JP2001322231A - Method and apparatus for on-press imaging lithography printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for on-press imaging lithography printing capable of dealing with digital image data and rapidly printing many printed products of a clear image at a low cost. SOLUTION: The method for on-press imaging lithography printing comprises the steps of mainly scanning by rotating a plate cylinder for mounting a plate material in the case of imaging by using an ink jet method for discharging an ink containing a lipophilic component from a recording head having a plurality of discharging channels, and continuously sub-scanning the head by using the head having the channels of [X*(N/K)+1] [pieces] at a constant speed [X*(N/K)+1] [dots/one circumference], wherein N[dots/25.4 mm] is an imaging resolution on the plate material in the sub-scanning direction, K [dots/25.4 mm] is a channel density of the head in the sub-scanning direction and X is an arbitrary positive integer, in the case of imaging while moving the head in parallel direction (sub-scanning direction) with an axis of the cylinder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing method for performing digital plate making on an on-press drawing press and a printing apparatus therefor, and more particularly, to plate making quality and printing using an ink containing at least a lipophilic component. Plate making with good image quality
The present invention relates to a printing method and a printing apparatus.

[0002]

2. Description of the Related Art In lithographic printing, printing is performed by providing an ink receptive area and an ink repellent area on the surface of a printing plate corresponding to an image original, and attaching printing ink to the ink receiving area. Normally, hydrophilic and lipophilic (ink-receptive) regions are formed imagewise on the surface of the printing plate, and the fountain solution is used to make the hydrophilic region ink-repellent.

Recording an image on a printing original plate (plate material) (plate making)
Prints the image original in analog or digital form on a silver halide photographic film, and then exposes the diazo resin or photopolymerizable photopolymer photosensitive material on the printing original plate,
It is a general method to perform elution and removal of the non-image area mainly using an alkaline solution.

In recent years, in the lithographic printing method, due to the recent improvement in digital drawing technology and the demand for more efficient processes,
Many systems for directly drawing digital image information on a printing plate have been proposed. This is CTP (Computer-t
o-Plate) or DDPP (Digial Direct Printin)
g Plate). As a plate making method,
For example, there is a system for recording an image in a light mode or a heat mode by using a laser, and some of the systems have been put into practical use.

However, in this plate making method, in both the optical mode and the thermal mode, generally, after the laser recording, the plate is processed by dissolving and removing the non-image portion by treating with an alkaline developer to discharge the alkaline waste liquid. , Not preferable for environmental protection.

Further, there is a method using the above-mentioned laser, but it is expensive and large. Therefore,
Attempts have been made to apply a system using an inkjet method, which is an inexpensive and compact drawing apparatus.

Japanese Patent Application Laid-Open No. 64-27953 discloses a method of performing plate making by drawing with an ink jet using a lipophilic wax ink as a hydrophilic plate material.

Japanese Patent Application Laid-Open No. 11-70632 discloses a method of performing plate making by drawing an image on a hydrophilic plate material using an aqueous solution or aqueous colloidal dispersion of a hydrophobic organic acid salt by inkjet. Have been.

However, in the above-described method, it is necessary to manually set the obtained printing plate on a plate cylinder of an offset printing press after performing plate making, so that a long time is required for loading, and in particular, printing of a plurality of colors is performed. , The problem of color misregistration is likely to occur.

Further, as a means for improving the efficiency of the printing process, there is a system for performing image drawing on a printing machine by applying an ink jet method.

Japanese Patent Application Laid-Open No. Hei 4-97848 discloses a system for performing such image drawing on a printing press. In this method, a surface drum is provided with a hydrophilic or lipophilic plate drum in place of a conventional plate cylinder, and an lipophilic or hydrophilic image is formed thereon by an ink jet method, and the image formed in this manner is formed. , And after the printing is completed, the image is cleaned and removed. However, this method has a disadvantage in that it is difficult to achieve both removal of a printed image (that is, ease of cleaning) and printing durability.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to firstly provide a digitally compatible lithographic printing method and printing apparatus which does not require development processing. To provide. Second, it is an object of the present invention to provide a lithographic printing method and a printing apparatus capable of printing a large number of prints of particularly clear and high-quality images with an inexpensive apparatus and a simple method.

[0013]

In order to achieve the above object, according to the invention of an on-press lithographic printing method according to claim 1 of the present application, a plate material is mounted on a plate cylinder of a printing press, and the plate material is removed. The recording head is subjected to main scanning by the rotation of a mounted plate cylinder, and the recording head is ejected from a recording head having a plurality of ejection channels based on a signal of image data from a recording head having a plurality of ejection channels. By moving in the direction parallel to the axis of the plate cylinder and performing drawing while performing sub-scanning, an image is formed directly on the surface of the plate material to create a printing plate, and lithographic printing is continued using the plate material in that state. In the on-press drawing lithographic printing method, the printing resolution on the plate material in the direction perpendicular to the plate cylinder rotation is N [dot / 25.4 mm], and the channel density in the printing cylinder rotation and the vertical direction is K [dot / dot]. 25.4 mm], When a positive integer of intent was X, [X
* (N / K) +1] [print heads] are used, and the sub-scanning movement of the print head is performed at the speed [X
* (N / K) +1] [dot / one round] and is performed continuously and at a constant speed. According to a second aspect of the present invention, in the on-press lithographic printing method according to the first aspect, the plate material is drawn before and / or during drawing on the plate material by the ink jet method using a recording head. The present invention is characterized in that dust existing on the surface is removed and / or at least after the completion of plate making, the recording head is cleaned. Further, according to the invention of the on-press lithographic printing apparatus according to the third aspect, the lipophilicity of the recording head having a plurality of ejection channels based on the image data signal on the plate material mounted on the plate cylinder of the printing press. On-press machine equipped with image forming means for directly forming an image by an ink jet drawing apparatus having a recording head for discharging ink containing components, and lithographic printing means for performing lithographic printing on a printing plate formed by the image forming means In the drawing printing apparatus, the image forming unit performs main scanning by rotating a plate cylinder on which the plate material is mounted, and performs sub-scanning by moving the recording head in a direction parallel to the axis of the plate cylinder. The image resolution on a plate material in the direction perpendicular to the plate cylinder rotation is N [dot / 25.4 m
m], K (dot / 25.4 mm) the channel density in the vertical direction with respect to the plate cylinder rotation of the recording head, and X as an arbitrary positive integer.
When a recording head having (X * (N / K) +1) [number] ejection channels is used, the sub-scanning movement of the recording head is performed at a speed (X * (N / K) +1) [dot / 1]. Lap]
, And is characterized in that it is performed continuously and at a constant speed. According to a fourth aspect of the present invention, in the on-press lithographic printing apparatus according to the third aspect, the image forming means exists on the plate material surface before and / or during the drawing on the plate material. The present invention is characterized in that a plate material surface dust removing means for removing dust is provided. According to the invention described in claim 5, in the on-press lithographic printing apparatus according to claim 3 or 4, the ink jet drawing apparatus causes the recording head to approach the plate cylinder when drawing on the plate material, A recording head separation / contact means for separating the recording head from the plate cylinder except when drawing on the plate material is provided. According to a sixth aspect of the present invention, in the on-press lithographic printing apparatus according to any one of the third to fifth aspects, the recording head performs cleaning of the recording head at least after the completion of plate making. A cleaning means is provided. According to a seventh aspect of the present invention, in the on-press lithographic printing apparatus according to any one of the third to sixth aspects, the lithographic printing means removes paper dust generated during lithographic printing. It is characterized by having means.
As described above, according to the present invention, when performing drawing using an inkjet method in which an ink containing a lipophilic component is ejected from a recording head having a plurality of ejection channels,
The main scanning is performed by rotating the plate cylinder with the plate material mounted, and the recording head is continuously moved at a constant speed in the direction parallel to the axis of the plate cylinder, and drawing is performed while performing sub-scanning. Sheet printing can be performed, and a printing plate corresponding to digital image data can be stably produced with high image quality directly on a printing machine, and low-cost, high-speed lithographic printing can be performed.

[0014]

Embodiments of the present invention will be described below in detail. The present invention is characterized in that an image is formed on a printing original plate (plate material) provided on a plate cylinder of a printing press by an inkjet method of discharging ink containing at least a lipophilic component. As the inkjet method according to the present invention, any method can be used as long as an ink containing a lipophilic component can be ejected.

More specifically, for example, “Imaging part 2 Latest Hard Copy Printer Technology” edited by the Society of Electrophotography, Chapter 3 Photographic Industry Publishing Company (1988), edited by Hiroshi Komon “Recording and Storage Technology Handbook”, Maruzen Co., Ltd. 19
1992), etc., which can be used, such as a piezo method, a thermal jet method, an electrostatic method, and a discharge method. Also, JP-A-10-175300, JP-A-6-175300
-23986, JP-A-5-131633,
JP-A-10-114073, JP-A-10-349
No. 67, JP-A-3-104650, JP-A-8
A system in which these are applied or combined, such as Japanese Patent Publication No. 300803, is also preferably used. As described above, according to the present invention, by performing plate making on a printing machine by an ink jet method, it is possible to print a large number of clear and high-quality printed images with an inexpensive apparatus and a simple method.

An example of the configuration of an on-press lithographic printing apparatus used for carrying out the lithographic printing method of the present invention will be described below.

FIG. 1 to FIG. 3 are overall structural views of an on-machine drawing single-color single-sided lithographic printing apparatus according to the present invention. FIG. 4 is a schematic configuration example of a drawing unit including a control unit, an ink supply unit, and a head separation / contact mechanism of the on-press lithographic printing apparatus of FIGS. FIG.
Indicates a head protection cover which is a specific example of the head protection means. FIGS. 6 and 7 show an example of an ink jet recording apparatus provided in the on-press lithographic printing apparatus shown in FIGS. 1 and 8. FIG. 8 is an example of the overall configuration of an on-press four-color single-sided planographic printing apparatus according to the present invention. 9 and 10 are explanatory diagrams for describing the sub-scanning control used in the present invention.

First, the printing process according to the present invention will be described with reference to the overall configuration diagram of the on-press drawing single-color single-sided lithographic printing press shown in FIG. As shown in FIG. 1, an on-press lithographic printing apparatus 1 (hereinafter, also referred to as a “printing apparatus”) includes a plate cylinder 11,
It has a blanket cylinder 12 and an impression cylinder 13 one by one, and is arranged so that the blanket cylinder 12 for transfer is pressed against the plate cylinder 11 at least when performing lithographic printing;
The blanket cylinder 12 is provided with an impression cylinder 13 for transferring the printing ink image transferred thereto to the printing paper P so as to be pressed against the blanket cylinder 12. FIG. 2 shows another configuration example of the printing apparatus according to the present invention. The printing apparatus is entirely covered with a hood F. The hood F has an intake port I and an exhaust port O, and a dustproof filter (not shown) is attached to the intake port I and the exhaust port O. It is desirable to provide a fan or the like in the hood in order to forcibly intake and exhaust air. Further, a solvent vapor removing device may be attached so as to prevent the solvent vapor used for the ink described below from being emitted to the outside of the hood. This eliminates the need to discharge the solvent vapor to the outside and eliminates problems such as generation of odor. It can be a good printing device. Although the entire printing apparatus is covered with the hood F in FIG. 2, the hood may cover only a part of the printing apparatus as shown in FIG. 3, and the present invention is not limited to this embodiment.

The plate cylinder 11 is usually made of metal, and its surface is plated with, for example, chromium to enhance abrasion resistance, but may have a heat insulating material on its surface as described later. . On the other hand, when using the electrostatic ink jet, the plate cylinder 11 is preferably grounded because it serves as a counter electrode of the recording head electrode. If the substrate of the plate material has a high insulating property, a conductive layer may be provided on the substrate. In this case, it is desirable to provide a means for grounding the plate cylinder from the conductive layer. In that case, a known means such as a brush, a leaf spring, or a roller having conductivity can be used.

Further, the printing apparatus 1 has an ink jet recording apparatus 2, and the
In accordance with the image data sent from the printer, an ink containing a lipophilic component is ejected onto the plate material 9 mounted on the plate cylinder 11 to form an image.

Further, the printing apparatus 1 is provided with a dampening water supply device 3 for supplying dampening water to a hydrophilic portion (non-image portion) on the printing plate 9. FIG. 1 shows a Molton water supply system as a representative example of the dampening water supply device 3. However, as the dampening water supply device 3, other known devices such as a synflo water supply system and a continuous water supply system can be used. Further, the printing device 1
The printing apparatus includes a printing ink supply device 4 and, if necessary, a fixing device 5 for strengthening an ink image drawn on the plate material 9. If necessary, a plate surface desensitizing device 6 may be provided for the purpose of enhancing the hydrophilicity of the surface of the plate material 9. Further, the printing apparatus 1 includes a dust removing unit 10 for removing dust existing on the surface of the plate material before or / and during drawing on the plate material.
Known dust removal means include suction removal, blow-off removal,
In addition to a non-contact method such as static removal, a contact method using a brush, a roller, or the like can be used.
Alternatively, it is used by blowing off with air or a combination thereof. In this case, an air pump usually used for a paper feeding device can be used for this purpose.

Further, there is provided an automatic plate feeding device 7 for automatically supplying the plate material 9 to be printed onto the plate cylinder 11 and an automatic plate discharging device 8 for automatically removing the plate material 9 after printing from the plate cylinder 11. A printing press having this device, which may be installed and is known as an auxiliary device for the printing press, such as the Hamada VS3
4A, B452A (Hamada Printing Machinery Co., Ltd.), Toko 8000 PFA (Tokyo Aviation Instruments), Ryobi 32
00ACD, 3200 PFA (Ryobi Magics Co., Ltd.), AMSIS Multi 5150FA (Nippon Am Co., Ltd.), Oliver 266EPZ (Sakurai Graphic Systems Co., Ltd.), Shinohara 66IV / IVP (Shinohara Shoji Co., Ltd.) and the like. Further, a blanket cleaning device 14 and an impression cylinder cleaning device 14 'may be provided. These automatic plate feeding device 7, automatic plate discharging device 8, and both cleaning devices 1
By using 4, 14 ', the printing operation becomes simpler and the printing time is shortened, so that the effect of the present invention can be further enhanced. In addition, it is preferable to install a paper dust generation prevention device 15 near the impression cylinder 13, so that paper dust adhering to the plate material can be prevented. As the paper dust generation preventing device 15, a method such as humidity control, suction by air or electrostatic force, or the like can be used.

The image data arithmetic control unit 21 receives image data from an image scanner, a magnetic disk device, an image data transmission device, etc., performs color separation, and has an appropriate number of pixels and gradation for the separated data. Divide into numbers. Further, in order to draw an ink image by using an ink jet recording head 22 (refer to FIG. 4 and described in detail later) included in the ink jet recording apparatus 2, a calculation of a dot area ratio is also performed.

As will be described later, the image data calculation control unit 21 controls the movement of the ink jet recording head 22 and the timing of ink ejection, and, if necessary, the plate cylinder 11, blanket cylinder 12, impression cylinder 13 and the like. The operation timing is also controlled.

With reference to FIGS. 1 to 3 and a part of FIG. 4, a printing plate making process by the printing apparatus 1 will be described in detail below.

First, the plate material 9 is mounted on the plate cylinder 11 by using the automatic plate feeding device 7. At this time, the plate material is closely fixed on the plate cylinder by a mechanical method using a known plate head / butt holding device, an air suction device, or the like, or an electrostatic method. It is possible to prevent the ink jet recording apparatus 2 from being damaged by contact with the ink jet recording apparatus 2. Further, a means for bringing the plate material into close contact with the plate cylinder only around the drawing position of the ink jet recording apparatus is provided, and at least at the time of drawing, the plate material can be prevented from coming into contact with the ink jet recording apparatus by acting. . Specifically, for example, there is a method of disposing a pressing roller upstream and downstream of the plate cylinder drawing position. In addition, in the process of fixing the printing plate, by providing a printing plate non-contact means for preventing the printing plate from contacting the ink supply roller, it is possible to prevent the printing plate from being stained and to reduce waste paper. Specifically, a pressing roller, a guide, electrostatic attraction, or the like is effective.

Image data from a magnetic disk device or the like
The image data calculation control unit 21 calculates the ejection position of the ink containing the lipophilic component and the dot area ratio at that position in accordance with the input image data. These calculation data are temporarily stored in the buffer. The image data calculation control unit 21 rotates the plate cylinder 11 as shown in FIG. 4 and moves the recording head 22 to a position close to the plate cylinder 11 by the head separation / contact device 31.
The distance between the recording head 22 and the surface of the plate material 9 on the plate cylinder 11 is
A predetermined distance is maintained during drawing by mechanical distance control such as a contact roller or control of a head separation / contact device by a signal from an optical distance detector. A multi-channel head is used as the recording head 22, and the main scanning is performed by rotating the plate cylinder 11. In that case, the arrangement direction of the discharge units is set in the axial direction. Further, the image data calculation control unit 2
1, the head 22 is continuously moved in the axial direction of the plate cylinder while rotating the plate cylinder 11 at a predetermined constant rotational speed,
The ink is discharged onto the plate material 9 mounted on the plate cylinder 11 at the discharge position and the dot area ratio obtained by the above calculation. As a result, a halftone dot image corresponding to the density of the print document is drawn on the plate material 9 with ink. This operation is continued until an ink image for one color of the printing original is formed on the plate material 9 and the printing plate is completed.
In this way, by performing main scanning by plate cylinder rotation,
The position accuracy in the main scanning direction can be improved, and high-speed drawing can be performed.

Next, in order to protect the recording head 22,
Except for drawing, the recording head 22 is retracted away from a position close to the plate cylinder 11. At this time, only the recording head 22 may be separated and connected, but the recording head 22 and the head sub-scanning unit 32 may be separated and connected together, or the recording head 22 and the ink supply unit 24 and all of the head sub-scanning unit 32 may be separated together. You can also touch. In addition to the recording head 22, the ink supply unit 24, and the head sub-scanning unit 32, the fixing device 5 and the greeting removing unit 10 are also provided with separating / separating units so that they can be retracted and made possible, so that normal printing can be handled.

This separation / contact means operates so as to separate the recording head from the plate cylinder by at least 500 μm except during drawing. The detachment operation may be a slide type, or the head may be fixed by an arm fixed to a certain axis, and the arm may be moved around the axis to move like a pendulum. By retracting the head during non-drawing in this manner, the head can be protected from physical damage or contamination, and a long life can be achieved.

Further, the formed ink image is reinforced by the fixing device 5 as necessary. As the ink fixing means, known means such as heat fixing, solvent fixing, and UV exposure fixing can be used. In the heat fixing, halogen lamp irradiation, hot air fixing using a heater, and heat roll fixing are generally used. In this case, in order to enhance the fixing property, means for heating the plate cylinder, means for preheating the plate material, means for drawing while applying hot air, means for coating the plate cylinder with a heat insulating material, fixing It is effective to use each unit alone or in combination, such as a unit that separates the plate material from the plate cylinder and heats only the plate material only at the time. Flash fixing using a xenon lamp or the like is known as a method for fixing electrophotographic toner, and has an advantage that fixing can be performed in a short time. In solvent fixing, a solvent capable of dissolving the resin component in the ink, such as methanol or ethyl acetate, is sprayed, and excess solvent vapor is collected. UV exposure fixing is useful when using UV inks. At least in the process from the formation of the ink image by the recording head 22 to the fixing by the fixing device 5, the dampening solution supply device 3, the printing ink supply device 4, and the blanket cylinder 12 do not contact the plate material 9 on the plate cylinder. It is desirable to be maintained as follows.

The printing process after the printing plate is formed is the same as the known lithographic printing method. That is, printing ink and dampening water are applied to the plate material 9 on which the ink image containing the lipophilic component is drawn to form a print image, and the print ink image is formed on the blanket cylinder 12 rotating together with the plate cylinder 11. Then, the printing ink image on the blanket cylinder 12 is transferred onto the printing paper P passing between the blanket cylinder 12 and the impression cylinder 13 to print one color. After the printing is completed, the plate material 9 is removed from the plate cylinder 11 by the automatic plate discharging device 8, and the blanket on the blanket cylinder 12 is cleaned by the blanket cleaning device 14 to be ready for the next printing.

Reference numeral 20a denotes digital control means provided for further improving the operability of the on-press lithographic printing apparatus 1 of the present invention.
Plate inspection devices and the like can be mentioned. The ink usage amount display device displays the required amount of ink in advance based on image data, and is very effective when performing plate making continuously as in the printing apparatus 1. In addition, since this apparatus performs on-machine drawing, plate inspection cannot be performed. This plate inspection device compensates for the disadvantage. That is, an image drawn on the plate is detected by a CCD camera or the like installed in the machine, and the plate is displayed on a monitor to enable plate inspection. At this time, it is also possible to further improve the plate inspection property by digital processing as compared with the case of visual observation.

Next, the ink jet recording apparatus 2 will be described in detail with reference to FIG.

As shown in FIG. 4, the planographic printing apparatus 1
The drawing unit used for the inkjet discharge head 2
2. The head protection unit 20b and the ink supply unit 24. The head protection means 20b includes (1) means for preventing foreign matter from adhering to the head, and (2) means for stopping drawing when an abnormality occurs. (1) As a foreign matter adhesion preventing means, for example, there is a head protection cover or the like. That is, when drawing is not performed, the head can be stored in the cover to prevent foreign matter from adhering. FIG. 5 shows an embodiment of the cover according to the present invention. The head 22 is stored in a cover 51 with a shutter 52 as shown in FIG.
2 is opened, and the head 22 is advanced to the drawing position to perform drawing. The inside of the cover 51 can be filled with ink or an ink solvent. In this case, even if drawing is not performed for a long time, trouble due to sticking of the ink to the head 22 can be prevented. (2) As an abnormal occurrence drawing stop means, for example, a dust detection device or an abnormal current detection device for the head is connected to the image data arithmetic control unit 21 and when an abnormal signal is generated from the device, the head is connected to the head. By providing a mechanism for stopping the voltage signal, damage to the head can be prevented. On the other hand, the ink supply unit 24 has an ink tank 25, an ink supply device 26, and an ink density control unit 29. The ink tank 25 may include a stirring unit 27 and an ink temperature management unit 28 as necessary. In this case, the stirring means 27 suppresses precipitation and aggregation of the solid components of the ink. Further, the ink temperature management means 28 is arranged such that a high-quality image can be stably formed without changing the physical properties of the ink due to a change in ambient temperature and without changing the dot diameter. In order to perform high-quality drawing, an ink density control unit 29 is provided as necessary. The ink density is measured by optical detection, physical property measurement such as conductivity measurement, viscosity measurement, or the like, or management based on the number of drawn images. When performing management by physical property measurement, an optical detector, conductivity meter, and viscosity meter are provided alone or in combination in the ink tank or ink flow path, and management based on the output signal and the number of drawn sheets is performed. When this is done, the supply of liquid from the replenishment concentrated ink tank or the dilution ink carrier tank (not shown) to the ink tank is controlled based on the number and frequency of plate making.

As described above, the image data calculation control section 21 calculates the input image data, moves the head by the head separation / contact device 31 or the head sub-scanning means 32, and Installed encoder 3
The timing pulse from 0 is taken in, and the head is driven according to the timing pulse. This allows
Position accuracy in the sub-scanning direction can be improved. The image data calculation control unit 21 further controls the above-described head protection unit 20b. In addition, when performing drawing by the ink jet recording apparatus, the position accuracy in the sub-scanning direction can be improved by using a high-precision driving unit different from the driving unit during printing. Blanket cylinder 12,
It is desirable that only the plate cylinder 11 be driven mechanically separated from the impression cylinder 13 and others. Specifically, for example, there is a method in which the output from a high-precision motor is reduced by a high-precision gear or a steel belt or the like, and only the plate cylinder 11 is driven. When performing high-quality drawing, such high-precision driving means is used alone or in combination.

Next, an example of sub-scanning control according to the present invention will be described with reference to FIGS. However, the present invention is not limited to the following. FIG. 9 shows a channel density (K) having three ejection channels (X = 1).
Is 300 (dots / 25.4 mm), and the printing resolution (N) on the plate material in the vertical direction and plate rotation is 600.
(Dot / 25.4 mm) is an example of a drawing position from the rotation of the first round to the rotation of the sixth round when drawing is performed at;
FIG. 10 is an example generally showing the drawing positions from the rotation of the (n-2) th rotation to the rotation of the (n + 3) th rotation. FIG. 9 shows the dot drawing positions on the plate cylinder in the first cycle, the dot drawing positions on the plate cylinder in the second cycle,. The positions of the dot drawing positions on the plate cylinder in the sixth lap are shown in a flatly developed manner, and are connected continuously from top to bottom in the figure. FIG. 10 is similar. In addition, although actually separated from the first dot in the main scanning direction, the second dot in the main scanning direction,..., The last dot in the main scanning direction, they are represented by lines here. Further, in this drawing, for the sake of simplicity, the drawing is illustrated so as to be drawn on the entire circumference of the plate cylinder. However, in practice, there are usually parts that are not used for drawing, such as the holding portion of the plate material. In FIG. 9, the first
The bold lines 1, 2, and 3 in the circumference indicate the drawing positions of the first, second, and third channels of the head, respectively. The top to bottom of the figure is the main scanning direction, and the left to right of the figure is the sub-scanning direction (in this case, the moving direction of the head). Therefore, the top of each of the thick lines 1, 2, and 3 in the first cycle is the first dot position of each channel in the main scanning direction, and the bottom of each of the thick lines 1, 2, and 3 is the final dot position. Looking at the second cycle, the last dot position (a) of the second cycle drawn by the first channel is the last dot position (b) of the line drawn by the second channel in the first cycle and the first dot. It can be seen that the third channel is located at an intermediate position between each of the last dots (c) of the drawn line on the circumference. That is, the first channel moves three dots in the sub-scanning direction in one round. The other channels also move 3 dots in the sub-scanning direction in one round. Similarly, looking at the third lap, the last dot (d) of the third lap drawn by the first channel is equal to the last dot (e) of the line drawn by the second channel in the second lap. It can be seen that the third channel is located at an intermediate position between each final dot (f) of the drawn line on the circumference. Hereinafter, the same applies. As a result, when looking at the sixth round (the bottom diagram in FIG. 9), it can be seen that the drawing positions of each channel in each round are developed at equal intervals of half the pitch of each channel.
FIG. 9 is a view from the first round, while FIG. 10 is a generalized view of FIG. In FIG. 10, the last dot position drawn by the first channel in the (n-1) th round is located at an intermediate position between the last dots in the second and third channels in the (n-2) th round. As a result, it can be seen that the drawing position of each channel on each circumference is developed at an equal interval of half the pitch of each channel. Above is 1 head 3
This is an example of channels, but even if the number of channels of one head changes, if the movement of the head in the sub-scanning direction is changed accordingly, it is possible to achieve a higher drawing resolution than the channel density of the head in the sub-scanning direction. May be. Here are some examples. 1) The drawing resolution on the plate material in the direction perpendicular to the plate cylinder rotation is 20
0 [dots / 25.4 mm], and the channel density in the vertical direction with respect to the plate cylinder rotation of the recording head was 100 [dots / 25.4 mm].
mm], the movement in the sub-scanning direction may be performed at a speed of 3 dots / periphery if a recording head having three ejection channels is used, and the sub-scanning may be performed if a recording head having five ejection channels is used. Speed of 5 dots /
It is good to go around. Further, in the case of seven ejection channels, the movement in the sub-scanning direction may be performed at a speed of 7 dots / perimeter. For 65 ejection channels, the movement in the sub-scanning direction may be performed at a speed of 65 dots / circle. 2) The image resolving power on the plate material in the direction perpendicular to the plate cylinder rotation is 30
0 [dots / 25.4 mm], and the channel density in the vertical direction with respect to the plate cylinder rotation of the recording head was 100 [dots / 25.4 mm].
mm], if a recording head having four ejection channels is used, the movement in the sub-scanning direction may be performed at a speed of 4 dots / periphery. What is necessary is just to carry out in dots / periphery. Furthermore, the speed may be 10 dots / periphery with ten ejection channels. Further, in the case of a recording head having 97 ejection channels, the movement in the sub-scanning direction may be performed at a speed of 97 dots / circle. 3) The image resolving power on the plate material in the vertical direction with respect to the plate cylinder rotation is 40
0 [dot / 25.4 mm], and the channel density in the vertical direction with respect to the plate cylinder rotation of the recording head was 200 [dot / 25.4].
mm], three ejection channels may be operated at a speed of 3 dots / circle, five ejection channels may be operated at 5 dots / circle, and seven ejection channels may be operated at a speed of 7 dots / circle. You only have to go around. Also 6
In the five ejection channels, the movement in the sub-scanning direction is performed at a speed of 65.
It suffices to perform dot / periphery. 4) The drawing resolution on the plate material in the direction perpendicular to the plate cylinder rotation is 60
0 [dot / 25.4 mm], and the channel density in the vertical direction with respect to the plate cylinder rotation of the recording head was 200 [dot / 25.4].
mm], the movement in the sub-scanning direction may be performed at a speed of 4 dots / periphery when a print head having four ejection channels is used, and in the sub-scanning direction when a print head having seven ejection channels is used. Should be performed at a speed of 7 dots / perimeter. Further, a recording head having 10 ejection channels may be operated at a speed of 10 dots / circle, and a recording head having 97 ejection channels may be operated at a speed of 97 dots / circle. The above is represented by the following general formula. The drawing resolution on the plate material in the direction perpendicular to the plate cylinder rotation is expressed as N [dot / 2
5.4 mm], the channel density in the vertical direction with respect to the plate cylinder rotation of the recording head is K [dot / 25.4 mm], and X is an arbitrary positive integer, and [X * (N / K) +1] [pieces] ], The sub-scanning movement of the recording head may be performed continuously and at a constant speed [X * (N / K) +1] [dots / 1 round]. In this way, according to the present invention, the dot position accuracy in the sub-scanning direction is improved without using an expensive sub-scanning control system as compared with a case where the recording head is sequentially moved, and a favorable Image quality will be obtained.

The recording head 22 may include a maintenance device such as a cleaning unit, if necessary. For example, when the pause state continues or when a problem occurs in image quality, the print head tip is wiped with a flexible brush, a brush, a cloth, or the like, only the ink solvent is circulated, only the ink solvent is supplied, Alternatively, a good drawing state can be maintained by performing means such as sucking the discharge unit while circulating the ink alone or in combination. In order to prevent the ink from sticking, it is effective to cool the head and suppress evaporation of the ink solvent. If the contamination is further severe, the ink is forcibly sucked from the ejection section, the jet of air, ink, or ink solvent is forcibly injected from the ink flow path, or the ultrasonic wave is applied while the head is immersed in the ink solvent. Is also effective, and these methods can be used alone or in combination.

Next, an on-press drawing multicolor planographic printing press will be described as a specific example of the present invention.

FIG. 8 shows an example of the overall configuration of an on-press 4-color single-sided lithographic sheet-fed printing press. As shown in FIG. 8, the four-color single-sided printing apparatus basically prints the plate cylinder 11, blanket cylinder 12, and impression cylinder 13 of the single-color single-sided printing apparatus shown in FIG. The structure is such that it has four at a time. Although not shown, a known transfer cylinder method or the like is used to transfer the printing paper indicated by K in the figure between adjacent impression cylinders. Although a detailed description is omitted, as can be easily imagined from the example of FIG. 8, the other multi-color single-sided printing apparatuses are also basically a plate cylinder 11 and a blanket cylinder 1 of a single-color single-sided printing apparatus.
2. It has a structure in which a plurality of impression cylinders 13 are provided so that printing is performed on the same surface of the printing paper P. When only one color plate is formed on the plate cylinder, only the number of printing colors is required. Plate cylinder,
Has a blanket cylinder. (Such a printing apparatus is called a unit-type printing apparatus.) On the other hand, common impression cylinder printing that shares one impression cylinder having a diameter that is an integral multiple of the plate cylinder diameter with respect to the plate cylinder and blanket cylinder for a plurality of colors. When the present invention is carried out by an apparatus, a plate cylinder for a number of colors to be printed and a blanket cylinder may share one impression cylinder, or a plate cylinder for a plurality of colors and a blanket cylinder share one impression cylinder. A structure may be used in which the number of plate cylinders and blanket cylinders is equal to the number of colors to be printed. In this case, the transfer of the printing paper between the adjacent common impression cylinders uses the known transfer cylinder method or the like. On the other hand, when a plate of a plurality of colors is formed on a plate cylinder, a plate cylinder and a blanket cylinder are required by a value obtained by dividing the number of colors to be printed by the number of plates on one plate cylinder. For example, when plate materials for two colors are prepared on a plate cylinder, four-color printing on one side can be performed by a printing machine having two plate cylinders and two blanket cylinders. In this case, the impression cylinder diameter is the same as the plate cylinder diameter for one color,
The impression cylinder is provided with a means for holding the printing paper until the printing of the required color is completed, if necessary, and the printing paper is transferred between the impression cylinders using a known transfer cylinder method or the like. For example, in the case of a printing press having two plate cylinders and two blanket cylinders each of which creates a plate material for the two colors described above, two-color printing is performed when one of the impression cylinders holds the printing paper and makes two rotations, and then The printing paper is transferred between the impression cylinders, and when the other impression cylinder holds the printing paper and makes two rotations, two-color printing is further performed to complete four-color printing. The number of impression cylinders may be the same as the number of plate cylinders. However, several impression cylinders and blanket cylinders may share one impression cylinder.

On the other hand, when the present invention is embodied as an on-press drawing multicolor double-sided lithographic printing press, a known printing paper reversing means is provided between at least one adjacent impression cylinder of the unit type printing apparatus. A structure in which a plurality of the above-described common impression cylinder type printing apparatuses are arranged and a known printing paper reversing means is provided between at least one adjacent impression cylinder, or the plate cylinder 11 and the blanket cylinder 12 of the single-color single-sided printing apparatus shown in FIG. Are printed on both sides of the printing paper P. In the latter structure, when only one color plate is formed on the plate cylinder, printing is performed on both sides of the printing paper. It has plate cylinders and blanket cylinders for the number of colors required for printing. On the other hand, when a plurality of color plates are formed on the plate cylinder as described above, the number of plate cylinders, blanket cylinders, and impression cylinders can be reduced. Further, when one plate cylinder is shared by several plate cylinders and blanket cylinders, the number of impression cylinders can be further reduced. The plate cylinder is provided with a means for holding printing paper until printing of a required color is completed, if necessary. The details will be omitted because they can be easily understood from the above-described example of the on-press drawing multicolor single-sided lithographic printing press.

The example of the sheet-fed printing press has been described as an embodiment of the on-press drawing multicolor lithographic printing press of the present invention. On the other hand, when the present invention is implemented as an on-press drawing multicolor WEB (rolled paper) lithographic printing press, the above-described unit type and common impression cylinder type can be suitably used. In the case where the present invention is embodied as an on-press drawing multicolor WEB (winding paper) double-sided printing machine, a structure in which a known web reversing means is provided between at least one adjacent impression cylinder in both the unit type and the common impression cylinder type. And a structure having a plurality of printing papers P so that printing is performed on both sides. The BB (blanket-to-blanket) type is the most suitable as an on-press drawing multicolor WEB (winding paper) double-side printing machine. This is a one-color plate cylinder for printing one side of the web, a blanket cylinder (without an impression cylinder) and a one-color plate cylinder for printing the other side, a blanket cylinder (also without an impression cylinder). Have a structure in which the blanket cylinders are pressed against each other during printing for the number of colors.
By passing the EB, multi-color double-sided printing is achieved.

As another example of an on-press lithographic printing press, one blanket cylinder has two plate cylinders, and while printing is being performed, drawing can be performed with the other plate cylinder. . In this case, it is desirable that the drive of the plate cylinder performing drawing is mechanically independent of the blanket. This makes it possible to perform drawing without stopping the printing press. As will be readily understood, this can be applied to an on-press drawing multicolor single-sided lithographic printing press and an on-press drawing multicolor double-sided lithographic printing press.

Although not described to avoid duplication, the hood, the digital control means, and the head protection means are appropriately used in all printing apparatuses to improve the operability of the printing apparatuses.

Next, the plate material (printing plate) used in the present invention will be described.

Examples of the plate material include metal plates such as aluminum and chrome-plated steel plates. In particular, graining,
An aluminum plate having excellent water retention and abrasion resistance on the surface by anodizing treatment is preferable. As an inexpensive plate material, a plate material provided with an image receiving layer on a water-resistant support such as water-resistant paper, plastic film or plastic-laminated paper can be used. The thickness of this plate material is 100 to 3
The thickness of the image receiving layer is suitably in the range of 5 to 30 m.

As the image receiving layer, a hydrophilic layer comprising an inorganic pigment and a binder or a layer which can be made hydrophilic by a desensitizing treatment can be used.

As the inorganic pigment used in the hydrophilic image receiving layer, clay, silica, calcium carbonate, zinc oxide, aluminum oxide, barium sulfate and the like can be used. Further, as a binder, polyvinyl alcohol, starch,
Hydrophilic binders such as carboxymethylcellulose, hydroxyethylcellulose, casein, gelatin, polyacrylate, polyvinylpyrrolidone, and polymethylether-maleic anhydride copolymer can be used. If necessary, a melamine formalin resin, a urea formalin resin, or another crosslinking agent for imparting water resistance may be added.

On the other hand, examples of the image receiving layer used after the desensitization treatment include a layer using zinc oxide and a hydrophobic binder.

The zinc oxide to be used in the present invention may be, for example, zinc oxide, zinc white, or zinc oxide, as described in “Pigment Handbook” edited by Japan Pigment Technical Association, p. 319, Seibundo Co., Ltd. (1968). Any of those commercially available as wet zinc white or activated zinc white may be used.

That is, depending on the starting materials and the production method, zinc oxide may be a dry method called a French method (indirect method), an American method (direct method), or a wet method. For example, Shodo Chemical Co., Ltd. Chemical Co., Ltd., Shirasu Chemical Co., Ltd.,
Examples include those commercially available from Honjo Chemical Co., Ltd., Toho Zinc Co., Ltd., and Mitsui Kinzoku Kogyo Co., Ltd.

Specific examples of the resin used as the binder include styrene copolymers, methacrylate copolymers,
Examples include an acrylate copolymer, a vinyl acetate copolymer, polyvinyl butyral, an alkyd resin, an epoxy resin, an epoxy ester resin, a polyester resin, and a polyurethane resin. These resins may be used alone or 2
More than one species may be used in combination.

The content of the resin in the image receiving layer is preferably from 9/91 to 20/80 in terms of the weight ratio of resin / zinc oxide.

Desensitization of zinc oxide is carried out by a conventional method using a desensitizing solution. Conventionally, this type of desensitizing solution contains a cyanide compound containing a ferrocyanate salt or a ferricyanate as a main component. Treatment liquid, cyanide-free treatment liquid mainly composed of ammine cobalt complex, phytic acid and its derivatives, guanidine-induced isomer, treatment liquid mainly composed of inorganic acid or organic acid that forms chelate with zinc ion, or water-soluble Processing solutions containing polymers are known.

For example, as a cyanide-containing treatment solution,
JP-B-44-9045 and JP-B-46-39403, JP-A-52-76101 and JP-A-57-1078.
Nos. 89, 54-117201 and the like.

The surface of the plate material opposite to the image receiving layer is
The Beck smoothness is preferably in the range of 150 to 700 (sec / 10 cc). As a result, the formed printing plate does not shift or slip on the plate cylinder even during printing,
Good printing is performed.

The Beck smoothness can be measured by a Beck smoothness tester. A Beck Smoothness Tester is a tester in which a test piece is placed at a constant pressure (1 kgf / cm ² , 9.8 N / c) on a highly smooth finished circular glass plate with a hole in the center.
m ² ) and measure the time required for a fixed amount (10 cc) of air to pass between the glass surface and the test piece under reduced pressure.

The lipophilic component contained in the ink of the present invention is preferably a hydrophobic resin or wax having a good affinity for the ink solvent. Hydrophobic resin dissolves in ink solvent

When the resin is used as the lipophilic component, the weight average molecular weight Mw of the resin is from 1 * 10 ² to 1 * 10 ⁶ , preferably from 5 * 10 ² to 8 * 10 ⁵ , more preferably from 1 * 10 ² to 8 * 10 ⁵ . * 10 ^{3 to} 5 * 10 ⁵ . Or it may be dispersed as a solid.

Specific examples of such resins include olefin polymers and copolymers (eg, polyethylene, polypropylene, polyisobutylene, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, ethylene-methacrylate copolymer). , Ethylene-methacrylic acid copolymer, etc.), vinyl chloride polymer and copolymer (for example,
Polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, etc.), vinylidene chloride copolymer, vinyl alkanoate polymer and copolymer, allyl alkanoate polymer and copolymer, styrene and its derivatives Polymers (eg, butadiene-styrene copolymer, isoprene-styrene copolymer, styrene-methacrylate copolymer, styrene-acrylate copolymer, etc.), acrylonitrile copolymer, methacrylonitrile copolymer, alkyl vinyl ether copolymer Coalesce, acrylate polymer and copolymer, methacrylate polymer and copolymer, itaconic diester polymer and copolymer, maleic anhydride copolymer, acrylamide copolymer, methacrylamide copolymer, Phenol resin, alkyd resin, polycarbonate Resin, ketone resin, polyester resin, silicone resin, amide resin, hydroxyl- and carboxyl-modified polyethyl resin, butyral resin, polyvinyl acetal resin, urethane resin, rosin resin, hydrogenated rosin resin, petroleum resin, hydrogenated petroleum resin, Maleic acid resin, terpene resin, hydrogenated terpene resin, cumarone-indene resin, cyclized rubber-methacrylic acid ester copolymer, cyclized rubber-acrylic acid ester copolymer, copolymer containing nitrogen-free heterocycle Polymers (for example, heterocycles such as a furan ring, a tetrahydrofuran ring, a thiophene ring, a dioxane ring, a dioxofuran ring, a lactone ring, a benzofuran ring, a benzothiophene ring, and a 1,3-dioxetane ring), an epoxy resin, and the like.

The content of the dispersed resin in the ink of the present invention is preferably 0.5 to 20% by weight of the whole ink. If the content is low, problems such as a decrease in printing durability are likely to occur.On the other hand, if the content is high, it is difficult to obtain a uniform dispersion, or ink is easily clogged in the recording head, and stable. It is difficult to obtain a proper ink discharge.

On the other hand, examples of the use of wax as a lipophilic component include compounds used in solid ink jet printing, which are disclosed in JP-A-2-69282,
JP-A-5-186723, JP-A-6-20636
8, US Pat. No. 3,653,932, 37
No. 15219, No. 4390369, No. 4
No. 484948, No. 4659383, No. 4684956, No. 4830671,
No. 4,889,560, No. 4,889,761, No. 4,992,304, and No. 5,084,099.

It is preferable that the ink used in the present invention contains a coloring material as a coloring component together with the lipophilic component for the purpose of plate inspection of the plate after plate making.

As the coloring material, any pigments and dyes conventionally used in ink compositions or liquid developers for electrostatography can be used.

As the pigment, those generally used in the technical field of printing can be used irrespective of inorganic pigments and organic pigments. Specifically, for example, carbon black, cadmium red, molybdenum red, chrome yellow, cadmium yellow, titanium yellow, chromium oxide, viridian, cobalt green, ultramarine blue, Prussian blue, cobalt blue, azo pigment, phthalocyanine pigment , Quinacridone-based pigments, isoindolinone-based pigments, dioxazine-based pigments, threne-based pigments, perylene-based pigments, perinone-based pigments, thioindigo-based pigments, quinophthalone-based pigments, metal complex pigments, and other known pigments. It can be used without.

As the dye, azo dye, metal complex dye,
Naphthol dye, anthraquinone dye, indigo dye,
Dyes such as a carbonium dye, a quinone imine dye, a xanthene dye, an aniline dye, a quinoline dye, a nitro dye, a nitroso dye, a benzoquinone dye, a naphthoquinone dye, a phthalocyanine dye, and a metal phthalocyanine dye are preferred.

These pigments and dyes may be used alone or in appropriate combination, but may be contained in the range of 0.01 to 5% by weight based on the whole ink. desirable.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto. Example 1 An electrostatic multi-channel head described in WO93 / 11866 was used as an inkjet apparatus. In the ink jet method, an ink having a high resistance in which solid and hydrophobic charged resin particles are dispersed at least at normal temperature in an insulating solvent is used, and a strong electric field is applied to the ink at a discharge position. An aggregate of particles is formed at the discharge position, and the aggregate is discharged from the discharge position by electrostatic means. The ink jet recording head used was 150 (dot / 25.4 m) of the type shown in FIG.
m), a 61-channel multi-channel inkjet head was used. FIG. 7 is a diagram obtained by removing the ink regulating plates 42 and 42 ′ from FIG. 6 for explanation. Here, a pump is used, and ink reservoirs are respectively provided between the pump and the ink inflow path (I) of the recording head, and between the ink recovery path (O) of the recording head and the ink tank. The stirring was performed by a heater and the above-described pump as ink temperature management means, the ink temperature was set to 35 ° C., and the temperature was controlled by a thermostat. 900 drawing resolution in both main and sub-scanning directions
(Dots / 25.4 mm), and the recording head was moved in the sub-scanning direction at a speed of 61 dots per rotation of the drum (relative to the drawing dots in the sub-scanning direction). Further, the circulation pump was also used as a stirring means for preventing precipitation and aggregation here. In addition, an optical density measuring device was arranged in the ink flow path, and density control was performed by diluting the ink or feeding the concentrated ink based on the output signal.

Next, a production example of the hydrophobic resin particles for ink (PL-1) used in the present ink jet apparatus will be described. Production Example 1 Production of Resin Particles (PL-1) A mixed solution of 10 g of a dispersion stabilizing resin (Q-1) having the following structure, 100 g of vinyl acetate, and 384 g of Isopar H was heated to a temperature of 70 ° C. while stirring under a nitrogen stream. 2,2'-azobis (isovaleronitrile) as a polymerization initiator
0.8 g (abbreviation AIVN) was added and reacted for 3 hours. Twenty minutes after addition of the initiator, cloudiness occurred and the reaction temperature rose to 88 ° C. Further, 0.5 g of this initiator was added, and after reacting for 2 hours, the temperature was raised to 100 ° C. and the mixture was stirred for 2 hours, and unreacted vinyl acetate was distilled off. 200 after cooling
After passing through a mesh nylon cloth, the obtained white dispersion was a latex having a degree of polymerization of 90% and an average particle diameter of 0.23 μm and having good monodispersibility. The particle size was measured with CAPA-500 (manufactured by Horiba, Ltd.).

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A part of the white dispersion was centrifuged (rotation speed: 1 * 10 4 rpm, rotation time: 60 minutes), and the precipitated resin particles were collected and dried. Weight average molecular weight of resin particles (Mw: GPC in terms of polystyrene)
Value) was 2 * 10 5 and the glass transition point (Tg) was 38 ° C.

Preparation of oil-based ink (IK-1) 10 g of a dodecyl methacrylate / acrylic acid copolymer (copolymerization ratio: 95/5 by weight), 10 g of nigrosine and 30 g of Shellsol 71 together with glass beads and a paint shaker ( (Manufactured by Tokyo Seiki Co., Ltd.) and dispersed for 4 hours to obtain a fine dispersion of nigrosine.

Preparation of Resin Particles for Ink 60 g of resin particles (PL-1) of Example 1 (as solid content), 2.5 g of the above nigrosine dispersion, FOC-1400 (tetradecyl alcohol manufactured by Nissan Chemical Co., Ltd.) 15 g and octene-half-maleic acid hexadecylamide copolymer 0.0
A black oil-based ink was prepared by diluting 8 g to 1 liter of Isopar G.

Next, an on-press lithographic printing apparatus (FIGS. 1 to 3)
2) of the oil-based ink (IK-1) prepared as described above was filled in an ink tank of the ink jet recording apparatus described in Reference Example 1). As a plate material, a 0.12 mm-thick aluminum plate subjected to graining and anodizing treatment was mounted with a plate head and a plate edge added by a mechanical device provided on a plate cylinder. Separate the dampening solution supply device, printing ink supply device, and blanket cylinder so that they do not come into contact with the plate material, remove the dust on the plate material surface by suctioning with an air pump, and then move the recording head close to the plate material to the drawing position and print. The image data to be transmitted to the image data calculation control unit, and the 61-channel recording head is moved at the above-mentioned recording head moving speed (moving in the sub-scanning direction by 61 dots per rotation of the drum) while rotating the plate cylinder. As a result, an oil-based ink was discharged onto the aluminum plate to form an image. At this time, the tip width of the ejection electrode of the ink jet head was set to 10 μm, and the distance between the head and the plate material was controlled to be always 1 mm according to the output from the optical gap detector. A voltage of 2.5 KV is always applied as a bias voltage, and 500 V
Is further superimposed, and the pulse voltage is
Drawing was performed while changing the area of the dot by changing the dot area in 256 steps from millisecond to 0.05 millisecond. No drawing defects due to greetings were seen at all, and no image deterioration due to changes in the dot diameter was observed even when the outside air temperature changed or the number of plate making increased, and was 6 times the channel density of the recording head in the sub-scanning direction. High-density drawing was obtained, and good plate making was possible.

Further, the image was strengthened by heating (pressure: 3 kg / cm ² ) by fixing with a heat roller (Teflon (registered trademark) sealed silicon rubber roller containing a 300 W halogen lamp), and a printing plate was prepared. In order to protect the ink jet head, the ink jet recording apparatus was retracted by 50 mm from a position close to the plate cylinder together with the sub-scanning means, and thereafter, printing was performed on the coated printing paper by the normal lithographic printing method as described above. . That is, a printing image is formed by applying a printing ink and a fountain solution, the printing ink image is transferred onto a rotating blanket cylinder together with the plate cylinder, and then a printing coat passing between the blanket cylinder and the impression cylinder. The printing ink image on the blanket cylinder was transferred onto the paper.

The printed matter obtained was an extremely clear image without any skipping or blurring in the printed image even after passing through 10,000 sheets. Also, for 10 minutes after the completion of the plate making, the head is supplied with Isopar G, and the head is stored in a cover filled with vapor of Isopar G after cleaning by dripping Isopar G from the opening of the head. A good printed matter could be produced without any maintenance work.

Example 2 A commercially available solid ink jet device (Phaser 340 manufactured by Sony Techtronics) was used as an ink jet device.
The drawing unit of J) was used. An ejection head of 63 channels was used according to the formula of claim 1 among the recording heads of 64 channels, and a 0.12 mm thick aluminum plate subjected to graining and anodizing was mounted as the plate material in the same manner as described above. . After removing dust from the surface of the plate by suction with an air pump, the wax ink is in a molten state, and the recording head ready for discharge is controlled to a distance of 2 mm from the plate by the output from the optical gap detector. Then, the image data to be printed is transmitted to the image data calculation control unit, and while the plate cylinder is being rotated, the resolution in the sub-scanning direction is set to 10 times the resolution of the recording head, and the sub-scanning moving speed of 73 [dots / one revolution] is set. By moving continuously and at a constant speed, the oil-based ink was discharged onto the aluminum plate to form an image. At the time of ejection, 600 dpi (dot / 25.
Writing was performed using the error diffusion method with a binary value of 4 mm).
No defective drawing due to dust was observed at all, and no image deterioration due to a change in dot diameter or the like was observed even when the outside air temperature changed or the number of plate making increased, and good plate making was possible.

Thereafter, printing was performed on the printing paper by the normal lithographic printing method as described above. That is, a printing image is formed by applying a printing ink and a fountain solution, the printing ink image is transferred onto a rotating blanket cylinder together with the plate cylinder, and then the printing image passes between the blanket cylinder and the impression cylinder. The printing ink image on the blanket cylinder was transferred onto the coated paper.

In the obtained printed matter, when the number of sheets passed through was 10,000, some of the highlights were skipped. However, up to 5,000 sheets, the printed image was very clear without any skipping or blurring. In addition, no maintenance was required after plate making, and a good printed matter could be produced even after 3 months or more.

Example 3 A 500-channel piezo inkjet apparatus of share mode (XaarJet500S manufactured by Xaar) was demanded as an inkjet recording apparatus mounted on four plate cylinders of a single-sided four-color lithographic printing apparatus (see FIG. 8). An oil-based ink (manufactured by the company) or a UV ink (manufactured by the company) was used according to the formula described in item 1. The gap adjustment (gap 0.8 mm) is performed by a Teflon contact roller, image data to be printed is transmitted to the image data calculation control unit, and ink is simultaneously ejected onto the aluminum plate on the four plate cylinders to form an image. Was formed, and plate making was performed 500 times for each of the oil-based ink and the UV ink. At the time of drawing, gradation expression was performed by setting the drawing resolution to 360 (dot / 25.4 mm 2) and changing the dot size in eight stages. As a result, good plate making was possible. No drawing failure due to dust and no influence due to a change in outside temperature were observed at all. The dot diameter was slightly changed by the increase in the number of plate making, but it was within the range where there was no effect. When the UV ink was used, the plate was cured by UV lamp irradiation (low-pressure mercury lamp UL2-350USP manufactured by Ushio Inc.). As a result, a very clear full-color printed matter was obtained without any skipping or blurring in the printed image even after 5,000 sheets were passed. In particular, when the UV ink was used, an extremely clear full-color printed matter was obtained without any jumping or blurring in the printed image even after passing 20,000 sheets.

After completion of plate making, the ejection portion of the head is wiped with non-woven paper and stored in a cover.
A good printed matter could be produced without maintenance work for three months.

Example 4 The drawing unit of a piezo ink-jet device (Calario PM750C manufactured by Epson) was used as the ink-jet device according to the mathematical formula described in claim 1, and the oil-based ink used in Example 3 was used. As the plate material, a paper plate material provided with a hydrophilic image receiving layer on the surface shown below was used.

A paper support in which a high-quality paper having a basis weight of 100 g / m ² is used as a substrate, and a water-resistant layer mainly composed of kaolin, a resin component of polyvinyl alcohol, SBR latex and a melamine resin is provided on both sides of the substrate. An image-receiving layer was provided on the above dispersion A so as to have a coating amount of 6 g / m ² after drying, and a paper plate material was prepared.

Dispersion A Gelatin (Wako Pure Chemicals first grade) 3 g Colloidal silica (Nissan Chemical: Snowtex C, 20% aqueous dispersion) 20 g Silica gel (Fuji Silysia Chemical: Sylysia # 310) 7 g Hardener 0 0.4 g of distilled water and 100 g of glass beads were dispersed for 10 minutes using a paint shaker.

The head is mounted on a single-sided single-color printing press (see FIGS. 1 to 3), the gap adjustment (gap 1.5 mm) is performed by a Teflon-made contact roller, and the image data to be printed is sent to the image data calculation control unit. The ink is transferred onto the plate material on the plate cylinder by moving the discharge head according to the formula described in the claims using a 31-channel multi-channel inkjet head for one color of the head while transmitting and rotating the plate cylinder. An image was formed by discharging, and plate making was performed. At the time of drawing, gradation resolution was performed using an error diffusion method with a drawing resolution of 720 dpi (dot / 25.4 mm). Further, the circulation pump was also used as a stirring means for preventing precipitation and aggregation here. In addition, an optical density measuring device was arranged in the ink flow path, and density control was performed by diluting the ink or feeding the concentrated ink based on the output signal. As a result, good plate making was possible. No drawing failure due to dust and no influence due to a change in outside temperature were observed at all. When printing was performed using the coated printing paper, an extremely clear printed matter was obtained without any skipping or blurring in the printed image even after 5,000 sheets were passed. However, after 5,000 sheets,
An elongation of 0.1 mm was observed in the longitudinal direction of the A3 image. On the other hand, when high quality paper was used as the printing paper, solid crushing failure occurred due to paper dust when printing 3,000 sheets. Was. As a result, printing failure did not occur, and the obtained printed matter was an extremely clear image without flying or blurring even after passing 5,000 sheets. However, after 5,000 sheets were passed, an elongation of 0.1 mm was observed in the longitudinal direction of the A3 image.

After the end of plate making, the head nozzles are sucked out and stored in the cover so that 3
Good prints could be made without any maintenance work for months.

Example 5 Instead of the aluminum plate of Example 1, a plate material provided with an image receiving layer which can be made hydrophilic by a desensitizing treatment was used on the surface described below, and a 150 (dot / 25) head was used. .4m
m), a 61-channel multi-channel inkjet head was used. The drawing resolution is 900 (dot / 25.4 mm) in both the main scanning direction and the sub-scanning direction, and the moving speed of the recording head in the sub-scanning direction is 61 dots per rotation of the drum (relative to the drawing dots in the sub-scanning direction). Was drawn. After the printing plate is prepared, the non-image area is hydrophilized by using a plate surface desensitizing device, and the plate material conductive layer is grounded by a conductive leaf spring (made of phosphor bronze) during drawing, and hot air is applied to the plate material. The same operation as in Example 1 was performed except that fixing was performed.

A high-quality paper having a basis weight of 100 g / m ² was used as a substrate, and a polyethylene film was laminated on both sides of the substrate to a thickness of 20 μm to form a water-resistant paper support. The layer coating is applied on one side, and after drying, the applied amount is 10 g / m ² ,
Further, the dispersion B was coated thereon after drying as a coating amount of 1.5
An image receiving layer was provided so as to have a g / m ² to obtain a plate material.

(1) Paint for conductive layer: 5.4 parts of carbon black (30% aqueous dispersion), 54.6 parts of clay (50% aqueous dispersion), SBR latex (solid content 50%, T
(g 25 ° C.) 36 parts and melamine resin (solid content 80%, Sumiretz Resin SR-613) 4 parts were mixed, and water was added so that the total solid content was 25% to obtain a paint. (2) Dispersion B: 100 g of dry zinc oxide, 3 g of binder resin (B-1) having the following structure, 17 g of binder resin (B-2), 0.15 g of benzoic acid and 155 g of toluene were mixed with a wet disperser homogenizer. Using Nippon Seiki Co., Ltd., the mixture was dispersed at 6,000 rpm for 8 minutes.

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As a result, a high-density drawing as high as 6 times the channel density in the sub-scanning direction was obtained, and good plate making was possible. No drawing failure due to dust and no influence due to a change in outside temperature were observed at all. Example 6 As an ink jet device, a thermal jet device (C
100 (dots / BJ35V manufactured by annon)
25.4 mm), and a drawing section of a 73-channel recording head was used. However, an ink having the following composition was prepared and used. Acrylic resin (DEGALANLS50 / 150 manufactured by Dagussa) 5% by weight Dye (Victoria Pure Blue manufactured by Hodogaya Chemical Co., Ltd.) 30% by weight Methyl ethyl ketone 55% by weight Ethylene glycol monoethyl ether 10% by weight After mounting and removing dust on the surface of the plate material by suction with an air pump, the distance between the recording material containing the ink and the plate material was controlled to 2 mm by an output from an optical gap detector. The image data to be printed is transmitted to the image data calculation control unit, and the drawing resolution is set to 600 (dot / 25.4) in both the main scanning and sub-scanning directions.
mm) and the moving speed of the recording head in the sub-scanning direction was set to 73 dots per rotation of the drum (relative to the dots drawn in the sub-scanning direction), and ink was ejected onto the entire surface of the plate material to form an image. As a result, high-density drawing as high as six times the channel density in the sub-scanning direction was obtained, and good plate making was possible. No drawing failure due to dust and no influence due to a change in outside temperature were observed at all.

Thereafter, printing on printing paper was performed in the same manner as described above. In the obtained printed matter, when the number of sheets passed through was 10,000, some of the highlights were skipped. However, up to 5,000 sheets, the printed image was an extremely clear image without any skipping or blurring.

After the end of plate making, the head nozzles are sucked out, the nozzles are cleaned with non-woven paper, and stored in the cover, so that good printed matter can be obtained without maintenance work for three months. Could be produced.

[0093]

According to the present invention, when performing drawing using an ink jet system in which ink containing a lipophilic component is ejected from a recording head having a plurality of ejection channels,
The main scan is performed by rotating the plate cylinder with the plate material mounted, the recording head is continuously moved at a constant speed in the direction parallel to the axis of the plate cylinder, and drawing is performed while performing sub-scanning. However, it is possible to print a large number of prints of a clear image. In addition, a printing plate corresponding to digital image data can be stably produced with high image quality directly on a printing press, and inexpensive and high-speed lithographic printing can be performed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram schematically illustrating an example of an on-press drawing single-color lithographic printing apparatus according to the present invention.

FIG. 2 is an overall configuration diagram schematically illustrating another example of the on-press drawing single-color lithographic printing apparatus according to the present invention.

FIG. 3 is an overall configuration diagram schematically showing still another example of the on-press drawing single-color lithographic printing apparatus according to the present invention.

FIG. 4 is a configuration diagram schematically illustrating an example of a drawing unit of the on-press drawing lithographic printing apparatus of FIGS. 1 to 3;

FIG. 5 is a configuration diagram schematically showing one embodiment of a head protection cover used in the present invention.

FIG. 6 is a schematic configuration diagram illustrating a main part of an inkjet recording apparatus used in the present invention.

FIG. 7 is a schematic configuration diagram in which a regulating plate has been removed from the ink jet recording apparatus of FIG. 6;

FIG. 8 is an overall configuration diagram schematically showing an on-press drawing four-color single-sided lithographic printing press as an example of a multi-color printing machine according to the present invention.

FIG. 9 is a first explanatory diagram of sub-scanning control used in the present invention.

FIG. 10 is a second explanatory diagram (general formula) of sub-scanning control used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 On-machine drawing lithographic printing apparatus 2 Ink jet recording apparatus 3 Dampening water supply apparatus 4 Printing ink supply apparatus 5 Fixing apparatus 6 Plate surface desensitization apparatus 7 Plate material automatic plate supply apparatus 8 Plate material automatic plate discharging apparatus 9 Plate material (printing plate) 10) Dust removing means 11 Plate cylinder 12 Blanket cylinder 13 Impression cylinder 14 Blanket cleaning device 14 'Pressure cylinder cleaning device 15 Paper dust generation prevention device 20a Digital control means 20b Head protection means 21 Image data calculation control unit 22 Recording head 22b Discharge electrode Reference Signs List 24 Ink supply unit 25 Ink tank 26 Ink supply device 27 Stirring unit 28 Ink temperature management unit 29 Ink density control unit 30 Encoder 31 Head separation / attachment device 32 Head sub-scanning unit 41 Head main body 42, 42 'Meniscus regulating plate 43 Ink groove 44 Partition walls 45, 45 'Discharge unit 46 Partition walls 5 Cover 52 shutter P printing paper F Food

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuo Ishii 4,000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture Inside Fujisha Shin Film Co., Ltd. Incorporated F term (reference) 2C034 AA12 BA02 2C056 EA24 EB32 EC21 EC29 FA04 FA10 FB01 FD02 HA06 HA11 HA23 HA46 2H084 AA25 AE05 BB04 BB16 CC05

Claims (7)

[Claims] 1. An ink comprising a plate material mounted on a plate cylinder of a printing press, a main scan performed by rotation of the plate cylinder mounted with the plate material, and an ink containing a lipophilic component on the plate material based on a signal of image data. Is formed from a recording head having a plurality of discharge channels, and the recording head is moved in a direction parallel to the axis of the plate cylinder to form an image directly on the surface of the plate material by performing drawing while performing sub-scanning. To make a printing plate,
In an on-press drawing lithographic printing method for performing lithographic printing using the plate material in that state, the resolution of drawing on the plate material in the direction perpendicular to the rotation of the plate cylinder is set to N [dot / 25.4 mm]. K: Rotation and vertical channel density
[Dot / 25.4 mm], and X is an arbitrary positive integer. Using a recording head having [X * (N / K) +1] [number] ejection channels, the sub-scanning movement of the recording head is performed. Speed [X * (N / K) +
1] An on-press drawing lithographic printing method characterized in that the printing is performed continuously and at a constant speed at [dots / 1 round]. 2. The method according to claim 1, further comprising: removing a dust present on a surface of the printing plate before drawing on the printing plate by the ink-jet method and / or during drawing, and / or cleaning the printing head at least after finishing printing. 2. The lithographic printing method for on-press drawing according to claim 1, wherein: 3. An ink jet drawing comprising a recording head for discharging an ink containing a lipophilic component from a recording head having a plurality of discharge channels based on a signal of image data on a plate material mounted on a plate cylinder of a printing press. An on-press drawing printing apparatus comprising: an image forming unit that directly forms an image by an apparatus; and a lithographic printing unit that performs lithographic printing with a printing plate formed by the image forming unit. The main scanning is performed by the rotation of the plate cylinder mounted with, and the sub-scan is performed by moving the recording head in the direction parallel to the axis of the plate cylinder, and the image is drawn on the plate material in the direction perpendicular to the rotation of the plate cylinder. When the resolving power is N [dot / 25.4 mm], the channel density of the recording head in the direction perpendicular to the cylinder rotation of the recording head is K [dot / 25.4 mm], and any positive integer is X, (X * (N / K) 1) Using a recording head having [number] ejection channels, performing the sub-scanning movement of the recording head continuously at a speed (X * (N / K) +1) [dots / 1 round] at a constant speed. An on-press lithographic printing apparatus characterized by the above-mentioned. 4. The image forming means includes a plate material surface dust removing means for removing dust present on the plate material surface before and / or during drawing on the plate material. 3. The on-press lithographic printing apparatus according to 3. 5. The ink jet drawing apparatus moves the recording head close to the plate cylinder when drawing on the plate material, and separates the recording head from the plate cylinder except when drawing on the plate material. The on-press lithographic printing apparatus according to claim 3 or 4, further comprising means. 6. The image forming apparatus according to claim 3, wherein said image forming means includes a print head cleaning means for cleaning said print head at least after the completion of plate making.
An on-press lithographic printing apparatus according to any one of the preceding claims. 7. The on-press lithographic printing apparatus according to claim 3, wherein said lithographic printing means includes paper dust removing means for removing paper dust generated during lithographic printing. .