JPH08142301A - Proof printing method and proof press - Google Patents

Abstract

PURPOSE: To provide a proof press capable of proof printing in a short time, smaller in size than a conventional 4-color machine. CONSTITUTION: This proof press comprises a plate slab 51, a blanket 59, and four ink supply means 54-57. When the ink supply means 54-57 are to be used, any one is selected out of the four ink supply means. In the proof press, four printing plates having the same images and different colors are exchanged in sequence and the ink supply means 54-57 to be used are also selected and switched accordingly. Thus, overprinting of four colors is performed and a proof printed matter is obtained. In the proof printing method using the proof press, the blanket 59 is continuously used without cleaning during the overprinting. Accordingly, labor and time for cleaning can be saved and back trapping of a pre-print ink can be prevented to some extent at start of printing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a proof printing method and a proofing machine using offset printing.

[0002]

2. Description of the Related Art Conventionally, before mounting a printing plate on a printing press to perform printing, a plate inspection is performed to inspect whether or not the printing plate is accurately prepared. In this plate inspection, the operator visually inspects the printing plate, but in the case of multicolor printing, the image is separated into four colors by scanning, etc. However, it is difficult to detect defects and defects, especially burn-out and misregistration of the pattern portion.

[0003]

Therefore, it is conceivable to perform proof printing using a conventional proofing machine and visually inspect the obtained proof printed matter to inspect the printing plate. This proofing machine is offered in three types: a single-color machine, a two-color machine, and a four-color machine.
The two-color machine can perform proof printing by two colors and the four-color machine can perform proof printing by four colors.

In a single-color machine, since only one plate surface plate, blanket, ink supply means, etc. are installed, if normal color proof printing is performed, ink is replaced four times each time the printing plate is replaced. Must be replaced.
In the case of normal proofing work, it is possible to reduce the number of ink changes by performing proofing printing of the same color all together, but when performing plate inspection, proofing printing is performed every time the printing plate is made. As a result, the ink must be changed four times. Therefore, if a conventional monochromatic machine is used for plate inspection, it is necessary to frequently wash the ink supply means and replace it with new ink, which takes time and complicates the work.

On the other hand, a four-color machine is provided with four plate plates, blankets, ink supply means, etc., so that four colors can be printed at one time, but four sets of main parts are required. There is a problem that the device becomes large and expensive. The two-color machine is located between the above-mentioned single-color machine and four-color machine, and has half of the defects of each. Therefore, there is a problem that it is time-consuming, large-sized and too expensive to use a conventional proofing machine when performing plate inspection.

Also, in the case of the conventional four-color machine, a blanket corresponding to each printing plate is provided. Therefore, when proof printing is performed using a four-color machine, there occurs a phenomenon called so-called back trapping, in which the ink previously printed on the printing paper is taken by the blanket to be printed later. Therefore, at the start of printing, the amount of previously printed ink becomes extremely low. This back trapping is stable if a predetermined number of proof prints are performed, but since prompt response is required in the plate inspection process, proof prints can be printed with a certain quality from a few sheets, preferably the first. I had to give it.

It is an object of the present invention to provide a proofing machine which can carry out proof printing in a short time and which is smaller than the conventional four-color machine. Another object of the present invention is to provide a proof printing method capable of performing proof printing in a short time and preventing back trapping to some extent.

[0008]

A proof printing method according to a first aspect of the present invention is a proof printing method using offset printing, in which printing plates of different printing colors of the same image are sequentially replaced to perform continuous monochromatic printing. In this case, printing is continuously performed using the same blanket without cleaning or replacing the blanket.

A proofing machine according to a second aspect of the invention is a proofing machine using offset printing, in which one printing plate on which a printing plate is placed and a printing plate placed on the printing plate are wetted. A dampening water supply means for supplying dampening water, four or more ink supply means for supplying ink to the printing plate placed on the plate surface plate, and a case where ink is supplied to the printing plate or not. Switching means for switching the ink supply means, one blanket for transferring the ink from the printing plate, a printing paper holding means for holding the printing paper on which the ink transferred to the blanket is retransferred, and the dampening water supply Means, the ink supply means, and a drive means for relatively moving the blanket and the platen.

A proofreading machine according to a third aspect of the present invention is the proofreading machine according to the second aspect, wherein the driving means is a plate surface plate driving means for moving the plate surface plate. The proofing machine according to claim 4 is the proofing machine according to any one of claims 2 to 3, further comprising a detection unit that detects information about a printing color of the printing plate from the printing plate before ink is supplied, The ink supply means is switched by the switching means on the basis of the print color information detected by the detection means.

[0011]

In the proof printing method according to the first aspect, when the printing plates of the same image having different printing colors are sequentially exchanged to perform single-color printing, the blanket is continuously washed using the same blanket without washing or exchanging. And print. That is, in the case of normal offset printing, a blanket is washed and used for each different ink, or a separate blanket is provided for each different ink, but this proof printing method uses the same blanket and blanket for each ink. Proofreading is done without cleaning. Therefore,
Even if there is only one blanket, the number of washings is reduced, and proof printing and eventually plate inspection work can be performed quickly. In addition, since only one blanket is used, the ink used in the proof printing first remains on the blanket, and back trapping is prevented to some extent.

In the proofreading machine according to a second aspect of the invention, first, the driving means relatively moves the dampening water supply means and only one plate surface plate, and the printing plate placed on the plate surface plate. The dampening water is supplied to. On the other hand, one of the four or more ink supply units is switched so that the ink supply unit corresponding to the printing color of the printing plate supplies ink to the printing plate. Then, the drive means relatively moves the ink supply means and the platen to supply the ink to the printing plate. Next, one blanket and the platen move relative to each other, the ink of the printing plate is transferred to the blanket, and is further transferred to the printing paper held by the printing paper holding means. In this way, when the proof printing of the first color printing plate is completed, the printing plate is replaced with the second and subsequent printing plates, and the ink supplying means used is switched by the switching means. However, other operations can be repeated as in the first color. Therefore, it is not necessary to wash the ink supply means, and multicolor proof printing can be performed.

In the proofreading machine according to the third aspect of the present invention, the platen is moved by the platen driving means, so that dampening water or ink is supplied to the printing plate placed on the platen. When transferring the ink to the blanket, it is not necessary to move the dampening water supply means, the ink supply means, and the blanket, so that the calibrator is downsized. The calibration machine according to claim 4,
The detection means detects the information of the printing color from the printing plate before supplying the ink, and the switching means switches the ink supply means based on the information, so that the ink is supplied by the ink supply means of the color corresponding to the printing plate. Supplied.

[0014]

【Example】

[First Embodiment] FIG. 1 and FIG. 2 are side sectional views of a calibrator adopting the first embodiment of the present invention. The calibrator mainly includes a fixed main body frame 1 and a carriage 2 that reciprocates on the main body frame 1 by a drive mechanism.
A plate surface plate 3 on which a printing plate is placed and a paper platen 4 on which a printing sheet is placed are provided on the upper surface of the substantially central portion of the main body frame 1, and the left side of FIG. A dampening water replenishing means 5 and a water leveling plate 6 for pumping and supplying dampening water are provided at the end portion of the above, and Y, M, C, and K color inks are kneaded at the right end portion. Ink kneading means 7, 8, 9 and 10 are provided respectively.

Positioning pins (not shown) provided on the plate surface plate 3 so as to be capable of projecting and retracting for positioning the printing plate,
A printing plate pressing mechanism (not shown) for pressing and fixing the printing plate on the platen is provided. The positioning pin and the printing plate pressing mechanism are configured to be manually operated by the operator, and the printing plates can be sequentially replaced and placed on the platen plate 3. Further, a printing paper pressing mechanism (not shown) for pressing and fixing the printing paper on the paper surface plate 4 is provided on the paper surface plate 4. The platen plate 3 is provided with a cooling mechanism (not shown) for cooling the printing plate to prevent the dampening water from drying.

The dampening water replenishing means 5 comprises a pallet 11 for storing dampening water and a water source roller 12 which is partially immersed in the pallet and rotates. When the dampening water supply roller 27 comes into contact with the water source roller 12 and rotates,
The dampening water provided on the carriage 2 is pumped up from the pallet 11 and supplied to the dampening water supply roller 27. Further, the water leveling plate 6 is made of flat molton, and when the dampening water supply roller 27 is in contact with the damming water supply roller 27,
The dampening water replenished on top is made uniform.

The ink kneading means 7, 8, 9 and 10 respectively include two rocking rollers 13, 14, 15 and 16 which rock in a direction perpendicular to the printing paper and these two rocking rollers. Intermediate rollers 17, 18, 19, 20 provided between 13, 14, 15, 16 are provided. Each ink kneading means 7, 8, 9, 10 is an ink supply roller 2.
The ink is transferred by contacting with 9, 30, 31, 32.

The carriage 2 receives dampening water from the dampening water replenishing means 5 and re-supplies it to the printing plate, and ink from the printing plate to re-transfer the ink to the printing paper. Ink supply means 23, 24, 2 for contacting one blanket 22 with each of the ink kneading means 7, 8, 9, 10 for supplying and receiving ink to supply the ink to the printing plate.
5, 26 are provided. And the body frame 1
Is provided with a cam plate (not shown) along the movement path of the carriage 2, and when the carriage 2 reciprocates, the dampening water supply means 5, the blanket 22, and the ink supply means 23, 24, The cam plates 25 and 26 move up and down to contact only the dampening water replenishing means 5, the printing plate, and the ink kneading means 7, 8, 9, and 10, respectively, as necessary.

The dampening water supply means 21 is provided with a plurality of dampening water supply rollers 27 and a free roller 28 installed in a free state on a part of the dampening water supply roller 27. As described above, the dampening water supply means 21 is composed of a plurality of rollers for the purpose of stabilizing and equalizing the dampening water holding amount. The dampening water supply roller 27 is the water source roller 12.
After receiving the dampening water from the water, contacting the water leveling plate 6 to level the dampening water, and contacting the printing plate to supply the dampening water.

The blanket 22 is the same rotating cylinder as a general printing machine or proofing machine. The blanket 22 contacts the printing plate supplied with dampening water and ink to transfer and receive the print image by the ink, and contacts the printing paper to retransfer the print image. Ink supply means 23, 24, 25, 2
6 is a plurality of ink supply rollers 29, 30, 31, 32
And a free roller 33 installed in a free state on a part of the ink supply rollers 29, 30, 31, 32,
34, 35, and 36 are provided. In this way, the ink supply means 23, 24, 25, 26 are also provided with a plurality of rollers in order to increase, stabilize, and make uniform the ink holding amount. Each ink supply roller 29, 30, 31, 32 contacts the ink kneading means 7, 8, 9, 10 to knead the ink, and then contacts the printing plate to supply the ink. In this embodiment, the ink supply means 23, 24, 25, 2
Only one of the six is selectively used.

The ink supply means 23, 24, 25 and 26 will be described in more detail with reference to FIG. In FIG. 3, the vicinity of the ink supply means 26 is shown enlarged. The ink supply means 26 is supported by a support frame 37, and the support frame 37 is an elevating mechanism 38 including an air cylinder or the like.
Move up and down. That is, when the ink supply unit 26 is not used, the elevating mechanism 38 retracts it above the carriage 2.

Although an air cylinder is used as the lifting mechanism 38 in this embodiment, a hydraulic cylinder, an electric motor, or the like may be used, or the lifting mechanism 38 may be manually moved up and down. Further, the ink is supplied to an ink supply roller, an ink kneading roller or the like by an ink application mechanism (not shown) or manually.

Next, the operation of this calibrator will be described. First, the operator places the printing plate on the platen 3,
In addition, the ink supply means corresponding to the printing color of the printing plate is selected from the ink supply means 23, 24, 25 and 26.
That is, the ink supply means not used is the lifting mechanism 38.
By this, it is retracted above the carriage 2. When the carriage 2 is on the right end side in FIG. 1, the ink supply means used comes into contact with the corresponding ink kneading means to knead and transfer the ink. When the carriage 2 is moved to the left end side by the drive mechanism, dampening water supply means 21 first supplies dampening water to the printing plate, and then ink is supplied from the used ink supply means to the printing plate.

When the carriage 2 moves to the left end side, the dampening water supply means 21 contacts the dampening water replenishing means 5 to replenish the dampening water. Further, the operator places the printing paper on the paper surface plate 4. Then, when the carriage 2 starts moving to the right end side again by the drive mechanism, the dampening water supply means 21 rolls on the water leveling plate 6 to level the dampening water. On the other hand, the selected ink supply means supplies ink to the printing plate again.
Then, the blanket 22 rolls the plate surface plate 3 to transfer the ink from the printing plate, and then rolls on the paper platen 4 to retransfer the ink to the printing paper. And dampening water supply means 2
1 newly supplies dampening water to the printing plate, and the carriage 2 returns to the right end side. The operator manually removes the printed printing paper.

After the above operation is cyclically performed and the proof printing is performed for a predetermined number of sheets, the printing plate is replaced. Along with this replacement, the ink supply means of a newly corresponding color is selected. On the other hand, the blanket 22 is used as it is without cleaning if it is a proof print of the same image. In addition, if the blanket is used as it is, the print quality will be lower than that of normal printing depending on the conditions of the ink and printing paper, but when inspecting the plate, only moderate quality is required, so there is no problem. I won't.

In this embodiment, a plurality of ink supply means 2
Since 3, 24, 25, and 26 are prepared and used by appropriately switching according to the color corresponding to the printing plate, it is not necessary to change the ink each time the printing color is changed. Further, since only one blanket 22 and one platen 3 are provided, the structure is simpler and space can be saved as compared with the conventional four-color machine. Further, in the proof printing of the same image, since the blanket 22 is not washed, the time required for the proof printing can be shortened and the plate inspection work can be performed quickly.

Although the ink supply means not used in this embodiment is retreated upward by the elevating mechanism 38,
It is also possible to switch the cam plates that bring the ink supply means 7, 8, 9, 10 into contact with the printing plate on the platen 3 so that only the necessary ink supply means comes into contact with the printing plate. [Second Embodiment] FIG. 4 is a side sectional view of a calibrator adopting a second embodiment of the present invention. This proofing machine includes a plate surface plate 51 on which a printing plate is placed, a plate surface plate moving mechanism 52 for reciprocating the plate surface plate 51, and a dampening water supply means 53 for supplying dampening water to the printing plate. , Ink supply means 54, 55, 56, 57 for supplying respective color inks of Y, M, C, K onto the printing plate.
A paper cylinder 58 that holds and rotates the printing paper, a blanket 59 that transfers the ink from the printing plate and retransfers it to the printing paper, and a feeding / discharging device for supplying / discharging the printing paper to / from the paper cylinder 58. A mechanism 60, a printing plate supply mechanism 61 for supplying a printing plate to the plate surface plate 51, and a printing plate discharge mechanism 62 for discharging a printing plate from the plate surface plate are provided.

The plate surface plate 51 is a plate surface plate moving mechanism 5 which will be described later.
2 reciprocates in the left-right direction in FIG. 4 along a guide guide (not shown). Further, on the platen plate 51, a positioning pin (not shown) that is provided so as to be retractable so as to position the printing platen, and a fixing means for fixing the printing platen by pressing to the platen plate 51 (see FIG. (Not shown) are provided. The platen plate moving mechanism 52 is rotationally driven by a pair of guide pulleys 63, a belt 64 stretched between the guide pulleys 63 and partially connected to the back surface of the platen plate 51, and a drive motor (not shown). Drive pulley 6 driven to drive belt 64
5 and. In addition, the belt 64 and the drive pulley 65
An auxiliary pulley 66 for guiding the belt 64 is provided in order to increase the contact area with the belt 64. The plate surface plate moving mechanism 52 reciprocates the plate surface plate 51 in accordance with the rotation of the drive pulley 65.

The dampening water supply means 53 includes a tray 67 for storing dampening water, a plurality of dampening water supply rollers 68 for supplying dampening water in contact with the printing plate, and a dampening water supply from the tray 67. A plurality of transfer rollers 69 for supplying dampening water to the rollers 68 are provided. The dampening water supply means 53 is fixed to the main body of the proofing machine, and the dampening water supply roller 68 is provided at a height where it contacts the printing plate when the plate surface plate 51 is reciprocated. Although the dampening water supply roller 68 is rotated by a transmission mechanism (not shown) in synchronization with the movement of the platen plate 51, another drive motor is provided to drive it in synchronization with the movement of the platen plate 51. You may do it. Ink supply means 54, 55, 5
Reference numerals 6 and 57 denote pump mechanisms 47 that are respectively connected to the ink tanks of the respective colors Y, M, C, and K and discharge the inks of the respective colors.
48, 49, 50 and a plurality of ink supply rollers 71, 72, 73 for kneading the discharged ink and supplying it to the printing plate.
And 74. For such an ink supply means, for example, the device disclosed in Japanese Patent Laid-Open No. 63-121146 is known. According to this, each pump mechanism 4
Nos. 7, 48, 49 and 50 are configured to be movable in the axial direction of the roller while ejecting ink, and the ink ejection amount can be varied and supplied according to the image density of each portion of the printing plate. .

FIG. 5 is a view showing the arrangement of the ink supply means 54. The ink roller 71 is provided below the pump mechanism 47, and has large diameter rollers 71A, 71B, 71C, 71.
D, small diameter rollers 71E, 71F and 71G, and arms 71H and 71I. The rollers 71A, 71F, 71B located directly under the pump mechanism 47 are fixed rollers having a fixed rotating shaft, and the rollers 71C, 7C that contact the printing plate.
1D and the rollers 71E and 71G provided thereon are free rollers. Further, with respect to the rotation axis of the roller 71B, the rollers 71C, 71 are provided via arms 71H, 71I.
D is rotated by a drive mechanism (not shown). Therefore, the arms 71H and 71I move up and down by the drive of the drive mechanism, and the rollers 71C and 71D move up and down with respect to the roller 71B accordingly. As a result, when the printing plate is supplied by the ink supply means 54, the roller 71 as shown in FIG.
When C and 71D are lowered and the printing plate is not supplied, the rollers 71C and 71D are raised as shown in FIG.
The other ink supply means 55, 56, 57 are also shown in FIG.
The ink roller means 54 has the same structure as the ink roller means 54.

The paper cylinder 58 is rotatably supported in synchronization with the blanket 59 by the engagement of a gear (not shown), and is a general sheet-fed type on a part of the peripheral surface of the paper cylinder 58. A gripping mechanism of a printing paper used in a printing machine or the like, that is, a blade 75 for sandwiching and fixing an end portion of the printing paper on a part of a body is provided. Therefore, the paper cylinder 58 rotates with the edge of the printing paper held by the blade 75.

The blanket 59 is a gear 7 capable of engaging and disengaging gears provided subordinate to the drive pulley 65.
It is connected to the drive pulley 65 by a belt 77 via 6. That is, the blanket 59 rotates in synchronization with the reciprocating movement of the platen 51 when the gear 76 is engaged with the drive pulley 65, and is free from the platen 51 when disengaged. become. On the other hand, a drive motor 78 that directly rotates the blanket 59 is also connected to the blanket 59. The drive motor 78 is for rotating the blanket 59 independently of the plate surface plate 51 when the gear 76 is in the disengaged state.

The blanket 59 is supported by a drive motor 78 so that it can be raised and lowered by an elevating mechanism.
That is, when the blanket 59 is located above, the blanket 59 is pressed against the paper cylinder 58 and connected so as to rotate synchronously by a gear (not shown), and the gear 76 is disengaged from the platen plate 51. Will be free. On the other hand, when the blanket 59 is located below, the blanket 59 is separated from the paper cylinder 58 and the gears are engaged with each other, so that the rotation of the blanket 59 and the movement of the platen plate 51 are synchronized.

The feeding / discharging mechanism 60 includes a supply pallet 79 for storing printing paper, a collection pallet 80 for collecting the printing paper after printing, a suction mechanism 81 for sucking and taking out the printing paper from the supply pallet 79. A roller transport mechanism 82 that transports the print paper taken out by the suction mechanism 81 to the paper cylinder 58, and a chain transport mechanism 8 that receives the print paper discharged from the paper cylinder 58 and transports it to the collection pallet 80.
3 is provided.

The supply pallet 79 is a dish-shaped container on which a plurality of printing sheets can be stacked, and is open at the top. The suction mechanism 81 is a suction cup 8 connected to a separately provided vacuum pump or the like.
The air cylinder 85 is vertically movable. Further, the suction mechanism 81 is reciprocally moved by a drive mechanism (not shown) so as to be able to come into contact with and separate from the roller transport mechanism 82.

The roller transport mechanism 82 includes a plurality of transport roller pairs 86 and a guide member 87 which is disposed between the transport roller pairs 86 and guides the transport of print paper.
The conveying roller pair 86 can be rotationally driven by a drive motor (not shown) to convey the printing paper to the paper cylinder 58. A stopper (not shown) is provided in the middle of the roller transport mechanism 82 so as to be retractable in the transport path in order to align the positions of the leading edge and the side edge of the printing paper.

The chain conveying mechanism 83 is composed of a chain delivery mechanism used in a sheet-fed printing machine or the like, and a chain provided with a nipping means (not shown) for nipping a printing paper is transferred from the paper cylinder 58 to the collection pallet 80. It is wound until it reaches. Therefore, by rotating the chain, the printing paper is nipped by the nip means and is collected from the paper cylinder 58 to the collection pallet 80.
Can be transported up to.

The recovery pallet 80 is composed of a dish-shaped container having an open upper surface, is slidable in the horizontal direction by a drive mechanism (not shown), and is configured so that the bottom part can be rotated to be opened. That is, when printing of a predetermined print color is completed, the collection pallet 80 is selectively moved to a position above the supply pallet 79 or a position deviated from above the supply pallet 79 as shown in FIG. Then, the bottom of the recovery pallet 80 is opened, and the printed printing paper slides down to the lower supply pallet 79 or the outside. Thus, when performing overprinting, the printing paper can be returned to the supply pallet 79 again, and the printing paper after the overprinting for four colors is completed can be discharged to the outside.

The printing plate supply mechanism 61 includes a mounting table 88 on which the printing plate is mounted, and a transport mechanism 89 for transporting the printing plate between the mounting table 88 and the platen 51. Mounting table 88
Are arranged so as to be space-saving, and the printing plate can be positioned and placed by the positioning pins 90. The transport mechanism 89 uses the belt transport mechanism 92 while the suction cup 91 connected to a separately provided vacuum pump can be moved up and down by an air cylinder (not shown).
8 and the platen plate 51 are configured to be reciprocally movable.

In the present embodiment, the mounting table 88 is provided so as to be inclined, but it may be installed horizontally. For example, when using this calibrator connected to a printing device, etc., by a conveyor, etc.,
By placing the mounting table 88 in a horizontal state so that the printing plate is directly conveyed from the conveyor, and by bringing the conveyed printing plate against the positioning pins 90 and positioning the printing plate with the end portion of the printing plate as a reference, it is necessary to manually move the printing plate. Automatic processing can be performed without intervention.

The printing plate discharging mechanism 62 is for discharging the printed printing plate from the platen plate 51, and a suction plate 93 connected to a separately provided vacuum pump is an air cylinder (not shown). The guide 9
4 is configured to be reciprocally movable between the plate surface plate 51 and the plate cleaning device 95. The plate cleaning device 95
Is a device for applying a cleaning liquid while transporting the printing plate and washing off the ink adhering to the printing plate with a cleaning roller, and a commercially available device can be connected and used.

Further, a sensor 96 for reading a bar code formed on the back surface of the printing plate is provided in the path along which the printing plate is conveyed from the mounting table 88 to the platen plate 51 by the conveying mechanism 89. This barcode is formed on the back surface of the printing plate by ink jet printing or sticking a sticker in the printing plate printing process, and records information such as the type of image and printing color of the printing plate. .
Therefore, when the calibrator is connected to a printing device or the like by a conveyor for continuous automatic operation, this sensor reads information such as the printing color of the printing plate and uses it as the printing color information of the printing plate to which ink should be supplied. Based on this, the drive mechanism of the ink supply means 54, 55, 56, 57 of the corresponding color is driven to supply the ink to the printing plate. As a result, it is possible to reliably supply the ink with the ink supply unit of the color corresponding to the printing plate.

It should be noted that a control device including a microcomputer for controlling the above-mentioned respective parts, a storage means, etc., an operating device for a worker to perform various operations, and a display device are provided. Next, the operation of the calibrator will be described using the flowchart of FIG. In step S1, first, the initial setting of each part, the origin return, and the like are performed. Next, in step S2, the printing plate placed on the mounting table 88 is placed on the platen plate 51 by the transport mechanism 89. That is, the suction cup 91 descends to the leading end side of the printing plate placed on the mounting table 88, that is, the side positioned by the positioning pin 90 to suck and hold it, and then the suction cup 91 rises to the leading end side of the printing plate. Is moved to the plate surface plate 51 positioned on the right end side in FIG. On the platen plate 51, a retractable positioning pin is projected, and the printing plate is lowered to position it. When the positioning is completed, the suction of the suction cup 91 is released to return it to the original position. Then, the printing plate is fixed to the plate surface plate 51 by the fixing means provided on the plate surface plate 51, and the positioning pins are retracted. When a barcode is formed on the back surface of the printing plate when the printing plate is conveyed, the sensor 96 reads the barcode to determine the printing color and the image type of the printing plate. At this time, if a printing plate of an image different from the previously printed image is supplied and the previously printed printing paper still remains in the supply cassette 79, an error alarm is issued to call attention to the operator. You can

Next, in step S3, the ink supply means to be used among the ink supply means 54, 55, 56, 57 is selected. That is, when the print color is determined by the sensor 96, the components other than the ink supply unit for the color are retracted upward by the elevating mechanism. When there is no bar code, the operator inputs a print color to instruct. The selected one of the ink supply means 54, 55, 56, 57 is
A predetermined amount of ink is kneaded according to a predetermined procedure, and preparation before supply is performed. The amount of ink is preferably determined from the image area ratio of the printing plate which is obtained in the previous step.

Next, the plate surface plate 51 starts moving from the right side to the left side in FIG. 4 by the plate surface plate drive mechanism 52. That is, in step S4, the dampening water supply means 53 supplies dampening water to the printing plate. Subsequently, in step S5, the selected one of the ink supply means 54, 55, 56, 57 supplies the ink of the printing color corresponding to the printing plate. In step S6, the blanket 59, which was previously set to rotate in synchronization with the platen 51, rolls the printing plate to transfer the ink. That is, the blanket 59 is lowered to the position where it rotates in synchronization with the platen plate 51 by the elevating mechanism. Therefore, the blanket 59 is not in contact with the cylinder 58 at this position.

In step S7, the print paper is supplied from the supply pallet to the paper cylinder 58 by the supply / discharge mechanism 60. First,
The suction mechanism 81 lowers the suction cup 84 by the air cylinder 85 to bring it into contact with the printing paper in the supply pallet 79,
Then, the vacuum pump is operated to adsorb the printing paper with the suction cup 84, and the suction cup 84 is raised. This raised position is set to a position where the sucked printing paper is at substantially the same height as the entrance of the roller transport mechanism 82. Then, the suction mechanism 81 is moved to the roller transport mechanism 82 side, and the printing paper is inserted into the entrance of the roller transport mechanism 82. When a predetermined sensor or the like detects that the printing paper is gripped in the roller transport mechanism 82, the suction of the suction cup 84 is released, and the suction mechanism 81 is returned to the original state. After positioning the leading edge and the side edge of the printing paper by the stopper, when the printing paper is inserted into the open blade 75 of the paper cylinder 58 by the roller transport mechanism 82, the blade 75
Close and hold the printing paper. The step S7 is
Since it has nothing to do with the operations of steps S2 to S6, step S
It may be performed in parallel before 6.

In step S8, proof printing is performed on the printing paper. First, the blanket 59 is raised by the elevating mechanism and comes into contact with the paper cylinder 58, and the synchronization with the platen plate 51 is released. Then, the blanket 59 is rotated by the drive motor 78, and at the same time, the paper cylinder 58 is synchronously rotated and pressure-contacted, and the ink on the blanket is retransferred to the printing paper.

In step S9, the printed printing paper is discharged from the paper cylinder 58 and collected in the collection pallet 80.
In this case, first, the blanket 59 is separated from the paper cylinder 58. Then, the paper cylinder 58 rotates and the blade 75
Is opened at a predetermined position, and the nipping means provided in the chain transport mechanism 83 nips the printing paper in place of the blade 75 at the same position. This allows
The printing paper moves from the paper cylinder 58 to the chain transport mechanism 83. Then, the holding means is moved by rotating the chain, and the printing paper is conveyed onto the collection pallet 80. Then, when the holding means is opened, the printing paper falls on the collection pallet 80.

In the next step S10, it is judged whether or not the number of prints set by the operator has reached a preset number. If the number of prints has not reached the predetermined number, the process returns to step S4 to perform proof printing again. If the predetermined number of prints has been reached in step S10, the process proceeds to the next step S11. In step S11, the printing plate is discharged from the platen plate 51. In this case, first,
The suction plate 93 is lowered with the plate surface plate 51 positioned at the left end of the plate, and the front end of the printing plate is suction-held. And sucker 9
3 is moved up and moved to the plate cleaning device 95 side along the guide 94 to convey the printing plate. When the printing plate reaches the conveyor at the entrance of the plate cleaning device 95, the suction of the suction cup 93 is released and the printing plate is dropped. The plate cleaning device 95 detects that the printing plate is placed on the conveyor with a sensor or the like, and conveys the printing plate into the device for cleaning.

In the next step S12, it is determined whether the same image has been overprinted for four colors. That is, it is determined whether or not the printing plates of the same image are continuously overprinted for four colors of Y, M, C, and K. This calibrator stores the type and printing color of the image of the printing plate obtained by the sensor 96 or input by the operator in the storage means of the control device. From this storage result, it is checked whether four colors of the same image have been printed. Therefore, when printing plates of different images are supplied in the course of overprinting as in step S2,
Overprinting is stopped due to an error. This step S1
If the printing of the same image in 2 is not completed for 4 colors, the color proof printing is not completed, so step S1
It returns to step S2 via 6. In step S16,
The bottom of the collection pallet 80 is opened, and the printed printing paper is dropped onto the supply pallet 79 again. Then, returning to step S2, overprinting with the printing plate of the next color is performed.

When it is determined in step S12 that the overprinting for four colors is completed, the process proceeds to the next step S13. In step S13, a cleaning device (not shown) is instructed to clean the blanket 59. Although this cleaning device is a general blanket automatic cleaning device, an operator may manually clean it based on a command without using the cleaning device. Various types of this blanket automatic cleaning device have been put to practical use, for example, a type is known in which the cleaning liquid is applied and wiped by contacting with a cloth roll.

In step S14, the printing paper is taken out of the collection pallet 80. That is, the collection pallet 80 is slid to a position retracted from above the supply pallet 79, the bottom of the pallet is opened, and the printing paper is dropped to the outside. Note that the worker may manually take out according to the display of print completion. In step S15, it is determined whether or not a series of operations has been completed. That is, if the operator gives an instruction to finish the work, each ink supply means 5
The machine is stopped after automatically cleaning 4, 55, 56 and 57, respectively. If the end of work is not instructed, step S
Return to 1.

As the automatic cleaning of the ink supply means, a general ink roller cleaning device, for example, a cleaning device of a type that scrapes off the ink cleaned with a rubber blade while applying a cleaning liquid is known. Illustration is omitted in this embodiment. [Other Embodiments] (1) In the above-described first and second embodiments, the case of four-color printing is described. However, even when five or more colors are used, the ink supply means is added. It can be carried out. (2) In the above-described first embodiment, the printing plate and the printing paper are manually supplied and discharged, but they may be automatically supplied. (3) In the above-described second embodiment, the printing plate is held in the paper cylinder by reciprocating only the plate surface plate. However, the paper platen is provided in place of the paper cylinder, and the plate surface plate is provided. May be reciprocated together with the plate.

[0054]

As described above, according to the proof printing method of the first aspect of the present invention, printing plates having different printing colors of the same image are sequentially replaced without washing or replacing the same blanket, and monochromatic printing is performed. Since it is done, the time for plate inspection work by the proof machine can be shortened, and the ink used in the previous proof printing remains on the blanket, so compared to the case of using the conventional 4 color machine. Back-trapping can be prevented to some extent, and good quality proof printing can be performed.

According to the proofreading machine of the second aspect, since four or more ink supplying means are switched to perform multicolor proof printing, there is no need to wash the ink supplying means, and the proof printing is performed in a short time. Can be done. Further, since only one blanket and one plate are provided, the structure is simpler than that of the conventional four-color machine, and the calibration machine can be downsized.

According to the proofreading machine of claim 3, when the platen is moved by the platen driving means, dampening water or the like is supplied to the printing plate placed on the platen. Since there is no need for a space for moving the dampening water supply means and the like, there is an effect that the calibrator can be further downsized. According to the proofreading machine of claim 4, since the information of the printing color is detected from the printing plate before the ink is supplied and the ink supplying means is switched based on the information, the color corresponding to the printing plate is detected. The ink can be surely supplied by the ink supply means.

[Brief description of drawings]

FIG. 1 is a side sectional view of a calibrator according to a first embodiment.

FIG. 2 is an enlarged partial view of the calibrator.

FIG. 3 is a diagram for explaining the raising and lowering of the ink supply means of the calibration machine.

FIG. 4 is a side sectional view of another calibrating machine according to the second embodiment.

FIG. 5 is a diagram for explaining the raising and lowering of the ink supply means of the proofreading machine.

FIG. 6 is a flowchart showing the operation of the calibrator.

[Explanation of symbols]

 2 carriage 3 plate surface plate 4 paper surface plate 5 dampening water supply means 7, 8, 9, 10 ink kneading means 21 dampening water supply means 22 blanket 23, 24, 25, 26 ink supply means 38 lifting mechanism 51 plate surface Board 52 plate surface moving mechanism 53 dampening water supply means 54, 55, 56, 57 ink supply means 58 paper cylinder 59 blanket 60 supply / discharge mechanism 96 sensor

Claims (4)

[Claims] 1. A proofreading printing method using offset printing, wherein when printing plates of different printing colors of the same image are sequentially replaced to perform continuous monochromatic printing, the same blanket is not washed or replaced. A proof printing method characterized by continuously printing using a blanket of. 2. A proofreading machine using offset printing, comprising one plate surface plate on which a printing plate is mounted, and dampening water for supplying dampening water to the printing plate surface mounted on the plate surface plate. Supplying means, four or more ink supplying means for supplying ink to the printing plate placed on the platen, and switching means for switching the ink supplying means with and without supplying ink to the printing plate A blanket for transferring ink from the printing plate; a printing paper holding means for holding a printing paper on which the ink transferred to the blanket is retransferred; the dampening water supply means, the ink supply means, A calibrator comprising: a blanket and a drive unit that relatively moves the platen. 3. The calibrating machine according to claim 2, wherein the driving means is a plate surface plate driving means for moving the plate surface plate. 4. The proofing machine according to claim 2, further comprising a detection unit for detecting information on the printing color of the printing plate from the printing plate before ink is supplied, and the detection unit detects the information. A calibrating machine, characterized in that the switching means switches the ink supply means on the basis of print color information.