JP2000211100A - Multicolor printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital printing machine being enough to run with few plate-making means, and easily corresponding to size and multicolor. SOLUTION: Each first printing unit and second printing unit includes a printing plate mountable with printing areas having two different colors in its circumferential surface respectively, and every when a form cylinder 15 rotates, printing is effected for respective two colors. Between impression cylinders 15 of each printing unit, this apparatus is formed such that printing paper is delivered by an intermediate conveyance part 4 comprising the paper ejection drum 17 of the first printing unit 1, three-delivery drums 40, and a paper feeding drum 16 of the second printing unit. The intermediate conveyance part 4 works to convey printing paper every intermittent rotation of the impression drum 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor printing apparatus having a plate making function for recording an image on a printing plate.

[0002]

2. Description of the Related Art In recent years, an unexposed printing plate is mounted on a plate cylinder, and the plate is made by laser exposure means provided around the plate cylinder.
There has been proposed a printing apparatus generally called a digital printing machine that performs printing with a printing plate made on the plate cylinder. Conventional digital printing presses have expensive laser exposure means for each cylinder of each color, which increases the price of the entire apparatus and complicates the mutual adjustment of the exposure amount and exposure position of each laser exposure means. There was a problem.

In this type of digital printing press, a plate making mechanism such as an unexposed printing plate supply means and a laser exposure means is provided around the plate cylinder in addition to a conventional printing mechanism such as an ink supply means and a blanket cylinder. It must be arranged, and depending on the type of printing plate, a dampening solution supply unit and a printing plate developing unit must also be arranged. Therefore, in the digital printing press, there is a problem that it is difficult to secure a space for disposing the various mechanisms.

[0004] In order to solve this problem, for example, a digital printing machine disclosed in Japanese Patent Application Laid-Open No. 10-272756 has been disclosed. In the digital printing press described in the above publication, the number of plate cylinders is reduced to two by mounting printing plates for two colors on each plate cylinder.
To enable ordinary four-color printing. Furthermore, by making the plate cylinder movable between the plate making position and the printing position,
The number of the laser exposure means can be further reduced, and a sufficient space for disposing the printing mechanism and the plate making mechanism can be secured.

[0005]

The digital printing press described in the above publication is effective for a relatively small to medium size printing press. However, in the case of a large-size printing machine, there is a problem that the plate cylinder that needs to be moved becomes large, and it is difficult to move the plate cylinder. In the configuration disclosed in the above publication, more than four colors, for example, six colors, eight colors,
It is difficult to configure a multi-color printing machine or the like due to an increase in the number of plate cylinders and an increase in plate cylinder diameter. According to the present invention, a printing mechanism and a plate making mechanism can be sufficiently arranged around the plate cylinder without moving the plate cylinder, and thus a multi-color printing apparatus optimal for a digital printing machine corresponding to a large size and multi-color printing is provided. The purpose is to do.

[0006]

According to the first aspect of the present invention, there is provided a plate cylinder having a printing plate corresponding to two printing areas;
Plate making means for making a plate on the printing plate; two ink supply means for supplying ink to each corresponding printing area; and a blanket cylinder abutting on the plate cylinder. ) / 2 times [n is a natural number] and has a printing unit composed of an impression cylinder capable of holding an odd number of printing papers on the peripheral surface thereof, and recording an image on a printing plate to make a plate. Thereafter, a multicolor printing apparatus that performs printing by supplying ink to the printing plate, and is provided between two or more printing units and the impression cylinders of each printing unit, and conveys printing paper between the impression cylinders. Intermediate printing means, wherein the two printing units synchronously supply and discharge printing paper for each printing area of each impression cylinder, and the intermediate feeding means for each printing area of each impression cylinder. The printing paper is transported from the former impression cylinder to the latter impression cylinder.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing an example of a multicolor printing apparatus according to the present invention, and FIG. 2 is a view for explaining conveyance of printing paper in the multicolor printing apparatus according to the present invention. FIG.
In the multi-color printing apparatus according to the present embodiment, a first printing unit 1 and a second printing unit 2 that can perform multi-color printing of two colors each, and a paper feeding unit 3 that supplies printing paper to the first printing unit An intermediate transport unit 4 that transports printing paper from the first printing unit 1 to the second printing unit 2;
And a paper discharge unit 5 for discharging print paper from the print unit 2.

The first printing unit 1 includes a plate cylinder 10 on its peripheral surface capable of holding printing plates corresponding to two printing regions, plate making means 11 for making a plate on the printing plate, and a corresponding printing region. Dampening water supply means 12 for supplying dampening water to the
a, 12b, two ink supply means 13a, 13b for supplying ink to each corresponding printing area, a blanket cylinder 14 having the same diameter as the plate cylinder and abutting on the plate cylinder,
It has a half diameter of the plate cylinder, can hold one sheet of printing paper on its peripheral surface, and supplies an impression cylinder 15 in contact with the blanket cylinder, and supplies printing paper to the impression cylinder 15. It comprises a paper feed cylinder 16 and a paper discharge cylinder 17 for discharging.

The plate cylinder 10 has two sets of gripping means (not shown) which are arranged on the peripheral surface thereof at 180 degrees so as to be able to hold two printing plates corresponding to printing areas of different colors. It is configured. In addition, by holding one printing plate having two printing areas of different colors continuously, substantially one printing plate is held.
Two printing areas may be provided on one plate cylinder.

A plate making means 11 supplies unexposed printing plates to the plate cylinder 10 and collects used printing plates from the plate cylinder 10. On the other hand, it comprises a laser exposure means 21 for drawing an image with a laser beam, and a developing means 22 for developing the printing plate exposed by the laser exposure means 21.

The plate feeding / discharging means 20 has a cassette capable of storing a sheet-shaped unexposed printing plate and a used printing plate, and the cassette is connected to the cassette by a conveying means including a plurality of conveying rollers and guide members. The printing plate is conveyed to and from the plate cylinder 10. The laser exposure unit 21 is configured so that an exposure head capable of irradiating the peripheral surface of the plate cylinder 10 with a laser can be moved in parallel along the axis of the plate cylinder 10. By the parallel movement of the exposure head, an unexposed printing plate held on the plate cylinder 10 can be scanned to draw an image. Note that the laser exposure unit 21 may be of a type that scans by deflecting the laser beam by the deflecting unit.

The developing means 22 is composed of a processing liquid tank storing a processing liquid and an application roller arranged partially immersed in the processing liquid. The processing solution is pumped up and supplied to the printing plate surface. In this embodiment, each processing liquid tank and application roller have two sets for development and fixing, respectively, and an elevating mechanism is provided so that each of them independently comes into contact with and separates from the plate cylinder 10. . Note that, depending on the type of the printing plate, a case where the developing unit is unnecessary may be considered.

The dampening water supply means 12a and 12b are means for selectively supplying dampening water to different printing areas on the plate cylinder 10, respectively. It comprises a plurality of dampening water rollers for pumping dampening water from the watercraft and supplying the dampening water onto the printing plate surface. Among the dampening solution rollers, at least a roller that comes into contact with the printing plate surface is configured to be brought into contact with or separated from the plate cylinder 10 by a cam mechanism or the like, and is provided in a corresponding printing area on the plate cylinder 10. Only the dampening solution can be supplied selectively. As in this embodiment, dampening solution supply means 12a,
12b is preferably provided individually for each printing color, in order to take into account the incorporation of ink into the dampening solution. Note that a dampening water supply unit such as a spray type that is not in contact with the plate surface may be employed so that a single dampening water supply device may be used.

The ink supply means 13a and 13b are means for selectively supplying ink to different printing areas on the plate cylinder 10 to which the dampening water has been supplied by the dampening water supply means 12a and 12b, respectively. And an ink fountain storing the ink, and a plurality of ink rollers for taking out the ink from the ink fountain and supplying the ink onto the printing plate surface. At least a roller of the ink roller that comes into contact with the printing plate is configured to come into contact with or separate from the plate cylinder 10 by a cam mechanism or the like, and is selected with respect to a corresponding printing area on the plate cylinder 10. The ink can be supplied in an appropriate manner. Note that the ink supply means 1 according to this embodiment
The colors of the inks of 3a and 13b are K (black) and C
(Cyan).

The blanket cylinder 14 has the same diameter as the plate cylinder 10 and has a blanket surface for transferring an ink image on a peripheral surface thereof. On this blanket surface, ink images corresponding to K and C colors are transferred from the printing plate on the plate cylinder 10. A blanket cleaning means 23 for cleaning the blanket surface is provided around the blanket cylinder 14.

The impression cylinder 15 has a half diameter of the plate cylinder 10, and a pair of gripping means (15 in FIG.
a) is provided. Therefore, on the peripheral surface of the impression cylinder 15, one sheet of printing paper having a size corresponding to one printing area of the plate cylinder can be held. The holding means 15a of the impression cylinder 15 receives the printing paper from the paper feeding cylinder 16 to be described later every other rotation, and opens and closes the paper so as to deliver the printing paper to the ejection cylinder 17 to be described later every rotation. I do. The configuration in which the gripper performs the opening / closing operation every alternate rotation is disclosed in, for example, Japanese Patent Application No. 9-293603 filed by the present applicant, and a description thereof will be omitted.

The feed cylinder 16 and the discharge cylinder 17 are
1 for holding printing paper on its circumference
A pair of jaw means (16a and 17a in FIG. 2) are provided. Both the paper feed cylinder 16 and the paper discharge cylinder 17 are rotated in synchronization with the impression cylinder 15, and the holding means 16a, 17a of each cylinder
The phase is set such that the gripper 15a of the impression cylinder 15 and the gripper 15a face each other. The gripping means 16a, 17a of the paper feed cylinder 16 and the paper discharge cylinder 17 also open and close so that the printing paper can be supplied and discharged every time the impression cylinder 15 rotates twice.

In the first printing unit 1, based on the difference between the diameter of the blanket cylinder 14 and the diameter of the impression cylinder 15,
Printing of K color or C color is performed alternately for each rotation of the impression cylinder. Therefore, when the impression cylinder 15 rotates twice while holding the printing paper, two-color printing can be performed on the printing paper. Here, “the impression cylinder makes two rotations while holding the printing paper” means that the printing paper on the impression cylinder 15 moves two times from the blanket cylinder 14.
This represents a rotation operation in which ink images for the colors are sequentially and successively transferred, and does not mean that the image is rotated exactly 360 ° × 2 while holding the printing paper. For example, in the present embodiment, since the arrangement angle of the paper feed cylinder 16 and the paper discharge cylinder 17 with respect to the impression cylinder 15 is about 120 degrees, 360 degrees from the moment when the impression cylinder 15 receives the printing paper from the paper feed cylinder 16. The printing paper is discharged from the impression cylinder 15 at the time when the rotation is +240 degrees.

Since the second printing unit 2 has basically the same configuration as the first printing unit, the same reference numerals are given in FIG. 1 and the description is omitted. However, the damping solution supply means of the second printing unit 2 is 12c and 12d, and the ink supply means is 13c and 13d. In the present embodiment, the color of the ink supplied by the ink supply units 13c and 13d is M
(Magenta) and Y (yellow).

The paper supply unit 3 includes a paper supply table 30 on which unprinted print papers are loaded, and a separation unit for separating and taking out only one uppermost print paper of the print papers loaded on the paper supply board 30. 3
1 and a transport conveyor 32 for transporting the printing paper separated by the separating means 31. The paper feed table 30 is a table-like member on which sheet-like printing paper can be stacked and placed, and rises upward as the number of printing paper decreases so that the topmost position of the loaded printing paper is always constant. It is configured to be. The separating means 31 is configured to suck and hold the uppermost printing paper by a suction disk (not shown), blow the compressed air to separate the printing paper, and the printing paper received by the suction disk is Conveyor 32
Is supplied to the paper feed cylinder 16 via the The separation and supply operation of the printing paper by the separation means 31 is performed by the feeding cylinder 16.
Is performed every other rotation of.

The intermediate transport section 4 transfers printing paper between the impression cylinder 15 of the first printing unit 1 and the impression cylinder 15 of the second printing unit. It comprises a cylinder 17, a paper feed cylinder 16 of the second printing unit 2, and three transfer cylinders 40. Each transfer cylinder 40 has a diameter twice as large as the impression cylinder, and two sets of jaw devices (40a and 40b in FIG. 2) are provided on the circumferential surface at positions opposed to each other by 180 degrees. And the holding means 40 of each transfer cylinder 40
The a and b and the gripping means 17a and 16a of the paper discharge cylinder 17 and the paper feed cylinder 16 are configured to open and close synchronously in a phase opposite to each other so as to transfer the printing paper.

As described above, since the impression cylinder 15 performs multicolor printing of two colors each time the impression cylinder 15 rotates twice, when the transfer cylinder 40 having a diameter twice as large as the impression cylinder is used, the peripheral surface of the transfer cylinder 40 has a diameter of 1 mm. Only a pair of gripping means 40a may be provided. That is,
In this case, each transfer cylinder 40 uses only half of its peripheral surface for transporting the printing paper. However, in the printing apparatus according to the present embodiment, each side of the impression cylinder only rotates once.
In order to provide a color printing function, each transfer cylinder 40 is provided with two sets of holding means. The single-sided two-color printing function will be described later.

The paper discharge unit 5 includes a chain discharge unit 50 that receives printing paper from the paper discharge cylinder 17 of the second printing unit 2.
And a discharge table 51 on which the print paper taken out and discharged by the chain discharge section 50 is stacked.

The chain discharging means 50 comprises two sets of endless chains which are wound between a plurality of pulleys and rotate synchronously, and a plurality of gripping means which are passed between the chains. The endless chain rotates in synchronization with the discharge cylinder 17, and the gripping means provided on the chain discharging means 50 opens and closes at a position opposed to the gripping means 17a of the discharge cylinder 17, and prints from the discharge cylinder. It is configured to receive paper. The gripping means of the chain discharging means 50 can discharge the printing paper onto the discharge base 51 by releasing the printing paper above the discharge base 51. The discharge table 51 is a pedestal member for stacking printing paper on which printing has been completed, and is configured to be sequentially lowered by the elevating means according to the discharge amount of the printing paper.

Next, the procedure for transporting the printing paper according to the present embodiment will be described. First, in FIG. 2A, print paper is fed to the paper feed cylinder 16 of the first print unit 1.
That is, the gripper 16a of the paper feed cylinder 16 opens and closes, and the leading end of the printing paper is gripped by the gripper 16a. In addition,
The paper is supplied to the paper feed cylinder 16 every time the paper feed cylinder is rotated every other rotation. In the following figures, only the first print sheet is shown.

Then, each cylinder rotates, and the printing paper is transferred from the paper supply cylinder 16 to the impression cylinder 15 as shown in FIG.
That is, the leading edge of the printing paper is
From the pressing cylinder 15 to the holding means 15a.

In this state, the impression cylinder 15 makes one rotation to perform K color printing on the printing paper. During the first rotation of the impression cylinder, the delivery of the printing paper is not performed with the holding means 15a, 16a, and 17a closed. Further, the impression cylinder 15 rotates,
As shown in FIG. 2C, the leading end of the printing paper is delivered to the paper discharge cylinder 17 while performing the subsequent C color printing. That is, the leading end of the printing paper is re-holded by the holding means 15a of the impression cylinder 15 to the holding means 17a of the discharge cylinder 17.

Further, each cylinder rotates, and the leading end of the printing paper is held back from the holding means 17a of the discharge cylinder 17 to the holding means 40a of the transfer cylinder 40 as shown in FIG. The printing paper is conveyed to the downstream side while being sequentially held by the holding means 40a of each transfer cylinder 40. In this example, since the impression cylinder 15 discharges the printing paper to the paper discharge cylinder 17 every alternate rotation, the gripping means 40b of the transfer cylinder 40 is not used.

Then, as shown in FIG. 2 (E), the printing paper is transferred from the grip means 40a of the final transfer cylinder 40 to the grip means 16a of the paper feed cylinder 16 of the second printing unit 2.
Thereafter, the same processing as that of the first printing unit 1 is performed in the second printing unit 2, and multicolor printing of four colors is performed as a whole.

In the printing apparatus according to the above-described embodiment, the first printing unit 1 prints K and C colors,
The printing unit can continuously perform the printing of the M color and the Y color, and can perform multicolor printing of a total of four colors. Further, since the plate cylinders of each printing unit are provided with two printing plates each corresponding to two colors, only two plate cylinders are required for four-color printing. There are few means. In addition, since the printing paper is connected between the impression cylinders of each printing unit so that the printing paper is delivered, a sufficient space can be secured around the plate cylinder of each printing unit, so that the printing mechanism and the plate making mechanism can be moved without moving the plate cylinder. Can be arranged.

In the printing apparatus according to the above-described embodiment, two printing units are provided to realize four-color printing. However, three or more printing units may be provided to perform multicolor printing of six or more colors. is there. In addition, each transfer cylinder 40 has two impression cylinders.
Although formed by a double cylinder having a double diameter, it may be configured by a transfer cylinder of another diameter, or may be configured by another method such as a chain transport type. Further, the impression cylinder 15 can print three printing papers.
Alternatively, the diameter may be such that an odd number of sheets such as five or five pieces can be held.

[Regarding Single-Side Two-Color Printing Function] In the above embodiment, printing plates of different colors are formed on the plate cylinder 10 of each printing unit. May be arranged. In this case, only one of the two ink supply means provided for each printing unit is used for the two areas. In this state, the impression cylinder 1
5, the printing paper is fed and discharged every rotation of the first and second rotations.
Printing unit can print two colors for convenience. That is, in the above-described embodiment, a total of two colors of one of the colors K or C and one of the colors M or Y can be printed.

In this example, the printing paper can be supplied and discharged every rotation of the impression cylinder 15, so that two-color printing can be performed at twice the speed of the above-described embodiment. As mentioned above,
In this embodiment, the transfer cylinder 40 includes one of the impression cylinders 15.
Each cylinder requires two sets of holding means 40a and 40b so that the printing paper can be conveyed for each rotation.

[0034]

According to the multicolor printing apparatus of the present invention,
The printing mechanism and the plate making mechanism can be sufficiently arranged around the plate cylinder without moving the plate cylinder, and the number of plate making means can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a multicolor printing apparatus used in an embodiment of the present invention.

FIG. 2 is a diagram showing a procedure for transporting printing paper in the multicolor printing apparatus used in the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st printing unit 2 2nd printing unit 3 paper supply part 4 intermediate conveyance part 5 paper discharge part 10 plate cylinder 11 plate making means 13a-13d ink supply means 14 blanket cylinder 15 impression cylinder 16 paper supply cylinder 17 paper discharge cylinder 40 transfer Torso

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C020 AA06 AA14 2C034 AA12 AA43 BA02 BA11 BB01 BB43

Claims (1)

[Claims] 1. A plate cylinder having a printing plate corresponding to two printing areas, plate making means for making a plate on said printing plate, two ink supply means for supplying ink to each corresponding printing area, Abuts the plate cylinder via the blanket cylinder,
A printing plate comprising: an impression cylinder having a diameter of (2n-1) / 2 times [n is a natural number] of the plate cylinder and capable of holding an odd number of printing sheets on a peripheral surface thereof; A multicolor printing apparatus for printing an image by recording an image on the printing plate and then supplying ink to the printing plate to perform printing, provided between two or more printing units and an impression cylinder of each printing unit. Intermediate printing means for transferring printing paper between the cylinders, the two printing units synchronously supply and discharge printing paper for each of the printing areas of each impression cylinder, and the intermediate feeding means, A multicolor printing apparatus wherein a printing sheet is transported from a preceding impression cylinder to a succeeding impression cylinder for each printing interval of each impression cylinder.