JP3530033B2 - Printing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for printing on a sheet of printing paper.

[0002]

2. Description of the Related Art In such a printing apparatus, the printing paper is conveyed by holding the front end of the printing paper by a holding member such as a gripper that moves in synchronization with the printing operation of the printing apparatus. There is. Then, in order to detect the occurrence of defective conveyance of the printing paper, the transportation status of the printing paper is constantly monitored by a printing paper detection sensor arranged inside the printing apparatus.

[0003]

When such a printing paper detection sensor is provided inside the printing apparatus, there is a problem that the printing paper detection sensor is contaminated and the printing paper cannot be accurately detected. Occur.

That is, the inside of the printing apparatus is filled with paper dust generated from the printing paper itself, ink, mist of dampening water, and the like. Further, in particular, in the printing paper discharge unit that discharges the printing paper from the printing apparatus, the show-through prevention powder for preventing the show-through of the printing paper is floating.

Therefore, when printing is continuously performed, such paper dust, mist of ink or dampening water, or show-through prevention powder adheres to the surface of the printing paper detection sensor. It becomes impossible to accurately detect the printing paper.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a printing apparatus capable of accurately detecting a printing paper by preventing the printing paper detection sensor from being contaminated. .

[0007]

According to a first aspect of the present invention, there is provided a printing device for performing printing on a sheet of printing paper, the holding device for holding the printing paper, and the printing device. A printing paper transport mechanism having a holding member moving means for transporting the printing paper by moving the holding member in synchronization with the operation, and a printing paper detection for detecting the printing paper transported by the printing paper transport mechanism. It is characterized by comprising a sensor and a cleaning member that cleans the printing paper detection sensor by moving by being driven by the holding member moving means.

According to a second aspect of the invention, in the first aspect of the invention, the holding member ejects the printing paper by holding the leading edge of the printing paper in a printing paper ejecting unit for ejecting the printing paper. The printing paper detection sensor detects the printing paper discharged by the gripper.

According to a third aspect of the present invention, in the second aspect, the holding member moving means includes an endless cord connected to the gripper, and the cleaning member is
It is attached to the rope.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the holding member is a gripper that conveys the printing paper by holding the leading edge of the printing paper on the outer peripheral portion of the cylinder. The cleaning member is attached to the outer peripheral portion of the cylinder, and the printing paper detection sensor detects the printing paper conveyed by the gripper.

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the cleaning member is brought into contact with the surface of the print sheet detection sensor to cause the print sheet detection sensor to move. Includes a brush to clean the surface.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view of a printing apparatus according to the present invention.

This printing apparatus includes first and second plate cylinders 11,
After the image is recorded on a printing plate on which the image held on 12 is not recorded and the plate is made, the ink supplied to the printing plate is transferred to the impression cylinder 15 through the first and second blanket cylinders 13 and 14. Printing is performed by transferring to the printing paper held.

This printing apparatus has a first plate cylinder 11 movable between a first printing position shown by a solid line in FIG. 1 and an image recording position shown by a chain double-dashed line, and a first plate cylinder shown by a solid line in FIG. The second plate cylinder 12 is movable between two printing positions and the image recording position.

The first plate cylinder 11 moved to the first printing position
Around the periphery of the ink, an ink supply device 20a for supplying, for example, black (K) ink to the printing plate, an ink supply device 20b for supplying, for example, magenta (M) ink to the printing plate, and a printing plate Damping water supply devices 21a and 21b for supplying dampening water are arranged. Further, around the second plate cylinder 12 that has moved to the second printing position, an ink supply device 20c for supplying, for example, cyan (C) ink to the printing plate, and for example, yellow (Y) to the printing plate.
An ink supply device 20d for supplying the ink, and a dampening water supply device 21c for supplying the dampening water to the printing plate,
21d and are arranged. Further, around the first plate cylinder 11 or the second plate cylinder 12 that has moved to the image recording position, the plate supply section 23, the plate discharge section 24, and the image recording device 25.
And a development processing device 26 are arranged.

In this printing apparatus, the first blanket cylinder 13 is provided so as to be able to contact the first plate cylinder 11, and the second blanket is provided so as to be contactable with the second plate cylinder 12. The impression cylinder 1 provided so as to be able to contact the cylinder 14 and the first and second blanket cylinders 13 and 14 at different positions.
5, a paper feed cylinder 16 for passing the printing paper supplied from the printing paper supply unit 27 to the impression cylinder 15, and a printed printing paper received from the impression cylinder 15 for discharging to the printing paper discharge unit 28. It has a paper discharge cylinder 17 around which a chain 19 is wound, a reversing cylinder 18 used when performing double-sided printing in this printing apparatus, and a blanket cylinder cleaning device 29.

Each of the chain 19 and the reversing cylinder 18 constituting the pressure drum 15, the paper feeding drum 16, and the paper discharging drum 17 holds the leading edge of the printing paper and moves the printing paper to press the printing cylinder 15. Grippers 83, 84, 85, and 86 that convey with the rotation of the chain 19 and the reversing cylinder 18 that form the paper feed cylinder 16 and the paper discharge cylinder 17 are provided.

The first and second plate cylinders 11 and 12 are respectively connected to a plate cylinder moving mechanism (not shown), and by driving the plate cylinder moving mechanism, the first and second printing positions described above can be set. It moves back and forth between the image recording position. Further, the first plate cylinder 11 rotates in synchronization with the first blanket cylinder 13 in the first printing position, and the second plate cylinder 12 rotates with the second blanket cylinder 14 in the second printing position. It is configured to rotate in synchronization. Further, a plate cylinder rotating mechanism (not shown) is disposed near the image recording position, and both the first and second plate cylinders 11 and 12 are moved to the image recording position when the plate cylinder is moved. It is configured to rotate by the drive of the rotating mechanism.

Around the first plate cylinder 11 or the second plate cylinder 12 which has moved to the image recording position, the plate supply section 23 and the plate discharge section 2 are provided.
4 and 4 are arranged.

The plate supply unit 23 includes a supply cassette 63 for accommodating a long roll printing plate on which no image is recorded in a light-tight state, and a leading end of the printing plate pulled out from the supply cassette 63. A guide member 64 and a guide roller 65 for guiding to the surface of the first plate cylinder 11 or the second plate cylinder 12, and a cutter 66 for cutting a long printing plate into a sheet-shaped printing plate. It is arranged. Further, the first and second plate cylinders 11 and 12 are provided with a pair of gripper jaws (not shown) for gripping the front end portion and the rear end portion of the printing plate supplied from the plate supply unit 23. .

The plate discharge unit 24 is provided for the first plate cylinder 1 after printing is completed.
A claw mechanism 73 for peeling the printing plate held on the first or second plate cylinder 12, a conveyor mechanism 69 for conveying the printing plate peeled by the action of the claw mechanism 73 to a discharge cassette 68, and a discharge It has a cassette 68.

The leading end of the printing plate pulled out from the supply cassette 63 in the plate supply unit 23 is guided by the guide roller 65 and the guide member 64, and the gripper of one of the first plate cylinder 11 and the second plate cylinder 12 is held. Can be added to your nails. Then, the first plate cylinder 11 or the second plate cylinder 12 is rotated by the drive of the plate cylinder rotating mechanism 30, and the printing plate is transferred to the first plate cylinder 11.
Alternatively, it is wound around the outer periphery of the second plate cylinder 12. Then, the trailing edge of the printing plate cut by the cutter 66 is gripped by the other gripper. In this state, while the first plate cylinder 11 or the second plate cylinder 12 is rotated at a low speed, the printing held on the outer peripheral portion of the first plate cylinder 11 or the second plate cylinder 12 by the image recording device 25. An image is recorded by irradiating the surface of the plate with a modulated laser beam.

The printing plate P mounted on the outer peripheral portion of the first plate cylinder 11 is moved by the image recording device 25 as shown in FIG.
As shown in, an image area 67a for printing with black ink and an image area 67b for printing with magenta ink are recorded. In addition, the second plate cylinder 12
The printing plate P mounted on the outer peripheral portion of the
Thus, as shown in FIG. 2B, an image area 67c for printing with cyan ink and an image area 67d for printing with yellow ink are recorded. The image area 67a and the image area 67b are recorded at positions where they are evenly distributed (that is, 180 degrees apart from each other) when mounted on the outer peripheral portion of the first plate cylinder 11. Similarly, the image area 67c and the image area 6
7d refers to a state in which the second plate cylinder 12 is mounted on the outer peripheral portion of the second plate cylinder 12 and is evenly distributed (that is, 1d to each other).
It is recorded at a position where it is separated by 80 degrees.

Referring again to FIG. 1, as described above, the ink supply device 20a and the ink supply device 20b are provided around the first plate cylinder 11 which has moved to the first printing position. An ink supply device 20c and an ink supply device 20d are arranged around the second plate cylinder 12 that has moved to the second printing position. These ink supply devices 20a, 20
Each of b, 20c, and 20d (collectively referred to as "ink supply device 20") has a plurality of ink rollers 71 and ink fountains 72.

The ink rollers 71 of the ink supply devices 20a and 20b swing by the action of a cam or the like (not shown). By this swinging operation, the two image areas 6 formed on the printing plate P held on the outer peripheral portion of the first plate cylinder 11 are formed.
By contacting the ink roller 71 of the ink supply device 20a or 20b with any image area of 7a and 67b, the ink can be supplied only to the necessary image area. In addition, similarly, the ink supply device 20
The ink rollers 71 of c and 20d also swing by the action of a cam or the like (not shown). And by this swinging motion,
The ink roller 71 of the ink supply device 20c or 20d comes into contact with an arbitrary image area of the two image areas 67c and 67d formed on the printing plate P held on the outer peripheral portion of the second plate cylinder 12. Thus, the ink can be supplied only to the necessary image area.

The dampening water supply devices 21a, 21b, 21c and 21d (these are collectively referred to as "dampening water supply device 21") are used before the ink is supplied to the printing plate P by the ink supply device 20. Further, dampening water is supplied to the printing plate P. Of these dampening water devices 21, the dampening water supply device 21a is the image area 67a on the printing plate P.
The dampening water supply device 21b is in the image area 67b of the printing plate P, the dampening water supply device 21c is in the image area 67c of the printing plate P, and the dampening water supply device 21d is in the image area 67d of the printing plate P. Respectively, dampening water is supplied.

A development processing device 26 is disposed below the first plate cylinder 11 or the second plate cylinder 12 that has moved to the image recording position. The developing device 26 has a developing unit, a fixing unit, and a diaphragm unit, and is configured to be movable up and down between a standby position shown by a two-dot chain line and a developing process position shown by a solid line in FIG.

When the printing plate P on which an image is recorded by the image recording device 25 is developed by the developing processing device 26, when the printing plate P rotates with the first plate cylinder 11 or the second plate cylinder, Then, the developing unit, the fixing unit and the diaphragm unit are brought into contact with each other in order.

The first and second blanket cylinders 13 and 14 provided so as to be able to contact the first and second plate cylinders 11 and 12 are
It has the same diameter as the first and second plate cylinders 11 and 12, and a blanket for ink transfer is mounted on the outer peripheral portion thereof. Then, the first and second blanket cylinders 13 and 1
Reference numeral 4 is configured to be able to come into contact with and separate from the first and second plate cylinders 11 and 12 and the impression cylinder 15 by a cylinder inserting mechanism (not shown).

The blanket cylinder cleaning device 29 arranged between the first and second blanket cylinders 13 and 14 has the take-up shaft 5 from the unwind shaft 542 through the pressing roller 544.
The cleaning liquid is supplied to the long cleaning cloth 541 spread on the path extending to 43, and the cleaning cloth is brought into contact with the first and second blanket cylinders 13 and 14 and then slid. The surfaces of the first and second blanket cylinders 13 and 14 are cleaned. The configuration of the blanket cylinder cleaning device 29 will be described later in detail.

The impression cylinder 15 provided so as to be able to come into contact with the first and second blanket cylinders 13 and 14 is the first and second plate cylinders 1.
1, 12 and first and second blanket cylinders 13, 14
It has a diameter of 1/2 of the diameter of. Further, the impression cylinder 15 has the above-mentioned gripper 83 for holding and conveying the leading end of the printing paper.

The paper feed cylinder 16 arranged adjacent to the impression cylinder 15 has the same diameter as the impression cylinder 15. The paper feed cylinder 16 holds the leading edge of the printing paper supplied one by one from the printing paper supply unit 27 by the reciprocating suction plate 74 by the gripper 84 and conveys it. The leading edge of the printing paper held by the gripper 84 is moved from the paper feed cylinder 16 to the impression cylinder 15
When the printing paper is delivered to the gripper 83 of the impression cylinder 15.
Held by.

The discharge cylinder 17 disposed adjacent to the impression cylinder 15 has the same diameter as the impression cylinder 15. The paper discharge cylinder 17 has a structure in which a pair of chains 19 are wound around both ends thereof, and a gripper 85 is arranged on each connecting member (not shown) that connects the pair of chains 19.
The leading edge of the printing paper held by the gripper 83 of the impression cylinder 15 is held by one of the grippers 85 of the paper ejection cylinder 17 when the printing paper is transferred from the impression cylinder 15 to the paper ejection cylinder 17. Then, this printing paper is conveyed and discharged onto the printing paper discharge unit 28 as the chain 19 moves. Instead of the chain 19, other cords such as a synchronous belt may be used.

The state of conveyance of the printing paper at this time is detected by the printing paper detection sensor 32 arranged below the chain 19. The configuration of the printing paper detection sensor 32 will be described later in detail.

The print paper discharge section 28 is provided with a powder supply means (not shown) for supplying show-through prevention powder to the print paper in order to prevent show-through by the print paper.

The paper feed cylinder 16 is connected to a drive motor via a belt (not shown). And the paper feed cylinder 1
6, the impression cylinder 15, the discharge cylinder 17, and the first and second blanket cylinders 13 and 14 are connected by gears attached to their ends. Further, the first blanket cylinder 13 and the first plate cylinder 11 moved to the first printing position, and the second blanket cylinder 14 and the second plate cylinder 12 moved to the second printing position, They are connected by gears attached to their ends. Therefore, the paper feed cylinder 16, the impression cylinder 15, and the paper ejection cylinder 1 are driven by a drive motor (not shown).
7, the first and second blanket cylinders 13 and 14, and the first and second plate cylinders 11 and 12 rotate in synchronization with each other.

FIG. 3 is a block diagram showing the main electrical construction of this printing apparatus. This printing device includes a ROM 141 in which an operation program necessary for controlling the device is stored,
RAM 142 in which data and the like are temporarily stored during control
And a CPU 143 that executes a logical operation. The control unit 140 includes an ink supply device 20, an image recording device 25, a development processing device 26, and a blanket cylinder cleaning device 2 via an interface 144.
It is connected to a drive circuit 145 for generating a drive signal for a drive unit or the like in the cylinder insertion mechanism or the like of the ninth, first and second blanket cylinders 13, 14. Although not shown in the drawing, a printing paper detection sensor 32 described later is provided.
Is also connected to the control unit 140 via the interface 144. The printing apparatus is controlled by the control unit 140 and executes a plate making operation and a printing operation described later.

Next, plate making and printing operations by this printing apparatus will be described. FIG. 4 is a flowchart showing an outline of plate making and printing operations by this printing apparatus.
The printing and plate-making operations are performed when multicolor printing is performed on the printing paper with four color inks of yellow, magenta, cyan, and black.

First, a plate-making process is performed in which an image is recorded on the printing plate P on the first and second plate cylinders 11 and 12 and a developing process is performed (step S1). This plate making process is executed according to the process shown in the flowchart of FIG. 5 as a subroutine.

That is, first, the first plate cylinder 11 is shown in FIG.
In step S11, the image is moved to the image recording position indicated by the chain double-dashed line.

Next, the printing plate P is supplied to the outer periphery of the first plate cylinder 11 (step S12). The supply of this printing plate P is
This is performed by gripping the leading edge of the printing plate P pulled out from the supply cassette 63 and the trailing edge of the printing plate P cut by the cutter 66 with a pair of grippers (not shown).

Then, an image is recorded on the printing plate P held on the outer periphery of the first plate cylinder 11 (step S13). This image is recorded by rotating the first plate cylinder 11 at a low speed and irradiating a modulated laser beam from the image recording device 25 to the printing plate P held on the outer periphery of the first plate cylinder 11. To be executed.

Next, the printing plate P on which the image is recorded is developed (step S14). In this developing process, the developing device 26 is raised from the standby position shown by the chain double-dashed line in FIG. 1 to the developing position shown by the solid line, and then the first plate cylinder 1 is moved.
The process is performed by bringing the developing unit, the fixing unit, and the diaphragm unit into contact with the printing plate P rotating together with 1.

When the above developing process is completed, the first plate cylinder 1
1 is moved to the first printing position indicated by the solid line in FIG. 1 (step S15).

Subsequently, the plate making process for the printing plate P held on the outer periphery of the second plate cylinder 12 is executed by the same operation as that of steps S11 to S15 (steps S16 to S2).
0). When the plate making on the printing plate P held on the outer peripheries of the first and second plate cylinders 11 and 12 is completed, the plate making process is ended.

Referring to FIG. 4 again, when the plate making process is completed, a printing process for printing on the printing paper using the printing plate P on the first and second plate cylinders 11 and 12 is executed (step S
2). This printing process is executed as follows.

That is, first, each dampening water supply device 21 and each ink supply device 20 are connected to the first and second plate cylinders 11 and 1.
Only the corresponding image area of the printing plate P held on 2 is brought into contact. Thereby, the image areas 67a, 67
b, 67c, 67d respectively corresponding dampening water supply devices 21
And dampening water and ink are supplied from each ink supply device 20. Then, the ink supplied to the printing plate P is transferred to the corresponding regions of the first and second blanket cylinders 13 and 14.

Then, the printing paper is supplied to the paper feed cylinder 16. The printing paper is passed from the paper feed cylinder 16 to the impression cylinder 15. When the impression cylinder 15 continues to rotate in this state, the impression cylinder 15
Has a diameter half that of the first and second plate cylinders 11 and 12 and the first and second blanket cylinders 13 and 14, so that the printing paper held on the outer periphery of the impression cylinder 15 is , The black and cyan inks in the first rotation,
In the second rotation, magenta and yellow inks are transferred.

In this way, the leading edge of the printing paper on which the four colors have been printed is transferred from the impression cylinder 15 to the paper ejection cylinder 17. Then, the printing paper on which the four colors have been printed is driven by the pair of chains 19 to drive the gripper 85 of the discharge cylinder 17.
At the same time, it is conveyed to and discharged from the printing paper discharge unit 28.

When the printing process is completed, the printing plate P used for printing is discharged (step S3). In order to discharge the printing plate P, first, the first plate cylinder 11 is moved to the image recording position shown by the chain double-dashed line in FIG. Then, the first plate cylinder 11 is rotated counterclockwise, and after the end portion of the printing plate P held on the first plate cylinder 11 is peeled off by the claw mechanism 73, the printing plate P is conveyed by the conveyor mechanism. The sheet is guided by 69 and discharged into the discharge cassette 68. Then, after returning the first plate cylinder 11 to the first printing position, the second plate cylinder 12 is moved from the second printing position to the image recording position, and the same operation as described above is executed. The printing plate P held on the second plate cylinder 12 is discharged into the discharge cassette 68.

When the discharging process of the printing plate P is completed, the blanket cylinder cleaning device 29 cleans the first and second blanket cylinders 13 and 14 (step S4).

When the cleaning of the first and second blanket cylinders 13 and 14 is completed, it is confirmed whether or not another printing operation of the printed matter is to be performed (step S5). When performing another printing operation, the operations of steps 1 to 4 are repeated.

When the printing operation is completed, the ink is washed (step S6). The cleaning of the ink is executed by removing and cleaning the ink adhering to the ink roller 71 and the ink fountain 72 in each ink supply device 20 by an ink cleaning device (not shown) provided in each ink supply device 20. .

When the ink washing step is completed, all steps are completed.

Next, the operation of detecting the printing paper by the printing paper detection sensor 32, which is a feature of the present invention, will be described. FIG. 6 is a schematic side view showing the chain 19 and the printing paper detection sensor 32 described above.

As shown in this figure, the chain 1 described above
9 has an endless shape wound between the paper discharge cylinder 17 and the sprocket 31. Further, grippers 85 are arranged on the chain 19 at a predetermined pitch. On the other hand, below the chain 19, a printing paper detection sensor 32 for detecting the printing paper whose tip is held and conveyed by the gripper 85 is arranged. In addition,
The gripper 85 functions as the holding member in the present invention, and the chain 19 and the like function as the holding member moving means in the present invention.

After the printing is finished, the printing paper is the chain 19
The front end of the gripper 85 is held by one of the grippers 85 attached to the paper, and is conveyed and discharged onto the print paper discharge unit 28 as the chain 19 moves. The conveyance status of the printing paper at this time is detected by the printing paper detection sensor 32 arranged below the chain 19.

FIG. 7 is an enlarged view showing the gripper 85, the printing paper detection sensor 32, etc. described above.

As shown in this figure, the gripper 85 attached to the chain 19 has a claw 3 rotatable about the shaft 40.
5 and a claw seat 36 that holds the leading edge of the printing paper by coming into contact with the claw 35. And this nail seat 36
Through the bracket 38, the printing paper detection sensor 3
A brush 37 for cleaning 2 is attached. In addition, this brush 37 is, as shown in FIG.
It is arranged only on one of the plurality of grippers 85 attached to the gripper 85.

On the other hand, the printing paper detection sensor 32 is arranged in the main body of the printing apparatus via a mounting bracket 33. A transparent plate 34 such as a glass plate for protecting the printing paper detection sensor 32 is arranged at the upper end of the printing paper detection sensor 32. The printing paper detection sensor 32 is a reflection type optical sensor that includes a light transmitting element and a light receiving element, and detects light reflected on the surface of the printing paper.

On the translucent plate 34 of the printing paper detection sensor 32, the show-through preventing powder supplied by the powder supply means (not shown) and the printing paper itself are provided as printing is continuously performed. Paper dust generated from the ink, mist of ink or dampening water, etc. adheres. For this reason,
It becomes impossible to accurately detect the printing paper by the printing paper detection sensor 32.

However, in the printing apparatus according to this embodiment, the brush 37 holds the tip of the printing paper together with the chain 19 in synchronization with the printing operation, so that the brush 37 moves to the left side shown in FIGS. 6 and 7. Move in the direction. The lower end of the brush 37 contacts the surface of the transparent plate 34 provided at the upper end of the printing paper detection sensor 32 and slides on the surface of the transparent plate 34.

As a result, the transparent plate 34 of the printing paper detection sensor 32 is cleaned by the brush 37. Therefore, it is ensured that the show-through preventing powder, the paper dust generated from the printing paper itself, or the mist of the ink or the dampening water adheres to the surface of the transparent plate 34 of the printing paper detection sensor 32. Can be prevented. Therefore, the print sheet detection sensor 32 can reliably detect the print sheet that is conveyed while being held by the gripper 85.

Since the brush 37 cleans the transparent plate 34 by sliding on the surface of the transparent plate 34 in the printing paper detection sensor 32, it can be used as a cleaning means utilizing high pressure air jetting or the like. Compared with this, it is possible to reliably remove the show-through prevention powder, the paper dust generated from the printing paper itself, or the mist such as ink or fountain of dampening water which is difficult to remove from the surface of the translucent plate 34. It becomes possible.

In the above-described embodiment, the printing paper detection sensor 3 for detecting the printing paper whose tip is held and conveyed by the gripper 85 as a holding member.
The case where 2 is cleaned by the brush 37 that moves together with the chain 19 that constitutes the holding member moving means has been described, but the present invention should not be limited to such an embodiment.

FIG. 8 is a schematic diagram showing another embodiment of the present invention.

In the embodiment shown in this figure, the tip end is held by a gripper 83 as a holding member arranged in the pressure drum 15 which constitutes the holding member moving means, and is conveyed as the pressure drum 15 rotates. The printing paper detection sensor 32 for detecting the printing paper is cleaned by the brush 39 attached to the surface of the impression cylinder 15. In this figure, the printing paper detection sensor 32 and the brush 39 are exaggerated in size for convenience of explanation.

This brush 39 is provided on the outer peripheral portion of the impression cylinder 15,
It is arranged with its tip facing outward. Also,
The printing paper detection sensor 32 is arranged at a position where it can come into contact with the tip of the brush 39 by the movement of the brush 39 as the impression cylinder 15 rotates.

The brush 39 is provided with the first and second blanket cylinders 13 and 14 and the paper feed cylinder 1 as the impression cylinder 15 rotates.
6 and the empty portion of the discharge cylinder 17 so that the first and second blanket cylinders 13, 1
4, it is arranged at a position where it does not interfere with the paper feed cylinder 16 and the paper discharge cylinder 17.

In such an embodiment, the tip of the printing paper is held by the gripper 83 attached to the impression cylinder 15, and is conveyed together with the impression cylinder 15 as the impression cylinder 15 rotates. At this time, the printing paper is conveyed in the impression cylinder 15
It is detected by the printing paper detection sensor 32 which is arranged to face.

The brush 39 attached to the impression cylinder 15 moves in synchronization with the printing operation. And this brush 3
The leading end of 9 comes into contact with the surface of the transparent plate 34 arranged at the upper end of the printing paper detection sensor 32, and slides on the surface of the transparent plate 34. As a result, the transparent plate 34 of the printing paper detection sensor 32 is cleaned by the brush 37.

Therefore, the show-through prevention powder, the paper dust generated from the printing paper itself, or the mist of ink or dampening water, etc., adheres to the surface of the transparent plate 34 of the printing paper detection sensor 32. Can be reliably prevented. For this reason, the print sheet detection sensor 32 can reliably detect the print sheet that is conveyed with its front end held by the gripper 83.

In the above-described embodiment, the brush 39 or 37 as a cleaning member is attached to the impression cylinder 15 or the chain 19 for directly moving the gripper 83 or 85 as a holding member. However, the brushes 37, 39 may be configured to move by being driven by some moving means for indirectly moving the holding member in synchronization with the printing operation. For example, the brush may be moved by a brush moving mechanism connected to the impression cylinder 15, the chain 19 and the like via some drive transmission means to clean the printing paper detection sensor.

[0074]

According to the invention described in claims 1 to 5, the printing member is provided with a cleaning member that cleans the printing paper detection sensor by moving by receiving the drive of the holding member moving means. The printing paper detection sensor can be cleaned by the cleaning member in synchronization with the operation. Therefore, the printing paper can be accurately detected by preventing the printing paper detection sensor from being contaminated.

[Brief description of drawings]

FIG. 1 is a schematic side view of a printing apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing an arrangement of image areas 67 on a printing plate P.

FIG. 3 is a block diagram showing a main electrical configuration of the printing apparatus.

FIG. 4 is a flowchart showing an outline of plate making and printing operations by the printing apparatus.

FIG. 5 is a flowchart showing a plate making process.

FIG. 6 is a schematic side view showing a chain 19, a printing paper detection sensor 32, and the like.

FIG. 7 is an enlarged view showing a gripper 85, a print sheet detection sensor 32, and the like.

FIG. 8 is a schematic diagram showing another embodiment of the present invention.

[Explanation of symbols]

11 First plate cylinder 12 Second plate cylinder 13 First Blanket Body 14 Second Blanket Body 15 impression cylinder 16 Paper feed cylinder 17 Output cylinder 19 chains 20 Ink supply device 21 Dampening water supply system 23 Plate Supply Department 24 Plate ejection section 25 Image recording device 26 Development Processing Equipment 27 Printing Paper Supply Unit 28 Printing paper discharge section 32 Print paper detection sensor 34 translucent plate 35 nails 36 Nail seat 38 brushes 39 brushes 85 gripper P printing plate

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A 63-137844 (JP, A) JP-A 6-15808 (JP, A) JP-A 4-220345 (JP, A) JP-A 62- 263452 (JP, A) JP 9-146367 (JP, A) JP 5-201583 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41F 21/00-21 / 14 B41F 33/00-33/18 B41F 35/00 B65H 5/08-5/14 B65H 7/00-7/20

Claims (5)

(57) [Claims] 1. A printing apparatus for printing on a sheet of printing paper, comprising: a holding member for holding the printing paper; and a holding member that is moved in synchronization with a printing operation. A printing paper transport mechanism having a holding member moving means for carrying the printing paper, a printing paper detection sensor for detecting the printing paper carried by the printing paper transportation mechanism, and a drive of the holding member moving means. A printing device comprising: a cleaning member that cleans the printing paper detection sensor by moving the cleaning device. 2. The printing apparatus according to claim 1, wherein the holding member is a gripper that ejects the printing paper by holding a leading edge of the printing paper in a printing paper ejection unit that ejects the printing paper, The printing paper detection sensor is a printing device that detects the printing paper discharged by the gripper. 3. The printing apparatus according to claim 2, wherein the holding member moving unit includes an endless cord member connected to the gripper, and the cleaning member is attached to the cord member. apparatus. 4. The printing apparatus according to claim 1, wherein the holding member is a gripper that conveys the printing paper by holding the leading end of the printing paper on the outer peripheral portion of the cylinder, and the cleaning member is the cleaning member. A printing apparatus which is attached to an outer peripheral portion of a body, and wherein the printing paper detection sensor detects a printing paper conveyed by the gripper. 5. The printing apparatus according to claim 1, wherein the cleaning member is a brush for cleaning the surface of the printing paper detection sensor by contacting the surface of the printing paper detection sensor. Printing device including.