JP2002311597A - Engraving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a printing plate which enables easy registering in colors while being made to correspond to the fan-out of printing paper as to an engraving device to be applied to a CTP(computer to plate) system. SOLUTION: In a so-called internal drum type engraving device for plotting the dot pattern of a pattern in a raw plate by selectively radiating laser light from a laser irradiation port 7 on the basis of the digital data of a sample pattern while performing the main scanning of a raw plate 5 in the width direction by rotating the irradiation direction of laser light from the port 7 on a face parallel with the axis of a cylindrical space 3 and performing the sub- scanning of the raw plate 5 in the vertical direction by rotating the port 7 around the axis of the space 3 relatively to the raw plate 5, the plotting speed of the dot pattern and plotting start time for each main scanning are controlled in accordance with the rotational phase of the port 7 against the raw plate 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate making apparatus for preparing a printing plate based on digital data of a sample picture.
In particular, the present invention relates to a plate making apparatus that draws a pattern on a raw plate provided on the inner peripheral surface of a drum (a so-called inner drum method).

[0002]

2. Description of the Related Art In recent years, digitization of a plate making process has been advanced, and CTP (Computing) for directly creating a printing plate based on digital data (image data) obtained by digitizing a sample pattern.
er toPlate) workflow has been established. According to a system using this workflow (hereinafter, referred to as a CTP system), there is no need to create an underlay film, so that costs can be reduced, and a sample pattern can be faithfully reproduced with high positional accuracy. There is.

As a plate making apparatus applied to such a CTP system, a so-called inner drum type plate making apparatus as shown in FIG. 9A is known. In this plate making apparatus, a laser irradiation port 1a of a laser drawing apparatus 1 is disposed in a cylindrical space inside a drum 3, and a raw plate (a plate on which no pattern is written) 5 is provided on the inner peripheral surface of the cylindrical space. Is installed. Then, while rotating the laser irradiation port 1a around the axis of the drum 3, a laser beam is selectively irradiated from the laser irradiation port 1a along the axial direction of the drum 3, so that a pattern is drawn on the raw plate 5. It has become.

In this plate making apparatus, the direction of movement of the laser beam from the laser irradiation port 1a is the main scanning direction, and the direction of rotation of the laser irradiation port 1a is the sub-scanning direction.
As shown in the figure, the pattern is written on the raw plate 5 in a spiral shape in an oblique direction. The pattern written on the raw plate 5 is to reproduce the sample pattern as faithfully as possible, and has the same scale as the sample pattern.

[0005]

However, in a printing machine, for example, a sheet-fed printing press, the dimensions of the printing paper (sheets) are reduced due to the non-uniform moisture content and surface properties of the printing paper (sheets) due to the use of dampening water. It is known that a spreading fan-out phenomenon occurs. 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.

In addition, in a multi-printing station type sheet-fed printing press, the printing paper is conveyed sequentially to the next printing station via an intermediate cylinder while holding the leading edge of the printing paper with the claws of the impression cylinder. The amount of fan-out for each station differs depending on the pressure caused by the pressure and the holding state with the claws.
Specifically, as shown in FIG.
C, the second station 2C, the third station 3C, and the fourth station 4C, the trailing edge of the printing paper gradually increases in order. 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.

As described above, in the plate making apparatus in the conventional CTP system, since the principle is to reproduce the sample pattern as faithfully as possible, the same scale is used regardless of the fan-out amount for each printing station. The pattern is drawn with. As a result, the pattern of each color printed at each printing station is misregistered between the colors by the amount corresponding to 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 to match the color registration.However, the butt expansion amount corresponding to the fan-out amount is, when the left and right width is 900 mm,
Since the expansion amount is extremely small at around 200 μm at the maximum, there is a problem that the adjustment requires skill. The present invention has been made in view of such a problem, and has been developed in consideration of CT.
It is an object of the present invention to provide a plate making apparatus capable of easily obtaining a printing plate capable of registering colors between colors in correspondence with a fan-out of printing paper in a P system.

[0009]

In order to achieve the above object, a plate making apparatus (first plate making apparatus) according to the present invention has a cylindrical space and a supporting means for supporting a raw plate on an inner peripheral surface of the cylindrical space. And a laser irradiation port disposed toward the inner peripheral surface of the cylindrical space; and an inner peripheral surface of the cylindrical space by selectively irradiating a laser beam from the laser irradiation port based on digital data of a sample picture. A pattern drawing means for drawing a dot pattern of a pattern on the raw plate supported by the raw plate, and rotating the irradiation direction of the laser beam from the laser irradiation port in a plane parallel to the axis of the cylindrical space, thereby forming the raw plate. Main scanning means for performing main scanning in the width direction of the plate, and sub-scanning of the plate in the vertical direction by rotating the laser irradiation port relative to the plate around the axis of the cylindrical space. Sub-scanning means for performing the Speed control means for controlling the drawing speed of the pattern according to the rotation phase of the laser irradiation port with respect to the raw plate, and drawing start timing for each main scan by the picture drawing means for the raw plate of the laser irradiation port. And a drawing start timing control means for controlling according to the rotation phase with respect to.

By controlling the drawing speed of the dot pattern by the pattern drawing means in accordance with the rotation phase, it is possible to arbitrarily set the enlargement ratio of the pattern in the left-right width direction in the vertical direction. By controlling the drawing start timing for each main scan by the pattern drawing means according to the rotation phase of the laser irradiation port with respect to the raw plate, the drawing position in the left-right width direction of the pattern can be set arbitrarily in the vertical direction. Will be possible. That is, according to the above-described first plate making apparatus, it becomes possible to make a plate for printing in which a picture is deformed into an arbitrary shape in the left-right width direction.

Preferably, the writing speed is controlled such that the writing speed controlled by the writing speed control means and the delay amount of the writing start time controlled by the writing start time control means are substantially proportional to each other. The control unit and the drawing start timing control unit are controlled. This makes it possible to make a printing plate in which the picture is deformed symmetrically in the left-right width direction.

More preferably, in accordance with the rotation of the laser irradiation port with respect to the raw plate by the sub-scanning means, the drawing speed control means controls the drawing speed so as to monotonously decrease the drawing speed from a reference speed. The control by the drawing start timing control means is performed so that the delay amount of the drawing start timing is monotonously reduced from the reference delay amount. This makes it possible to make a printing plate in which the pattern is symmetrically deformed into a trapezoidal shape.

In this case, it is more preferable that the drawing speed control means and the drawing start time control means be arranged such that the drawing speed and the delay amount of the drawing start time are monotonously reduced for each main scan by the main scanning means. Is controlled by. As a result, it is possible to smoothly expand the left and right width of the picture from the gripping head side to the gripping butt side without causing distortion in the horizontal width direction.

Further, in order to achieve the above object, another plate making apparatus (second plate making apparatus) of the present invention comprises a supporting means having a cylindrical space and supporting a raw plate on an inner peripheral surface of the cylindrical space; A laser irradiation port disposed toward the inner peripheral surface of the cylindrical space; and a laser beam selectively radiating from the laser irradiation port based on digital data of a sample pattern to support the inner peripheral surface of the cylindrical space. A pattern drawing means for drawing a dot pattern of a pattern on the raw plate, and a width of the raw plate by rotating an irradiation direction of a laser beam from the laser irradiation port in a plane parallel to an axis of the cylindrical space. Main scanning means for performing main scanning in the direction, sub-scanning means for performing vertical scanning of the raw plate by rotating the laser irradiation port about an axis of the cylindrical space, and the pattern drawing means Printing speed of the dot pattern by the printing condition ( Species, printing pressure, is characterized in that a drawing speed control means for controlling on the basis of a predetermined control pattern in accordance with the position or the like) on the print line of the corresponding printing station.

By controlling the drawing speed of the dot pattern by the pattern drawing means based on the predetermined control pattern corresponding to the printing condition, the pattern drawn on the raw plate is made to correspond to the fan-out of the printing paper. Thus, it is possible to deform the sample pattern in the left-right width direction. Preferably, the image forming apparatus further includes a drawing start timing control unit, and controls a drawing start timing for each main scan by the picture drawing unit based on a predetermined control pattern according to a printing condition. As described above, in addition to the drawing speed of the dot pattern by the picture drawing means, the drawing start timing of each main scan by the picture drawing means is controlled based on a predetermined control pattern corresponding to the printing condition, whereby the raw printing is performed. Can be deformed into an arbitrary shape in the left-right width direction with respect to the sample pattern in accordance with the fan-out of the printing paper.

In this case, more preferably, the control pattern of the drawing speed by the drawing speed control means and the control pattern of the drawing start time by the drawing start time control means are respectively fanned out in the width direction of the printing paper in a database. Is stored for each printing condition in accordance with the printing condition, each control pattern corresponding to the printing condition input through the input unit is searched from the database by the searching unit, and the drawing speed and the drawing speed are determined based on the searched control pattern. The drawing start timing is controlled.

Further, in order to achieve the above object, another plate-making apparatus (third plate-making apparatus) of the present invention comprises a support means having a cylindrical space and supporting the raw plate on the inner peripheral surface of the cylindrical space; A laser irradiation port disposed toward the inner peripheral surface of the cylindrical space; and a laser beam selectively radiating from the laser irradiation port based on digital data of a sample pattern to support the inner peripheral surface of the cylindrical space. A pattern drawing means for drawing a dot pattern of a pattern on the raw plate, and a width of the raw plate by rotating an irradiation direction of a laser beam from the laser irradiation port in a plane parallel to an axis of the cylindrical space. Main scanning means for performing main scanning in the direction, and sub-scanning in the vertical direction of the raw plate by rotating the laser irradiation port relative to the raw plate about the axis of the cylindrical space. Sub-scanning means, and the laser irradiation port of the sub-scanning means Rotation speed control means for controlling the rotation speed for the raw plate based on a predetermined control pattern corresponding to printing conditions (paper type, printing pressure, position of a corresponding printing station on a printing line, etc.). Features.

In this way, by controlling the rotation speed of the laser irradiation port with respect to the raw plate by the sub-scanning means based on a predetermined control pattern corresponding to printing conditions, a pattern drawn on the raw plate can be printed on a printing paper. Can be deformed in the vertical direction with respect to the sample picture in accordance with the fan-out. In this case, preferably, the control pattern of the rotation speed by the rotation speed control means is stored in a database for each printing condition according to the fan-out in the width direction of the printing paper, and is input via the input means. The control means searches the database for a control pattern corresponding to the printing condition, and controls the rotation speed based on the searched control pattern.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. First, FIGS. 1 to 5 show the first embodiment of the present invention.
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 inner drum type plate making apparatus, and a drum (supporting means) 3 for supporting a raw plate 5 on a cylindrical inner peripheral surface, as in the related art, A laser drawing device 1 for drawing a pattern on the raw plate 5 by irradiating a laser beam.

The laser drawing device 1 includes a laser output device 4 for outputting a laser beam, a laser irradiation mirror 7 serving as a laser beam irradiation port, and a polygon mirror for guiding the laser beam output from the laser output device 4 to the laser irradiation mirror 7. 6 mainly. In the present embodiment, the laser output device 4 includes a plurality of semiconductor laser transmitters therein, and can output a plurality of laser beams at a time.

The laser irradiation mirror 7 is disposed on the axis of the drum 3 and inclined with respect to the axis. On the back surface, a mirror shaft 7 concentric with the axis of the drum 3 is provided.
a is fixed. A low-speed motor 8 that rotates at a low rotation speed is connected to the mirror shaft 7a, and the laser irradiation mirror 7 can be rotated slowly around the axis of the drum 3 by the low-speed motor 8. Also,
Although a detailed description of the mechanism is omitted here, the laser output device 4 described above and the polygon mirror 6 described later also rotate around the axis of the drum 3 at the same rotation speed as the laser irradiation mirror 7.

The polygon mirror 6 is disposed on the optical axis of the laser beam from the laser output device 4. The polygon mirror 6 has a built-in polygon motor 6a, and is rotated by the polygon motor 6a. Polygon motor 6a
Is connected to the polygon motor driving device 9. In the present embodiment, the polygon motor driving device 9 controls the polygon motor 6a to rotate the polygon mirror 6 in one direction at a constant speed. Here, the polygon mirror 6 rotates in a plane passing through the axis of the drum 3, and the laser beam output from the laser output device 4 also passes through this plane.

The laser beam output from the laser output device 4 is reflected on the surface of the polygon mirror 6, and furthermore,
The laser beam is reflected again on the surface of the laser irradiation mirror 7 and irradiates the raw plate 5. The polygon mirror 6 rotates at a constant speed as described above, so that the reflection direction of the laser beam on the surface of the polygon mirror 6 is The laser beam rotates in one direction in a plane passing through the axis, and accordingly, the reflection direction of the laser beam on the surface of the laser irradiation mirror 7 also rotates in one direction in a plane passing through the axis of the drum 3. Thus, the laser irradiation mirror 7
The main scanning in the width direction of the raw plate 5 is performed by rotating the direction of irradiation of the laser beam onto the raw plate 5 in one direction within a plane passing through the axis of the drum 3. That is, in the present embodiment, the main scanning means is constituted by the polygon mirror 6 and the polygon motor driving device 9 for driving the polygon mirror.

The main scanning range (picture drawing range) of the raw plate 5 in the width direction is determined by the relationship between the output speed and output timing of the laser beam from the laser output device 4 and the rotation speed of the polygon mirror 6. . Here, when a laser beam is output at an output time and an output timing when a later-described drawing frequency and a delay amount of a drawing start time are set to reference values, a pattern is drawn in a reference drawing area in the raw plate 5. Thus, the rotation speed of the polygon mirror 6 is set. The reference drawing area described above is a drawing area for a picture when there is no fan-out on the printing paper.

An optical sensor 2 is disposed outside the scanning start end of the picture drawing area in the main scanning plane of the laser beam. A weak laser beam for phase detection is continuously output from the laser output device 4 separately from a laser beam for exposing the raw plate 5. By detecting the laser beam for phase detection by the optical sensor 2, the zero point of the rotational phase of the laser beam emitted from the laser irradiation mirror 7 is detected. The optical sensor 2 also rotates around the axis of the drum 3 at the same rotation speed as the laser irradiation mirror 7.

The plate making apparatus according to the present embodiment controls the output of the laser beam from the laser output device 4 (that is, controls the drawing speed and drawing start timing on the raw plate 5), and irradiates the laser with the low-speed motor 8. A control device 10 for controlling the rotation speed of the mirror 7 is provided. As shown in FIG. 1, 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, a drawing clock generation device 15, a low-speed motor drive device 16, and a search device. 17, a database 18, a pulse period-speed converter 19, and a laser phase detector 20.

First, the output control of the laser output device 4 will be described. This control mainly includes a print image data generating device 11, an image buffer 12, a laser driver 13, an image start trigger generating device 14, and a drawing clock generating device 15.
This is performed using The print image data generation device 11 includes:
This is an apparatus that generates image data for printing (digital data of a sample picture) 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 device 11, and the RIP uses this to generate text data (documents) 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.

The image data stored in the image buffer 12 is based on the drawing clock signal from the drawing clock generator 15 using the image start trigger signal from the image start trigger generator 14 as the transmission start timing for each scan by the polygon mirror 6. Is transmitted serially to the laser driver 13 based on the The laser driver 13 is connected to the image buffer 12
A laser output signal is output to each laser transmitter in the laser output device 4 in synchronization with the image data transmitted from the.
Each laser transmitter in the laser output device 4 receives a laser output signal from the laser driver 13 and outputs a laser beam. That is, in the present embodiment,
The print image data generation device 11 and the image buffer 1
2, laser driver 13, image start trigger generator 14
The drawing clock generating device 15 and the above-described laser drawing device 1 constitute a picture drawing means according to the present invention.

The image start trigger generator 14 receives the zero point signal from the laser phase detector 20 and the search device 1 described later.
The image start trigger signal is generated based on the control pattern searched in step 7. The optical sensor 2 is connected to the laser phase detector 20. When the optical sensor 2 receives the laser beam for phase detection, it outputs a zero point signal to the image start trigger generator 14. The image start trigger generator 14 generates an image start trigger signal when a delay time (delay amount) specified by the control pattern data has elapsed after receiving the zero point signal. The control pattern will be described later.

The drawing clock generator 15 generates a drawing clock signal based on a control pattern retrieved by a retrieval device 17 described later. The drawing clock generator 15 is a device that can variably control the frequency of the drawing clock (drawing frequency). Here, a DDS element (for example,
The drawing clock is generated using ANALOG DEVICE's AD9852).

Although the drawing frequency depends on the plate size, the drawing time, the resolution, etc., it is assumed that the plate size is 1100 mm (width) × 7.
If 00 mm (length), resolution is 2400 dpi, drawing time is 2 minutes, and the number of laser beams is 32, the number of scans is 2188, the scanning time is 55 msec, and the drawing frequency is 2 MHz. This 2 MHz drawing frequency is
For example, it can be obtained by converting a fixed frequency of 100 MHz to 16 MHz using a DDS element and further using a ８ frequency dividing circuit.

In this case, the fluctuation (jitter) of the drawing clock is 23 psec ÷ 16 = 1.5 psec.
Since the frequency error of the drawing clock due to this jitter is 0.01% or less, there is no practical problem. In the present embodiment, the conversion parameters of the DDS element are variably set based on control pattern data to be described later.
The drawing frequency is variably controlled. The control pattern will be described later.

On the other hand, the rotation speed control of the laser irradiation mirror 7 by the low-speed motor 8 is mainly performed by the low-speed motor driving device 1.
6 and the pulse period-speed conversion device 19. That is, in the present embodiment, the picture drawing means according to the present invention is constituted by the low-speed motor driving device 16, the pulse period-speed conversion device 19, and the above-mentioned low-speed motor 8.

The low-speed motor driving device 16 is a device for controlling a current value supplied to the low-speed motor 8, and outputs a current having a magnitude corresponding to the rotation speed command signal from the pulse period-speed conversion device 19. The motor 8 is supplied. The pulse period-speed conversion device 19 detects the pulse period of the zero point signal (scanning period of the laser beam) from the zero point signal transmitted from the laser phase detection device 20, and detects the pulse detected by the rotation speed of the low speed motor 8. The rotation speed command signal is generated so as to have a speed corresponding to the cycle.

Here, the conversion coefficient used when converting the pulse period to the rotation speed of the low-speed motor 8 is set so that there is no overlap or gap between the dot patterns drawn for each scan. The drawing dots are set so as to be continuous in the vertical direction (mirror rotation direction) (see FIG. 5).
The above conversion coefficient is variably set within a range in which the continuity of the drawing dots in the vertical direction is not impaired by a conversion coefficient setting signal from the search device 17 described later.

FIG. 2 is a time chart showing an output pattern from the start to the end of drawing in one scanning cycle of the laser beam output from the laser output device 4. As shown in FIG. 2, the output of the laser beam is started at an output timing synchronized with the drawing start trigger signal generated with a delay to the zero point signal, and thereafter, the laser beam is output in synchronization with the drawing clock. . The drawing is terminated when a predetermined number of clocks have been counted from the start of the drawing.

In this embodiment, since the polygon mirror 6 rotates at a constant speed, the scanning frequency is always constant, and the position of the optical sensor 4 in the width direction with respect to the raw plate 5 is always constant. The time from the start of drawing to the end of drawing corresponds to the drawing width of the pattern on the raw plate 5, and the position of the drawing start trigger signal on the time axis corresponds to the drawing start position of the pattern in the width direction of the raw plate 5. . The time from the start of drawing to the end of drawing corresponds to the drawing speed, that is, the drawing clock frequency (drawing frequency). The position of the drawing start trigger signal on the time axis is the delay of the drawing start trigger signal with respect to the zero point signal. It corresponds to time (the amount of delay). Therefore, by variably controlling the drawing frequency and the delay time according to the rotation phase of the laser irradiation mirror 7, the shape of the pattern drawn on the raw plate 5 can be deformed in the width direction.

Therefore, in the present embodiment, the drawing frequency and the delay time of the drawing start time are shown in FIG.
By controlling with the control pattern as shown in FIG. 3B, the fan-out of the printing paper, in particular, such that it gradually spreads in a trapezoidal shape in the left-right width direction from the front side to the bottom side like a sheet of paper. It realizes printing plate making for fan-out. Specifically, as the laser irradiation mirror 7 rotates in both the drawing frequency and the delay time, the reference value (reference speed, reference delay amount) is monotonously decreased for each scan. Here, the reference values of the drawing frequency and the delay time are the set values of the drawing frequency and the delay time when it is assumed that there is no fan-out on the printing paper.

The main printing by the rotation of the polygon mirror 6 and the sub-scanning by the rotation of the laser irradiating mirror 7 make the raw plate 5
The pattern is written in a diagonal direction in a spiral manner, but the movement of the laser beam on the raw plate 5 is controlled by controlling the drawing frequency and the delay time of the drawing start timing by each control pattern as described above. The trajectory (drawing line of the pattern) is shown in FIG.
As shown in FIG. The locus indicated by a solid line in the figure is a drawing line when the drawing frequency and the delay time are controlled as described above, and the locus indicated by a two-dot chain line sets the drawing frequency and the delay time to reference values, respectively. The drawing line at the time.

As shown in FIG. 4A, since the drawing frequency monotonously decreases in each scan, the drawing width (length of the drawing line) of the pattern on the raw plate 5 changes monotonically in each scan. To expand. Further, since the delay time of the drawing start time monotonously decreases for each scan, the drawing start position in the width direction on the raw plate 5 (the starting point of the drawing line) shifts outward for each scan. In the present embodiment, the deviation amount of the drawing start position for each scan is always equal to the deviation amount outside the drawing end position, that is, the center position of the drawing line in the width direction is always constant. The delay time is made proportional to the drawing frequency.

As a result, as shown in FIG. 4B, the pattern drawn on the raw plate 5 gradually becomes horizontal in the width direction from the top to the bottom as well as the fan-out of the printing paper. It will be enlarged to the shape. The region indicated by the two-dot chain line in the figure indicates the drawing region of the pattern when the drawing frequency and the delay time are set to the reference values, respectively, and the region indicated by the solid line controls the drawing frequency and the delay time as described above. The drawing area of the pattern at the time is shown.

When the control is performed as described above, the interval between the drawing dots in the width direction is increased in each scan, and if the enlargement ratio per scan is too large, as shown in FIG. The pattern is distorted at the transition point of scanning. Although this distortion is minute, it may be perceived as an interference pattern when seen by human eyes, and may lead to a decrease in image quality. Therefore, in the present embodiment, 1% of the dot diameter
The change rate of the drawing frequency is set with the degree being the upper limit of the enlargement rate per scan. 4A and 4B.
In the figure, the enlargement ratio in the left-right width direction is exaggerated for easy understanding of the control method of the present embodiment.

In the present embodiment, each control pattern as described above is 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 of the printing station where the plate is mounted on the printing line 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 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 reduction rate of the drawing frequency and the delay time with respect to the rotation phase of the laser irradiation mirror 7 is set to be large.

The database 18 also stores the values of the conversion coefficients according to the printing conditions along with the above-described control patterns. The conversion coefficient is a coefficient used for converting the pulse period into the rotation speed of the micro-speed motor 8 in the pulse period-speed conversion device 19, and the sub-scanning by the rotation of the laser irradiation mirror 7 according to the size of the conversion coefficient. The speed will change. For example, as the conversion coefficient increases, the sub-scanning speed increases, and as shown in FIG.
The interval between the drawing lines above is enlarged. 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 to be larger than the reference value. Note that the reference value of the conversion coefficient is a set value of the conversion coefficient when it is assumed that there is no vertical fan-out on the printing paper.

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 according to the printing conditions as described above, and as shown in FIG. The pattern can be deformed in correspondence with the fan-out in the direction. The area indicated by the two-dot chain line in the figure indicates the drawing area of the pattern when the conversion coefficient is set to the reference value, and the area indicated by the solid line sets the conversion coefficient to be larger than the reference value as described above. The drawing area of the pattern in the case is shown.

In the search device 17, the database 1
8 to retrieve control patterns and conversion coefficients that match the printing conditions. The retrieved drawing frequency control pattern is inputted to the drawing clock generator 15, the delay time control pattern is inputted to the image start trigger generator 14, and the conversion coefficient is inputted to the pulse period-speed converter 19. The printing conditions are input via an input device (not shown). This input device may be a device such as a keyboard which is manually input by an operator, or a device which is input online from a downstream printing process.

As described above, the output control of the laser beam and the control of the rotation speed of the laser irradiation mirror 7 are performed, so that the plate making apparatus according to the present embodiment
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.

Therefore, according to the plate making apparatus according to the present embodiment, a printing press which can easily register the color registration in correspondence with the fan-out of the printing paper without using the fan-out vise as in the related art. It becomes possible to obtain a plate. In addition, according to the control method of the present embodiment, strictly speaking, the interval between the dots is partially different between the gripping head side and the gripping butt side, but the amount is sufficiently small and does not cause any problem. Assuming that the width of the right and left of the drum 3 is 900 mm and the spread amount is 200 μ, the gap of the drawn pattern per rotation of the drum 3 is (200 μm ÷ 10 mm / sec ÷ 300 ms)
ec) = 0.7μ.

Next, a second embodiment of the present invention will be described with reference to FIGS. The plate making apparatus according to the present embodiment has the same configuration as that of the plate making apparatus according to the first embodiment shown in FIG. 1, and therefore, will be described below using the same reference numerals as those in the first embodiment. In the first embodiment, the laser output device 4
Only the control method of the output control of the laser beam from the first embodiment, that is, each control pattern of the drawing speed and the delay time of the drawing start timing is different from the first embodiment. Here, FIG. 7 is a time chart showing an example of each control pattern according to the present embodiment, and FIG. 8 is a diagram showing a drawing state of a pattern by the control pattern of FIG.

This embodiment simplifies the output control of the laser beam compared to the first embodiment by not switching the drawing frequency and delay time for each scan. That is, as shown in FIG. 7A, in the present embodiment, the drawing frequency is set to be smaller than the reference value, and the drawing is performed on the drawing clock generator 15 at the set frequency regardless of the rotation phase of the laser irradiation mirror 7. A clock is generated. Also, as shown in FIG. 7B, the delay time is set smaller than the reference value,
Irrespective of the rotation phase, the image start trigger generator 14 generates an image start trigger signal with the set delay time. Note that the amount of decrease in the drawing frequency and the delay time with respect to each reference value is set according to the printing conditions as described later.

By controlling the drawing frequency and the delay time of the drawing start timing by each control pattern as described above,
The movement trajectory of the laser beam (the drawing line of the pattern) on the raw plate 5 is as shown in FIG. The locus indicated by a solid line in the figure is a drawing line when the drawing frequency and the delay time are controlled as described above, and the locus indicated by a two-dot chain line sets the drawing frequency and the delay time to reference values, respectively. The drawing line at the time.

As shown in FIG. 8A, when the drawing frequency is set lower than the reference value, the raw plate 5
The drawing width (length of the drawing line) of the pattern on the upper side is larger than when drawing with the reference value. Further, by setting the delay time of the drawing start time to be smaller than the reference value, the drawing start position in the width direction on the raw plate 5 (the starting point of the drawing line) is shorter than when drawing is started with the reference value. It shifts to the outside. In the present embodiment, the amount of decrease in the delay time with respect to the reference value is set in accordance with the amount of decrease in the drawing frequency with respect to the reference value so that the center position of the drawing line in the width direction is always constant.

As a result, the pattern drawn on the raw plate 5 is uniformly enlarged in the width direction as shown in FIG. 8B. The region indicated by the two-dot chain line in the figure indicates the drawing region of the pattern when the drawing frequency and the delay time are set to the reference values, respectively, and the region indicated by the solid line controls the drawing frequency and the delay time as described above. The drawing area of the pattern at the time is shown.

Also in this embodiment, the above-described control patterns are prepared for each printing condition and stored in the database 18. For example, a control pattern corresponding to a printing condition with a large fan-out has a larger amount of decrease in the drawing frequency with respect to a reference value so that an enlargement ratio in the left-right width direction is larger than a control pattern corresponding to a printing condition with a small fan-out. Is set large. Further, the delay amount of the drawing start time is set for each printing condition according to the drawing frequency so that the center of the pattern coincides with the center of the raw plate 5.

Further, as in the first embodiment, the value of the conversion coefficient used in the pulse period-speed conversion device 19 is stored in the database 18 for each printing condition together with each control pattern. The sub-scanning speed by the rotation of the laser irradiation mirror 7 is variably controlled according to the magnitude of the conversion coefficient together with the drawing frequency and the delay time of the drawing start timing.

As described above, according to the plate making apparatus of the present embodiment, it is possible to draw on the raw plate 5 a pattern that is uniformly enlarged in the left-right width direction with respect to the sample pattern. Also,
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 each control pattern and conversion coefficient.

Therefore, according to the plate making apparatus according to the present embodiment, the printing plate which can easily register the color registration in correspondence with the fan-out of the printing paper without using the fan-out vise unlike the related art. Can be obtained. Further, according to the present embodiment, there is an advantage that it is possible to cope with the fan-out of the printing paper by simpler control than in the first embodiment.

The first embodiment is particularly applicable to a fan-out that deforms in a trapezoidal shape from the front to the rear end, such as the fan-out of a sheet printed by a sheet-fed printing press. Although a printing plate made by a control pattern is preferable, the present invention is applied to 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. A printing plate made by a control pattern of the form is preferable.

Although the two embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be variously modified and implemented without departing from the gist of the present invention. Needless to say. For example,
According to the configuration of the plate making apparatus according to the above-described embodiment, the drawing frequency and the drawing start time can be arbitrarily controlled according to the rotation phase of the laser irradiation mirror 7, so that the pattern is arbitrarily deformed in the width direction. be able to. Therefore, the control pattern for controlling the drawing frequency and the delay time of the drawing start timing is not limited to those in the above-described embodiments, and an arbitrary control pattern is set according to the fan-out state of the printing paper. It is possible.

Further, according to the configuration of the plate making apparatus according to the above-described embodiment, the zero point of the rotation phase of the laser beam is detected by the optical sensor 2 and the rotation speed of the polygon mirror 6 is constant. The rotation phase of the laser beam can be calculated based on the elapsed time from the point detection. Therefore, not only the drawing frequency can be changed according to the rotation phase of the laser irradiation mirror 7, but also the drawing frequency can be changed according to the rotation phase of the laser beam in the main scanning. This makes it possible to make a printing plate in which a picture is partially deformed in the width direction.

Further, the conversion coefficient used in the pulse period-speed conversion device 15 may be variably set according to the rotation phase of the laser irradiation mirror 7. This makes it possible to change the sub-scanning speed due to the rotation of the laser irradiation mirror 7 in accordance with the rotation phase of the laser irradiation mirror 7, and to make a printing plate whose picture is partially deformed in the vertical direction. Will be possible. In this case, it is preferable that the setting pattern (control pattern) of the conversion coefficient according to the rotation phase of the laser irradiation mirror 7 is easily stored in advance in the database 18 for each printing condition.

In the above-described second embodiment, the delay amount of the drawing start time is set in accordance with the drawing frequency. However, the position of the printing plate in the width direction can be adjusted when the printing plate is mounted on the printing press. For example, the delay amount may be constant regardless of the drawing frequency. Further, in the above-described embodiment, the sub-scanning is performed by rotating the laser irradiation mirror 7. However, the laser irradiation mirror 7 may be rotated relatively to the raw plate 5. 7 is to rotate the drum 3 in a fixed state,
It is also possible to rotate both of them.

[0063]

As described above in detail, according to the plate making apparatus (first plate making apparatus) of the present invention, the drawing speed of the dot pattern is controlled in accordance with the rotation phase, so that the pattern in the horizontal width direction can be obtained. The enlargement ratio can be set arbitrarily in the vertical direction, and the drawing start timing for each main scan is controlled according to the rotation phase of the laser irradiation port with respect to the raw plate, so that the drawing position in the left and right width direction of the pattern is Since it can be set arbitrarily in the vertical direction, it is possible to draw a pattern that has been transformed into an arbitrary shape in the left and right width direction with respect to the sample pattern on the raw plate, and it can be easily adapted to the fan-out of printing paper There is an effect that it is possible to obtain a printing plate capable of registering colors.

In particular, by performing control so that the drawing speed and the delay amount of the drawing start timing are substantially proportional to each other, the picture can be deformed symmetrically in the left-right width direction, and symmetrically in the left-right width direction. There is an effect that it is possible to obtain a printing plate corresponding to a great fan-out. In addition, the drawing speed is monotonously decreased from the reference speed in accordance with the rotation of the laser irradiation port with respect to the raw plate, and the control is performed so that the delay amount of the drawing start time is monotonically decreased from the reference delay amount, so that the pattern can be shifted right and left. It can be symmetrically deformed into a trapezoidal shape, and it is possible to obtain a printing plate compatible with fan-out that spreads symmetrically in a trapezoidal shape in the left and right width direction from the mouth side to the butt side. is there. In particular, by performing control such that the drawing speed and the delay amount of the drawing start timing are monotonically reduced for each main scan, the distortion is not generated in the left-right width direction, so that the left-right width from the top of the grip to the bottom of the grip is obtained. Has the effect that a pattern enlarged smoothly can be drawn.

Further, according to another plate making apparatus (second plate making apparatus) of the present invention, the drawing speed of the dot pattern is controlled based on a predetermined control pattern corresponding to the printing condition, thereby controlling the printing speed according to the printing condition. Since a pattern that is deformed in the width direction of the sample pattern can be drawn on the raw plate, it is possible to obtain a printing plate that can easily register the color registration in correspondence with the fan-out of printing paper. There is an effect that it becomes possible.

In particular, the drawing start timing for each main scan is also controlled based on a predetermined control pattern according to the printing conditions, so that the sample pattern can be arbitrarily deformed in the left-right direction in the raw plate according to the printing conditions. This makes it possible to obtain a printing plate that can draw a drawn pattern and that can more easily register the colors in correspondence with the fan-out of printing paper.

The control pattern of the drawing speed and the control pattern of the drawing start time are stored in the database for each printing condition according to the fan-out in the width direction of the printing paper. By controlling the drawing speed and the drawing start timing based on the pattern, it is possible to easily obtain a printing plate according to the printing conditions.

Further, according to another plate-making apparatus (third plate-making apparatus) of the present invention, the rotation speed of the laser irradiation port with respect to the raw plate is controlled based on a predetermined control pattern corresponding to the printing conditions, thereby enabling printing. According to the conditions, it is possible to draw on the raw plate a pattern that is deformed in the vertical direction with respect to the sample pattern, and obtain a printing plate that can easily match the color registration according to the fan-out of the printing paper The effect is that it becomes possible.

In particular, a control pattern of the rotation speed of the laser irradiation port with respect to the raw plate is stored in the database for each printing condition according to the fan-out of the printing paper in the width direction, and the control pattern retrieved from the database is stored in the database. By controlling the rotation speed of the laser irradiation port with respect to the raw plate on the basis of this, there is an effect that it is possible to easily obtain a printing plate according to printing conditions.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating a configuration of a plate making apparatus according to a first embodiment of the present invention.

FIG. 2 is a time chart showing an output pattern of a laser beam in one scanning cycle according to the first embodiment of the present invention.

FIG. 3A is a diagram illustrating a control pattern of a drawing frequency according to the first embodiment of the present invention, and FIG. 3B is a diagram illustrating a control pattern of a delay time of a drawing start speed.

4A and 4B are diagrams showing a drawing state of a picture by the control pattern of FIG. 3, wherein FIG. 4A shows a drawing line on a raw plate;
(B) is a diagram showing a drawing area of a picture.

FIG. 5 is a diagram for explaining setting of a change rate of a drawing frequency according to the first embodiment of the present invention, and is a diagram illustrating a state of a shift of a drawn dot between scans.

6A and 6B are diagrams showing a drawing state of a picture when the drawing speed is further changed in FIG. 4, wherein FIG. 6A shows a drawing line on a raw plate, and FIG. 6B shows a drawing area of the picture. FIG.

FIG. 7A is a diagram illustrating a control pattern of a drawing frequency according to a second embodiment of the present invention, and FIG. 7B is a diagram illustrating a control pattern of a delay time of a drawing start speed.

8A and 8B are diagrams showing a drawing state of a picture by the control pattern of FIG. 7, and FIG. 8A is a diagram showing a drawing line on a raw plate;
(B) is a diagram showing a drawing area of a picture.

9A is a diagram showing a schematic configuration of a conventional general inner drum type plate making apparatus, and FIG. 9B is a view showing a drawing state of a pattern by the plate making apparatus 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.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser writing device 2 Optical sensor 3 Drum 4 Laser output device 5 Raw plate 6 Polygon mirror 6a Polygon motor 7 Laser irradiation mirror 8 Fine speed motor 9 Polygon motor drive device 10 Control device 11 Image data generation device for printing 12 Image buffer 13 Laser driver 14 Image start trigger generator 15 Drawing clock generator 16 Low-speed motor drive 17 Search device 18 Database 19 Pulse period-speed converter 20 Laser phase device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H084 AE03 AE09 2H097 AA03 AA16 AB08 BA10 BB01 CA17 LA01

Claims (9)

[Claims] 1. A plate making apparatus for making a printing plate for printing a picture on a printing paper, comprising: a support means having a cylindrical space and supporting a raw plate on an inner peripheral surface of the cylindrical space; A laser irradiation port disposed toward the inner peripheral surface of the space, and is supported on the inner peripheral surface of the cylindrical space by selectively irradiating a laser beam from the laser irradiation port based on digital data of a sample picture. Pattern drawing means for drawing a dot pattern of a pattern on a raw plate, and by rotating the irradiation direction of a laser beam from the laser irradiation port in a plane parallel to the axis of the cylindrical space, in the width direction of the raw plate Main scanning means for performing main scanning of the original plate; and sub-scanning for performing vertical scanning of the original plate by rotating the laser irradiation port relative to the original plate about an axis of the cylindrical space. Means, and a dot pattern by the picture drawing means. A drawing speed control means for controlling a drawing speed in accordance with a rotation phase of the laser irradiation port with respect to the raw plate; and a drawing start timing of the laser irradiation port with respect to the raw plate for each main scan by the picture drawing means. A plate-making apparatus, comprising: a drawing start timing control unit that controls the drawing in accordance with the timing. 2. The method according to claim 1, wherein said drawing speed controlled by said drawing speed control means and a delay amount of said drawing start timing controlled by said drawing start timing control means are substantially proportional to each other. Item 2. A plate making apparatus according to Item 1. 3. The drawing speed control means monotonically reduces the drawing speed from a reference speed as the laser irradiation port rotates relative to the raw plate. 3. The plate making apparatus according to claim 2, wherein the delay amount of the drawing start timing is monotonously decreased from a reference delay amount as the plate rotates relative to the raw plate. 4. The drawing speed control means and the drawing start timing control means monotonically decrease the drawing speed or the delay amount of the drawing start timing for each main scan by the main scanning means. The plate making apparatus according to claim 3, wherein 5. A plate making apparatus for making a printing plate for printing a picture on a printing paper, comprising: a support means having a cylindrical space and supporting a raw plate on an inner peripheral surface of the cylindrical space; A laser irradiation port disposed toward the inner peripheral surface of the space, and is supported on the inner peripheral surface of the cylindrical space by selectively irradiating a laser beam from the laser irradiation port based on digital data of a sample picture. Pattern drawing means for drawing a dot pattern of a pattern on a raw plate, and by rotating the irradiation direction of a laser beam from the laser irradiation port in a plane parallel to the axis of the cylindrical space, in the width direction of the raw plate Main scanning means for performing main scanning of; a sub-scanning means for performing vertical scanning of the raw plate by rotating the laser irradiation port around an axis of the cylindrical space; and dots by the picture drawing means. Adjust the pattern drawing speed according to the printing conditions. A drawing speed control means for controlling based on the predetermined control pattern. 6. A drawing start time control means for controlling a drawing start time for each main scan by the picture drawing means based on a predetermined control pattern in accordance with a printing condition. Plate making equipment. 7. An input means for inputting printing conditions, and a control pattern of the drawing speed by the drawing speed control means and a control pattern of the drawing start time by the drawing start time control means in a width direction of the printing paper. A database stored for each printing condition according to the fan-out; and a search unit for searching the database for each control pattern corresponding to the printing condition input via the input unit. 7. The plate making apparatus according to claim 6, wherein the drawing start timing control means controls the drawing speed or the drawing start timing based on the control patterns searched by the search means, respectively. 8. A plate making apparatus for making a printing plate for printing a picture on a printing paper, comprising: a support means having a cylindrical space and supporting a raw plate on an inner peripheral surface of the cylindrical space; A laser irradiation port disposed toward the inner peripheral surface of the space, and is supported on the inner peripheral surface of the cylindrical space by selectively irradiating a laser beam from the laser irradiation port based on digital data of a sample picture. Pattern drawing means for drawing a dot pattern of a pattern on a raw plate, and by rotating the irradiation direction of a laser beam from the laser irradiation port in a plane parallel to the axis of the cylindrical space, in the width direction of the raw plate Main scanning means for performing main scanning of the original plate; and sub-scanning for performing vertical scanning of the original plate by rotating the laser irradiation port relative to the original plate about an axis of the cylindrical space. Means, and said laser irradiation port by said sub-scanning means. A plate making apparatus comprising: a rotation speed control unit that controls a rotation speed of a raw plate based on a predetermined control pattern according to a printing condition. 9. An input unit for inputting printing conditions, a database storing the control pattern of the rotation speed by the rotation speed control unit for each printing condition in accordance with a fan-out in a width direction of the printing paper, and Search means for searching the database for a control pattern corresponding to the printing condition input via the means, wherein the rotation speed control means controls the rotation speed based on the control pattern searched by the search means. The plate making apparatus according to claim 8, wherein: