speed of the writing device with respect to the rotation speed of the drum according to printing conditions;
Moving speed control means for controlling the moving speed of the writing device with respect to the rotation speed of the drum in synchronization with the writing speed of the writing device;
The moving speed control means,
As the writing device advances from the axial start to the center of the drum, the moving speed of the writing device increases, and as the writing device advances from the axial center of the drum to the end, the writing device A plate making apparatus characterized by reducing a moving speed. 22. The plate making apparatus according to claim 21 , wherein a speed deviation with respect to a movement speed of the writing device at an axial center of the drum is set symmetrically at an axial start end and an axial end. 23. The plate making apparatus according to claim 22 , wherein the moving speed of the writing device near the writing start position and near the writing end position is set to substantially match the reference speed. Input means for inputting printing conditions;
A database storing a control pattern of a writing speed of the writing device by the writing speed control means for each printing condition in accordance with a vertical fan-out of the printing paper;
Search means for searching the database for a control pattern corresponding to the printing condition input via the input means,
The prepress according to any one of claims 21 to 23 , wherein the writing speed control means controls the writing speed of the writing device based on the control pattern searched by the search means. apparatus.

Images