JP2007276275A - Cleaning method of press roller of perfecting printing equipment, and stencil printing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem caused by bringing a cleaning member into contact with a press roller which comes into contact with and off from a plate cylinder, in order to prevent paper soiling. <P>SOLUTION: Perfecting printing equipment 10 has a plate cylinder 11, a platemaking part 14 which makes a master 23 to be wound on the plate cylinder, a press roller 12 which presses paper against the plate cylinder 11 in a printing part 13 and a paper feeding means 15 which feeds the paper to the printing part 13. In regard to this equipment, a cleaning method of the press roller of the perfecting printing equipment is so constituted that it has a process of winding the master not being made into a plate wherein the master not being made into the plate by the platemaking part 14 is wound on the plate cylinder 11 after completion of perfecting printing and a paper feeding process for cleaning wherein the paper is fed between the plate cylinder 11 whereon the master not being made into the plate is wound and the press roller 12 which is in contact with the plate cylinder. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the double-sided printing mode by the double-sided printing apparatus, the present invention first presses one side of the paper and then presses the other side of the paper to press the paper against the plate cylinder during double-sided printing. The present invention relates to a roller cleaning method and a stencil printing apparatus.

Printing in the stencil printing apparatus is performed by pressing a sheet with a press roller onto a porous cylindrical plate cylinder around which a plate making master on which a printing image is formed by plate making means.
The press roller in a stencil printing machine capable of double-sided printing contacts the printing surface side of the surface-printed paper and presses the surface-printed paper against the plate cylinder in the process of performing the backside printing following the surface printing. Therefore, the undried image ink on the surface image surface is transferred to the press roller. As the amount of ink transferred to the press roller increases with an increase in the number of times of duplex printing, the paper in subsequent printing is soiled with that ink.

  2. Description of the Related Art Conventionally, as a means for cleaning a press roller to which undried image ink is adhered, there has been known a press roller cleaning method and apparatus for removing ink on a press roller by pressing a cleaning member against a peripheral surface of a rotating press roller. .

In Patent Document 1, in a double-sided printing process in a double-sided printing apparatus, a press is performed by pressing a cleaning roller as a cleaning member against a press roller that makes contact with the front surface printing surface of a sheet and presses the back surface against a plate cylinder to perform double-sided printing. An apparatus for cleaning rollers is described.
Patent Document 2 describes a pressure cylinder cleaning device in a stencil printing apparatus that presses a cleaning sheet against a pressure cylinder that presses a sheet against the plate cylinder during printing by pressing means, and wipes ink on the pressure cylinder. .

JP-A-2005-112568 JP 11-91225 A

In the press roller cleaning device described in Patent Document 1, it is not only necessary to provide a cleaning member for removing undried image ink that contacts the press roller and adheres to the press roller, but also removes ink. Therefore, it is necessary to replace the dirty cleaning member.
In the impression cylinder cleaning device described in Patent Document 2, in order to remove ink on a rotating impression cylinder with a cleaning sheet, a cleaning sheet is fixed to one end of the cleaning sheet and then pressed against the plate cylinder. Necessitating pressing means.

  The objective of this invention is providing the press roller cleaning method and stencil printing apparatus of the double-sided printing apparatus which solved the trouble in the cleaning apparatus of the above-mentioned press roller.

According to a first aspect of the present invention, in the press roller cleaning method of a double-sided printing apparatus, a plate cylinder on which a master is wound, plate making means for making a master wound on the plate cylinder, and a plate unit in a printing unit. In a double-sided printing apparatus comprising a press roller for pressing paper, a paper feeding means for feeding paper to the printing unit, and a paper discharge tray for receiving printed paper, plate making by the plate making means after completion of double-sided printing A non-plate master winding process for winding a non-plate master that is not performed on the plate cylinder, and cleaning for feeding paper between a plate cylinder on which the plate master is wound and a press roller in contact with the plate cylinder And a paper feeding process.
According to a second aspect of the present invention, in the press roller cleaning method of the double-sided printing apparatus according to the first aspect, the plate cylinder has a plate-making image corresponding to the surface image and a plate-making image corresponding to the back image on the peripheral surface thereof. The master formed side by side in the rotation direction of the plate cylinder is wound, and double-sided printing is performed by reversing the surface-printed paper and feeding it again to the printing unit.
According to a third aspect of the present invention, in the press roller cleaning method of the double-sided printing apparatus according to the first or second aspect, the number of sheets fed to the printing unit in the paper feeding step can be arbitrarily set.
According to a fourth aspect of the present invention, in the press roller cleaning method of the double-sided printing apparatus according to any one of the first to third aspects, the cleaning paper that has passed through the printing section of the plate cylinder around which the plate-making master is wound is used. The sheet is discharged to a discharge unit different from the discharge tray.
According to a fifth aspect of the present invention, in the press roller cleaning method of the double-sided printing apparatus according to the fourth aspect, the another discharge unit is a discharge unit dedicated to the cleaning paper.
According to a sixth aspect of the present invention, in the press roller cleaning method for a double-sided printing apparatus according to any one of the first to third aspects, the plate making is performed in a state in which a sorter or a multistage discharge tray is installed in the double-sided printing apparatus. The cleaning paper discharge unit that has passed through the printing unit of the plate cylinder on which the master is wound is a tray different from the tray on which the double-side printed sheets of the sorter or the multi-stage discharge tray are discharged and stacked.
The invention according to claim 7 is the press roller cleaning method of the double-sided printing apparatus according to any one of claims 1 to 3,
When the double-sided printing device is equipped with a tape marker and a sorting device, when the paper is passed through the printing section of the plate cylinder on which the pre-plate master is wound and the cleaning paper is discharged, the tape marker and sorter are operated. Thus, it is possible to distinguish between the cleaning sheet and a normal printed sheet.
According to an eighth aspect of the present invention, in the press roller cleaning method of the double-sided printing apparatus according to any one of the first to seventh aspects, when a conveyance jam that may stain the press roller with ink is generated, Detecting and automatically executing the unprinted master winding step and the cleaning paper feeding step.
According to a ninth aspect of the present invention, in the press roller cleaning method of the double-sided printing apparatus according to the eighth aspect, the plate is fed to the printing unit rather than the master plate-making size wound around the plate cylinder when the conveyance jam occurs. When the sheet to be printed is small, warning display and / or cleaning of the press roller with the sheet is stopped.
According to a tenth aspect of the present invention, in the press roller cleaning method for a double-sided printing apparatus according to any one of the first to eighth aspects, the printing unit is fed more than a maximum image area of a master wound around a plate cylinder. When the sheet to be printed is small, warning display and / or cleaning of the press roller with the sheet is stopped.
The invention according to claim 11 is a plate cylinder, plate making means for making a master wound around the plate cylinder, a press roller for pressing the sheet against the plate cylinder in a printing unit, and feeding the sheet to the printing unit A double-sided printing apparatus comprising a sheet feeding means and a paper discharge tray, wherein the press roller cleaning method of the double-sided printing apparatus according to any one of claims 1 to 10 is performed.

  According to the present invention, a double-sided printing apparatus comprising a plate cylinder on which a master is wound, plate making means for making a master wound around the plate cylinder, and paper feeding means for feeding paper to a printing unit. In accordance with the cleaning instruction of the press roller, the unmade master winding for winding the unmade master on the plate cylinder, and the plate cylinder on which the unmade master is wound and the press roller in contact therewith By controlling the printing apparatus so that the paper feed for cleaning is performed, the press roller can be cleaned without installing a cleaning member for the press roller. .

  FIG. 1 shows a stencil duplex printing apparatus according to an embodiment of the present invention. In the figure, a stencil duplex printing apparatus 10 includes a plate cylinder 11, a press roller 12, a printing unit 13, a plate making unit 14, a paper feeding unit 15, a plate discharging unit 16, a paper discharge unit 17, an image reading unit 18, an auxiliary tray 19, A refeed unit 20 and a discharge path switching member 21 are provided.

The printing unit 13 located approximately in the center of the apparatus main body is formed by the plate cylinder 11 and the press roller 12. The plate cylinder 11 is rotatably supported by the apparatus main body, and is driven to rotate in the direction of the arrow by a plate cylinder driving means (not shown).
The plate cylinder 11 has a master clamping clamper 22 that can be freely opened and closed on the outer peripheral surface thereof. The plate making is performed by the plate making unit 14 on the outer peripheral surface of the plate cylinder 11, and the divided plate making is held at the leading edge by the clamper 22. The finished master 23 is wound.

  In the divided plate-making master 23, a plate-making image corresponding to the front image and a plate-making image corresponding to the back image are formed side by side in the rotation direction of the plate cylinder 11, and there is an unmade portion between the plate making images. ing. The divided master-making master 23 is wound on the plate cylinder 11 so that the plate-making image corresponding to the front surface image corresponds to the front surface area, the plate-making image corresponding to the back surface image corresponds to the back surface area, and the non-plate making portion corresponds to the intermediate area. Be dressed. A rotary encoder (not shown) that detects the rotation angle and the number of rotations of the plate cylinder 11 is provided in the vicinity of the outer peripheral surface of the plate cylinder 11.

The press roller 12 disposed below the plate cylinder 11 is made of an elastic body having water repellency such as a fluororesin, and both ends thereof are rotatably supported by arm members (not shown). The arm member is swingably supported by swing support means (not shown), and contacts and separates the press roller 12 from the plate cylinder 11.
The press roller 12 selects a separation position shown in FIG. 1 where the circumferential surface is separated from the plate cylinder 11 and a pressing position where the press roller 12 is pressed against the plate cylinder 11 via the divided plate-making master 23 and the paper on the plate cylinder 11. Occupied. The press roller 12 is configured to be rotationally driven in the direction of the arrow by a press roller driving means (not shown) when occupied in the separation position, and to be driven and rotated by the plate cylinder 11 when occupied in the pressed position. ing.

In the vicinity of the right side of the press roller 12 in FIG. 1, re-feeding for transporting the surface-printed paper sent from the re-feeding unit 20 to the printing unit 13 along the peripheral surface of the press roller 12. A paper guide unit 25 is provided.
Below the press roller 12, there is provided a refeed resist roller 26 that feeds the paper discharged from the printing unit 13 onto the auxiliary tray 19 while making contact with the peripheral surface of the press roller 12. A refeed conveyance unit 27 having an auxiliary tray 19 on the upper surface is disposed on the lower left side of the press roller 12, and a refeed positioning member 28 is provided on this.
A paper receiving plate 30 that is movable along the upper surface of the auxiliary tray 19 is provided above the refeed conveyance unit 27.

  The paper refeeding means 20 includes an auxiliary tray 19, a paper refeeding guide unit 25, a paper refeeding registration roller 26, a paper refeeding positioning member 28, a paper refeeding conveyance unit 27, and a paper receiving plate 30.

  A path switching member 21 is provided on the paper transport path on the downstream side of the printing unit 13. The end of the passage switching member 21 on the downstream side in the sheet conveyance direction is supported by the apparatus main body so as to be swingable. The path switching member 21 is swung by driving means such as a solenoid (not shown), and has a first position indicated by a solid line in the drawing. It selectively occupies the second position indicated by the two-dot chain line. The paper that has passed through the printing unit 13 is guided to the paper discharge unit 17 when the path switching member 21 occupies the first position, and is guided to the auxiliary tray 19 when it occupies the second position. .

  The plate making section 14 adjacent to the plate cylinder 11 has a known configuration including a master holding member, a platen roller, a thermal head, a cutting means, a master stock section, a tension roller pair, a reversing roller pair, and the like. A master 23 is created.

  The sheet feeding unit 15 disposed below the plate making unit 14 has a known configuration including a sheet feeding tray 31, a sheet feeding roller 32, a separation roller 33, a separation pad 34, a registration roller pair 35, and the like.

  The plate discharging unit 16 adjacent to the plate cylinder 11 is also a known configuration having an upper plate discharging member, a lower plate discharging member, a plate discharging box, a compression plate, and the like, and the used divided plate-making master 23 is peeled off from the outer peripheral surface of the plate cylinder 11. And dispose of in the waste box.

The paper discharge unit 17 provided below the plate discharge unit 16 includes a peeling claw, a paper discharge conveyance unit 36, a paper discharge tray 37, and the like.
The paper discharge conveyance unit 36 has a driving roller, a driven roller, an endless belt spanned between these rollers, a suction fan, and the like, and in the direction of the arrow in the drawing while sucking printed paper on the upper surface of the endless belt. The paper is conveyed and discharged onto the paper discharge tray 37. The paper discharge tray 37 has an end fence 38 and a pair of left and right side fences 39, and stacks printed sheets on the upper surface thereof.

  The image reading unit 18 forms a contact glass on which a document is placed, a pressure plate provided so as to be able to come in contact with and away from the contact glass, a light source for scanning and reading a document image, a reflection mirror, and a scanned document image. And a well-known configuration having an image sensor for processing a received image and an image sensor.

Below the paper discharge tray 37, a cleaning paper tray 40 is disposed as a discharge portion for discharging cleaning paper, which will be described later, after cleaning the press roller 12.
A cleaning paper guide plate 41 is disposed between the cleaning paper tray 40 and the paper discharge path switching member 21. An edge of the cleaning paper guide plate 41 on the cleaning paper tray 40 side is pivotally supported by a shaft 42 so as to guide the cleaning paper to the cleaning paper tray 40 in the cleaning mode.

  An operation panel 50 shown in FIG. 2 is provided on the upper surface on the front side of the duplex printing apparatus 10. The operation panel 50 includes a plate making start key 51, a printing start key 52, a stop key 53, a numeric keypad 54, a display device 55 composed of a 7-segment LED, a display device 56 composed of an LCD, a cleaning key 57, A cleaning mode setting key 58 and the like are provided.

  The control means for controlling the printing operation of the duplex printing apparatus 10 is composed of a microcomputer having a CPU, a ROM, a RAM and the like inside, and performs predetermined control according to a command from the operation panel 50.

Hereinafter, the operation of the duplex printing apparatus 10 will be described.
When a manuscript is set in the image reading unit 18 and the plate making start key 51 is pressed by the operator, the image reading unit 18 performs a manuscript image reading operation and the plate discharging unit 16 operates to start from the outer peripheral surface of the plate cylinder 11. The used divided plate-making master 23 is peeled off and accommodated in the plate removal unit 16. After the plate removal, the plate making unit 14 is operated to make a new divided plate making master 23 and is wound around the plate cylinder 11.

  After the winding of the divided plate-making master 23 around the plate cylinder 11 is completed and the duplex printing apparatus 10 enters the print standby state, when the printing start key 52 is pressed by the operator after setting various printing conditions, the plate cylinder 11 is moved. While being rotated at a predetermined speed, the paper feed roller 32 and the separation roller 33 are rotated to feed one sheet of paper P on the paper feed tray 31, and the paper P is temporarily stopped by the registration roller pair 35. After that, the sheet is fed toward the printing unit 13 between the plate cylinder 11 and the press roller 12 at a predetermined timing.

  When the plate cylinder 11 is rotated to a predetermined angle and the surface area occupies a predetermined position corresponding to the press roller 12, the press roller 12 occupies the pressing position, so that the sheet is divided on the plate cylinder 11 and the master is divided. 23, and a surface image is printed on one surface thereof. The sheet that has been printed on the front surface is peeled off from the outer peripheral surface of the plate cylinder 11 and then sent to the refeed conveyance unit 27 by the switching member 21 occupying the second position. At this time, the leading edge of the sheet is received by the sheet receiving plate 30 and placed on the auxiliary tray 19 from the rear end side. The paper on the auxiliary tray 19 is transported in the direction of the arrow in FIG. 1 by the paper refeeding transport unit 27, and temporarily stops in a state where the leading end is in contact with the paper refeeding positioning member 28.

  The plate cylinder 11 continues to rotate while the first sheet is being guided on the auxiliary tray 19, and the second sheet is fed from the sheet feeding unit 15 at the same timing as the first sheet. Is done. Similarly to the first sheet, the second sheet that has been fed has a surface image printed on one surface thereof by the press roller 12, and is then fed again by the switching member 21 that occupies the second position. It is sent to the transport unit 27.

  After the second sheet is fed from the sheet feeding unit 15, the re-feeding registration roller 26 operates at a timing slightly earlier than the back surface area of the plate cylinder 11 reaches the position corresponding to the press roller 12. The first sheet stored on the auxiliary tray 19 is pressed against the peripheral surface of the press roller 12, and the sheet is directed to the printing unit 13 by the press roller 12 that is pressed against the plate cylinder 11 and rotated. The back image is printed on the other surface by being pressed against the divided plate-making master 23.

  The first sheet, which has been printed on both sides by printing the back image, is guided to the sheet discharge conveyance unit 36 by the switching member 21 occupying the first position, and is discharged onto the sheet discharge tray 37. The Thereafter, the above operation is repeated up to the set number of prints, and when the set number of prints is reached, the operation of each part is stopped and the double-sided printing operation is completed.

  In the double-sided printing process described above, the surface-printed paper is conveyed from the auxiliary tray 19 to the printing unit 13 by the refeed resist roller 26 and the press roller 12, so that the undried ink of the surface image of the paper Is transferred to the press roller 12, and the peripheral surface of the press roller 12 is soiled.

  Hereinafter, in the double-sided printing process, cleaning of the press roller on which the undried ink of the surface image on the paper has transferred to the peripheral surface will be described.

When the cleaning key 57 on the operation panel 50 is pressed, the plate removal unit 16 is activated to separate the used divided plate-making master 23 from the plate cylinder 11. After the plate removal, the plate making unit 13 is actuated to wind an unmade plate master that does not punch the master around the plate cylinder 11 (unmade plate making process).
In response to a command from the cleaning key 57, the control means prohibits the plate making operation of the plate making unit 14 and carries the master to the plate cylinder 11.

The paper is fed to the printing unit 13 between the plate cylinder 11 around which the unprinted master is wound and the press roller 12 in contact with the plate cylinder (cleaning paper feeding step).
The paper that has passed through the printing unit 13 (hereinafter referred to as “cleaning paper”) is sent to the paper refeeding conveyance unit 27 by the switching member 21 occupying the second position, and the paper refeeding registration roller 26 and the press roller 12. And is again conveyed to the printing unit 13.
After the cleaning paper is sent to the refeed conveyance unit 27, the cleaning paper guide plate 41 occupies the paper discharge position indicated by the dotted line 43 around the shaft 42. The cleaning sheet conveyed again to the printing unit 13 is discharged to a cleaning sheet tray 40 which is a discharge unit different from the discharge tray 37 by a cleaning sheet guide plate 41 occupying the discharge position.
The ink in the undried state adhering to the press roller 12 is removed by the cleaning paper pressure-conveyed to the press roller 12.
By discharging the cleaning paper to the cleaning paper tray 40 dedicated to the cleaning paper different from the paper discharge tray 37 as described above, the trouble of removing the cleaning paper discharged to the paper discharge tray 37 can be saved.

The number of sheets fed to the printing unit 13 in the cleaning paper feed process can be arbitrarily set.
Since the degree of stain on the press roller varies depending on the type of ink, the environmental temperature, the number of double-sided printed sheets, and the like, the number of cleanings corresponding to the degree of stain, that is, the number of sheets to be fed is set in advance. The number of cleanings is set by pressing the cleaning mode key 58 on the operation panel 50 and instructing the number of cleanings with the numeric keypad 54. For example, when “3” is instructed, cleaning is performed three times with three cleaning sheets, and the three sheets are discharged to the cleaning sheet tray 40.

When the well-known sorter or multi-stage paper discharge tray (both not shown) is installed in the double-sided printing apparatus 10 as the printed paper receiving means, the cleaning paper is the tray on which the double-sided printing paper is discharged and stacked by the control means. The paper is discharged to another tray, and the paper discharge tray 37 and the cleaning paper tray 40 are not used.
The movement path of the cleaning paper in the state where the sorter or the multi-stage paper discharge tray is installed is the same as that when double-sided printing is performed, and the cleaning paper guide plate 41 is not used. As described above, the cleaning of the press roller in the double-sided printing apparatus combined with the sorter or the multi-stage discharge tray has an advantage that the cleaning paper tray 40 and the cleaning paper guide plate 41 are not required.

  The cleaning sheet tray 40 and the cleaning sheet guide plate 41 are not required even in a double-sided printing apparatus in which a tape marker (also referred to as a tape sorter) for distinguishing stacked sheets discharged to the sheet discharge tray 37 and a sorting device are installed. .

  When a tape marker is provided on the paper discharge tray 37, when the cleaning paper is discharged onto the printed paper stacked on the paper discharge tray 37, the sorting tape is dropped from the tape marker on the cleaning paper and printed. Differentiated from paper.

When the paper discharge tray 37 is provided with a sorting device, the cleaning paper is distinguished from the printed paper by slightly shifting the cleaning paper discharged onto the printed paper to the paper feeding side.
The sorting apparatus is normally arranged below the paper discharge conveyance unit 36 and is configured to shift the uppermost printed paper discharged by the expansion and contraction operation of its arm to the paper supply side.
When the tape marker and the sorting device are activated for sorting the cleaning paper according to a command from the control means, the printing operation of the duplex printing device is temporarily stopped.

As described above, the stain due to the ink on the press roller 12 is caused by the paper transport path before the paper is transported to the printing unit 13 in addition to the stain caused by the ink transfer from the front surface printed paper in the back surface printing process. It also occurs when a paper transport jam occurs.
The ink smear of the press roller 12 due to the paper conveyance jam is due to the direct transfer of the ink extruded from the back surface region of the plate cylinder 11 in a state where the press roller 12 is pressed against the plate cylinder 11 in the back surface printing process.

The following four forms can be considered as the paper transport jam.
The first form is a jam in which the paper from the paper supply unit 15 does not reach the registration roller pair 35 in spite of the paper supply command, and the second form is a registration roller pair in spite of the paper reaching the registration roller pair 35. A jam in which the paper is not fed out from 35, a jam in which the paper fed out by the registration roller pair 35 does not reach the paper discharge transport unit 36 as a third mode, and a paper from the refeed transport unit 27 as a fourth mode However, a jam that is not re-fed by the press roller 12 can be considered.

  In order to detect the sheet conveyance jam of the first to fourth embodiments, a sheet leading edge detection sensor 61 as a first sensor is disposed on the front side of the registration roller pair 35, and a second sensor is disposed behind the registration roller pair 35. A registration detection sensor 62 as a sensor is provided in the paper discharge conveyance unit 36, a paper discharge detection sensor 63 as a third sensor, and a paper detection sensor as a fourth sensor in the vicinity of the refeed guide member 25. 64 is provided.

The press roller 12 is pressed against the plate cylinder 11 through a sheet at a certain timing in accordance with a command from the control unit based on the sheet detection signal of the second sensor 62.
Therefore, when the first and second sensors 61 and 62 do not detect the paper, the press roller 12 does not come into pressure contact with the plate cylinder 11, so that the press roller 12 is not smeared with ink.

  However, when the third sensor does not detect the paper even though the second sensor 62 detects the paper, the second sensor 62 and the second sensor 62 are connected after the press roller 12 starts to press the plate cylinder 11. This means that there is a possibility that the paper has not reached the printing unit 13, and therefore the press roller 12 may be stained with ink from the plate cylinder 11.

  Similarly, when the fourth sensor 64 does not detect the surface-printed paper to be sent out from the re-feed conveyance unit 27 by the press roller 12 and the re-feed resist roller 26, and the fourth sensor 64 detects the paper. However, even when the third sensor 63 does not detect, there is a possibility that the sheet does not reach the printing unit 13 and the press roller 12 may be soiled.

Depending on the pressure contact operation timing of the press roller 12 to the plate cylinder 11 in the duplex printing process, the press roller 12 may not be soiled.
The press-contact operation timing is determined by the layout of the printing apparatus, after the paper is detected by the fourth sensor 64, and the press-contact operation of the press roller 12 to the plate cylinder 11 starts or when the re-feeding registration roller 26 is started. Depending on whether the pressure welding operation starts or not, there is a difference.
Therefore, in a layout in which the press roller 12 starts pressing operation against the plate cylinder 11 after the fourth sensor 64 detects the paper, if the fourth sensor 64 does not detect the paper, the press roller 12 11, the press roller 12 is not smudged with ink.

When the first to fourth sheet detection sensors detect the possibility of sheet conveyance jam in the sheet conveyance path, the cleaning mode is set by the control means based on the signals from these sheet detection sensors, and the unprinted master winding The press roller 12 is cleaned by automatically executing the loading process and the cleaning paper feeding process.
According to such cleaning of the press roller by detecting the paper conveyance jam, there is an advantage that an operator does not require a cleaning instruction operation.

On both sides of the paper feed tray 31, a pair of side fences 70 are provided that can move in the width direction of the paper placed on the paper feed tray 31. The position of the side fence 70 on the paper feed tray 31 is detected by a size detection sensor (not shown) arranged on the paper feed tray 31.
When the width of the paper on the paper feed tray 31 when the paper transport jam occurs is smaller than the width of the divided master-making master 23 on the plate cylinder 11, the cleaning paper feed process is automatically executed as described above. And the part which is not cleaned arises in the both ends side of the press roller 12.
The size comparison between the paper and the divided plate-making master 23 is calculated by the control means based on the value detected by the size detection sensor. If the paper is smaller than the width of the divided plate-making master 23, the display device 55 of the operation panel 50 is displayed. A warning is displayed to indicate that the press roller is improperly cleaned, and control to stop the cleaning operation is performed.

Such warning display by the control means and stop of the cleaning operation are similarly executed even when the sheet is smaller than the maximum image area of the plate-making master wound around the plate cylinder.
The warning display regarding the cleaning of the press roller and the stop of the cleaning operation have the effect of preventing insufficient cleaning of the press roller.
As the double-sided printing apparatus, there is a two-plate cylinder type double-sided printing apparatus including a front-side printing plate cylinder and a back-side printing plate cylinder in addition to the one-plate cylinder type double-sided printing apparatus described above. The present invention can also be implemented in a two-plate cylinder type duplex printing apparatus.

It is a front view which shows an example of the double-sided printing apparatus which implements this invention. It is a top view which shows an example of the operation panel used for the double-sided printing apparatus of FIG.

Explanation of symbols

10 Double-sided printing device 11 Plate cylinder
DESCRIPTION OF SYMBOLS 12 Press roller 13 Printing part 14 Plate making part 15 Paper feeding part 23 Split master making completed master 27 Re-feed conveyance unit 37 Paper discharge tray 40 Cleaning paper tray 50 Operation panel 61 Paper leading edge detection sensor 62 as the first sensor Second Registration detection sensor 63 as a sensor Paper discharge detection sensor 64 as a third sensor Paper detection sensor as a fourth sensor

Claims (11)

A plate cylinder, plate making means for making a master wound around the plate cylinder, a press roller for pressing paper against the plate cylinder in a printing unit, a paper feeding unit for feeding paper to the printing unit, and paper discharge A duplex printing apparatus comprising a tray,
After completion of double-sided printing, a non-plate making master winding step of winding a plate making master that does not perform plate making by the plate making means around the plate cylinder;
A paper feed process for cleaning that feeds paper between a plate cylinder wound with an unprinted master and the press roller in contact therewith,
A press roller cleaning method for a double-sided printing apparatus. In the press roller cleaning method of the double-sided printing apparatus of Claim 1,
A master in which a plate-making image corresponding to the front surface image and a plate-making image corresponding to the back surface image are arranged in the rotation direction of the plate cylinder is wound around the surface of the plate cylinder. A method for cleaning a press roller of a double-sided printing apparatus, wherein double-sided printing is performed by reversing and refeeding the printing unit. In the press roller cleaning method of the double-sided printing apparatus of Claim 1 or 2,
The method of cleaning a press roller of a double-sided printing apparatus, wherein the number of sheets fed to the printing unit in the cleaning sheet feeding step can be arbitrarily set. In the press roller cleaning method of the double-sided printing device according to any one of claims 1 to 3,
A method of cleaning a press roller of a double-sided printing apparatus, wherein the cleaning sheet that has passed through a printing unit of a plate cylinder around which an unprocessed master is wound is discharged to a discharge unit that is different from the discharge tray. In the press roller cleaning method of the double-sided printing apparatus according to claim 4,
The method of cleaning a press roller of a double-sided printing apparatus, wherein the another discharge unit is a discharge unit dedicated to the cleaning paper. In the press roller cleaning method of the double-sided printing device according to any one of claims 1 to 3,
When the sorter or multi-stage output tray is installed on the duplex printing device, the discharge section of the cleaning paper that has passed through the printing section of the plate cylinder on which the master plate master is wound is the double-sided printed paper on the sorter or multi-stage output tray. A method for cleaning a press roller of a double-sided printing apparatus, wherein the tray is different from the tray on which the paper is discharged and stacked. In the press roller cleaning method of the double-sided printing device according to any one of claims 1 to 3,
When the double-sided printing device is equipped with a tape marker and a sorting device, when the paper is passed through the printing section of the plate cylinder on which the pre-plate master is wound and the cleaning paper is discharged, the tape marker and sorter are operated. A method of cleaning a press roller of a double-sided printing apparatus, wherein the cleaning sheet and a normal printed sheet can be identified. In the press roller cleaning method of the double-sided printing apparatus according to any one of claims 1 to 7,
A double-sided printing machine that detects a conveyance jam that may contaminate the press roller with ink, and automatically executes the unprinted master winding process and the cleaning paper feeding process. A method for cleaning a press roller of a printing apparatus. In the press roller cleaning method of the double-sided printing apparatus of Claim 8,
When the paper fed to the printing unit is smaller than the master plate-making size wound around the plate cylinder when the conveyance jam occurs, a warning display and / or cleaning of the press roller with the paper is stopped. A press roller cleaning method for a double-sided printing apparatus. In the press roller cleaning method of the double-sided printing device according to any one of claims 1 to 8,
A double-sided printing apparatus characterized by displaying a warning and / or stopping cleaning of a press roller by a sheet when a sheet fed to a printing unit is smaller than a maximum image area of a master wound around a plate cylinder. Press roller cleaning method. A plate cylinder, plate making means for making a master wound around the plate cylinder, a press roller for pressing paper against the plate cylinder in a printing unit, a paper feeding unit for feeding paper to the printing unit, and paper discharge A stencil printing apparatus for performing a press roller cleaning method of a double-sided printing apparatus according to any one of claims 1 to 10, comprising a tray.

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