CN111688352B

CN111688352B - Intermittent printing machine

Info

Publication number: CN111688352B
Application number: CN202010168715.3A
Authority: CN
Inventors: 藤原铃司; 小田岛和见; 油谷努; 鱼住忍
Original assignee: Miyakoshi Printing Machinery Co Ltd
Current assignee: Miyakoshi Printing Machinery Co Ltd
Priority date: 2019-03-14
Filing date: 2020-03-12
Publication date: 2022-08-16
Anticipated expiration: 2040-03-12
Also published as: AU2020201139A1; JP7088556B2; EP3711952B1; CN111688352A; EP3711952A1; JP2020146941A; KR20200110171A

Abstract

An intermittent printer is provided, which can not generate sliding when a printing substrate is driven, and can not generate printing register deviation. A print substrate W is moved forward by driving a feed-side reverse roller 6 and a discharge-side reverse roller 10 in a synchronized forward rotation manner, an image is printed on the print substrate W by a platen 9 and a blanket cylinder 8, and the print substrate W is moved backward by driving the feed-side reverse roller 6 and the discharge-side reverse roller 10 in a synchronized reverse rotation manner. A printing substrate W is wound around the peripheral surface of the pressure cylinder 9 at a predetermined wrap angle, and the printing substrate W is pressed against the peripheral surface of the pressure cylinder 9 by a nip roller 42 for the pressure cylinder, and the pressure cylinder 9 is rotationally driven in the forward direction and rotationally driven in the reverse direction in synchronization with the feed-side reverse roller 6 and the discharge-side reverse roller 10.

Description

Intermittent printing machine

Technical Field

The present invention relates to a batch printing press.

Background

The intermittent printer prints an image while repeatedly moving a printing substrate in the forward direction, and after printing, moves the printing substrate in the reverse direction without printing an image, and prints an image by moving the printing substrate in the forward direction again, thereby reducing the gap between the image and the printing substrate.

For example, a batch printer is disclosed in japanese patent application laid-open No. 2-75561.

The intermittent printing machine is provided with a plurality of printing units between two feed rollers which are driven in forward rotation and in reverse rotation, wherein the printing units are provided with a plate cylinder, a blanket cylinder and a pressing cylinder. The peripheral surface of the blanket cylinder has a large diameter portion which is in pressure contact with the peripheral surface of the pressing cylinder and a small diameter portion which is spaced apart from the peripheral surface of the pressing cylinder.

When the printing substrate is moved forward by driving the two feed rollers in forward rotation, the large diameter portion of the blanket cylinder and the circumferential surface of the impression cylinder are pressed against each other to print an image on the printing substrate. After printing an image, the two feed rollers are driven in reverse rotation to move the substrate to be printed in the reverse direction. When the printing substrate travels in the reverse direction, the printing substrate passes through the gap between the small diameter portion of the blanket cylinder and the peripheral surface of the impression cylinder, and therefore no image is printed.

By repeating this operation, the image is printed on the printing substrate with the gap in the vertical direction reduced.

In this intermittent printing machine, the printing substrate passes through the gap between the small diameter portion of the blanket cylinder and the circumferential surface of the blanket cylinder when traveling in the reverse direction, and therefore the printing substrate is not sandwiched between the blanket cylinder and is in a state where the movement is not restricted.

Therefore, when the printing substrate travels in the reverse direction, the printing substrate is likely to be misaligned or loosened. If the substrate to be printed is misaligned or loosened, the substrate to be printed may be damaged or contaminated by contact with a blanket cylinder or a blanket cylinder.

A batch printer that eliminates this problem is disclosed in japanese patent laid-open No. 2006-247869.

In this intermittent printing machine, two guide rollers are provided, and a printing substrate is wound around the circumferential surface of a platen at a predetermined winding angle, and the platen is driven to rotate forward and backward in synchronization with the two feed rollers.

According to this intermittent printer, the printing substrate is wound around the circumferential surface of the platen, and the movement of the printing substrate is restricted when the printing substrate travels in the reverse direction. Therefore, when the printing substrate travels in the reverse direction, the printing substrate does not become misaligned or loose.

Disclosure of Invention

Problems to be solved by the invention

As disclosed in japanese patent application laid-open No. 2006-247869, when printing is performed by an intermittent printer in which a printing substrate is wound around a platen and the platen is driven in forward and reverse rotations, there is a case where a deviation in printing registration occurs. In particular, when printing is performed using a printing target substrate having a high surface smoothness and using a film as a printing target substrate, a variation in printing registration occurs significantly.

The present inventors have examined the cause of the occurrence of the misalignment of printing, and as a result, have found the following, and have made the present invention.

Since the printing substrate is wound around the circumferential surface of the platen, it is difficult to move the printing substrate in a sliding manner on the circumferential surface of the platen, and therefore, the printing substrate moves in the forward direction and the reverse direction by driving the platen in forward rotation and in reverse rotation in synchronization with the feed roller.

Therefore, when the printing target substrate travels in the reverse direction or when the direction is switched, the circumferential surface of the platen and the small diameter portion of the blanket cylinder are separated, the printing target substrate is not in contact with the small diameter portion of the blanket cylinder, and the printing target substrate travels only by the frictional force generated between the circumferential surface of the platen and the printing target substrate.

If a slip occurs between the peripheral surface of the impression cylinder and the printing substrate, when the printing substrate is moved in the forward direction and an image is printed, the position where the tip of the large diameter portion of the blanket cylinder in the rotation direction comes into contact with the printing substrate is shifted in the vertical direction, and therefore, the printing registration is shifted.

Further, since the length of the slip is not constant and varies, the printing register varies.

When printing is performed using a printing target substrate having a high surface smoothness, slippage is likely to occur between the printing target substrate and the circumferential surface of the platen, and therefore, a variation in printing registration occurs significantly.

When a film is used as the printing substrate, since the film has a high density and air does not flow, the air remaining between the peripheral surface of the press cylinder and the film cannot escape from the surface of the film through the film in a state where the film is wound around the peripheral surface of the press cylinder.

Further, if the rotation speed of the platen (the traveling speed of the printing substrate) increases, air may be drawn between the peripheral surface of the platen and the film to form an air layer.

From these facts, it is understood that, when a film is used as a printing substrate, since the friction force between the circumferential surface of the platen and the film is small and the slip is likely to occur, the deviation of the printing registration occurs remarkably.

The present invention has been made to solve the above-described problems, and an object thereof is to provide an intermittent printing press in which, when a printing substrate is moved, no slippage occurs between the peripheral surface of a platen and the printing substrate, and no deviation in printing registration occurs.

Means for solving the problems

An intermittent printer includes a paper feeding unit for feeding a substrate to be printed; a printing section having a plurality of printing units for printing an image on a substrate to be printed fed from the paper feeding section; and a paper discharge unit for discharging the printed substrate on which the image is printed,

the paper feeding part is provided with a buffer device on the paper feeding side and a back roller on the paper feeding side, and the buffer device on the paper feeding side stores the printed base materials into a ring shape; the reverse roller on the paper feeding side is driven by forward rotation for moving the printing substrate in the forward direction and reverse rotation for moving the printing substrate in the reverse direction,

the printing unit includes a platen and a blanket cylinder having an image area in contact with the peripheral surface of the platen and a non-image area not in contact with the peripheral surface of the platen,

the paper discharge unit has a paper discharge-side reverse roller that is driven to rotate forward to move the printing substrate in a forward direction and a paper discharge-side buffer device that stores the printing substrate on which the image is printed in a ring shape,

the printing substrate is moved forward by driving the feed-side reverse roller and the discharge-side reverse roller in a synchronized forward rotation, an image is printed on the printing substrate in an image range of the blanket cylinder and the peripheral surface of the platen, and the printing substrate is moved backward by driving the feed-side reverse roller and the discharge-side reverse roller in a synchronized reverse rotation, through a gap between the peripheral surface of the platen and a non-image range of the blanket cylinder,

the intermittent printing press is characterized in that,

a paper-feeding side guide roller and a paper-discharging side guide roller for winding the printing substrate passing through the space between the peripheral surface of the pressing cylinder and the blanket cylinder at a predetermined winding angle on the peripheral surface of the pressing cylinder,

a grip roller for pressing the printing substrate wound around the circumferential surface of the pressing cylinder against the circumferential surface of the pressing cylinder,

the platen is driven to rotate forward in synchronization with the paper feed-side reverse roller and the paper discharge-side reverse roller when the printing substrate is moved in the forward direction, and the platen is driven to rotate backward in synchronization with the paper feed-side reverse roller and the paper discharge-side reverse roller when the printing substrate is moved in the reverse direction,

comprises a drying device for drying the printed substrate wound around the circumferential surface of the pressing cylinder and a cooling device for cooling the pressing cylinder,

the drying device is located upstream of the nip roller for the platen in the forward rotation direction of the platen.

In the intermittent printing press according to the present invention, the paper feed-side guide roller and the paper discharge-side guide roller are provided such that an extension line of a paper feed-side travel path between the paper feed-side guide roller and the platen intersects with an extension line of a paper discharge-side travel path between the paper discharge-side guide roller and the platen.

According to this intermittent printer, the roll angle of the printing substrate wound around the circumferential surface of the platen can be set to 180 degrees or more, the frictional force between the circumferential surface of the platen and the printing substrate is large, and the occurrence of slippage can be reliably prevented.

In the intermittent printing press of the present invention, the blanket cylinder is normally rotated at a constant speed equal to the blanket cylinder when the blanket cylinder is rotated from the printing start position in the image range to print an image on a printing substrate, the blanket cylinder is decelerated and normally rotated from the constant speed to stop the rotation when the blanket cylinder is rotated from the printing end position in the non-image range, the blanket cylinder is accelerated and reversely rotated until a predetermined reverse rotation driving speed after the rotation is stopped, the blanket cylinder is decelerated and reversely rotated from the predetermined reverse rotation driving speed to stop the rotation, and the blanket cylinder is accelerated and normally rotated until the constant speed after the rotation is stopped, so that the rear end of the print image printed on the printing substrate is brought into contact with the front end of the printing range of the blanket cylinder.

According to this intermittent printer, since the platen roller gradually stops rotating and gradually starts rotating, the generation of slip between the printed substrate and the peripheral surface of the platen roller can be prevented, and a failure or the like does not occur in the drive system of the platen roller.

In the intermittent printing press of the present invention, a curve showing a change in a rotational drive speed ratio of the deceleration forward rotation drive and a curve showing a change in a rotational drive speed ratio of the acceleration forward rotation drive of the platen are line-symmetric, a curve showing a change in a rotational drive speed ratio of the acceleration reverse rotation drive and a curve showing a change in a rotational drive speed ratio of the deceleration reverse rotation drive of the platen are line-symmetric, and a rotational drive speed ratio of the platen from the constant speed to the predetermined reverse rotational drive speed and a rotational drive speed ratio of the platen from the predetermined reverse rotational drive speed to the constant speed smoothly change along a substantially U-shaped curve.

According to this intermittent printing machine, since the platen smoothly changes the speed and the printing substrate smoothly travels in the reverse direction and the forward direction, it is possible to prevent the occurrence of slippage between the printing substrate and the circumferential surface of the platen and to accurately print on the printing substrate.

In the intermittent printer of the present invention, a register adjusting device is provided between the printing units, and the register adjusting device is configured to adjust the printing register by changing the length of the traveling path of the printing target substrate between the printing units.

According to this intermittent printing machine, since the length of the traveling path between the printing units is changed to adjust the printing register before printing, the printing register can be adjusted in a state where the printing substrate is wound around the circumferential surface of the platen.

In the intermittent printing press of the present invention, the registration adjusting device has a pull roll on a paper feed side, a pull roll on a paper discharge side, and a movable roll, and is configured to change a length of a travel path between the pull roll on the paper feed side and the pull roll on the paper discharge side by moving the movable roll, and the pull rolls are respectively provided with pinch rolls for pull rolls which are driven by forward rotation driving for moving the printed substrate in a forward direction and reverse rotation driving for moving the printed substrate in a reverse direction in synchronization with the reverse roll on the paper feed side and the reverse roll on the paper discharge side, and press the printed substrate wound around the peripheral surfaces of the pull rolls against the peripheral surfaces of the pull rolls.

According to this intermittent printing press, since no slip occurs between the peripheral surface of the feed-side pull roller and the printing substrate, and no slip occurs between the peripheral surface of the discharge-side pull roller and the printing substrate, no deviation in printing registration occurs due to the registration adjusting device.

In the intermittent printing press of the present invention, the rotation speed of the feed-side reverse roller, the rotation speed of the discharge-side reverse roller, the rotation speed of the press cylinder of each printing unit, the rotation speed of the feed-side pull roller and the rotation speed of the discharge-side pull roller of each registration adjustment device may be controlled individually.

According to this intermittent printer, the tension of the printed substrate can be adjusted for each printing unit.

In the intermittent printing press of the present invention, at least two pull rolls on which the printing substrate is wound are provided on a traveling path of the printing substrate between the printing units, and the pull rolls are provided with pinch rolls for pull rolls which are driven by forward rotation for traveling the printing substrate in a forward direction and reverse rotation for traveling the printing substrate in a reverse direction in synchronization with the feed-side reverse roll and the discharge-side reverse roll, and press the printing substrate wound around the peripheral surface of each of the pull rolls against the peripheral surface of each of the pull rolls.

According to this intermittent printer, the printed substrate traveling on the traveling path between the printing units does not become misaligned or loose.

Further, the friction force between the peripheral surface of the pull roll and the printing substrate is increased, and the slip does not occur between the peripheral surface of the pull roll and the printing substrate, and the deviation of printing registration does not occur due to the installation of the pull roll.

In the intermittent printer of the present invention, the substrate to be printed is a film.

According to this intermittent printer, an image can be printed on a film without causing a deviation in printing registration.

According to the intermittent printing press of the present invention, when the printing substrate is caused to travel, since no slip occurs between the peripheral surface of the platen and the printing substrate, no deviation in printing registration occurs.

Since the ink of the image printed on the printing substrate is fixed and dried by the drying device, there is no disturbance of the image due to contact of the nip roller for the platen and the like, and there is no contamination of the nip roller for the platen with the ink.

Since the platen is cooled by the cooling device, the platen and the printing substrate do not have a high temperature.

The printed base material can be stored in a ring shape by the buffer device on the paper feeding side and the buffer device on the paper discharging side, and the printed base material can smoothly travel in the forward direction and the reverse direction.

Drawings

Fig. 1 is an overall front view of an intermittent printer of an embodiment of the present invention.

Fig. 2 is an enlarged front view of a paper feeding unit and a paper feeding unit of the intermittent printer shown in fig. 1.

Fig. 3 is an enlarged front view of a paper discharge section and a post-processing section of the intermittent printer shown in fig. 1.

Fig. 4 is an enlarged front view of two printing unit portions of the intermittent printer shown in fig. 1.

FIG. 5 is a view illustrating the construction of the cliche, the blanket cylinder and the impression cylinder.

Fig. 6 is an explanatory diagram of the operation from the start of printing to the end of printing when the printing unit first prints.

Fig. 7 is an explanatory diagram of the operation of the printing unit from the end of the first printing to the start of the second printing.

Fig. 8 is an explanatory view of the operation from the start of printing to the end of printing in the second printing.

Fig. 9 is a graph showing the ratio of the rotation angle and the rotational driving speed of the platen to the rotation angle of the blanket cylinder.

Fig. 10 is a graph showing a change in the rotational driving speed of the platen.

Fig. 11 is an explanatory diagram of a printing unit in which a blanket having a short size is installed.

Fig. 12 is a graph showing the ratio of the rotation angle and the rotational driving speed of the platen to the rotation angle of the blanket cylinder.

Fig. 13 is an explanatory view of a printing unit mounted with a long-sized blanket.

Fig. 14 is a graph showing the ratio of the rotation angle and the rotational driving speed of the platen to the rotation angle of the blanket cylinder.

Fig. 15 is an enlarged front view of the platen portion of the printing unit shown in fig. 4.

Fig. 16 is a front view of the mounting portion of the grip roller for the platen shown in fig. 4.

Fig. 17 is a sectional view a-a of the mounting portion of the grip roller for the platen shown in fig. 16.

Fig. 18 is a front view of the mounting portion of the platen shown in fig. 4.

Fig. 19 is a B-B sectional view of the mounting portion of the platen shown in fig. 18.

Fig. 20 is an enlarged front view of the registration adjustment apparatus shown in fig. 4.

Fig. 21 is a C-C sectional view of the registration adjustment apparatus shown in fig. 20.

Fig. 22 is an explanatory diagram of tension adjustment of the printing target substrate in each printing unit.

Fig. 23 is a front view showing another embodiment of a path along which a printing substrate travels between printing units.

Detailed Description

Preferred modes for carrying out the invention

The overall basic structure of the intermittent printer of the present invention is explained based on fig. 1. Fig. 1 is an overall front view of an intermittent printer of an embodiment of the present invention.

The intermittent printer 100 includes a paper feed unit 1A that feeds a printing target substrate W; a paper feeding unit 1B for feeding a supplied printing substrate W from the paper feeding unit 1A; a printing unit 2 for printing an image on the substrate W fed from the paper feeding unit 1B; a paper discharge unit 3A that discharges a printed substrate W on which an image is printed (hereinafter simply referred to as a printed substrate W); and a post-processing section 3B for performing post-processing on the printing substrate W.

The printing substrate W used in the intermittent printer 100 of this embodiment is a flexible film having high surface smoothness. For example, the raw material of the flexible package is used.

In general, a flexible package is a packaging material made of a material having high flexibility, and is a generic name of a package in which a thin flexible material such as polypropylene (PP) or Polyethylene (PE) is used alone or in a stuck state.

Since they are film materials, they have higher surface smoothness and flexibility than paper. Further, as the same substrate W to be printed, synthetic paper by a film method or the like can be used.

In the embodiment of the present invention, the paper feed portion 1A is a paper feed device 4 described later in detail that feeds a printing target substrate W.

The paper feeding section 1B has a buffer 5 on the paper feeding side for storing the printing substrate W fed from the paper feeding device 4 in a loop; and a paper-feeding-side reverse roller 6 for running the printing substrate W stored in the paper-feeding-side buffer 5.

The printing section 2 has a plurality of printing units. For example, a first printing unit 2a having a function of printing with ink of a color of black (K); a second printing unit 2b that prints using ink of a color of cyan (C); a third printing unit 2c that prints using magenta (M) color ink; a fourth printing unit 2d that prints using ink of a color of yellow (Y); and 6 printing units of a fifth printing unit 2e and a sixth printing unit 2f for performing solid white printing.

The first to fourth printing units 2a to 2d perform different monochromatic color printing on the printing substrate W.

After the color printing, the fifth and

sixth printing units

2e and 2f perform solid white printing on the printing substrate W.

The color printing is recognized from the side passing through the printing target substrate W on the opposite side of the printing surface side. White solid is used as a background color for improving the visibility of color printing.

Since the printing section 2 has 6

printing units

2a, 2b, 2c, 2d, 2e, and 2f, the length of the path of the substrate W to be printed between the backing rollers (the distance from the backing roller 6 on the paper feed side to the backing roller 10 on the paper discharge side described later) is longer than that of an intermittent printer having 4 printing units as in the printing section disclosed in japanese patent laid-open No. 2006-247869, and thus, the deviation of the printing registration is likely to occur.

The 6

printing units

2a, 2b, 2c, 2d, 2e, 2f are of identical construction, with 3 cylinders of a plate cylinder 7, a blanket cylinder 8 and a impression cylinder 9.

The paper discharge section 3A has a paper discharge-side reverse roller 10 for running the printing substrate W; a buffer device 11 on the paper discharge side for storing the printing substrate W running from the reverse roller 10 on the paper discharge side in a loop; an automatic registration device 38 described later; and a monitoring device 39.

In the embodiment of the present invention, the post-processing section 3B is a winding device 12 that winds the printing substrate W stored in the buffer device 11 on the paper discharge side.

The basic printing operation of this intermittent printer is as follows.

In a state where the printing substrate W is stored in a loop by the buffer 5 on the paper feeding side and the buffer 11 on the paper discharging side, the reverse roller 6 on the paper feeding side and the reverse roller 10 on the paper discharging side are driven to rotate forward in synchronization, and the printing substrate W is moved in the forward direction (the direction from the paper feeding unit 1B to the paper discharging unit 3A) to print an image.

After printing, the paper-feeding-side reverse roller 6 and the paper-discharging-side reverse roller 10 are synchronously driven in reverse rotation to run the printed substrate W in the reverse direction (the direction from the paper-discharging unit 3A toward the paper-feeding unit 1B), and if the vertical position is adjusted so that the rear end of the printed image becomes the next printing start position, the image is printed while the paper-feeding-side reverse roller 6 and the paper-discharging-side reverse roller 10 are driven in forward rotation to run the printed substrate W in the forward direction. This operation is repeated to print an image on the printing substrate W with a gap in the vertical direction reduced. That is, the basic printing operation is the same as that of the conventional intermittent printer.

A paper feeding device 4 having a paper feeding shaft 20 on which a printing substrate W is wound in a roll shape as shown in fig. 2; a feed roller 21 for feeding out the printing substrate W mounted on the paper feed shaft 20; a corona treatment device 24 described in detail later; a tension detecting device 25; and a bending travel prevention device 26. That is, the paper feeding device 4 is provided from the paper feeding shaft 20 to the feeding roller 21.

A magnetic particle brake, not shown, is coupled to the paper feed shaft 20, and can apply rotational resistance to the paper feed shaft 20.

The printing substrate W fed from the paper feed shaft 20 is wound around the circumferential surface of the feed roller 21. A drive motor (not shown) is connected to the feed roller 21, and the feed roller 21 is rotated and driven by the drive motor only in the direction in which the printing substrate W is fed out (clockwise direction in fig. 2).

The feed roller 21 is not rotationally driven in the direction opposite to the feeding direction (counterclockwise in fig. 2).

At least one nip roller 22 is pressed against the peripheral surface of the feed roller 21. The pinch roller 22 and the feed roller 21 thus pinch the printing substrate W, and the feed roller 21 is rotationally driven by the drive motor, whereby the printing substrate W is stretched, and the paper feed shaft 20 is rotated to discharge the roll-shaped printing substrate W and reliably feed the roll-shaped printing substrate W toward the buffer device 5 on the paper feed side. The grip roller 22 is pressed against the circumferential surface of the feed roller 21 within a range in which the printing substrate W is wound.

When the printing substrate W is fed out, the paper feed shaft 20 rotates, but since a rotational resistance is applied to the paper feed shaft 20 by the magnetic particle brake, a tension having a value that offsets the magnitude of the rotational resistance (braking force) is generated in the printing substrate W.

A running path 23 of the printing substrate W from the paper feed shaft 20 to the feed roller 21 is provided with a corona treatment device 24, a tension detection device 25, and a meandering prevention device 26.

The corona treatment device 24 performs corona treatment on the surface of the printing substrate W. By performing the corona treatment, the surface of the printing substrate W is modified, and the fixing property of the ink to the printing substrate W is improved. The substrate W to be printed used in this embodiment is a material for flexible packaging such as a film, and is preferably subjected to corona treatment because ink fixing property is inferior to that of paper.

The tension detecting device 25 detects the tension of the printing substrate W fed from the paper feed shaft 20. The detected tension value is compared with a set tension value by a control unit, not shown. The control unit adjusts the braking force of the magnetic powder brake so that the detected tension value and the set tension value are the same, and normally the printing substrate W can be discharged at the set tension value.

The meandering preventing device 26 detects the position of the printing substrate W in the width direction, and moves the printing substrate W in the width direction to the position in the predetermined width direction when the position deviates from the predetermined position. This prevents the widthwise position of the printing substrate W from being displaced. The width direction of the printing substrate W is a direction perpendicular to the discharge direction.

As shown in fig. 2, the buffer 5 on the paper feeding side has an upwardly recessed portion 5A such as a box having an open upper portion and a suction device (not shown) for sucking air in the upwardly recessed portion 5A, and the air in the upwardly recessed portion 5A is sucked by the suction device, whereby the printing substrate W is sucked into the upwardly recessed portion 5A and stored in a ring shape. The suction force of the suction device is controlled to be a tension at which the to-be-printed substrate W stored in the upper concave portion 5A travels without bending.

The rotation speed of the feed roller (transport roller) 21 is controlled in accordance with the output of a sensor (not shown) attached to the buffer device 5 so that the length of the printing substrate W stored in the upper concave portion 5a is within a predetermined range.

As shown in fig. 2, the backward roller 6 on the paper feeding side includes two driving rollers 27 and at least two pinch rollers 28, the two driving rollers 27 are driven by a driving motor, not shown, in a forward rotation manner and in a reverse rotation manner, and the at least two pinch rollers 28 are pressed against the peripheral surfaces of the respective driving rollers 27. The two driving rollers 27 are provided at intervals in the vertical direction.

The printing substrate W runs across the two driving rollers 27 in a reverse S-shape by winding, and is nipped by the driving rollers 27 and the nip roller 28. The two nip rollers 28 are pressed against the printing substrate W at positions spaced apart from each other in the rotational direction within a range around the peripheral surface of the driving roller 27.

Therefore, the printing substrate W can be reliably moved in the forward and reverse directions by driving the driving roller 27 in the forward and reverse directions.

In this embodiment, the paper feeding unit 1A (paper feeding device 4) and the paper feeding unit 1B (buffer device 5 on the paper feeding side, reverse roller 6 on the paper feeding side) are configured as a single unit, but the present invention is not limited thereto.

For example, the paper feeding unit 1A (paper feeding device 4) may be one unit, and the paper feeding unit 1B (the buffer device 5 on the paper feeding side and the reverse roller 6 on the paper feeding side) may be another unit. In this case, it is preferable to provide a feed roller on the paper feed side of the buffer 5 on the paper feed side. That is, in the paper feeding unit 1A and the paper feeding unit 1B shown in fig. 2, the feed roller 21 of the paper feeding device 4 also serves as the feed roller of the buffer device 5 on the paper feeding side.

As shown in fig. 3, the reverse roller 10 on the paper discharge side includes two drive rollers 30 that are driven by a drive motor, not shown, in a forward rotation manner and a reverse rotation manner, and at least two pinch rollers 31 that are pressed against the peripheral surfaces of the drive rollers 30. The two drive rollers 30 are provided at a distance in the vertical direction.

The printing substrate W travels over the two driving rollers 30 while being wound in an S-shape, and is sandwiched between the driving rollers 30 and the nip roller 31. The two nip rollers 31 are pressed at positions spaced apart from each other in the rotational direction in a range in which the printing substrate W is wrapped around the peripheral surface of the drive roller 30.

Therefore, the printing substrate W can be reliably moved in the forward and reverse directions by driving the driving roller 30 in the forward and reverse directions.

The reverse roller 10 (drive roller 30) on the paper discharge side and the reverse roller 6 (drive roller 27) on the paper feed side are driven to rotate in the forward direction and in the reverse direction in synchronization with each other.

The buffer 11 on the paper discharge side has an upward recessed portion like a box with an open upper portion; a suction device (not shown) for sucking air in the upper recess 11 a; and a feed roller 33 for conveying the printing substrate W toward the post-processing section 3B, wherein the suction device sucks the air in the upwardly recessed portion 11a, thereby sucking the printing substrate W into the upwardly recessed portion 11a and storing the printing substrate W in a loop.

The suction force of the suction device is controlled to a tension at which the printing substrate W stored in the upward concave portion 11a does not curve.

The rotation speed of the feed roller 33 is controlled in accordance with the output of a sensor (not shown) attached to the buffer device 11 so that the length of the printing substrate W stored in the upper concave portion 11a falls within a predetermined range.

The printing substrate W fed from the buffer device 11 on the paper discharge side is wound around the circumferential surface of the feed roller 33. A drive motor (not shown) is coupled to the feed roller 33, and the printing substrate W is rotationally driven by the drive motor only in a direction of being conveyed toward the post-processing section 3B (clockwise in fig. 3), and does not rotate in a direction of being conveyed in a direction opposite to the post-processing section 3B (counterclockwise in fig. 3).

At least two nip rollers 34 are pressed against the peripheral surface of the feed roller 33. The printing substrate W is thereby nipped between the nip roller 34 and the feed roller 33, and the feed roller 33 is rotationally driven by the drive motor, whereby the printing substrate W can be stretched and reliably conveyed toward the post-processing section 3B.

The two nip rollers 34 are pressed against the circumferential surface of the feed roller 33 at positions spaced apart from each other in the rotational direction of the range around which the printing substrate W is wound.

An automatic registration device 38 and a monitoring device 39 for detecting a deviation of printing registration are provided on a traveling path 37 of the printing substrate W between the reverse roller 10 on the paper discharge side and the printing portion 2 (sixth printing unit 2 f). The automatic registration device 38 is located on the printing section 2 side, and the monitoring device 39 is located on the reverse roller 10 side on the paper discharge side.

The automatic registration device 38 reads dots printed on the printing substrate W from the printing units 2a to 2f, measures the pitch between the dots, finds the deviation of the printing registration of the printing units 2a to 2f, and performs fine adjustment of the printing registration during the printing operation. The fine adjustment of the printing registration by the automatic registration device 38 is automatically performed by controlling the printing units 2a to 2f based on information of the printing press set in advance.

The monitoring device 39 includes a camera unit 39a for capturing an image printed on the printing substrate W and a monitor, not shown, for displaying the captured image as an image.

The camera unit 39a captures images of the register marks of the respective colors printed on the printing substrate W by the printing units 2a to 2f, and displays the images on a monitor. Since the operator can know which print unit is out of print registration in the vertical direction and whether or not print registration in the width direction is shifted by viewing the image of the monitor, the operator can manually correct the shift in print registration in the vertical direction and the shift in print registration in the width direction.

The vertical printing register and the width printing register are adjusted by driving one driving motor (not shown) for rotationally driving the plate cylinder 7 and the blanket cylinder 8 shown in fig. 1 and a driving motor (not shown) for moving the plate cylinder 7 in the width direction.

Therefore, the vertical printing registration and the width printing registration can be adjusted by automatically controlling the respective drive motors by the automatic registration device 38 and by controlling the respective drive motors by the operator based on the result of the monitoring device 39.

As shown in fig. 3, the winding device 12 includes a winding shaft 32 for winding the printing substrate W and a tension detecting device 36 described later.

A drive motor (not shown) is coupled to one end of the winding shaft 32, and is rotationally driven only in a direction of winding the printing substrate W (clockwise in fig. 3) by the drive motor, and is not rotated in a direction opposite to the winding direction (counterclockwise in fig. 3).

A tension detection device 36 for detecting the tension of the printing substrate W traveling on the traveling path 35 is provided on the traveling path 35 of the printing substrate W from the feed roller 33 to the take-up shaft 32.

The tension value detected by the tension detecting device 36 is compared with a tension value set by a control unit, not shown, and the rotational speeds of the take-up shaft 32 and the feed roller 33 are controlled so that the detected tension value becomes the set tension value.

That is, since the tension is generated in the printing substrate W traveling on the traveling path 35 by increasing the rotation speed of the take-up shaft 32 more than the rotation speed of the feed roller 33, the magnitude of the tension is determined by the difference in rotation speed between the feed roller 33 and the take-up shaft 32, and therefore the rotation speed difference is changed so that the detected tension value matches the set tension value.

The post-processing section 3B is not limited to the winding device 12.

For example, the post-processing unit 3B may be a processing device that processes the printing substrate W, a unit that conveys the printing substrate W to another device provided on the downstream side, a transfer unit, or the like.

The printing units 2a to 2f will be described with reference to fig. 4. Fig. 4 is a partially enlarged front view of two

printing units

2a, 2b of the intermittent printer shown in fig. 1.

The plate cylinder 7, the blanket cylinder 8, the platen cylinder 9, and the members described later are provided in the machine frame 2A of the printing unit, and the cylinders and the members are shown by solid lines for easy understanding.

The plate cylinder 7 and the blanket cylinder 8 are rotated in opposite directions (arrow directions in fig. 4) in synchronization with each other by a single drive motor (not shown).

The platen 9 is driven to rotate forward and backward in synchronization with the feed-side reverse roller 6 and the discharge-side reverse roller 10 by a platen drive motor to be described later.

The structure of the plate cylinder 7, the blanket cylinder 8, and the platen cylinder 9 will be described based on fig. 5.

As shown in fig. 5, a printing plate 7a shorter than the entire circumference (the circumferential length of the circumferential surface) of the plate cylinder 7 is attached to the circumferential surface of the plate cylinder 7. Ink is supplied to the printing plate 7a of the plate cylinder 7 from an ink supply device, not shown, provided adjacent to the plate cylinder 7.

A blanket 8a shorter than the entire circumference of the blanket cylinder 8 is attached to the circumferential surface of the blanket cylinder 8.

As shown in fig. 5(a), the plate cylinder 7 and the blanket cylinder 8 are configured such that the printing plate 7a and the blanket 8a are in contact with each other to transfer an image of the printing plate 7a to the blanket 8a, and a circumferential surface portion of the plate cylinder 7 to which the printing plate 7a is not attached and the blanket 8a of the blanket cylinder 8 are not in contact with each other.

As shown in fig. 5(B), the blanket cylinder 8 and the impression cylinder 9 are configured such that the circumferential surfaces of the blanket 8a and the impression cylinder 9 contact each other via the printing substrate W, and an image of the blanket 8a is printed on the printing substrate W. That is, the blanket 8a is an image range of the blanket cylinder 8.

As shown in fig. 5(C), the circumferential surface portion of the blanket cylinder 8 to which the blanket 8a is not attached does not contact the circumferential surface of the pressure cylinder 9. That is, the circumferential surface portion of the blanket cylinder 8 to which the blanket 8a is not attached is a non-image range of the blanket cylinder 8.

The intermittent printing operation of the intermittent printer 100 according to the embodiment of the present invention will be described with reference to fig. 6, 7, and 8.

In the embodiment, the length of the circumference of the plate cylinder 7, the length of the circumference of the blanket cylinder 8, and the length of the circumference of the impression cylinder 9 are the same.

The plate cylinder 7 and the blanket cylinder 8 are continuously rotationally driven at the same speed in opposite directions (clockwise direction of the plate cylinder 7 and counterclockwise direction of the blanket cylinder 8) as indicated by solid arrows in the intermittent printing operation.

The platen 9 rotates clockwise as indicated by the solid line arrow, that is, by forward rotational driving, the printing substrate W travels forward as indicated by the solid line arrow, and rotates counterclockwise as indicated by the broken line arrow, that is, by reverse rotational driving, the printing substrate W travels in the reverse direction as indicated by the broken line arrow. In this case, in fig. 6, 7, and 8, the feed-side reverse roller 6 and the discharge-side reverse roller 10, which are not shown, are driven to rotate in the forward direction and in the reverse direction in synchronization with the platen 9.

The operation from the start of printing to the end of printing in the first printing (printing of the first page) will be described with reference to fig. 6.

Fig. 6 shows changes in the rotation angle of the blanket cylinder 8 and the impression cylinder 9 in chronological order from the start of the first printing to the end of the printing.

As shown in fig. 6(a), the press cylinder 9 is driven to rotate in the forward direction, the printing target substrate W moves in the forward direction, and the leading end 8a-1 of the blanket 8a comes into contact with the printing target substrate W in contact with the circumferential surface of the press cylinder 9, thereby starting printing of the image of the blanket 8a on the printing target substrate W. The leading end 8a-1 of the blanket 8a refers to an end on the downstream side in the rotational direction of the blanket 8 a.

From this state, the platen 9 is driven to rotate forward at a constant speed equal to the speed of the blanket cylinder 8, and the blanket cylinder 8 and the platen 9 are driven to rotate, whereby the first image is printed sequentially from the blanket 8a onto the printing substrate W as shown in fig. 6 (B).

As shown in fig. 6(C), the rear end 8a-2 of the blanket 8a comes into contact with the printing target substrate W in contact with the circumferential surface of the platen 9, and the first printing is completed.

The rear end 8a-2 of the blanket 8a refers to an end on the upstream side in the rotation direction of the blanket 8 a.

That is, the feed-side reverse roller 6, the discharge-side reverse roller 10, and the pressure cylinder 9 are driven to rotate at a constant speed in a forward direction in synchronization with each other, so that the blanket 8a is brought into contact with the printing substrate W while the printing substrate W is moved at a constant speed in the forward direction, and an image of the blanket 8a is first printed on the printing substrate W.

The rotation angle α of the blanket cylinder 8 is an angle formed by a straight line b connecting the rotation center 8b of the blanket cylinder 8 and the rotation center 9c of the impression cylinder 9 and the rear end 8a-2 of the blanket 8a, and the position of the straight line b at the end of printing is set to 0 degrees and the normal rotation direction is set to positive. The rotation angle β of the platen 9 is an angle formed by the straight line b and the rear end G-1 of the print image G printed on the printing target substrate W, and the position of the straight line b at the end of printing is defined as 0 degrees and the normal rotation direction is defined as positive. That is, when the printing is completed in fig. 6(C), α and β are equal to 0, and α and β are increased by the blanket cylinder 8 and the platen cylinder 9 being driven to rotate in the positive direction from the printing-completed state.

The length of the print image G (the distance from the rear end G-1 to the front end G-2 of the print image G), i.e., the print range of 1 page amount, initially printed on the substrate W to be printed coincides with the size of the blanket 8a (the distance from the front end 8a-1 to the rear end 8a-2 of the blanket 8 a). The rear end G-1 of the print image G is an upstream end of the platen 9 in the forward rotation direction. The leading end G-2 of the print image G is an end portion on the downstream side in the forward rotation direction of the platen 9.

The rotation angle from the straight line b of the blanket cylinder 8 at the end of printing to the leading end 8a-1 of the blanket 8a is a first blanket cylinder rotation angle α -1, and the rotation angle from the straight line b of the impression cylinder 9 to the leading end G-2 of the print image G is a first impression cylinder rotation angle β -1. Since the blanket cylinder 8 and the impression cylinder 9 are driven at the same rotational speed, and the size of the blanket 8a and the length of the print image G are the same, α -1 and β -1 are the same angle.

The print image G is printed on the surface of the print target substrate W, but is shown inside the circumferential surface of the platen 9 in fig. 6 for ease of understanding. In fig. 7 and 8, which will be described later, a print image is also shown inside the circumferential surface of the platen 9.

Since the platen 9 is driven to rotate at a constant speed when the printing shown in fig. 6(C) is completed, the platen 9 is driven to rotate at a reduced speed and to gradually stop the rotation of the platen 9 after the printing is completed, thereby preventing the slip from occurring between the printing substrate W and the peripheral surface of the platen 9 and preventing the malfunction in the drive system of the platen 9 and the like. That is, if the platen 9 that is rotationally driven at a constant speed is rapidly stopped from rotating, the slip between the printing substrate W and the circumferential surface of the platen 9 is caused, and an excessive force acts on a drive system of the platen 9 or the like, which causes a failure.

The platen 9 is stopped from rotating at a position rotated positively by a predetermined rotation angle from the position at the end of printing shown in fig. 6(C) as shown in fig. 6(D) in order to stop the rotation gradually after the end of printing. That is, the rotation angle β of the platen 9 at the position where the rotation is stopped is the second platen rotation angle β -2.

In the state where the platen 9 stops rotating, the rotation angle α of the blanket cylinder 8 is the second blanket cylinder rotation angle α -2 as shown in fig. 6 (D).

The rotation angle alpha-2 of the second blanket cylinder is larger than the rotation angle beta-2 of the second pressing cylinder. That is, the blanket cylinder 8 is also rotationally driven at a constant speed after the printing is completed, but the blanket cylinder 9 is rotationally driven at a reduced speed after the printing is completed, so that α -2 > β -2.

When the platen 9 is rotated only at the deceleration positive rotation angle β -2 from the position (β ═ 0) at the end of printing, the printing substrate W and the blanket 8a are separated from each other, and the printing substrate W is not sandwiched between the platen 9 and the blanket cylinder 8, so that slippage is likely to occur between the peripheral surface of the platen 9 and the printing substrate W.

The operation from the first printing end to the second printing start (printing of the second page) will be described with reference to fig. 7.

Fig. 7 shows changes in the rotation angle of the blanket cylinder 8 and the impression cylinder 9 in chronological order from when the rotation of the impression cylinder 9 is stopped to when the second printing is started.

As shown in fig. 7(a), the platen 9, which stops rotating after the first printing operation is completed, is accelerated and reversely rotated as indicated by the broken line arrow, and the printing substrate W is moved in the reverse direction as indicated by the broken line arrow.

As shown in fig. 7B, when the platen 9 is reversely rotated by the second platen rotation angle β -2 only and the trailing edge G-1 of the print image G printed on the print target substrate W first moves to the position at the end of printing (β ═ 0), the platen 9 is set at a predetermined reverse rotation driving speed. The predetermined reverse rotation driving speed is the fastest reverse rotation driving speed, and is slower than a constant speed in printing.

The rotation angle α of the blanket cylinder 8 in the state shown in fig. 7(B) is the third blanket cylinder rotation angle α -3. Alpha-3 > alpha-2.

Thereafter, the pressure cylinder 9 is driven to rotate in the reverse direction at a reduced speed, and the rotation of the pressure cylinder 9 is gradually stopped. In the state where the platen 9 stops rotating, as shown in fig. 7C, the rotation angle β of the platen 9 is shifted to the paper feeding side by a third platen rotation angle β -3 from the position (β ═ 0) at the end of printing.

The rotation angle beta-3 of the third pressing cylinder is the same as the rotation angle beta-2 of the second pressing cylinder. β -3 ═ β -2.

The blanket cylinder 8 is rotated until the rotation angle α thereof becomes a fourth blanket cylinder rotation angle α -4(α -4 > α -3), and the leading end 8a-1 of the blanket 8a approaches the printing start position of the impression cylinder 9. The angle formed by the leading end 8a-1 of the blanket 8a and the line b is the fifth blanket cylinder rotation angle alpha-5. α -5 ═ 360 degrees- (. alpha. -1+ α -4), α -5 > β -3.

Since the platen 9 gradually stops rotating, the generation of slip between the printed substrate W and the peripheral surface of the platen 9 is prevented, and no malfunction or the like occurs in the drive system of the platen 9.

Further, the feed-side reverse roller 6 and the discharge-side reverse roller 10 are rotationally driven in the same manner as the platen 9.

As shown in fig. 7a to 7C, the printing target substrate W travels toward the paper inlet 1B side (travels in the reverse direction) through the gap between the circumferential surface portion of the blanket cylinder 8 to which the blanket 8a is not attached and the circumferential surface of the press cylinder 9, and therefore the printing target substrate W is not sandwiched between the press cylinder 9 and the blanket cylinder 8, and therefore, when traveling in the reverse direction, slippage is likely to occur between the circumferential surface of the press cylinder 9 and the printing target substrate W.

As shown in fig. 7(C), the platen 9 is driven by accelerating the forward rotation from the state where the platen 9 stops rotating, and the platen 9 is driven by the forward rotation gradually, so that the printing substrate W travels in the forward direction.

Further, if the rotation angle β of the platen 9 is just rotationally driving the third platen rotation angle β -3, the leading end 8a-1 of the blanket 8a comes into contact with the trailing end G-1 of the print image G (β ═ 0), as shown in fig. 7D.

In this state, the platen 9 is driven to rotate at a constant speed equal to that of the blanket cylinder, and the second printing is started. Further, the feed-side reverse roller 6 and the discharge-side reverse roller 10 are rotationally driven in the same manner as the platen 9.

Since the platen 9 gradually starts to rotate, the generation of slip between the printed substrate W and the circumferential surface of the platen 9 is prevented, and no malfunction or the like occurs in the drive system of the platen 9.

Therefore, the blanket cylinder 8 makes 1 rotation (360 degrees) at the time of the first printing. While the blanket cylinder 8 rotates 1 rotation, the impression cylinder 9 rotates only the size (image range) of the blanket 8a rotating during printing in the positive direction.

As shown in fig. 7(C), the platen 9 is driven in a decelerating reverse rotation manner, and after the rotation is stopped, the platen 9 is driven in an accelerating forward rotation manner again, and as shown in fig. 7(D), the printing substrate W and the blanket 8a are separated from each other until the forward rotation is started, and the printing substrate W is not sandwiched between the platen 9 and the blanket cylinder 8, so that a slip is likely to occur between the peripheral surface of the platen 9 and the printing substrate W.

That is, the operation from the end of the first printing to the start of the second printing is to make the printing substrate W travel in the reverse direction and the forward direction by accelerating the reverse rotation driving, decelerating the reverse rotation driving, and accelerating the forward rotation driving the feed-side reverse roller 6, the discharge-side reverse roller 10, and the platen 9 in synchronization after the rotation of the platen 9 is stopped after the first printing is finished, so that the trailing end G-1 of the printed image G becomes the second printing start position.

The operation from the start of printing to the end of printing when the second printing (printing of the second page) is performed will be described with reference to fig. 8.

Fig. 8 shows changes in the rotation angle of the blanket cylinder 8 and the impression cylinder 9 in chronological order from the start of the second printing to the end of the second printing.

As shown in fig. 8(a), the second printing is started by driving the platen 9 in forward rotation at the same constant speed as the blanket cylinder 8 in a state where the trailing end G-1 of the first printed print image G and the leading end 8a-1 of the blanket 8a are in contact. As shown in FIG. 8(B), the leading edge H-2 of the second printed image H is continuous with the trailing edge G-1 of the first printed image G.

If the cylinder 9 is rotating to drive the first cylinder by the first cylinder rotation angle β -1, the rear end 8a-2 of the blanket 8a coincides with the rear end H-1 of the second printed image H, as shown in fig. 8(C), and the second printing is finished.

By driving the platen 9 in the decelerating positive rotation state, the platen 9 is rotated by the second platen rotation angle β -2 to stop the rotation, as shown in fig. 8 (D). That is, the second printing is performed in the same manner as the first printing.

The printing after the third printing is performed in the same manner as the second printing.

The rotation angle and the rotation drive speed ratio of the platen cylinder 9 with respect to the rotation angle of the blanket cylinder 8 in a period from the end of printing to the start of printing to the end of printing, that is, in a case where one printing operation is performed, will be described with reference to fig. 9.

Fig. 9 is a graph (graph) showing the rotation angle and the rotation driving speed ratio of the platen 9 with respect to the rotation angle of the blanket cylinder 8, and the horizontal axis shows the rotation angle of the blanket cylinder 8 and is represented by 0 to 360 degrees to show one printing operation. That is, the horizontal axis represents the rotation angle α. The vertical axis represents the rotation angle of the platen 9 and the rotation driving speed ratio of the platen 9, and the rotation angle of the platen 9 at the end of printing and at the start of printing is defined as 0 degree, and the positive sign represents the rotation angle during positive rotation driving, and the negative sign represents the rotation angle during reverse rotation driving. That is, the rotation angle of the platen 9 on the vertical axis is the rotation angle β. The rotation driving speed ratio is set to 100% for the printing speed and 0% for the platen 9 when the rotation is stopped.

The change in the rotational driving speed ratio of the platen 9 is indicated by a solid line X, and the rotation angle of the platen 9 is indicated by a solid line Y.

Section 1 in fig. 9 shows the stop of the rotation of the platen 9 from the printing end in fig. 6(C) and 8(C) to the printing end in fig. 6(D) and 8 (D).

In the section 1, the rotational driving speed of the platen 9 smoothly changes from a constant speed (100%) during printing to 0% at which the platen 9 stops rotating, as indicated by a solid line X.

The rotation angle of the platen 9 smoothly changes from 0 degrees to the second platen rotation angle β -2 as indicated by the solid line Y.

The rotation angle of the blanket cylinder 8 changes from 0 degrees to a second blanket cylinder rotation angle alpha-2.

Section 2 in fig. 9 shows the pressure cylinder 9 in fig. 7(a) and (B) driven by the accelerated reverse rotation until a predetermined reverse rotation driving speed is reached.

In the section 2, the rotational driving speed of the platen 9 smoothly changes from 0% to a rotational driving speed ratio that is a predetermined reverse rotational driving speed, as indicated by the solid line X. The rotation angle of the platen 9 smoothly changes from the second platen rotation angle β -2 to 0 degrees as indicated by the solid line Y.

The rotation angle of the blanket cylinder 8 varies from the second blanket cylinder rotation angle alpha-2 to the third blanket cylinder rotation angle alpha-3.

The change in the rotation angle of the blanket cylinder 8 is larger in the section 2 than in the section 1, but this is because the change in the rotation driving speed ratio of the platen is gentle in the section 2 than in the section 1.

Section 3 in fig. 9 shows the pressure tube 9 driven by the deceleration and reverse rotation of fig. 7(B) and (C) until the rotation is stopped.

In the section 3, the rotational driving speed of the platen 9 smoothly changes from a rotational driving speed ratio at a predetermined reverse rotational driving speed to 0%, as indicated by a solid line X. The rotation angle of the platen 9 smoothly changes from 0 degrees to the third platen rotation angle β -3 as indicated by the solid line Y.

The rotation angle of the blanket cylinder 8 changes until the fourth blanket cylinder rotation angle alpha-4.

Section 4 in fig. 9 shows that the platen 9 is driven to rotate in the forward direction at a constant printing speed until the printing start position is reached in fig. 7(C) and (D).

In the section 4, the rotational driving speed of the platen 9 smoothly changes from 0% to 100% of a constant positive rotational driving speed during printing, as indicated by a solid line X. The rotation angle of the platen 9 smoothly changes from the third platen rotation angle β -3 to 0 degrees as indicated by the solid line Y.

The rotation angle of the blanket cylinder 8 is changed until the sum of the fourth blanket cylinder rotation angle alpha-4 and the fifth blanket cylinder rotation angle alpha-5.

The change in the rotation angle of the blanket cylinder 8 is larger in the section 3 than in the section 4, but this is because the change section 3 in the rotation driving speed ratio of the platen is gentler than in the section 4. The range from zone 1 to zone 4 is a non-printing range.

The interval 5 in fig. 9 indicates that the rotational driving speed of the platen 9 during printing is 100% as indicated by the solid line X, and the rotational angle of the platen 9 linearly changes from 0 degrees to the first platen rotational angle β -1 as indicated by the solid line Y. The section 5 is a printing range.

The curve representing the change in the rotation driving speed ratio of the deceleration positive rotation driving of the platen roller 9 in the section 1 and the curve representing the change in the rotation driving speed ratio of the acceleration positive rotation driving of the platen roller 9 in the section 4 are line-symmetric.

The curve representing the change in the rotation driving speed ratio of the acceleration reverse rotation driving of the platen 9 in the section 2 and the curve representing the change in the rotation driving speed ratio of the deceleration reverse rotation driving of the platen 9 in the section 3 are line-symmetric.

The rotation driving speed ratio of the platen 9 from a constant speed to a predetermined reverse rotation driving speed and the rotation driving speed ratio from the predetermined reverse rotation driving speed to the constant speed smoothly change along a substantially U-shaped curve.

Fig. 10 is a graph showing a change in the rotational driving speed of the platen roller, and shows the case of two different printing speeds of the rotational driving speed of the platen roller 9 with respect to the rotation angle of the blanket cylinder 8. Since the speed change from the constant speed during printing to the predetermined reverse rotation driving speed and the speed change from the predetermined reverse rotation driving speed to the constant speed during printing of the platen 9 smoothly change along the substantially U-shaped curve independently of the printing speed, the platen 9 smoothly changes the speed, and the printing substrate W smoothly travels in the reverse direction and the forward direction, and therefore, the occurrence of slip between the printing substrate W and the peripheral surface of the platen 9 can be prevented, and printing can be performed accurately on the printing substrate W.

As shown in fig. 11, if a small-sized blanket 8a is attached to the blanket cylinder 8 and the platen cylinder 9 is rotationally driven to perform printing as in the previous embodiment, the platen cylinder 9 is subjected to acceleration reverse rotation driving and deceleration reverse rotation driving after the printing is completed, and a fifth blanket cylinder rotation angle α -5 formed by the leading end 8a-1 of the blanket 8a and the straight line b when the platen cylinder 9 stops rotating becomes larger than the angle shown in fig. 7 (C).

Therefore, when the platen 9 is driven to rotate in the forward direction, the rear end G-1 of the print image G and the front end 8a-1 of the blanket 8a do not contact each other, and printing cannot be performed correctly.

That is, in fig. 12, similarly to fig. 9, the change in the rotational driving speed ratio of the platen 9 is indicated by a solid line X, and the rotation angle of the platen 9 is indicated by a solid line Y, but since the size of the blanket 8a is small, the rotation angle at which the blanket cylinder 8 rotates during printing of the section 5 is small, and since the rotation angle of the blanket cylinder 8 from the end of printing by the platen 9 to the start of printing is large, if the platen 9 is rotationally driven as in the previous embodiment, accurate printing cannot be performed.

Therefore, as shown in fig. 12, the rotation driving speed ratio of the deceleration forward rotation driving of the platen 9 in the section 1, the rotation driving speed ratio of the acceleration reverse rotation driving of the section 2, the rotation driving speed ratio of the deceleration reverse rotation driving of the section 3, and the rotation driving speed ratio of the acceleration forward rotation driving of the section 4 are changed so that the rear end G-1 of the print image G and the front end 8a-1 of the blanket 8a are brought into contact at the print start position. That is, in the case of the small blanket 8a, the second platen rotation angle β -2 and the third platen rotation angle β -3 are increased as the fifth blanket rotation angle α -5 is increased.

As shown in fig. 13, if a large blanket 8a is attached to the blanket cylinder 8 and the platen cylinder 9 is rotationally driven to perform printing as in the previous embodiment, the platen cylinder 9 is subjected to acceleration reverse rotation driving and deceleration reverse rotation driving after the printing is completed, and when the platen cylinder 9 stops rotating, a fifth blanket cylinder rotation angle α -5 formed by the front end 8a-1 of the platen cylinder 8a and the straight line b is smaller than the angle shown in fig. 7 (C).

That is, in fig. 14, similarly to fig. 9, the change in the rotational driving speed ratio of the platen 9 is indicated by a solid line X, and the rotation angle of the platen 9 is indicated by a solid line Y, but since the blanket 8a has a large size, the rotation angle at which the blanket cylinder 8 rotates during printing of the section 5 is large, and since the rotation angle of the blanket cylinder 8 from the end of printing to the start of printing is small, accurate printing cannot be performed if the platen 9 is rotationally driven as in the previous embodiment.

Therefore, as shown in fig. 14, the rotation driving speed ratio of the deceleration forward rotation driving of the platen 9 in the section 1, the rotation driving speed ratio of the acceleration reverse rotation driving of the section 2, the rotation driving speed ratio of the deceleration reverse rotation driving of the section 3, and the rotation driving speed ratio of the acceleration forward rotation driving of the section 4 are changed so that the rear end G-1 of the print image G and the front end 8a-1 of the blanket 8a come into contact at the position where printing starts. That is, in the case of the large blanket 8a, the second platen rotation angle β -2 and the third platen rotation angle β -3 are made smaller as the fifth blanket rotation angle α -5 is made smaller.

When the number of printed sheets per unit time is changed by changing the printing speed, the rotation angle of the blanket cylinder 8 when the platen cylinder 9 starts decelerating from a constant speed and reaches the constant speed may be changed by changing the acceleration of the forward and reverse rotational driving of the platen cylinder 9 without changing the rotation angle.

For example, as shown in fig. 10, when the printing speed indicated by the broken line is slower than the printing speed indicated by the solid line, the acceleration when the platen 9 is driven in the forward and reverse rotation is reduced without changing the rotation angle of the blanket cylinder 8 when the platen 9 starts to decelerate from the constant speed and the rotation angle of the blanket cylinder 8 when the platen 9 reaches the constant speed.

Next, a structure in which the printing substrate W is wound around the circumferential surface of the platen 9 will be described.

As shown in fig. 4, the printing substrate W is wound around the circumferential surface of the platen 9 from the paper feeding side traveling path 15a to the paper discharging side traveling path 15 b.

The paper-feeding-side traveling path 15a is a traveling path on the upstream side in the traveling direction when the printing substrate W travels in the forward direction, and is a traveling path on the downstream side in the traveling direction when the printing substrate W travels in the reverse direction.

The paper ejection side travel path 15b is a travel path on the downstream side in the travel direction when the printing substrate W travels in the forward direction, and is a travel path on the upstream side in the travel direction when the printing substrate W travels in the reverse direction.

The printing substrate W running between the blanket cylinder 8 and the platen cylinder 9 is wound around the peripheral surface of the platen cylinder 9 at a predetermined wrap angle by the paper-in-side guide roller 40 and the paper-discharge-side guide roller 41.

The guide roller 40 on the paper feeding side is provided on the traveling path 15a on the paper feeding side.

The guide roller 41 on the sheet discharge side is provided on the traveling path 15b on the sheet discharge side.

By changing the position of at least one of the paper-feeding-side guide roller 40 and the paper-discharging-side guide roller 41, the wrap angle of the printing substrate W to the peripheral surface of the platen 9 changes.

The paper-entry-side guide roller 40 and the paper-discharge-side guide roller 41 are freely rotatable rollers and are not rotationally driven by a drive motor or the like.

As shown in fig. 15, the guide roller 40 on the paper feeding side is provided closer to the paper feeding portion 1B than the platen 9.

The position 40a where the to-be-printed substrate W contacts the circumferential surface of the guide roller 40 on the paper feed side is located below the position (hereinafter referred to as a printing position) 9a where the to-be-printed substrate W contacts the blanket 8a of the blanket cylinder 8 on the circumferential surface of the platen cylinder 9, and the to-be-printed substrate W traveling on the traveling path 15a on the paper feed side travels obliquely between the lower portion of the circumferential surface of the guide roller 40 on the paper feed side and the upper portion of the circumferential surface of the platen cylinder 9 so that the position 40a where the to-be-printed substrate W contacts the guide roller 40 on the paper feed side becomes lower and the position where the to-be-printed substrate W starts to contact the circumferential surface of the platen cylinder 9 becomes higher.

Therefore, a winding start position 16a on the paper feeding side (a position on the paper feeding side which comes into contact with the circumferential surface of the platen 9) at which the printed substrate W traveling on the paper feeding side traveling path 15a starts to be wound around the circumferential surface of the platen 9 is lower than the printing position 9a on the paper feeding side of the platen 9.

The guide roller 41 on the paper discharge side is provided closer to the paper inlet 1B than the platen 9 and closer to the travel path 15a on the paper inlet side. The position 41a on the side of the platen 9 where the peripheral surface of the guide roller 41 on the paper discharge side comes into contact with the printed substrate W is located above the lower position 9b on the peripheral surface of the platen 9, and the printed substrate W running on the side of the platen 9 than the guide roller 41 on the paper discharge side in the running path 15b on the paper discharge side travels obliquely between the lower portion on the peripheral surface of the platen 9 and the upper portion on the peripheral surface of the guide roller 41 on the paper discharge side so that the position where the printed substrate W comes into contact with the peripheral surface of the platen 9 becomes lower and the position 41a where the printed substrate W comes into contact with the guide roller 41 on the paper discharge side becomes higher. The lower position 9b of the peripheral surface of the platen 9 is an intersection of a straight line a passing through the printing position 9a and the center 9c of the platen 9 and the lower portion of the peripheral surface of the platen 9.

Therefore, the winding start position 16b on the paper discharge side (the position on the paper discharge side where the printing substrate W starts to contact the peripheral surface of the platen 9) where the printing substrate W traveling on the paper discharge side traveling path 15b starts to be wound around the peripheral surface of the platen 9 is higher than the lower position 9b on the paper entrance side than the lower position 9b on the peripheral surface of the platen 9.

That is, a straight line connecting a position 40a where the printed substrate W contacts the circumferential surface of the paper-feeding-side guide roller 40 and a paper-feeding-side winding start position 16a on the circumferential surface of the platen 9 (an extension of the paper-feeding-side travel path 15a between the paper-feeding-side guide roller 40 and the platen 9) intersects a straight line connecting a position 41a where the printed substrate W contacts the circumferential surface of the paper-discharging-side guide roller 41 and a paper-discharging-side winding start position 16b on the circumferential surface of the platen 9 (an extension of the paper-discharging-side travel path 15b between the paper-discharging-side guide roller 41 and the platen 9).

Therefore, the wrap angle θ at which the printing substrate W is wrapped around the circumferential surface of the platen 9 is an angle larger than 180 degrees, and 270 degrees in fig. 15, and the contact area between the printing substrate W and the circumferential surface of the platen 9 is large, and the frictional force generated therebetween is large.

The reason why the frictional force has a large value is as follows.

By winding the printing substrate W around the circumferential surface of the platen 9, a force is generated from the printing substrate W toward the center 9c of the platen 9 with respect to the platen 9 in the wound range.

As a reaction to this force, a vertical resistance is generated in a range where the printing substrate W is wound around the circumferential surface of the platen 9.

Since the frictional force acting on the printing substrate W is proportional to the vertical resistance with respect to the entire range in which the printing substrate W is wound around the circumferential surface of the platen 9, the wider the range in which the printing substrate W is wound around the circumferential surface of the platen 9, the greater the frictional force.

Therefore, if the wrap angle θ at which the printing substrate W is wrapped around the circumferential surface of the platen 9 is a large angle, the frictional force generated between the printing substrate W and the circumferential surface of the platen 9 has a large value.

If the frictional force generated between the printing substrate W and the circumferential surface of the platen 9 is a large value, the slip generated between the circumferential surface of the platen 9 and the printing substrate W can be suppressed when the platen 9 is driven in reverse rotation and the printing substrate W travels in the reverse direction.

As shown in fig. 4, a nip roller 42 for the platen and a drying device 43 are provided so as to face a portion of the peripheral surface of the platen 9 where the printed substrate W is wound (a peripheral surface portion between the winding start position 16a on the paper feeding side and the winding start position 16b on the paper discharging side shown in fig. 15).

The platen nip roller 42 is provided in pressure contact with the circumferential surface of the platen 9, and the printing substrate W normally travels while being nipped between the platen nip roller 42 and the circumferential surface of the platen 9. That is, the platen nip roller 42 presses the printing substrate W against the circumferential surface of the platen 9.

By providing the grip roller 42 for the platen, the frictional force generated between the printing substrate W and the peripheral surface of the platen 9 is increased at the portion pressed by the grip roller 42 for the platen, and the frictional force has a large value.

When the platen 9 is driven in the reverse rotation direction to run the printing target substrate W in the reverse direction, the peripheral surface of the platen 9 and the peripheral surface of the blanket cylinder 8 are separated from each other, and the printing target substrate W is not in contact with the blanket cylinder 8, so that the printing target substrate W running in the reverse direction is stretched in the running direction on the downstream side in the running direction from a portion (nip position 42a in fig. 15) pressed against the peripheral surface of the platen 9 by the nip roller 42 for the platen.

By stretching the printing substrate W in the traveling direction, a force is generated from the printing substrate W toward the center 9c of the platen 9 with respect to the circumferential surface of the platen 9.

Since the air remaining between the circumferential surface of the platen 9 and the printing substrate W escapes by the force of the air, and the formation of the air layer is suppressed, the friction between the circumferential surface of the platen 9 and the printing substrate W is less likely to decrease by the air layer.

Further, the frictional force between the circumferential surface of the platen cylinder 9 and the printing substrate W is increased by a force toward the center of the platen cylinder 9 from the circumferential surface of the platen cylinder 9.

These factors complement each other in that, when the platen 9, the feed-side reverse roller 6, and the discharge-side reverse roller 10 are driven to move the printing substrate W in the reverse direction, when the platen 9 moves in the forward direction from the printing start position to the stop of rotation, and when the printing substrate W moving in the reverse direction moves in the forward direction from the printing start position (that is, when the printing substrate W moves away from the blanket 8a and moves in a state where the printing substrate W is sandwiched between the platen 9 and the blanket cylinder 8), no slip occurs between the printing substrate W and the circumferential surface of the platen 9.

Therefore, the occurrence of the deviation of the printing registration can be prevented.

The friction between the circumferential surface of the platen 9 and the print target substrate W is increased by suppressing the formation of the air layer as described above, and the length of the portion of the stretched print target substrate W that contacts the circumferential surface of the platen 9 (the length from the paper-feeding-side winding start position 16a to the paper-discharging-side winding start position 16b shown in fig. 15) is more effective.

Therefore, as shown in fig. 15, the grip roller 42 for the platen is provided so that a grip position 42a pressed against the peripheral surface of the platen 9 is closer to the guide roller 41 on the paper discharge side than a print position 9a of the platen.

That is, the nip position 42a of the nip roller 42 for the platen roller is pressed against the circumferential surface of the platen roller 9, and when the printing target substrate W travels in the reverse direction, the upstream side in the traveling direction of the printing target substrate W (upstream side in the reverse rotation direction) is located more upstream than the printing position 9a of the platen roller 9.

The nip position 42a is preferably a position closest to the guide roller 41 on the paper discharge side, not beyond the winding start position 16b on the paper discharge side.

If the nip position 42a goes beyond the winding start position 16b on the paper discharge side, as will be described later, when the nip roller 42 for the platen is spaced from the peripheral surface of the platen 9, the winding angle of the printing substrate W to the peripheral surface of the platen 9 changes, and the length of the travel path changes, so that the printing registration shifts.

The grip roller 42 for the platen is movable over a position pressed against the peripheral surface of the platen 9 and a position spaced apart from each other.

The mounting structure of the grip roller 42 for the platen will be described based on fig. 16 and 17.

The printing unit machine frame 2A includes a frame 2A-1 on one operation side and a frame 2A-2 on the other drive side in a direction perpendicular to the traveling direction of the substrate W to be printed.

The support shaft 50 of the paper discharge-side guide roller 41 is axially positioned and rotatably attached to the operating-side frame 2A-1 and the driving-side frame 2A-2, and the paper discharge-side guide roller 4 is rotatably attached to the support shaft 50. One end of the support shaft 50 in the longitudinal direction protrudes outward from the operating-side frame 2A-1.

Base end portions of the support arms 51 are fixedly attached to two positions of the support shaft 50 spaced apart in the longitudinal direction, respectively, so as not to rotate. A grip roller shaft 52 is fixedly attached between the distal end portions of the two support arms 51 so as not to rotate, and a grip roller 42 for a platen is rotatably attached to the grip roller shaft 52.

A grip roller moving cylinder 53 is rotatably attached to an outer surface (front surface) of a frame 2A-1 on the operation side of the printing unit machine frame 2A, and a base end portion of a rod 54 is rotatably attached to a piston rod 53a of the grip roller moving cylinder 53. A support shaft 50 is fixedly attached to a distal end portion of the rod 54 so as not to rotate.

Then, by extending the piston rod 53a of the grip roller moving cylinder 53, the rod 54 rotates counterclockwise in fig. 16, the support shaft 50 rotates counterclockwise by a predetermined rotation angle, the support arm 51 rotates toward the circumferential surface of the pressure cylinder 9, and the grip roller 42 for the pressure cylinder moves to a position of pressure contact with the circumferential surface of the pressure cylinder 9.

By reducing the piston rod 53a of the grip roller moving cylinder 53, the rod 54 is rotated clockwise in fig. 16, the support shaft 50 is rotated clockwise by a predetermined rotation angle, the support arm 51 is rotated in a direction away from the peripheral surface of the platen 9, and the grip roller 42 for the platen is moved to a position away from the peripheral surface of the platen 9.

Therefore, during the printing operation, the grip roller 42 for the platen is moved to a position in pressure contact with the circumferential surface of the platen 9 to prevent the occurrence of slippage, and during the maintenance and inspection work, the grip roller 42 is moved to a position spaced apart from the circumferential surface of the platen 9, thereby facilitating the maintenance and inspection work and the like.

When an image is printed on the printing substrate W, the circumferential surface of the platen 9 and the blanket 8a of the blanket cylinder 8 contact each other through the printing substrate W, and therefore, even if the grip roller 42 for the platen is not provided, no slippage occurs between the circumferential surface of the platen 9 and the printing substrate W (see fig. 6). Even if the grip roller 42 for the platen is spaced apart from the peripheral surface of the platen 9, the length of the travel path 15b on the paper discharge side between the position 41a on the platen 9 side where the printing substrate W starts to contact the peripheral surface of the guide roller 41 on the paper discharge side and the straight line connecting the winding start position 16b on the paper discharge side on the peripheral surface of the platen 9 is not changed. Therefore, even if the grip roller 42 for the platen is spaced apart from the peripheral surface of the platen 9, the printing register is not deviated (see fig. 15).

As shown in fig. 4, the drying device 43 fixes and dries the ink of the image printed on the printing substrate W. In this embodiment, since printing is performed using ultraviolet-curable ink, a drying device that performs drying by irradiation with ultraviolet rays is used. As the light source of ultraviolet rays, a mercury lamp, a metal halide lamp, an LED lamp, or the like can be appropriately selected, but the LED lamp is more preferable in order to reduce the influence of heat on the printing substrate W.

The drying device 43 is provided between the printing position 9a of the platen 9 and the nip roller 42 for the platen. That is, the drying device 43 is provided upstream of the platen nip roller 42 in the normal rotation direction.

Therefore, since the nip roller 42 for the platen roller comes into contact after the ink of the printed image is fixed and dried, the image is not disturbed by the contact of the nip roller 42 for the platen roller.

The platen 9 and the printing substrate W may be at high temperatures due to heat generated in the drying device 43, and the printing substrate W may be adversely affected by the heat. In particular, when a flexible package material such as a film is used as the printing substrate W, it is susceptible to adverse effects caused by heat. As an adverse effect due to heat generation, there is a case where the printing substrate W is elongated by heat, causing misalignment of printing.

Therefore, by providing the cooling device 72 to the platen 9, the platen 9 is cooled, and the platen 9 and the printing substrate W are not adversely affected by heat generation and thus do not reach a high temperature.

The cooling device 72 of the platen 9 is explained based on fig. 18 and 19.

The platen 9 has a hollow cylindrical shape including a cylindrical body 60, one end plate 61 for closing one opening of the cylindrical body 60, and the other end plate 62 for closing the other opening of the cylindrical body 60.

One support shaft 63 is provided on one end plate 61, and the one support shaft 63 is rotatably supported by the operating-side frame 2A-1 via an eccentric bearing 64.

The other support shaft 65 is provided on the other end surface plate 62, and the other support shaft 65 is rotatably supported by the frame 2A-2 on the drive side by the eccentric bearing 64. Further, a motor fixing eccentric element 64a for fixing a drive motor 68 for a cylinder is attached to the other eccentric bearing 64.

A motor support frame 67 is attached to the drive-side frame 2A-2 via a stay 66, a motor fixing eccentric element 64a is rotatably attached to the motor support frame 67, and a drive motor 68 for a platen is attached to the motor fixing eccentric element 64 a.

A rotation shaft, not shown, of the drive motor 68 for a platen is coupled to the other support shaft 65 by a coupling, not shown.

The platen 9 is driven to rotate forward and backward by a platen drive motor 68.

The drive motor 68 for the platen is controlled independently of the drive motors (not shown) of the plate cylinder 7 and the blanket cylinder 8 in synchronization with the drive motor of the feed-side reverse roller 6 and the drive motor of the discharge-side reverse roller 10.

Therefore, the platen 9 is driven to rotate forward and backward in synchronization with the feed-side reverse roller 6 and the discharge-side reverse roller 10.

A tube not shown for the purpose of cooling water flow is provided in the hollow portion of the pressure cylinder 9. The pipe penetrates one end surface plate 61 and one support shaft 63, protrudes from the operation-side frame 2A-1 to the outside, and is connected to a cooling water supply pipe 70 and a cooling water discharge pipe 71 via a rotary joint 69. A supply pipe 70 for the cooling water is connected to the output side of the cooling water supply pump, and a discharge pipe 71 for the cooling water is connected to the tank for the cooling water.

Then, the cooling water flows into the pipe from the cooling water supply pipe 70, flows through the pipe, and flows out from the cooling water discharge pipe 71.

As a result, the cooling water flows through the pipe, the platen 9 is cooled, and the platen cooling device 72 is configured.

The rotation centers of the eccentric bearings 64 and the motor-fixing eccentric element 64a and the rotation centers of the

support shafts

63 and 65 are eccentric, and the rotation mechanism 73 rotates the eccentric bearings 64 by a predetermined rotation angle, thereby eccentrically rotating the pressure cylinder 9 and the cylinder-pressing drive motor 68 by a predetermined rotation angle.

The eccentric rotation of the platen 9 changes the position of the platen 9 with respect to the blanket cylinder 8, and the contact pressure (printing pressure) between the circumferential surface of the platen 9 and the blanket 8a of the blanket cylinder 8 can be adjusted.

The rotation mechanism 73 will be explained.

A rotation shaft 74 is rotatably installed throughout the frame 2A-1 on the operation side and the frame 2A-2 on the drive side. A worm wheel 75 mounted on this rotary shaft 74 meshes with a worm 77 mounted on a shaft 76. The rotation shaft 74 is rotated by rotating a handle 76a fixed to the shaft 76.

A sector gear 78 is attached to each eccentric bearing 64, and each gear 78 meshes with a gear 79 attached to each side of the rotating shaft 74 in the longitudinal direction.

Therefore, when the shaft 76 is rotated by the handle 76a, each eccentric bearing 64 is rotated by a predetermined rotation angle.

As shown in fig. 1, registration adjusting devices 80 are provided between the printing units of the printing section 2. Specifically, the registration adjusting devices 80 are provided between the first printing unit 2a and the second printing unit 2b, between the second printing unit 2b and the third printing unit 2c, between the third printing unit 2c and the fourth printing unit 2d, between the fourth printing unit 2d and the fifth printing unit 2e, and between the fifth printing unit 2e and the sixth printing unit 2f, respectively.

The registration adjusting device 80 adjusts the printing registration according to the vertical length of the printed image before starting printing.

In the intermittent printer disclosed in japanese patent application laid-open No. 2-75561, the distance between the printing units is changed by moving the printing units in a state where the rotation of the platen roller is stopped, and the printing registration is adjusted.

The reason for this is that, in the intermittent printer of the present invention, since the printing target substrate W is wound around the circumferential surface of the platen 9, if the printing units 2a to 2f are moved, the platen 9 is also moved, and the printing target substrate W may be stretched and cut or loosened by the movement of the platen 9.

The register adjusting apparatus 80 of the present invention adjusts the printing register by changing the length of the path of travel of the printing substrate W (the length of the paper path) between the printing units.

Therefore, even if the printing substrate W is wound around the circumferential surface of the platen 9, the printing register can be adjusted.

A registration adjusting device 80, as shown in fig. 4, having a pull roller 81 on the paper feed side; a pull roller 82 on the paper discharge side disposed below the pull roller 81 on the paper feed side; a movable roller 83 provided between the paper feed-side draw roller 81 and the paper discharge-side draw roller 82 and moving in the horizontal direction; and a guide roller 84 provided on the paper discharge side of the pull roller 82 on the paper discharge side.

The printing substrate W travels in a winding manner from the feed-side draw roller 81 to the movable roller 83, from the movable roller 83 to the discharge-side draw roller 82, and from the discharge-side draw roller 82 to the guide roller 84 in this order.

That is, when the printing substrate W travels in the forward direction (the direction of the solid arrow), the traveling direction is changed by winding the printing unit (first printing unit 2a) on the paper feeding side around the movable roller 83 via the pull roller 81 on the paper feeding side, the traveling direction is changed again by winding the printing substrate W around the pull roller 82 on the paper discharge side, and the printing substrate W travels to the printing unit (second printing unit 2b) on the paper discharge side via the guide roller 84.

When the printing substrate W travels in the reverse direction (the direction of the broken-line arrow), the printing substrate W travels from the printing unit on the paper discharge side (the second printing unit 2b) to the pull roller 82 on the paper discharge side via the guide roller 84, changes the traveling direction, and then, the printing substrate W is wound around the movable roller 83, changes the traveling direction again, and travels to the printing unit on the paper feed side (the first printing unit 2a) via the pull roller 81 on the paper feed side.

The movable roller 83 is movable between a paper-feeding-side position 83a and a paper-discharging-side position 83 b. The movable roller 83 moves, and the length of the travel path 85a of the printing substrate W between the paper-entry-side pull roller 81 and the paper-discharge-side pull roller 82 changes. That is, since the traveling path 85a between the paper-feeding-side pull roller 81 and the paper-discharging-side pull roller 82 is formed in a loop shape folded back by the movable roller 83, the length of the traveling path 85a changes as the movable roller 83 moves.

Therefore, the length of the traveling path 85a between the feed-side draw roller 81 and the discharge-side draw roller 82 changes, and the length of the traveling path 85 of the printing substrate W between the printing position 9a of the first printing unit 2a and the printing position 9a of the second printing unit 2b (hereinafter referred to as the traveling path 85 of the printing substrate W between the printing units) changes.

If the movable roller 83 is at the paper-entry-side position 83a, the length of the path 85 along which the printing substrate W travels between the printing units is the shortest. If the movable roller 83 is at the paper discharge side position 83b, the length of the travel path 85 of the printing substrate W between the printing units is longest.

Therefore, since the length of the path 85 of the printed substrate W between the printing units changes by the movable roller 83 moving between the paper-feeding side position 83a and the paper-discharging side position 83b, the printing registration can be adjusted before printing. For example, the length of the travel path 85 of the printing target substrate W between the printing units is an integral multiple of the length in the vertical direction of the printed image.

The

rollers

81, 82, 83, and 84 are provided in the housing 80A of the registration adjustment device 80, but the

rollers

81, 82, 83, and 84 are indicated by solid lines for easy understanding.

The paper-feeding-side draw roller 81 and the paper-discharging-side draw roller 82 are driven and controlled to rotate by respective drive motors, not shown. The paper feed-side draw roller 81 and the paper discharge-side draw roller 82 are driven to rotate forward and backward in synchronization with the paper feed-side reverse roller 6 and the paper discharge-side reverse roller 10.

The movable roller 83 is rotatably mounted on a movable body, not shown, movably provided in the housing 80A. The movable roller 83 is moved by moving the movable body by a movement mechanism not shown.

The moving mechanism is a mechanism in which a feed screw is rotated by a motor and screwed into a screw hole of a moving body, a mechanism using a rack and a pinion, a mechanism using a cylinder, or the like.

Since the printing substrate W is wound within 180 degrees of the circumferential surface of the movable roller 83, the printing substrate W is normally wound within 180 degrees even if the movable roller 83 moves, and since the winding angle does not change, the length of the traveling path 85 of the printing substrate W between the printing units can be accurately changed by only 2 times the moving distance of the movable roller 83. However, in order to wind the printing medium within 180 degrees, the area of contact between the printing substrate W and the circumferential surface of the movable roller 83 is large, and the running resistance of the printing substrate W increases. Therefore, when the printing substrate W travels in the forward direction, slip is likely to occur between the peripheral surface of the pull roll 82 on the paper discharge side and the printing substrate W, and when the printing substrate W travels in the reverse direction, slip is likely to occur between the peripheral surface of the pull roll 81 on the paper feed side and the printing substrate W.

Therefore, a grip roller 86 for a paper-feeding-side pull roller pressed against the peripheral surface of the paper-feeding-side pull roller 81 and a grip roller 87 for a paper-discharging-side pull roller pressed against the paper-discharging-side pull roller 82 are provided.

The printing substrate W is nipped by the peripheral surface of the feed-side draw roller 81 and the feed-side pinch roller 86, and the printing substrate W is nipped by the peripheral surface of the discharge-side draw roller 82 and the discharge-side pinch roller 87.

Therefore, since the frictional force between the peripheral surface of the feed-side pull roll 81 and the printing substrate W is increased and no slip is generated therebetween, and the frictional force between the peripheral surface of the discharge-side pull roll 82 and the printing substrate W is increased and no slip is generated therebetween, the misalignment of the printing registration is not generated by providing the registration adjusting device 80.

The nip roller 86 for the pull roller on the paper entry side is movable to a position pressed against the circumferential surface of the pull roller 81 on the paper entry side and a position separated therefrom.

The grip roller 87 for the paper discharge side pull roller is movable over a position pressed against the peripheral surface of the paper discharge side pull roller 82 and a position spaced apart from the position.

The mounting structure of the pinch roller 86 for the pull roller on the paper feed side will be described with reference to fig. 20 and 21. The frame 80A includes a frame 80A-1 on one operation side and a frame 80A-2 on the other drive side, which are perpendicular to the traveling direction of the printing substrate W.

The support shaft 90 is axially positioned and rotatably attached to the frame 80A-1 on the operation side and the frame 80A-2 on the drive side of the housing 80A, and one end in the longitudinal direction of the support shaft 90 protrudes outward from the frame 80A-1 on the operation side. The base end portions of the support arms 91 are fixedly attached to two positions of the support shaft 90 spaced apart in the longitudinal direction, respectively, so as not to rotate. A pinch roller shaft 92 is fixedly attached between the distal end portions of the two support arms 91 so as not to rotate, and a pinch roller 86 for a pull roller on the paper feed side is rotatably attached to the pinch roller shaft 92.

A grip roller moving cylinder 93 is rotatably attached to an outer surface (front surface) of the frame 80A-1 on the operation side of the frame 80A, and a base end portion of a rod 94 is rotatably attached to a piston rod 93a of the grip roller moving cylinder 93. A support shaft 90 is fixedly attached to a distal end portion of the rod 94 so as not to rotate.

Then, by extending the piston rod 93a of the grip roller moving cylinder 93, the lever 94 is rotated clockwise in fig. 20, the support shaft 90 is rotated clockwise by a predetermined rotation angle, the support arm 91 is rotated toward the peripheral surface of the paper-entry-side pull roller 81, and the grip roller 86 for the paper-entry-side pull roller is moved to a position where it is pressed against the peripheral surface of the paper-entry-side pull roller 81.

By reducing the piston rod 93a of the grip roller moving cylinder 93, the lever 94 rotates counterclockwise in fig. 20, the support shaft 90 rotates counterclockwise by a predetermined rotation angle, the support arm 91 rotates in a direction away from the peripheral surface of the paper feed-side pull roller 81, and the paper feed-side pull roller grip roller 86 moves to a position away from the peripheral surface of the paper feed-side pull roller 81.

Since the pinch roller 87 for the pull roller on the paper discharge side is similarly attached, the same members are given the same reference numerals, and description thereof is omitted.

Further, by moving the pinch roller 86 for the pull-in roller and the pinch roller 87 for the pull-out roller on the paper-feeding side to positions spaced apart from each other, the work (paper passing work) of passing the printing target substrate W into the registration adjusting device 80 and the maintenance work of the rollers are facilitated before the start of printing.

When the movable roller 83 is moved, the grip roller 42 for the platen, the grip roller 86 for the pull-in roller on the paper-feeding side, the grip roller 87 for the pull-out roller on the paper-discharging side, and the other grip rollers are moved to positions separated from each other, and the movable roller 83 is moved so that the printing substrate W is moved while sliding along the rollers.

In the intermittent printing machine of the present invention, a printing substrate W is wound around the circumferential surface of a platen 9 of each of printing units 2a to 2f, and a nip roller 42 for the platen is pressed against the circumferential surface of each platen 9. The grip roller 86 for the pull roller on the paper feed side is pressed against the peripheral surface of the pull roller 81 on the paper feed side of each registration adjusting device 80, and the grip roller 87 for the pull roller on the paper discharge side is pressed against the peripheral surface of the pull roller 82 on the paper discharge side.

Therefore, even if the rotation speed of the feed-side reverse roller 6 and the rotation speed of the discharge-side reverse roller 10 are controlled, the tension of the printing substrate W traveling through the printing units 2a to 2f and the registration adjusting devices 80 is not uniform, and therefore, by controlling the rotation speeds of the feed-side reverse roller 6 and the discharge-side reverse roller 10, the tension of the printing substrate W traveling through the printing units 2a to 2f and the registration adjusting devices 80 cannot be set to a predetermined value.

Therefore, in the intermittent printer of the present invention, the feed-side reverse roller 6, the press cylinders 9 of the printing units 2a to 2f, the feed-side pull rollers 81, the discharge-side pull rollers 82, and the discharge-side reverse roller 10 of the registration adjusting devices 80 are individually driven to rotate, and the rotational speeds of the rollers are individually controlled, so that the tension of the printing substrate W traveling through the printing units 2a to 2f and the registration adjusting devices 80 is set to a predetermined value. This adjustment operation of the tension is performed for each printing unit in turn from the first printing unit 2a toward the sixth printing unit 2 f.

For example, as shown in fig. 22, the tension of the printing substrate W traveling in the section 17a between the reverse roller 6 on the paper feeding side and the platen 9 of the first printing unit 2a is controlled; tension of the to-be-printed substrate W traveling in the section 17b between the platen 9 of the first printing unit 2a and the pull roll 81 on the paper feed side; tension of the printing substrate W traveling in the section 17c between the feed-side draw roller 81 and the discharge-side draw roller 82; tension of the to-be-printed substrate W traveling in the section 17d between the pull roll 82 on the paper discharge side and the platen 9 of the second printing unit 2 b; tension of the to-be-printed substrate W traveling in the section 17e between the platen 9 of the second printing unit 2b and the pull roll 81 on the paper feed side; tension of the printing substrate W traveling in the section 17f between the feed-side draw roller 81 and the discharge-side draw roller 82; tension of the to-be-printed substrate W traveling in the section 17g between the pull roll 82 on the paper discharge side and the platen 9 of the third printing unit 2 c; tension of the to-be-printed substrate W traveling in the section 17h between the platen 9 of the third printing unit 2c and the pull roll 81 on the paper feed side; and the tension of the printing substrate W traveling in the section 17i between the feed-side draw roller 81 and the discharge-side draw roller 82.

Further, the tension of the printing substrate W traveling in the section 17j between the pull roll 82 on the paper discharge side and the platen 9 of the fourth printing unit 2d is controlled; tension of the printing target substrate W traveling in the section 17k between the platen 9 of the fourth printing unit 2d and the pull roll 81 on the paper feed side; tension of the printing substrate W traveling in the section 17i between the feed-side pull roll 81 and the discharge-side pull roll 82; tension of the to-be-printed substrate W traveling in the section 17m between the pull roll 82 on the paper discharge side and the platen 9 of the fifth printing unit 2 e; tension of the to-be-printed substrate W traveling in the section 17n between the platen 9 of the fifth printing unit 2e and the pull roll 81 on the paper feed side; tension of the printing substrate W traveling in the section 17o between the feed-side draw roller 81 and the discharge-side draw roller 82; tension of the to-be-printed substrate W traveling in the section 17p between the pull roll 82 on the paper discharge side and the platen 9 of the sixth printing unit 2 f; and the tension of the printing substrate W traveling in the section 17q between the platen 9 and the paper-ejection-side reverse roller 10 of the sixth printing unit 2 f.

The tension of the printing substrate W traveling in each zone is controlled such that the rotation speed of the downstream roller in the traveling direction of the printing substrate W is faster than the rotation speed of the upstream roller in the traveling direction, and the feeding amount of the printing substrate W by the downstream roller is larger than the feeding amount of the printing substrate W by the upstream roller.

For example, when the printing substrate W is moved in the forward direction, the tension of the printing substrate W moving in the section 17q between the platen 9 of the sixth printing unit 2f and the reverse roller 10 on the paper discharge side is set to be greater than the tension of the printing substrate W moving in the section 17a between the feed-side reverse roller 6 and the platen 9 of the first printing unit 2a, and the tension of the printing substrate W moving in the other section is set to be the same as the tension of the printing substrate W moving in the section 17a between the feed-side reverse roller 6 and the platen 9 of the first printing unit 2 a.

When the printed substrate W is caused to travel in the reverse direction, the tension of the printed substrate W traveling in the section 17a between the feed-side reverse roller 6 and the platen 9 of the first printing unit 2a is made greater than the tension of the printed substrate W traveling in the section 17q between the platen 9 of the sixth printing unit 2f and the discharge-side reverse roller 10, and the tension of the printed substrate W traveling in the other section is made equal to the tension of the printed substrate W traveling in the section 17q between the platen 9 of the sixth printing unit 2f and the discharge-side reverse roller 10.

In the intermittent printer of the present invention, images were printed on the printing substrate W in 3 different states, and the vertical misalignment of the printing registration was measured in each state. The deviation of the printing registration is measured by the automatic registration device 38 and the monitoring device 39.

In the first state, the grip roller 42 for the platen is spaced from the peripheral surface of the platen 9, the feed-side pull roller 81 is not rotationally driven but freely rotatable, the grip roller 86 for the feed-side pull roller is spaced from the peripheral surface of the feed-side pull roller 81, the feed-side pull roller 81 is made to be similar to the guide roller, the discharge-side pull roller 82 is not rotationally driven but freely rotatable, and the grip roller 87 for the discharge-side pull roller is spaced from the peripheral surface of the discharge-side pull roller 82, the discharge-side pull roller 82 is made to be similar to the guide roller, and in this state, the platen 9 is rotationally driven forward and rotationally backward in synchronization with the feed-side reverse roller 6 and the discharge-side reverse roller 10.

The second state is a state in which the grip roller 42 for the platen is pressed against the peripheral surface of the platen 9 in the first state, and in this state, the platen 9 is driven in forward rotation and reverse rotation in synchronization with the feed-side reverse roller 6 and the discharge-side reverse roller 10.

In the third state, the grip roller 42 for the platen is pressed against the circumferential surface of the platen 9, the grip roller 86 for the pull roller on the paper feed side is pressed against the circumferential surface of the pull roller 81 on the paper feed side, and the grip roller 87 for the pull roller on the paper discharge side is pressed against the circumferential surface of the pull roller 82 on the paper discharge side (a state in which the

grip rollers

42, 86, 87 are moved to the pressing positions), and in this state, the platen 9, the back roller 6 on the paper feed side, the back roller 10 on the paper discharge side, the pull roller 81 on the paper feed side, and the pull roller 82 on the paper discharge side are synchronously driven in forward and reverse rotations.

As a result, the occurrence of the variation in printing registration is the largest when printing is performed in the first state, the largest when printing is performed in the second state, and the smallest when printing is performed in the third state.

Therefore, it is found that providing the grip roller 42 for the platen and the

grip rollers

86 and 87 for the pull roller (pull rollers 81 and 82) is effective in preventing the deviation of the printing registration.

In this embodiment, the registration adjusting device 80 is provided between the printing units, but the registration adjusting device 80 may not be provided.

In this case, a pull roller is provided on the traveling path 85 of the printing target substrate W between the printing units so that the printing target substrate W is not deviated or slackened.

For example, as shown in fig. 23, pull rolls 110 are provided on the paper entrance side and the paper discharge side of the travel path 85 of the printing target substrate W between the printing units, and the printing target substrate W is wound around the peripheral surface of each pull roll 110. Each pull roll 110 is rotatably disposed in the frame 120 between the printing units. Each of the draw rollers 110 is driven to rotate forward and backward in synchronization with the feed-side reverse roller 6 and the discharge-side reverse roller 10 by a drive motor, not shown.

Therefore, the printing substrate W traveling on the traveling path 85 between the printing units does not deviate or loosen.

Further, pinch rollers 111 for pinch the printing substrate W wound around the peripheral surface of each draw roller 110 against the peripheral surface of the draw roller 110 are provided, and the printing substrate W is pinched by the peripheral surface of each draw roller 110 and the pinch rollers 111 for pinch the printing substrate W.

Therefore, the friction between the peripheral surface of each pull roll 110 and the printing substrate W is increased, and the slip does not occur therebetween, and the deviation of the printing registration does not occur by providing the pull rolls 110.

The pinch rollers 111 for the pull rollers are movable over positions pressed against the circumferential surfaces of the pull rollers 110 and over positions spaced apart from each other.

For example, the pair of support arms 113 are fixed to the support shaft 112 rotatably attached to the frame 120, and the shaft 114 is fixed between the pair of support arms 113. The grip roller 111 for the pulling roller is rotatably mounted on a shaft 114.

When the rod 116 rotated by the cylinder 115 is fixed to the support shaft 112, the rod 116 rotates, the support shaft 112 rotates by a predetermined rotation angle, the support arm 113 rotates, and the pinch roller 111 for the pull roller moves to a position where it is pressed against the pull roller 110 and a position where it is spaced apart from the pull roller. This structure is the same as the structure of the nip roller for the movable pulling roller of the registration adjusting apparatus 80.

Further, the number of the pulling rolls 110 may be 3 or more. That is, at least two pulling rolls 110 may be provided.

Further, the length of the running path may be changed by providing a movable roller between two draw rollers 110 in the running path 85 of the printing substrate W, or between the draw roller 110 and the printing unit, or both.

Claims

1. An intermittent printer includes a paper feeding unit for feeding a substrate to be printed; a printing section having a plurality of printing units for printing an image on a substrate to be printed fed from the paper feeding section; and a paper discharge unit for discharging the printed substrate on which the image is printed,

the paper discharge unit has a paper discharge-side reverse roller that is driven to rotate forward to move the printed base material in the forward direction and a paper discharge-side buffer device that stores the printed base material on which the image is printed in a loop form,

the intermittent printing press is characterized in that,

the platen is driven to rotate forward in synchronization with the paper feed-side reverse roller and the paper discharge-side reverse roller when the printing substrate is caused to travel in the forward direction, and the platen is driven to rotate backward in synchronization with the paper feed-side reverse roller and the paper discharge-side reverse roller when the printing substrate is caused to travel in the reverse direction,

2. The intermittent printing press of claim 1,

the guide roller on the paper feeding side and the guide roller on the paper discharge side are provided such that an extension line of a paper feeding side traveling path between the guide roller on the paper feeding side and the platen intersects with an extension line of a paper discharge side traveling path between the guide roller on the paper discharge side and the platen.

3. The intermittent printing press of claim 1,

the blanket cylinder is rotated from a printing start position to print an image on a printing substrate, and is rotated forward at a constant speed,

the blanket cylinder is rotated in a non-image range from a printing end position, and is rotated at a speed-reduced forward rotation speed from the constant speed to a stop, and is rotated at a speed-reduced reverse rotation speed to a predetermined reverse rotation speed after the stop, and is rotated at a speed-reduced reverse rotation speed to a stop, and is rotated at a speed-reduced reverse rotation speed to the constant speed after the stop, and is rotated at a speed-increased forward rotation speed to a position at which a rear end of a print image printed on a printing substrate is brought into contact with a front end of a printing range of the blanket cylinder.

4. The intermittent printing press of claim 2,

the blanket cylinder is rotated from a printing start position in an image range to print an image on a printing substrate, and is driven to rotate positively at a constant speed equal to that of the blanket cylinder,

5. The intermittent printing press of claim 3,

a curve showing a change in the rotation driving speed ratio of the deceleration positive rotation driving of the platen and a curve showing a change in the rotation driving speed ratio of the acceleration positive rotation driving are line-symmetric,

a curve showing a change in the rotation driving speed ratio of the acceleration reverse rotation driving of the pressure cylinder and a curve showing a change in the rotation driving speed ratio of the deceleration reverse rotation driving are line-symmetric,

the rotation driving speed ratio of the platen from the constant speed to the predetermined reverse rotation driving speed and the rotation driving speed ratio of the platen from the predetermined reverse rotation driving speed to the constant speed smoothly change along a substantially U-shaped curve.

6. The intermittent printing press of claim 4,

a curve showing a change in the rotation driving speed ratio of the acceleration reverse rotation driving of the platen and a curve showing a change in the rotation driving speed ratio of the deceleration reverse rotation driving are line-symmetric,

7. The intermittent printing press according to any one of claims 1 to 6,

the printing unit is provided with a register adjusting device between the printing units, and the register adjusting device is configured to change the length of the traveling path of the printing substrate between the printing units to adjust the printing register.

8. The intermittent printing press of claim 7,

the register adjusting device is provided with a pull roll on a paper feeding side, a pull roll on a paper discharging side and a movable roll, and is configured to change the length of a running path between the pull roll on the paper feeding side and the pull roll on the paper discharging side by moving the movable roll,

the both draw rolls are provided with pinch rolls for draw rolls, which are driven in synchronization with the feed-side reverse roll and the discharge-side reverse roll to rotate in the forward direction and in the reverse direction, respectively, to press the printing substrate wound around the peripheral surfaces of the both draw rolls against the peripheral surfaces of the both draw rolls.

9. The intermittent printing press of claim 8,

the rotation speed of the feed-side reverse roller, the rotation speed of the discharge-side reverse roller, the rotation speed of the press cylinder of each printing unit, the rotation speed of the feed-side pull roller and the rotation speed of the discharge-side pull roller of each register adjustment device can be controlled individually.

10. The intermittent printing press of any one of claims 1 to 6,

at least two pull rolls on which the printing substrate is wound are provided on a traveling path of the printing substrate between the printing units, and the pull rolls are provided with pinch rolls for pull rolls which are driven by forward rotation for traveling the printing substrate in a forward direction and reverse rotation for traveling the printing substrate in a reverse direction in synchronization with the feed-side reverse roll and the discharge-side reverse roll, and press the printing substrate wound around the peripheral surface of each pull roll against the peripheral surface of each pull roll.

11. A batch printing press as claimed in any one of claims 1 to 6, wherein the substrate to be printed is a film.

12. The intermittent printer of claim 7 wherein the substrate to be printed is a film.

13. The intermittent printer of claim 8 wherein the substrate to be printed is a film.

14. The intermittent printing press of claim 9, wherein the substrate to be printed is a film.

15. The intermittent printer of claim 10 wherein the substrate to be printed is a film.