JP5103646B2 - Paper peeling apparatus, paper peeling method, printing apparatus and printing method - Google Patents

Description

  The present invention relates to a paper peeling apparatus and a paper peeling method for peeling a paper pressed by a stencil paper wound around a rotating plate cylinder from the stencil paper, and blowing air toward the plate cylinder for peeling. The present invention relates to a sheet peeling apparatus, a sheet peeling method, a printing apparatus using these, and a printing method.

  2. Description of the Related Art Conventionally, printing apparatuses have been widely used as apparatuses useful for forming, for example, the same image on a large number of sheets. As one type of such a printing apparatus, a stencil printing apparatus is widely known. A stencil printing device winds a stencil sheet made on a rotating plate cylinder and presses the sheet onto the stencil sheet wound on the plate cylinder, thereby transferring ink from the stencil sheet side to the sheet for printing. Do.

  The printed paper is discharged from the stencil printing apparatus and needs to be peeled from the stencil paper against the viscosity of the ink in order to enable continuous printing. Therefore, as disclosed in [Patent Document 1] to [Patent Document 3] and the like, the separation claw is caused to enter between the stencil sheet and the leading edge of the sheet, and the sheet is stenciled as the plate cylinder rotates. 2. Description of the Related Art A stencil printing apparatus provided with a peeling device that peels from a sheet is known.

  Further, as disclosed in [Patent Document 1], [Patent Document 2] and the like, in addition to the peeling claw, air is blown toward the plate cylinder in order to more favorably peel the paper from the stencil paper, and the air 2. Description of the Related Art A peeling device provided with a peeling fan that allows a sheet to enter between a stencil sheet and a sheet is known. In addition, the peeling fan described in [Patent Document 1] and [Patent Document 2] adjusts the air flow rate according to the print image area.

  On the other hand, as disclosed in [Patent Document 3] and the like, in a stencil printing apparatus capable of printing on both sides, the peeling claw is arranged along the rotation direction R ′ of the plate cylinder 312 as shown in FIG. A plurality of peeling devices are known. In the figure, reference numerals 310 and 384 denote peeling claws, reference numeral 313 denotes a press roller, reference numeral 340 denotes a peeling fan, and reference numeral 364 denotes a stencil sheet.

  The peeling device disclosed in [Patent Document 3] is provided with a plurality of peeling claws from a peeling claw (peeling claw 384 in FIG. 13) for discharging the paper peeled from the stencil paper as it is, and from the stencil paper. This is because the peeled paper is turned over and then fed again, and a peeling claw (peeling claw 310 in FIG. 13) for performing double-sided printing is provided separately. In the printing apparatus described in [Patent Document 3], two plate-making images can be formed on the stencil sheet along the rotation direction of the plate cylinder, and both sides are printed by printing on the front and back of the paper with each plate-making image. Printing is to be performed.

JP-A-9-193526 JP 2004-50564 A JP 2003-266906 A

  However, even if the peeling fan described in [Patent Document 1] and [Patent Document 2] is diverted as it is to the peeling device disclosed by [Patent Document 3] in order to more favorably peel the paper from the stencil paper, There is a high possibility that the paper peeling performance will be insufficient. This is because the more the upstream side in the rotational direction of the plate cylinder, in other words, the closer the pressing position is to press the paper against the stencil paper, the more difficult the paper is to peel from the stencil paper, but such a peeling fan depends on the print image area. This is because the amount of air blowing is merely adjusted, and the peeling claw close to the pressing position is likely to cause insufficient paper peeling performance. Such a defect is not limited to a stencil printing apparatus capable of performing double-sided printing, and can generally occur in a configuration in which a plurality of peeling nails are provided along the rotation direction of the plate cylinder.

  Further, as shown in FIG. 13, when the air is blown toward the plate cylinder like the peeling fan described in [Patent Document 1] and [Patent Document 2], the stencil sheet 364 is wrinkled with respect to the plate cylinder 312. May result in

  For example, in the printing apparatus described in [Patent Document 3], when two plate-making images are formed on a stencil sheet along the rotation direction of the plate cylinder to perform double-sided printing, the stencil sheet is pressed by pressing the sheet against the stencil sheet. The plate making contact with the plate cylinder is performed at separate timings for a portion corresponding to the plate-making image on the downstream side in the same rotation direction and a portion corresponding to the plate-making image on the upstream side in the same rotation direction. Therefore, the latter part receives air blown by the peeling fan with the rotation of the plate cylinder before plate printing is performed. At this time, as shown in FIG. 13, for example, the latter portion, that is, the portion that is not yet in close contact with the plate cylinder 312 is blown by air blowing, so that the stencil sheet 364 is wrinkled or folded. Thus, the ink sticks to the surface of the plate cylinder 312 having viscosity.

If the stencil sheet 364 is stuck in such a state, the stencil sheet 364 is pressed against the surface of the plate cylinder 312 in a state where the stencil sheet 364 is disturbed, and printing is performed with the stencil sheet 364 wound around the plate cylinder 312. If this is done, abnormal images will be printed repeatedly.
Therefore, it is necessary that the air blown toward the plate cylinder does not cause defects such as wrinkles on the stencil sheet.

  The present invention relates to a sheet peeling apparatus and a sheet peeling method for performing a peeling operation for peeling a paper pressed by a stencil sheet wound around a rotating plate cylinder from the stencil sheet, and directed to the plate cylinder by a blowing means. An object of the present invention is to provide a paper peeling device, a paper peeling method, a printing device using these, and a printing method that perform air blowing appropriately while avoiding problems with stencil paper while exhibiting good peeling performance. .

  In order to achieve the above object, the invention according to claim 1 is a sheet peeling apparatus that performs a peeling operation for peeling a sheet pressed by a stencil sheet wound around a rotating plate cylinder from the stencil sheet. A plurality of members arranged along the rotation direction of the plate cylinder, and performing a separation operation by entering between the stencil sheet and the paper, and air blowing toward the plate cylinder to perform the separation operation In the sheet peeling device including the blowing unit, the strength of the blowing by the blowing unit is increased as the peeling operation is performed with the peeling member positioned upstream in the rotation direction among the plurality of peeling members. In the paper peeling device.

  According to a second aspect of the present invention, in the paper peeling apparatus according to the first aspect of the present invention, the strength of the air blow by the air blowing means is greater on the plate cylinder than on the portion of the stencil sheet pressed against the plate cylinder. It is characterized by weakening the strength against the unpressed portion.

  The invention according to claim 3 is the sheet peeling apparatus according to claim 1 or 2, wherein a first peeling mode for performing the peeling operation on the stencil sheet on which one plate-making image is formed along the rotation direction; The stencil sheet on which a plurality of plate-making images are formed along the rotation direction has a second peeling mode in which the peeling operation is performed by sequentially using a plurality of peeling members.

  The invention according to claim 4 is the sheet peeling apparatus according to claim 3, wherein the first peeling mode is a mode used for single-sided printing, and the second peeling mode is a mode used for double-sided printing. And

  According to a fifth aspect of the present invention, in the paper peeling apparatus according to the third or fourth aspect, the first peeling mode is a mode used for normal printing in which printing is performed on one sheet per rotation of the plate cylinder. The second peeling mode is a mode used for high-speed printing in which the plate cylinder performs printing on a plurality of sheets per rotation.

  The invention according to claim 6 is a sheet peeling apparatus for performing a peeling operation for peeling the paper pressed by the stencil sheet wound around the rotating plate cylinder from the stencil sheet, along the rotation direction of the plate cylinder. A plurality of separation members, and a separation member that performs the separation operation by entering between the stencil sheet and the paper, and a blower that blows air toward the plate cylinder to perform the separation operation. In the peeling apparatus, when performing the peeling operation on the stencil sheet on which a plurality of plate-making images are formed along the rotation direction, the strength of the air blown by the blowing means is pressed against the plate cylinder of the stencil sheet. The sheet peeling apparatus weakens the strength against the portion not pressed against the plate cylinder rather than the strength against the portion.

  The invention according to claim 7 is a paper peeling method for performing a peeling operation for peeling the paper pressed by the stencil paper wound around the rotating stencil paper from the stencil paper, along the rotation direction of the stencil paper. And a plurality of separation members that perform the separation operation by entering between the stencil sheet and the paper, and a blower that blows air toward the plate cylinder to perform the separation operation. In the peeling method, there is a paper peeling method in which the strength of the air blown by the blowing unit is increased as the peeling member that performs the peeling operation is positioned upstream in the rotation direction.

  The invention according to claim 8 is a sheet peeling method for performing a peeling operation for peeling the paper pressed by the stencil sheet wound around the rotating plate cylinder from the stencil sheet, and along the rotation direction of the plate cylinder. And a plurality of separation members that perform the separation operation by entering between the stencil sheet and the paper, and a blower that blows air toward the plate cylinder to perform the separation operation. In the peeling method, when performing the peeling operation on the stencil sheet on which a plurality of plate-making images are formed along the rotation direction, the strength of the air blown by the blowing means is pressed against the plate cylinder of the stencil sheet. In this method, the strength against the portion not pressed against the plate cylinder is weakened rather than the strength against the portion.

  A ninth aspect of the invention is a printing apparatus using the paper peeling device according to any one of the first to sixth aspects or the paper peeling method according to the seventh or eighth aspect.

  According to a tenth aspect of the present invention, there is provided a paper peeling apparatus according to any one of the first to sixth aspects, a paper peeling method according to the seventh or eighth aspect, or a printing using the printing apparatus according to the ninth aspect. Is in the way.

  The present invention is a sheet peeling apparatus for performing a peeling operation for peeling a sheet pressed by a stencil sheet wound around a rotating plate cylinder from the stencil sheet, and a plurality of sheets are disposed along a rotation direction of the plate cylinder. In the sheet peeling apparatus having a peeling member that performs the peeling operation by entering between the stencil sheet and the paper, and a blowing unit that blows air toward the plate cylinder to perform the peeling operation, Since there is a paper peeling device that increases the strength of the air blow by the blower means as the peeler member is located upstream in the rotation direction among the plurality of peeler members, The strength of the sheet can be set to the strength required for the peeling operation, and the peeling performance can be satisfactorily exhibited, and the energy required for driving the blowing means and the noise generated by the blowing are reduced. Can win, it is possible to provide a sheet peeling apparatus can contribute to good printing.

  If the strength of the air blown by the blower means is less than the strength of the stencil sheet pressed against the plate cylinder, the strength against the non-pressed part of the plate cylinder is reduced. The strength of the air blowing by the air can be made as strong as the peeling operation is necessary, and the peeling performance can be exhibited well, and the energy required for driving the air blowing means and the noise generated by the air blowing can be suppressed. In addition, it is possible to provide a sheet peeling apparatus that can perform printing and perform printing well and contribute to good printing.

  A first peeling mode for performing the peeling operation on the stencil sheet on which one plate-making image is formed along the rotation direction, and a plurality of the stencil sheets on which a plurality of plate-making images are formed along the rotation direction. If it has the 2nd peeling mode which performs the said peeling operation | movement using the said peeling member one by one, especially in the 2nd peeling mode, the intensity | strength of the ventilation by a ventilation means is made into the intensity | strength according to the necessity of peeling operation | movement. Paper peeling device that can be adjusted and can exhibit its peeling performance satisfactorily, can suppress the energy required for driving the air blowing means and noise caused by the air blowing, and can contribute to good printing Can be provided.

  Assuming that the first peeling mode is a mode used for single-sided printing and the second peeling mode is a mode used for double-sided printing, in particular, in the double-sided printing in which the second peeling mode is used, air blowing by the blowing means. The strength of the sheet can be adjusted to the strength required for the peeling operation, the peeling performance can be satisfactorily exhibited, and the energy required for driving the blowing means and the noise generated by the blowing can be suppressed. It is possible to provide a paper peeling device that can contribute to good double-sided printing.

  The first peeling mode is a mode used for normal printing in which printing is performed on one sheet per rotation of the plate cylinder, and the second peeling mode is performed on a plurality of sheets per rotation of the plate cylinder. If it is a mode used for high-speed printing in which printing is performed, it is possible to adjust the strength of air blowing by the blowing means to a strength according to the necessity of the peeling operation particularly in high-speed printing in which the second peeling mode is used. And a paper peeling device that can exert its peeling performance satisfactorily and can suppress energy required for driving the blowing means and noise generated by the blowing to contribute to good high-speed printing. be able to.

  The present invention is a sheet peeling apparatus for performing a peeling operation for peeling a sheet pressed by a stencil sheet wound around a rotating plate cylinder from the stencil sheet, and a plurality of sheets are disposed along a rotation direction of the plate cylinder. In the sheet peeling apparatus having a peeling member that performs the peeling operation by entering between the stencil sheet and the paper, and a blowing unit that blows air toward the plate cylinder to perform the peeling operation, When the peeling operation is performed on the stencil sheet on which a plurality of plate-making images are formed along the rotation direction, the strength of the air blown by the blowing unit is set to the strength of the stencil sheet against the portion of the stencil sheet that has been pressed against the plate cylinder. Since the sheet peeling device weakens the strength against the unpressed portion of the plate cylinder rather than the stencil sheet, the stencil sheet is wound on the unpressed portion of the stencil sheet by the air blow by the conveying means. Disturbed DOO possible to prevent or suppress, whereby the plate with can be performed well, it is possible to provide a sheet peeling apparatus can contribute to good printing.

  The present invention is a sheet peeling method for performing a peeling operation for peeling a sheet pressed by a stencil sheet wound around a rotating plate cylinder from the stencil sheet, and a plurality of sheets are disposed along a rotation direction of the plate cylinder. In a sheet peeling method using a peeling member that performs the peeling operation by entering between the stencil sheet and the paper, and a blowing unit that blows air toward the plate cylinder to perform the peeling operation, Since there is a paper peeling method in which the strength of the air blown by the air blowing means is increased as the peeling member that performs the peeling operation is positioned upstream in the rotation direction, the strength of the air blown by the air blowing means is required for the peeling operation. It is possible to make the strength according to the pressure, and the peeling performance can be satisfactorily exhibited, and the energy required for driving the blowing means and the noise generated by the blowing can be suppressed. Paper peeling method can contribute to can be provided.

  The present invention is a sheet peeling method for performing a peeling operation for peeling a sheet pressed by a stencil sheet wound around a rotating plate cylinder from the stencil sheet, and a plurality of sheets are disposed along a rotation direction of the plate cylinder. In a sheet peeling method using a peeling member that performs the peeling operation by entering between the stencil sheet and the paper, and a blowing unit that blows air toward the plate cylinder to perform the peeling operation, When the peeling operation is performed on the stencil sheet on which a plurality of plate-making images are formed along the rotation direction, the strength of the air blown by the blowing unit is set to the strength of the stencil sheet against the portion of the stencil sheet that has been pressed against the plate cylinder. Since there is a paper peeling method that weakens the strength against the unpressed portion of the plate cylinder, the stencil sheet is unwound on the portion of the stencil sheet that is not pressed against the plate cylinder by the air blow by the conveying means. Disturbed DOO possible to prevent or suppress, whereby the plate with can be performed well, it is possible to provide a sheet peeling method can contribute to good printing.

  Since the present invention is in such a paper peeling device or a printing device using such a paper peeling method, the strength of the air blown by the air blowing means can be set to an appropriate strength, and the paper rolls up or the printed image is disturbed. It is possible to provide a printing apparatus capable of performing good printing with prevention or suppression.

  The present invention resides in such a paper peeling apparatus, or such a paper peeling method, or a printing method using such a printing apparatus. In addition, it is possible to provide a printing method capable of performing good printing while preventing or suppressing disturbance of the printed image.

  Hereinafter, embodiments of the present invention (hereinafter referred to as “embodiments”) will be described with reference to the drawings. In the figure, components that are configured in a pair and do not need to be specifically distinguished and described are described by appropriately describing one of them for the sake of simplification of description. In addition, in order to simplify the drawings and the description, even if the components are to be represented in the drawings, the components that do not need to be specifically described in the drawings may be omitted as appropriate.

  FIG. 1 shows a duplex printing apparatus 1 which is a stencil printing apparatus as a printing apparatus to which an embodiment of the present invention is applied. In the figure, a duplex printing apparatus 1 includes a printing unit 2, a plate making unit 3, a paper feeding unit 4, a plate discharging unit 5, a paper discharging unit 6, an image reading unit 7, a refeeding tray 8 as a refeeding storage unit, As shown in FIG. 9, an operation panel 103 as input means for making various settings for the double-sided printing apparatus 1, As shown in FIG. 2, the control unit 200 controls the operation of the entire duplex printing apparatus 1.

  In FIG. 1, reference numeral 11 denotes a printing apparatus main body that forms the framework of the double-sided printing apparatus 1. The printing unit 2 has a printing drum 12 serving as a plate cylinder and a press roller 13 serving as a pressing unit, which is disposed in the approximate center of the printing apparatus main body 11 and is disposed on the outer periphery.

  The printing drum 12 includes a plate cylinder body including a pair of flanges (not shown) rotatably supported by the support shaft 14, a cylindrical porous support plate wound around the outer peripheral surface of each flange, and a plate cylinder body. It is mainly composed of a mesh screen (not shown) wound around the outer peripheral surface. In the plate cylinder main body, a printable image forming area (hereinafter referred to as “opening”) having a large number of ink-permeable holes and a non-image forming area (hereinafter referred to as “non-opening”) of the clamper 19 arrangement portion. Are formed along the rotation direction R of the printing drum 12. The image forming area includes a first image area 12A (hereinafter referred to as “front surface area 12A”), an intermediate area 12S, and a second image area 12B (hereinafter referred to as “back surface area 12B”) in the printing drum 12 in FIG. )) At least.

  The printing drum 12 is rotationally driven in a direction R that is a clockwise direction in FIG. 1 by a printing drum driving unit 121 shown in FIG. 10 including a main motor made of, for example, a DC motor. The printing drum 12 is a component of a drum unit (not shown) that is detachable from the printing apparatus main body 11 and is substantially integrated, including an ink supply means 15 (not shown), an ink pump (not shown), and an ink container support member (not shown). It is configured as. In the present embodiment, the printing drum 12 has a size capable of obtaining a maximum A3 size printed material during single-sided printing.

  A single ink supply means 15 is arranged inside the printing drum 12. The ink supply means 15 includes a support shaft 14 that also serves as an ink supply pipe, an ink roller 16, a doctor roller 17, and the like. The ink roller 16 is rotatably supported between side plates (not shown) provided in the printing drum 12, and its peripheral surface is the inner peripheral surface of the printing drum body (hereinafter simply referred to as “inside of the printing drum 12”). It is arranged in the vicinity of the peripheral surface) and is driven to rotate in the same direction as the printing drum 12 by a driving means (not shown). The doctor roller 17 is also rotatably supported between the side plates, and its peripheral surface is disposed close to the peripheral surface of the ink roller 16, and is rotated in the opposite direction to the printing drum 12 by a driving means (not shown). . A plurality of small holes are formed in the support shaft 14, and the ink supplied from the support shaft 14 is accumulated in a wedge-shaped space formed in the vicinity of the ink roller 16 and the doctor roller 17. An ink reservoir 18 is formed.

  A stage portion (not shown) formed on the outer peripheral surface of the plate cylinder main body of the printing drum 12 (hereinafter simply referred to as “the outer peripheral surface of the printing drum 12”) along a plane line of the outer peripheral surface of the printing drum 12. A clamper 19 is disposed on the outer peripheral surface of the printing drum 12 so as to be openable and closable with respect to the stage portion, and holds the tip of the master punched and made by the plate making portion 3. The clamper 19 is opened and closed by an opening / closing means (not shown) when the printing drum 12 is rotated to a predetermined position.

  Below the printing drum 12, a press roller 13 that can freely come into contact with and separate from the outer peripheral surface of the printing drum 12 is disposed. The press roller 13 is configured by integrally fixing an elastic body such as rubber to a metal shaft 13 a and is provided so as to extend in the axial direction of the printing drum 12. As shown in FIG. 2, the press roller 13 includes a pair of printing arms 20 (on the near side of the paper surface) as pressing means support members disposed on the near side and the far side of the paper surface via both ends of the shaft 13a. Is omitted). Each printing pressure arm 20 is substantially L-shaped, and is integrated by a swing shaft 21 attached to a portion near the bent portion and a connection reinforcing member (not shown). As shown in FIG. 6, the swing shaft 21 has a bearing 48b between housing side plates 11a and 11b (the right housing side plate 11a in FIG. 6 is omitted) fixed to the printing apparatus main body 11 side. It is supported so that it can rotate freely. The press roller 13 is formed of, for example, nitrile rubber (NBR) or silicone rubber (Q), which is an oil-resistant elastic body, and at least the outer peripheral surface of the rubber has ink repellency such as polytetrafluoroethylene resin. And the film which has oil resistance is coated smoothly.

  Between the printing pressure arms 20, in addition to the press roller 13, a refeed guide member 22, a refeed registration roller 23 as a refeed registration means, a refeed positioning member 24, a refeed transport means 25, A cleaning roller 26, a guide plate 27, and the like are provided as cleaning means.

  The refeed guide member 22 is integrally provided on each of the support shafts 28 a, 29 a, and 30 a disposed in the vicinity of the right side of the press roller 13, and each peripheral surface thereof is pressed against the outer peripheral surface of the press roller 13. A plurality of rollers 28, 29, 30, and a sheet guide plate 31 formed in a curved shape for causing the sheet P to follow the outer peripheral surface of the press roller 13. Each support shaft 28a, 29a, 30a is rotatably supported at each end by each printing pressure arm 20, and is urged toward the shaft 13a by urging means (not shown). Each of the rollers 28, 29, and 30 is integrally attached to the corresponding support shaft 28 a, 29 a, 30 a with a predetermined interval over substantially the entire width of the press roller 13. The paper guide plate 31 is disposed at a position away from the peripheral surface of the press roller 13 by a predetermined distance that is smaller than the radius of each of the rollers 28, 29, and 30. It is fixed to. The paper guide plate 31 is formed to have a circumferential curved surface centered on the shaft 13 a, and the peripheral surface of each of the rollers 28, 29, and 30 is contacted with the peripheral surface of the press roller 13. A plurality of openings for making contact are formed.

  Below the press roller 13, a skew-feed roller-like (hereinafter referred to as “roller-like”) re-feed resist roller 23, which is a re-feed resist member, is disposed. The refeed resist roller 23 is rotatably supported by a support shaft 23a, and the support shaft 23a is attached to one end of a swing arm 32 as a refeed resist support member. The oscillating arm 32 has a substantially square shape, and a bent portion thereof is supported on a support shaft 32a fixed between the printing pressure arms 20 so as to be freely oscillated. The position at which the swing arm 32 is disposed is determined so that the re-feeding registration roller 23 is positioned at a substantially central portion in the width direction of the press roller 13 and is located at an intermediate position between the rollers 30. It has been. At the other end of the swing arm 32, a plunger 33a of a solenoid 33 attached to one printing pressure arm 20 via a bracket (not shown) and one end fixed to the one printing pressure arm 20 are attached to the swing arm 32. On the other hand, the other end of the tension spring 34 is attached, which applies a turning biasing force in the counterclockwise direction in FIG. With this configuration, when the solenoid 33 is energized and activated, the re-feeding registration roller 23 occupies the press contact position indicated by the solid line in FIG. When the energization of the solenoid 33 is cut off and this operation is released, the re-feeding registration roller 23 is separated from the peripheral surface of the press roller 13 by a two-dot chain line in FIG. Occupies the non-printing position shown. As described above, the refeeding resist contact / separation mechanism 40 as the refeeding resist contact / separation means is configured by the swing arm 32, the support shaft 32a, the solenoid 33, and the tension spring 34.

  A refeed positioning member 24 is disposed near the upper portion of the refeed resist roller 23. The refeed positioning member 24 is made of a plate material having an L-shaped cross section, and is formed so that the width thereof is substantially the same as the width of the press roller 13. The re-feeding positioning member 24 is fixed to each printing pressure arm 20 at both ends so that the stopper portion 24a faces upward. The refeed positioning member 24 has a notch (relief) (not shown) that does not collide when the refeed resist roller 23 swings.

  Below the press roller 13 and to the left of the refeed positioning member 24, a refeed transport means 25, also called a belt-type suction transport device, is disposed. The refeed conveyance means 25 includes a conveyance member body 35, a refeed tray 8, a driving roller 36, a driven roller 37, an endless belt 38, a suction fan 39, and the like.

  The transport member main body 35 has a casing formed such that its upper surface is opened and its width is slightly smaller than the interval between the printing pressure arms 20. The transport member main body 35 has bearings (not shown) on both upstream and downstream sides of the paper transport direction Xa. These bearings (not shown) support the drive shaft 36a and the driven shaft 37a so as to be rotatable. Yes. Both ends of the drive shaft 36 a pass through both side surfaces of the transport member main body 35, and the both ends penetrated are rotatably supported by bearing members (not shown) provided in the printing apparatus main body 11. A drive gear (not shown) is attached to one end of the drive shaft 36a. The drive shaft 36a is rotationally driven by a conveying member drive motor 122 shown in FIG. The driven shaft 37 a is configured such that both end portions thereof do not penetrate both side surfaces of the conveying member main body 35. Bosses 35a are integrally provided on both outer sides of the upstream end portion in the paper conveyance direction Xa of the conveyance member main body 35, and each boss 35a is formed in a long hole (not shown) formed in each printing pressure arm 20. Each is fitted. With this configuration, the conveying member main body 35 allows the drive shaft 36a to be moved along with the swinging of each printing pressure arm 20 when the press roller 13 is brought into and out of contact with the printing drum 12 by the printing pressure range varying means 55 described later. Oscillation around the center is possible.

  The plurality of drive rollers 36 have a roller shape and are integrally attached to the drive shaft 36a. A predetermined interval is provided between the drive rollers 36. The plurality of driven rollers 37 have the same shape as the driving roller 36 and are integrally attached to the driven shaft 37 a at the same interval as each driving roller 36. An endless belt 38 having a plurality of holes (not shown) is stretched between the drive rollers 36 and the corresponding driven rollers 37 corresponding thereto with a predetermined tension. The endless belt 38 is made of a friction resistance member such as rubber, and is moved in the direction indicated by the arrow in FIG. 2 when the drive shaft 36a is rotationally driven by the conveying member drive motor 122.

  A suction fan 39 incorporating a transmission motor is integrally attached to the lower surface of the transport member body 35, and the refeed tray 8 is integrally attached to the upper surface of the transport member body 35. The re-feed tray 8 has a function as a re-feed storage unit that temporarily stores the surface-printed paper having a printed image formed on the surface thereof in the printing unit 2. The re-feed tray 8 is formed with a plurality of openings (not shown) for allowing the endless belts 38 to face the sheet conveying surface, and the unillustrated surface conveyed at the downstream end in the sheet conveying direction Xa. An end fence 8a for receiving printed paper is integrally formed. The lower surface of the conveying member main body 35 is a mounting surface for the suction fan 39, and a hole (not shown) is provided on the mounting surface. As a result, the suction fan 39 is actuated to generate a negative pressure inside the transport member main body 35 that is a casing, and the surface-printed paper is sucked onto the upper surface of each moving endless belt 38. The suction force of the suction fan 39 and the frictional resistance force of the endless belt 38 are such that when the front end of the front surface printed paper comes into contact with the stopper portion 24a of the refeed positioning member 24, the front surface printed paper and each endless belt 38 is set to such a strength that a slip occurs between them. In other words, if an excessive conveying force is generated by the suction force and the frictional resistance force, the strength of the front surface printed paper is reduced when the front end of the front surface printed paper comes into contact with the stopper portion 24a. Since it overcomes and buckles the surface-printed paper or causes it to bend, the suction force and the frictional resistance force are set to such an extent that these problems do not occur.

  As described above, the surface-printed paper stored in the refeed tray 8 by the refeed guide member 22, the refeed registration roller 23, the refeed positioning member 24, and the refeed transport means 25. The sheet refeeding means 9 is configured to reverse the sheet and refeed toward the printing unit 2.

  A cleaning roller 26 that cleans the peripheral surface of the press roller 13 is disposed in the vicinity of the press roller 13 and above the refeed conveyance means 25. The cleaning roller 26 has substantially the same width as that of the press roller 13, and at least its surface is made of a highly hygroscopic material such as Japanese paper or sponge, and has a shaft 26a integrally therewith. Yes. The cleaning roller 26 is rotatably supported by fitting a shaft 26a into a long hole (not shown) formed in each printing pressure arm 20, and is urged by a biasing means (not shown) provided in the long hole. It is always urged toward the press roller 13, and its peripheral surface is always pressed against the peripheral surface of the press roller 13 with a predetermined pressing force. The cleaning roller 26 is about one-tenth of the peripheral speed of the press roller 13 in the same direction as the press roller 13 when the press roller 13 rotates by a cleaning roller driving means (not shown) provided on one printing pressure arm 20. It is rotationally driven at a peripheral speed of.

  A guide plate 27 made of a plate material is disposed on the upper left side of the cleaning roller 26. Both ends of the guide plate 27 are fixed to the printing pressure arms 20, so that the paper P pressed against the printing drum 12 by the press roller 13 does not touch the cleaning roller 26, and the refeed tray 8 has a function of guiding the vehicle toward the 8th. The guide plate 27 is disposed at a position close to the peripheral surfaces of the press roller 13 and the cleaning roller 26.

  As shown in FIGS. 2 and 3, rotatable cam followers 41 are arranged on the other end side of each printing pressure arm 20 opposite to the one end side where the press roller 13 is supported in such a manner as to face each other. ing. Further, each printing pressure arm 20 at a substantially central portion of the swing shaft 21 and the cam follower 41 is attached with the other end of a printing pressure spring 42 having one end fixed to the printing apparatus main body 11. As a result, each printing pressure arm 20 is given a rotation biasing force in the clockwise direction in FIGS. 2 and 3 around the swing shaft 21.

  In the vicinity of the left side of each cam follower 41, as will be described later with reference to FIG. The pressure release cam assembly 43 is integrally attached to a portion near one end portion of the cam shaft 44. Both ends of the cam shaft 44 are supported between the housing side plates 11a and 11b via a bearing 48a and are movable in the left-right direction in FIG. A drive gear 45 is integrally attached to one end of the cam shaft 44. In the vicinity of one end of the cam shaft 44, a support shaft 46 that is rotatably supported by the housing side plate 11b via a bearing (not shown) is provided. A transmission gear 47 having a long tooth width is integrally attached to the end portion of the support shaft 46, which receives the rotational force from the printing drum driving means 121 that rotates the printing drum 12 and always meshes with the driving gear 45. . Therefore, the pressure release cam assembly 43 is transmitted with the rotational force from the printing drum driving means 121 via the transmission gear 47 and the driving gear 45 meshed therewith, and is rotated in the clockwise direction in FIG. .

  With reference to FIG. 2 thru | or FIG. 6, the detailed structure around the means and mechanism which determines the printing pressure range of the press roller 13 including the pressure release cam assembly 43 is demonstrated. 2 and 3, in the vicinity of the other end of each printing pressure arm 20, the pressing roller 13 is prohibited from swinging while the pressing roller 13 occupies the non-printing position, and the printing roller 13 is not printed. Locking means 180 for locking the press roller, which is held in position, is provided. The locking means 180 is connected to a hook member 183 fixed to a support shaft 182 whose one end is rotatably supported by a predetermined angle on the casing side plate, and to the other end of the hook member 183 via a pin. Pull-type solenoid 181 provided with a plunger 181a, and an urging means whose one end is locked to a hook member 183 between a support shaft 182 and the pin, and the other end is locked to the housing side plate side As a tension spring 184. At the other end of the hook member 183, a hook portion 183a that selectively engages with a notch 20a formed at the other end of the printing pressure arm 20 is formed. The tension spring 184 swings and urges the hook portion 183a of the hook member 183 in the clockwise direction around the support shaft 182, that is, the direction in which the tension spring 184 is always engaged with the notch portion 20a of the printing pressure arm 20.

  The state in which each printing pressure arm 20 is held and the state in which the holding is released are selectively switched by on / off switching control of the solenoid 181. As shown in FIG. 3, when the solenoid 181 is energized and turned on, the hook portion 183a swings counterclockwise and downward to disengage from the notched portion 20a of the printing pressure arm 20, Each printing pressure arm 20 swings clockwise and upward about the swinging shaft 21 and is given printing pressure by the press roller 13. As shown in FIG. 2, the solenoid 181 is operated in a state in which the cam follower 41 is in contact with the large-diameter portion of each of the pressure release cams 43 a, 43 b, 43 c constituting the pressure release cam assembly 43.

  As described above, the pressure release cam assembly 43 is integrally attached to a portion near one end portion of the cam shaft 44, and always meshes with the transmission gear 47 that is driven to rotate in synchronization with the rotation of the printing drum 12. The rotational force from the printing drum driving means 121 is transmitted through the driving gear 45, and is rotated in the clockwise direction in FIGS. In the example of this embodiment, the crest portions of the pressure release cams 43a, 43b, 43c, that is, any one large-diameter portion of each cam 43a, 43b, 43c resists the biasing force of each printing pressure spring 42. By pressing the cam follower 41, the printing pressure by the press roller 13 is turned off and released. The press roller 13 occupies the non-printing position shown in FIG. Any one large diameter portion of each of the pressure release cams 43a, 43b, 43c is released from the pressure contact with the cam follower 41, and the outer peripheral surface of the press roller 13 is the outer periphery of the printing drum 12 by the urging force of each printing spring 42. When pressed against the surface, the press roller 13 occupies the printing position shown in FIG. A position where the sheet P is pressed against the master 64 wound around the printing drum 12 when the press roller 13 occupies the printing position is referred to as a printing nip portion N as a pressing position.

  As shown in FIGS. 4 and 6, the pressure release cam assembly 43 includes three cams, that is, a pressure release cam 43b as a first cam, a pressure release cam 43c as a second cam, and a third cam. The pressure release cam 43a is also referred to as a multistage cam. Each of the pressure release cams 43a, 43b, and 43c is a plate-like cam having a large diameter portion and a small diameter portion, and each of the pressure release cams 43a, 43b, and 43c is unique to the cam shaft 44 that can move and rotate in the left-right direction in FIG. It is fixed with the phase relationship of 2 and 3 show only the central pressure release cam 43a shown in FIG. 6, and the other two pressure release cams 43a and 43c are not shown. 2 and 3, the cross-sectional hatching display of the pressure release cam 43a is omitted for simplification of the drawings, and the cam shaft 44 and the cross sections of the pressure release cams 43a and 43c in FIG. 4 are omitted for the same purpose. The hatching display is omitted.

  The pressure release cam 43a is used as a reference for normal printing (also for single-sided printing). As shown in FIG. 4, the pressure release cam 43 a includes an A portion, a B portion, and a C portion as viewed in the rotational direction. The portion A is a portion where the printing pressure is turned on during front surface printing, the portion B is a portion where the printing pressure is turned on during back surface printing, and the portion C is a portion where the clamper 19 protrudes from the outer periphery of the printing drum 12 This is the part where the printing pressure is off to escape.

  In FIG. 4, a pressure release cam 43b drawn next to the pressure release cam 43a is used for the first printing of the first sheet. The pressure release cam 43b includes an A portion, a B portion, and a C portion as viewed in the rotational direction. The portion A is a portion where the printing pressure is turned on during front surface printing, the portion B is a portion where the printing pressure is off because there is no backside printing, and the portion C is a protruding portion of the clamper 19 on the outer periphery of the printing drum 12 It is the part of the printing pressure off to escape.

  In FIG. 4, the pressure release cam 43 c drawn on the left side of the pressure release cam 43 b is used for printing the last sheet at the end of printing. The pressure release cam 43c includes an A portion, a B portion, and a C portion as viewed in the rotational direction. The portion A is a portion where printing pressure is off because there is no surface printing, the portion B is a portion where printing pressure is turned on at the time of backside printing, and the portion C is a protruding portion of the clamper 19 on the outer periphery of the printing drum 12 It is the part of the printing pressure off to escape.

  FIG. 5 is an expanded view of the printing pressure range of the press roller 13 for easy understanding. In FIG. 5, the divided master-making master 65 is formed with an area portion of the front plate-making image 65A and an area portion of the back-side plate-making image 65B, and an intermediate non-plate-making area 65S is provided between them. It is. Here, the leading side of the divided pre-printed master 65, which is also referred to as a leading edge margin portion 65a sandwiched and fixed by the clamper 19 of the printing drum 12, is the left end side.

  The printing pressure range pattern for normal printing including single-sided printing is as shown in III, and both A and B are turned on, that is, the area portion of the front plate-making image 65A and the area of the back-side printing plate image 65B. The pressure release cam 43a is selected so that the portion is continuously printed.

  At the first printing start, as shown in the printing pressure range pattern I, A is printing pressure on but B is printing pressure off, that is, only the area portion of the surface plate-making image 65A is printed. Thus, the pressure release cam 43b is selected.

  When the last sheet is printed, the printing pressure range pattern II is set so that A is turned off but B is turned on, that is, only the area portion of the back plate-making image 65B is printed. In addition, the pressure release cam 43c is selected.

  The above can be summarized with reference to FIGS. 1 and 5 as follows. That is, the printing pressure range pattern I as a first printing pressure range pattern that applies printing pressure only to the surface area 12A corresponding to the surface plate-making image 65A in the divided plate-making master 65 on the printing drum 12, and the printing drum 12 In the divided plate-making master 65, a printing pressure range pattern II as a second printing pressure range pattern for applying printing pressure only to the back surface area 12B corresponding to the back surface plate-making image 65B, and the back surface area 12B from the front surface area 12A. One of at least three printing pressure range patterns and a printing pressure range pattern III as a third printing pressure range pattern for applying printing pressure can be selectively switched. FIG. 6 shows a mechanism relating to a printing pressure range varying means for selectively switching one of these three printing pressure range patterns.

  From the above, the formation range of the small diameter portions of the pressure release cams 43a, 43b, 43c is as follows. In the pressure release cam 43b, the contact range between the press roller 13 and the printing drum 12 is a range in which all of the front surface region 12A, the intermediate region 12S, and the back surface region 12B shown in FIG. The pressure release cam 43c is formed so that the intermediate region 12S and the back surface region 12B are combined from the downstream end of the front surface region 12A so as to be in the same range as the region 12A. Further, the cam width of each of the pressure release cams 43a, 43b, 43c is set to be sufficiently larger than the plate thickness of the printing pressure arm 20.

  As shown in FIG. 6, the printing pressure range variable means 55 includes a pressure release cam assembly 43 integrally connected in a manner that the pressure release cams 43a, 43b, and 43c are overlapped, and the pressure release cam assembly 43. A cam shaft 44 that is fixed and supported so as to be movable (slidable) in the left-right direction and rotatable in the clockwise direction in FIG. 6; The rollers 50a and 50b that can roll while sandwiching both side surfaces of the rotating disk 49 and the shaft that supports the rollers 50a and 50b so as to freely roll can be fixed and moved in the left-right direction in FIG. A slide member 51 having a rack tooth 51a formed at the lower part thereof and a downward projection 51b formed at the other end, and a pinion gear 52 that always meshes with the rack tooth 51a of the slide member 51 are attached and fixed to the output shaft. Release cam switching The motor 53 (hereinafter simply referred to as “motor 53”) and a cam home position sensor 54 that selectively engages with the protrusion 51b for detecting the home position of the pressure release cam assembly 43 are mainly configured. Yes. The printing pressure range variable means 55 is sometimes called a press roller contacting / separating mechanism (pressing means contacting / separating means).

  FIG. 6 shows a state during normal printing, and shows a state in which the cam follower 41 of each printing pressure arm 20 is engaged with and in contact with the pressure release cam 43 a of the pressure release cam assembly 43. The motor 53 is composed of, for example, a stepping motor capable of forward / reverse rotation, and has a function as a printing pressure range switching driving means for switching to any one of the three pressure release cams 43a, 43b, 43c. The motor 53 is fixed on the printing apparatus main body 11 side. When the closed loop control is performed on the motor 53, the above-described cam home position sensor 54 and the protrusion 51b may be omitted, but it is preferable to consider the case of step-out. The motor 53 may be an electric motor such as a DC motor capable of forward and reverse rotation.

  As shown in FIG. 3, the pressure release cams 43a, 43b, and 43c apply the biasing force of each printing spring 42 with high accuracy when the press roller 13 occupies the printing position, thereby applying an appropriate printing pressure. Thus, the small diameter part of each pressure release cam 43a, 43b, 43c and the cam follower 41 are comprised so that it may not contact. 6, guide members (not shown) for guiding the slide member 51 through a roller so as to slide in a substantially parallel manner in the drawing are disposed on the front side and the back side of the paper surface in FIG. The cam home position sensor 54 is, for example, a transmissive photosensor including a light emitting element and a light receiving element, and is fixed to the printing apparatus main body 11 side. For the rotating disk 49, for example, polyacetal resin (POM) or polyamide resin (nylon: trade name) or the like is preferably used as a lubricating resin having good wear resistance and a small friction coefficient.

  On the camshaft 44, as shown in FIG. 6, the pressure release cam 43a (third cam) set corresponding to the printing pressure range pattern III is set as the center and corresponding to the printing pressure range pattern I. The pressure release cam 43b (first cam) and the pressure release cam 43c (second cam) set corresponding to the printing pressure range pattern II are disposed on both sides of the pressure release cam 43a (third cam). They are arranged on the camshafts 44, respectively.

  As described above, it is preferable to dispose the pressure releasing cam assembly 43, the cam follower 41, and the printing pressure spring 42 on the respective printing pressure arms 20 side because the uniform pressing force of the press roller 13 can be obtained. However, the pressure release cam assembly 43, the cam follower 41, and the printing pressure spring 42 are arranged on the far side of the paper surface shown in FIGS. 2 and 3, for example. You may arrange | position only to the printing pressure arm 20 side.

  In FIG. 1, near the left side of the contact position between the printing drum 12 and the press roller 13 and on the paper conveyance path, a single-sided printed paper, a front-side printed paper, or a double-sided printed paper (hereinafter referred to as any one of these). A switching member 10 is provided for switching the conveyance path of one sheet (sometimes simply referred to as “paper P”). The switching member 10 is made of a plate material having substantially the same width as the printing drum 12 and the press roller 13, and is fixed to a spindle that is rotatably supported by the printing apparatus main body 11 at the downstream end portion in the paper transport direction Xa. Yes. The switching member 10 is connected to a tension spring (not shown) and a solenoid 123 shown in FIG. 10, and the upstream end of the sheet conveying direction Xa formed with an acute cross section when the solenoid 123 is actuated is shown by a solid line in FIG. 1. The first position shown and the second position shown by a two-dot chain line are selectively positioned. When the switching member 10 occupies the first position, the tip of the switching member 10 is located near the outer peripheral surface of the press roller 13 so as not to interfere with the clamper 19 on the printing drum 12 and occupies the second position. Sometimes, the tip is placed at a position close to the peripheral surface of the printing drum 12. The paper P passing between the printing drum 12 and the press roller 13 is guided to the paper discharge unit 6 when the switching member 10 occupies the first position, and the switching member 10 occupies the second position. Sometimes, it is guided to the refeed tray 8 through the guide plate 27 and the guide plate 56 fixed to the printing apparatus main body 11.

  A plate making unit 3 is disposed in the upper right part of the printing apparatus main body 11. The plate making unit 3 includes a master holding member 57, a platen roller 58, a thermal head 59, a cutting means 60, a master stock unit 61, a tension roller pair 62, a reverse roller pair 63, and the like.

  The plate making unit 3 performs plate making on the master 64 and, as shown in FIG. 7, the first plate making image 65A for surface printing along the rotation direction of the printing drum 12 (hereinafter referred to as “surface plate making image 65A”). And the second plate-making image 65B for back-side printing (hereinafter referred to as “back-side plate-making image 65B”), or the master plate 65 that has been subjected to the plate-making, as shown in FIG. It has a function and configuration for producing a master-making master 66 having a third plate-making image 66A (hereinafter referred to as “single-side plate-making image 66A”) having an image area for two sides of the plate-making image 65A and the back-side plate-making image 65B. . The front plate-making image 65A is formed at a position corresponding to the front surface region 12A shown in FIG. 1 when the divided pre-printed master 65 is wound on the outer peripheral surface of the printing drum 12, and the back surface plate-making image 65B is the same back surface region 12B. And corresponding positions.

  The master holding member 57 is provided on each plate-making side plate pair (not shown) of the printing apparatus main body 11, and a master 64 obtained by bonding a thermoplastic resin film and a porous support is wound around the core tube 64b in a roll shape. The both ends of the core tube 64b of the master roll 64a thus formed are supported rotatably and detachably.

  The platen roller 58 is disposed downstream of the master holding member 57 in the master conveyance direction, and is rotatably supported by the plate making side plate pair. The platen roller 58 is connected to a stepping motor through driving force transmission means such as a gear and a belt, and is rotationally driven by a plate making driving means 124 shown in FIG. 10 including the stepping motor. The thermal head 59 has a large number of heat generating elements that are selectively driven to generate heat through a plate making control unit and a thermal head drive circuit (not shown). The thermal head 59 is disposed below the platen roller 58, and includes a cam (not shown), a cam drive motor (not shown) for rotating the cam, a spring as a biasing means, and the like, a well-known thermal head not shown (not shown). The platen roller 58 is configured so as to be freely contacted and separated by the means. The thermal head 59 has its heating element surface pressed against the platen roller 58 by the urging force of the thermal head contacting / separating means and the urging means. The thermal head 59 has a function as plate making means for selectively making the heat generating element generate heat while making contact with the thermoplastic resin film surface of the master 64 and punching and making the master 64.

  A cutting means 60 is disposed on the left side of the platen roller 58 and the thermal head 59. The cutting means 60 has a fixed blade 60a fixed to a frame (not shown) of the printing apparatus main body 11, and a movable blade 60b supported movably by the fixed blade 60a. The cutting means 60 has a well-known configuration for cutting the master 64 when the movable blade 60b rotates relative to the fixed blade 60a.

  A master stock portion 61 is disposed below the cutting means 60 on the downstream side in the master conveyance direction. The master stock unit 61 has a space for temporarily storing the divided master-making master 65 or the master-making master 66, and the interior thereof is partitioned by a plurality of plate members. Is arranged. By operating this suction fan, a negative pressure is generated inside the master stock portion 61 that is a substantially sealed space, and the divided master-making master 65 or the master-making master 66 that has been transported by plate-making is the master stock portion. It is stored toward the innermost part of 61.

  A tension roller pair 62 is disposed at a portion between the cutting means 60 and the master stock portion 61. The tension roller pair 62 includes a driving roller 62a and a driven roller 62b, which are rotatably supported by the plate making side plate pair, respectively. It is in pressure contact. The tension roller pair 62 sandwiches and conveys the master 64 when the driving roller 62a is rotationally driven by the plate-making driving means 124 described above. The driving roller 62a is set to have a circumferential speed slightly higher than the circumferential speed of the platen roller 58, and a torque limiter (not shown) is provided inside the driving roller 62a. As a result, a predetermined tension is applied to the master 64 between the platen roller 58 and the tension roller pair 62.

  A reverse roller pair 63 is disposed downstream of the master stock unit 61 in the master conveyance direction. The reverse roller pair 63 includes a drive roller 63a and a driven roller 63b that are rotatably supported by the plate making side plate pair. The reverse roller pair 63 sandwiches and conveys the master 64 by a driving roller 63a that is rotationally driven by the plate-making driving means 124 and a driven roller 63b that is pressed against the driving roller 63a (not shown). A one-way clutch (not shown) is provided inside the drive roller 63a.

  A movable master guide plate (not shown) is disposed between the tension roller pair 62 and the reverse roller pair 63. The movable master guide plate is swingably supported by a support member (not shown), and the upper surface of the movable master guide plate forms a transfer path for the master 64 by a solenoid (not shown), and the master 64 enters the master stock section 61. Is selectively positioned at a retracted position that does not hinder the movement.

  A sheet feeding unit 4 is disposed below the plate making unit 3. The sheet feeding unit 4 includes a sheet feeding tray 67 as a sheet feeding table, a sheet feeding roller 68, a separation roller 69, a separation pad 70, a registration roller pair 71, and the like. The sheet feed tray 67 is configured to be capable of stacking a large number of sheets P, is supported by the printing apparatus main body 11 so as to be movable up and down, and includes a sheet feed driving means 125 shown in FIG. Is moved up and down. The paper feed tray 67 is configured so that A3 size paper P can be placed vertically, and a pair of rails (not shown) are supported on the upper surface of the paper feed tray 67 so as to be movable in the paper width direction perpendicular to the paper transport direction Xa. A side fence 72 is provided. A plurality of paper size detection sensors 73 that detect the size of the stacked paper P are provided on the right end side of the paper feed tray 67.

  Above the paper feed tray 67, a paper feed roller 68 having a high frictional resistance member on the surface is disposed. The paper feed roller 68 is rotatably supported by a bracket (not shown) that is swingably supported by the printing apparatus main body 11. When the paper feed tray 67 is lifted by lifting means (not shown), it is supplied with a predetermined pressure. The uppermost sheet P on the paper tray 67 is pressed against. The sheet feeding roller 68 is transmitted at a predetermined timing synchronized with the printing drum 12 together with a separation roller 69 described later by transmitting the rotational driving force from the printing drum driving unit 121 by a driving force transmitting unit (not shown) such as a gear or a cam. Is driven to rotate.

  On the left side of the paper feed roller 68, a separation roller 69 and a separation pad 70 each having a high friction resistance member on the surface are disposed. The separation roller 69 is drivingly connected to the paper feed roller 68 via a timing belt 69a, and is driven to rotate in the same direction in synchronization with the rotation of the paper feed roller 68. The separation pad 70 is pressed against the separation roller 69 by an urging force of a compression spring (not shown) as an urging means, and has a function of separating and conveying the sheets P one by one by cooperation with the separation roller 69. Between the shaft of the paper feed roller 68 and a paper feed roller pulley (not shown) that spans the timing belt 69a on the side of the paper feed roller 68, and between the shaft of the separation roller 69 and the timing belt 69a on the side of the separation roller 69. A one-way clutch (not shown) is interposed between separation roller pulleys (not shown). As a result, the paper feed roller 68 and the separation roller 69 are rotatable only in the clockwise direction in FIG. 1, which is the direction in which the paper P is sent in the paper transport direction Xa.

  A registration roller pair 71 is disposed on the left side of the separation roller 69 and the separation pad 70. The registration roller pair 71 includes a driving roller 71a and a driven roller 71b. The driving roller 71a performs printing by transmitting the rotational driving force from the printing drum driving unit 121 by a driving force transmitting unit (not shown) such as a gear or a cam. The outer peripheral surface of the printing drum 12 and the outer peripheral surface of the press roller 13 in the printing unit 2 are formed in pressure contact with each other by a driven roller 71b that rotates at a predetermined timing synchronized with the drum 12 and is pressed against the driving roller 71a. The paper P is fed toward the nip portion at a predetermined timing.

  The rotation driving of the paper feeding roller 68 and the separation roller 69 is not limited to the printing drum driving means 121 but is a paper feeding motor comprising a stepping motor, for example, a motor driven by pulse input, which is provided independently of this. You may go. Similarly, the rotational driving of the registration roller pair 71 is not limited to the printing drum driving unit 121 but may be performed by a registration motor including a stepping motor as a motor driven by pulse input provided independently of the printing drum driving unit 121. . In this case, in particular, the registration timing is adjusted in consideration of slippage of the paper P due to the paper type and environmental conditions at the registration roller pair 71, and each plate-making image of the plate-making master and the divided plate-making master on the printing drum 12 is used. There is an advantage that it is possible to easily adjust the position of the top and bottom.

  At the upper left of the printing unit 2, a plate removal unit 5 is disposed. The plate discharging unit 5 includes an upper plate discharging member 74, a lower plate discharging member 75, a plate discharging box 76, a compression plate 77, and the like. The upper plate removal member 74 includes a driving roller 78, a driven roller 79, an endless belt 80, and the like. The drive roller 78 is rotationally driven in the clockwise direction in FIG. 1 by the plate discharge driving means 126 shown in FIG. 10 including the plate discharge motor, so that the endless belt 80 moves in the arrow direction in FIG. The lower plate removing member 75 includes a driving roller 81, a driven roller 82, an endless belt 83, and the like. The driving roller 81 is driven to rotate in the counterclockwise direction of FIG. 1 by transmitting the driving force of the above-mentioned plate discharging driving means 126 that rotationally drives the driving roller 78 by a driving force transmitting means (not shown) such as a gear or a belt. As a result, the endless belt 83 moves in the direction of the arrow in FIG. Further, the lower plate discharge member 75 is movably provided by a moving unit (not shown) included in the plate discharge drive unit 126, and an endless belt 83 positioned on the outer peripheral surface of the driven roller 82 and the position shown in the drawing is provided in the printing drum 12. And a position that abuts on the outer peripheral surface.

  The plate ejection box 76 stores a used master therein and is detachably attached to the printing apparatus main body 11. The compression plate 77 is supported by the printing apparatus main body 11 so as to be movable up and down so that the used master carried by the upper plate discharging member 74 and the lower plate discharging member 75 is pushed into the plate discharging box 76. Is moved up and down by a lifting / lowering means (not shown) including a lifting / lowering motor.

  A paper discharge unit 6 is disposed below the plate discharge unit 5. The paper discharge unit 6 includes a peeling claw 84, a paper discharge transport means 85, a paper discharge tray 86 as a paper discharge stand, a blower means 140, and the like. A plurality of peeling claws 84 are arranged in the width direction of the printing drum 12 and are integrally attached to respective support shafts that are swingably supported by the printing apparatus main body 11. The plurality of peeling claws 84 are swung by a claw rocking means (not shown), and their tips are close to the peripheral surface of the printing drum 12 to avoid obstacles such as the clamper 19 and the like. It selectively occupies the position where the tip is separated from the outer peripheral surface of the printing drum 12. The claw swinging means (not shown) transmits the driving force from the printing drum driving means 121 by the driving force transmission means (not shown), and swings the peeling claw 84 in synchronization with the rotation of the printing drum 12.

  The paper discharge conveying means 85 is disposed below the peeling claw 84 and to the left of the switching member 10 and is also called a belt-type suction conveyance device. The paper discharge conveying unit 85 includes a driving roller 87, a driven roller 88, an endless belt 89, a suction fan 90, and the like. A plurality of drive rollers 87 have a roller shape and are attached at a predetermined interval to a support shaft (not shown) that is rotatably supported on a unit side plate (not shown), and includes a paper discharge motor 127 shown in FIG. Are driven to rotate integrally with each other. A plurality of driven rollers 88 are also provided on a support shaft (not shown) rotatably supported on the same side plate at regular intervals with each drive roller 87. A plurality of driven rollers 88 and corresponding driven rollers 88 corresponding thereto are provided. An endless belt 89 having a plurality of holes is stretched over each other. Below the driving roller 87, the driven roller 88, and the endless belt 89, a suction fan 90 incorporating a fan motor is disposed. The paper discharge transport unit 85 sucks the paper P onto each endless belt 89 by the suction force of the suction fan 90, and transports the paper P in the direction of the arrow in FIG. The paper discharge tray 86 is for stacking the paper P conveyed by the paper discharge conveying means 85 on the upper surface thereof, and has one end fence 91 movable in the paper conveyance direction Xa and movable in the paper width direction. And a pair of side fences 92.

  The blowing means 140 includes a peeling fan 141 that generates an airflow by rotation, a casing 142 that houses the peeling fan 141 and blows the airflow generated by the rotation of the peeling fan 141 toward the printing drum 12, and as shown in FIG. And air blowing control means 143 for controlling the driving of the peeling fan 141. The output of the peeling fan 141 is variable by the control by the air blowing control means 143. The casing 142 is a portion of the printing drum 12 downstream of the printing nip N in the direction R of the air flow generated by the rotation of the peeling fan 141, and the sheet P is transferred from the master 64 by the switching member 10 and the peeling claw 84. It is comprised so that it may spray on the part to peel. The air blowing control unit 143 controls the output of the peeling fan 141 in addition to switching between operation and non-operation of the peeling fan 141, and controls the strength of the air blowing toward the printing drum 12 by the air blowing unit 140, in other words, the strength of the air blowing. To do. Therefore, the ventilation control means 143 functions as an air volume control means. The air blowing control unit 143 starts the operation of the separation fan 141 at the timing when the rotation driving of the paper feed roller 68 and the separation roller 69 is started, and continues the operation of the separation fan 141 for a predetermined time from that timing. The predetermined time is normally sufficient for the paper P sent out by the rotational driving of the paper feed roller 68 and the separation roller 69 to be printed and stacked on the paper discharge tray 86, and is measured by a timer. Is done. The air blowing control unit 143 is actually realized by the control unit 200, but in FIG. 10, for convenience of explanation, the air blowing control unit 143 is illustrated as a part of the configuration of the air blowing unit 140.

  The blowing unit 140 performs a peeling operation to peel off the paper P pressed by the master 64 wound around the printing drum 12 rotating in the direction R by blowing air toward the printing drum 12. However, this peeling operation is also performed by the switching member 10 and the peeling claw 84. The peeling operation by the blowing means 140 is performed together with the peeling operation performed by the switching member 10 and the peeling claw 84. That is, the master 64 wound around the printing drum 12 rotating in the direction R and the front end of the paper P that is pressed against the master 64 by the press roller 13 at the printing nip portion N and is in close contact with the master 64 due to the viscosity of the ink. As a result, the switching member 10 and the peeling claw 84 can easily enter between the master 64 and the leading edge of the paper P, and the switching member 10 and the peeling claw 84 are also moved. However, when the paper 64 enters between the master 64 and the front end of the paper P and the paper P is to be peeled off from the master 64 as the printing drum 12 rotates, air is blown between the master 64 and the paper P. Such peeling is performed smoothly.

  An image reading unit 7 is disposed on the upper part of the printing apparatus main body 11. The image reading unit 7 includes a contact glass 93 on which a document is placed, a pressure plate 94 provided so as to be able to come in contact with and away from the contact glass 93, reflection mirrors 95, 96, 97, 98 for scanning and reading a document image, and a fluorescent lamp. 99, a lens 100 for converging the reflected light related to the scanned original image, an image sensor 101 such as a CCD for performing photoelectric conversion processing on the reflected light related to the focused original image, and a plurality of original size detecting sensors for detecting the original size 102, an image memory 135 for storing the read image data, and the like. The document image reading operation is performed by the operation of the reading drive means 128 shown in FIG.

  As shown in FIG. 1, a dog 133 is attached to the outer surface of a flange (not shown) constituting the printing drum 12. A home position sensor 134 attached to the printing apparatus main body 11 is disposed in the vicinity of the periphery of the printing drum 12. The home position sensor 134 detects the dog 133 when the print drum 12 occupies the position where the clamper 19 faces the press roller 13, and transmits a detection signal to the control means 200.

  The operation panel 103 shown in FIG. 9 is arranged on the upper front surface of the printing apparatus main body 11 in FIG. The operation panel 103 has a plate making start key 104, a printing start key 105, a trial printing key 106, a continuous key 107, a clear / stop key 108, a numeric key 109, an enter key 110, a program key 111, a mode clear key 112, printing on the upper surface thereof. A speed setting key 113, a four-direction key 114, a paper size setting key 115, a double-sided printing key 117, a single-sided printing key 118, a display device 119 including a 7-segment LED, a display device 120 including an LCD, and the like.

  The plate making start key 104 is pressed when the duplex printing apparatus 1 performs the plate making operation. When the plate making start key 104 is pressed, the plate making operation is performed after the plate discharging operation and the document reading operation are performed. The attaching operation is performed, and the duplex printing apparatus 1 enters a print standby state. The print start key 105 is pressed when the double-sided printing apparatus 1 performs a printing operation. When the double-sided printing apparatus 1 enters a print standby state and various printing conditions are set, the printing start key 105 is pressed to perform a printing operation. Is done. The trial printing key 106 is pressed when the duplex printing apparatus 1 performs a trial printing, and only one sheet is printed by pressing the trial printing key 106 after various conditions are set. The continuous key 107 is pressed before pressing the plate making start key 104 when performing the plate making operation and the printing operation continuously. After pressing the continuous key 107, the printing plate start key 104 is pressed after the printing conditions are input. Then, the printing operation is performed following the plate discharging operation, the document reading operation, and the plate making operation.

  The clear / stop key 108 is pressed when the operation of the duplex printing apparatus 1 is stopped or when the number is cleared. The numeric keypad 109 is used for numerical input. The enter key 110 is pressed when setting a numerical value or the like during various settings, and the program key 111 is pressed when registering or calling a frequently performed operation, and the mode clear key 112 is used for clearing various modes. Press to return to the initial state. The print speed setting key 113 is pressed when setting the print speed prior to the printing operation, and when it is desired to obtain a darker image or when the ambient temperature is low, the print speed is slow and a lighter image is desired. Or, when the ambient temperature is high, the printing speed is set fast. The four-way key 114 has an up key 114a, a down key 114b, a left key 114c, and a right key 114d. When adjusting the image position during image editing or when selecting a numerical value or item at various settings, etc. Pressed. The paper size setting key 115 is pressed when an arbitrary paper size is input, and the paper size input with the paper size setting key 115 has priority over the paper size detected by the paper size detection sensor 73.

  The duplex printing key 117 is pressed before the plate making start key 104 is pressed when the duplex printing apparatus 1 performs the duplex printing operation. When the duplex printing key 117 is pressed, the LED 117a disposed in the vicinity thereof is lit. It is displayed that the duplex printing mode is set. Similarly to the double-sided printing key 117, the single-sided printing key 118 is pressed before the start key 104 is pressed when the double-sided printing apparatus 1 performs the single-sided printing operation, and when the single-sided printing key 118 is pressed, it is arranged in the vicinity thereof. The LED 118a is turned on to indicate that the single-sided printing mode is set. In the duplex printing apparatus 1, the LED 118 a is lit in the initial state after turning on the power switch (not shown), and the single-sided printing mode is set.

  A display device 119 composed of a 7-segment LED mainly displays numbers such as the number of printed sheets. The display device 120 has a hierarchical display structure. By selecting and pressing selection setting keys 120a, 120b, 120c, and 120d provided below the display device 120, various modes such as scaling and position adjustment can be performed. It can be changed and set in each mode. Further, the display device 120 displays the state of the double-sided printing apparatus 1 such as “can be made / printed” as shown in the figure, warnings such as plate-making or discharge jam, paper feed or paper discharge jam, and printing. Supply instructions for supplies such as paper, master and ink are also displayed.

  As shown in FIG. 10, the switching member 10, the peeling claw 84, and the air blowing means 140 already described constitute a paper peeling device 150. The paper peeling device 150 performs a peeling operation for peeling the paper P pressed by the master 64 wound around the printing drum 12 rotating in the direction R from the master 64. The switching member 10 and the peeling claw 84 perform such a peeling operation by entering between the master 64 wound around the printing drum 12 rotating in the direction R and the paper P pressed against the master 64. It functions as a peeling member that performs such a peeling operation. The switching member 10 and the peeling claw 84 are arranged from the upstream side in the direction R downward in the order of the switching member 10 and the peeling claw 84 in a manner facing the printing drum 12 along the direction R. As already described, the peeling claw 84 also functions as a part of the paper discharge unit 6, but in FIG. 10, for convenience of illustration, it is illustrated as a configuration provided only in the paper peeling device 150. .

  As shown in FIG. 10, the control unit 200 includes a microcomputer having a CPU 201, a ROM 202, a RAM 203, a timer (not shown), and the like, which are connected by a signal bus (not shown). As shown in FIG. 1, the control device 200 is provided in a control board arrangement section in the printing apparatus main body 11.

  Based on various signals from the operation panel 103, detection signals from various sensors provided in the printing apparatus main body 11, and an operation program called from the ROM 202, the CPU 201 prints the printing unit 2, the plate making unit 3, the paper feeding unit 4, Each of the drive means provided in the plate discharge unit 5, the paper discharge unit 6, and the image reading unit 7, the refeed resist contact / separation mechanism 40 provided in the refeed unit 9, the transport member drive motor 122, and the sheet peeling device 150. The operation and the like are controlled, and the operation of the entire duplex printing apparatus 1 is controlled. The ROM 202 stores an operation program for the entire duplex printing apparatus 1, and this operation program is appropriately called by the CPU 201. The RAM 203 has a function of temporarily storing calculation results of the CPU 201, a function of storing data signals and ON / OFF signals set and input from various keys and various sensors on the operation panel 103 as needed. The control unit 200 also grasps the rotation position of the printing drum 12 based on a home position signal from the home position sensor 134 and a signal from an encoder (not shown) provided in the printing drum driving unit 121. ing.

  Here, the control functions of the control means 200 in relation to the above-described printing pressure range variable means 55 will be summarized. First, the control unit 200, when continuously performing double-sided printing on a predetermined number N of sheets of paper P, the surface of the first first sheet P1 fed from the paper feed unit 4 at the start of the printing operation. In order to perform printing with the printing pressure range pattern I, the printing pressure range pattern II is formed on the back surface of the last front printed sheet PN discharged to the refeed tray 8 immediately before the end of the printing operation. The printing pressure is applied to the other sheets P2 to P (N-1) except for printing with reference to the signal from the cam home position sensor 54 so that printing is performed with the printing pressure range pattern III. It has a function as a first control means for controlling the motor 53 of the range variable means 55.

  Secondly, the control means 200 performs printing using only two printing pressure range patterns, ie, a printing pressure range pattern I and a printing pressure range pattern II, in the printing printing process or the trial printing printing process. With reference to a signal from the cam home position sensor 54, it functions as a second control means for controlling the motor 53 of the printing pressure range variable means 55.

  Based on the above-described configuration, the operation including the operation procedure of the duplex printing apparatus 1 in the present embodiment will be described in detail with reference to the flowchart of FIG. This flowchart describes the main part to the extent that it can be carried out, and the single-sided printing process and detailed flow when the single-sided printing mode is set are omitted.

  First, the case of performing single-sided printing will be described. The operator loads the paper P to be used for printing on the paper feed tray 67, opens the pressure plate 94 and places a document to be printed on the contact glass 93, and then closes the pressure plate 94 again. Thereafter, after setting the plate making conditions using various keys on the operation panel 103, the single-sided printing key 118 is pressed to set the single-sided printing mode, and the plate-making start key 104 is pressed.

  The operator confirms the single-sided printing mode by turning on the LED 118a, and then presses the plate making start key 104 (see step S1). When the plate making start key 104 is pressed, a paper size detection signal is sent from the paper size detection sensor 73 and a document size detection signal is sent from the document size detection sensor 102 to the control means 200. Compare each signal. At this time, if the paper size and the document size are the same, the image reading operation is immediately performed. If the paper size and the document size are different, the control unit 200 displays the fact on the display device 120 and pays attention to the operator. Prompt. When the paper size and the document size are different, enlargement / reduction scaling may be automatically performed in response to a command from the control unit 200 to match the document size and the image size.

  When the plate making start key 104 is pressed to generate a start signal and is input to the control means 200, first, the plate discharging unit 5 performs a plate discharging operation for peeling the used master from the outer peripheral surface of the printing drum 12. When the plate making start key 104 is pressed, the printing drum 12 starts rotating. When the printing drum 12 reaches the home position shown in FIG. 1, the dog 133 is detected by engaging with the home position sensor 134, and the home position sensor is detected. A home position signal is sent from 134 to the control means 200. Receiving the home position signal, the control means 200 measures the number of pulses generated by an encoder (not shown) based on the home position, and the tip of the used master wound around the outer peripheral surface of the printing drum 12 is the driven roller 82. When it is determined that the predetermined plate discharging position corresponding to the endless belt 83 located on the outer peripheral surface has been reached, the operation of the printing drum driving means 121 is stopped.

  When the printing drum driving unit 121 is stopped and the printing drum 12 is stopped at a predetermined discharging position, the printing drum driving unit 121 and the discharging plate driving unit 126 are operated to rotate and drive the driving rollers 78 and 81, and lower discharging plate. The member 75 moves to the printing drum 12 side, and the endless belt 83 located on the outer peripheral surface of the driven roller 82 comes into contact with the used master. Then, the used master scooped up from the outer peripheral surface of the printing drum 12 by the rotation of the printing drum 12 and the movement of the endless belt 83 is nipped and conveyed by the lower plate discharging member 75 and the upper plate discharging member 74 to be outer periphery of the printing drum 12. It peels from the surface. The used master that has been peeled off is discarded into the discharge box 76 and then compressed by the compression plate 77. Even after all used masters are peeled off from the outer peripheral surface, the printing drum 12 continues to rotate, and the clamper 19 rotates to a predetermined plate feed standby position located at the upper right and stops. When the printing drum 12 stops at the plate feeding standby position, an opening / closing means (not shown) is operated to open the clamper 19, and the duplex printing apparatus 1 enters a plate feeding standby state.

  In parallel with the above-described plate discharging operation, a document image reading operation is performed by the image reading unit 7. Reading of the original image is performed by reflecting the reflected light illuminated by the fluorescent lamp 99 by the respective reflection mirrors 95, 96, 97, and 98, and the reflected light related to the read original image is focused by the lens 100. Later, it enters the image sensor 101 and undergoes photoelectric conversion. The photoelectrically converted electrical signal is input to an A / D (analog / digital) converter (not shown) in the printing apparatus body 11 and then stored in the image memory 135 as an image data signal.

  In parallel with the plate discharging operation and the image reading operation, the plate making unit 3 performs the plate making operation. The platen roller 58, the tension roller pair 62, and the reverse roller pair 63 are driven to rotate, and the master 64 is pulled out from the master roll 64a. At this time, a movable master guide plate (not shown) is positioned at the transport position. When the master 64 is pulled out and the image forming area reaches a position corresponding to the heat generating element of the thermal head 59, the image data signal stored in the image memory 135 is called after image processing is performed, and the thermal recording is performed. When the head drive circuit selectively generates heat from each heating element of the thermal head 59, a one-side plate-making image 66A is formed on the thermoplastic resin film surface of the master 64 as shown in FIG. When the master 64 is conveyed while being made and its tip is sandwiched between the reverse roller pair 63, a movable master guide plate (not shown) is moved to the retracted position and the rotation of the reverse roller pair 63 is stopped.

  The platen roller 58 and the tension roller pair 62 continue to rotate even after the rotation of the reversing roller pair 63 is stopped, and the plate-making master 66 made by the thermal head 59 is stored in the master stock unit 61. When the reversing roller pair 63 is stopped, a suction fan (not shown) provided in the master stock unit 61 is operated, and the master-making master 66 is stored in the master stock unit 61 by being sucked by a suction fan (not shown). It will be done.

  During the plate making operation described above, when the plate discharging operation is completed and the duplex printing apparatus 1 enters the plate feed standby state, the reverse roller pair 63 starts to rotate and the plate-made master 66 stored in the master stock unit 61 is released. It is conveyed toward the clamper 19 that is being used. When the control means 200 determines from the number of steps of the stepping motor in the plate making drive means 124 that the leading end of the plate making master 66 has been transported to a predetermined position that can be held by the clamper 19, an opening / closing means (not shown) is activated. Then, the clamper 19 is closed, and the pre-printed master 66 is held on the outer peripheral surface of the printing drum 12 at the tip.

  Thereafter, the printing drum 12 is intermittently rotated in the direction R, and the winding operation of the pre-printed master 66 around the printing drum 12 is performed. At this time, the reversing roller pair 63 stops rotating, and the driving roller 63a is rotated along with the drawing-out master 66 being pulled out by a one-way clutch (not shown) provided therein. Then, when the image data signal from the image memory 135 is interrupted, the operation of the thermal head 59 is stopped, and when the plate-making master 66 for one plate is conveyed, the platen roller 58, the tension roller pair 62, and the reverse roller pair 63 are turned on. Each of the rotations is stopped and the cutting means 60 is operated to cut the master-making master 66. The cut master 66 that has been cut is pulled out from the plate making unit 3 by the rotation of the printing drum 12, and the printing drum 12 rotates to the home position and stops, whereby the plate making operation and the plate feeding operation are completed.

  Although description will be made before and after, the solenoid 181 of the locking means 180 remains off during the plate discharging operation or the plate feeding operation executed after the plate making start key 104 is pressed, and the press roller 13 is connected to the printing drum 12. It is separated from the outer peripheral surface and occupies the non-printing position and remains held. The control means 200 drives and controls the motor 53 of the printing pressure range varying means 55 while referring to the signal from the cam home position 54 after the plate making start key 104 is pressed and during the plate feeding operation. The slide member 51 is moved so that the pressure release cam that contacts the cam follower 41 of the pressure arm 20 becomes the pressure release cam 43a for normal printing. The control means 200 determines that the pressure release cam 43 a has come into contact with the cam follower 41 from the signal from the cam home position sensor 54 and the number of pulses (or the number of steps) supplied to the motor 53.

  The printing operation is performed following the plate feeding operation. When the printing drum 12 stops at the home position, the solenoid 123 is actuated to position the switching member 10 at the first position. Next, the paper feed roller 68, the separation roller 69, the drive roller 87, the suction fan 90, and the peeling fan 141 are driven, and the printing drum 12 is driven to rotate in the direction R at a low speed and stacked on the paper feed tray 67. Then, the uppermost sheet of the sheet P is pulled out, and its leading end is abutted against the nip portion of the registration roller pair 71 and stopped. Then, the drive roller 71a is rotationally driven at a predetermined timing when the image area leading end of the single-side plate-making image 66A in the direction R of the plate-making master 66 wound on the printing drum 12 reaches the position corresponding to the press roller 13. The drawn paper P is fed between the printing drum 12 and the press roller 13.

  Thus, the fact that the leading and trailing edges of the paper P are fed between the printing drum 12 and the press roller 13 is arranged on the paper conveyance path between the registration roller pair 71 and the printing drum 12 and the press roller 13. When the paper sensor as a paper detection means (not shown) provided is detected within a predetermined time counted by the timer of the control means 200, the locking means 180 is actuated by a command from the control means 200. Thereby, the holding state in the non-printing position of the press roller 13 shown in FIG. 2 is released.

  On the other hand, in synchronization with the rotation of the printing drum 12, the camshaft 44 and the pressure release cam assembly 43 in the printing pressure range varying means 55 are driven to rotate, and as described above, can be brought into contact with the cam follower 41. As shown in FIGS. 2 and 3, the moved pressure release cam 43 a separates the large diameter portion from the cam follower 41 at the predetermined timing.

  At a predetermined timing, the press roller 13 presses the outer peripheral surface thereof against the outer peripheral surface of the printing drum 12 by the biasing force of the printing pressure spring 42. As a result, a printing nip portion N is formed between the outer peripheral surface of the printing drum 12 and the outer peripheral surface of the press roller 13, and the paper P fed by the registration roller pair 71 is wound around the printing drum 12. Pressed by the master-making master 66. By this pressing operation, the press roller 13, the paper P, the master plate master 66, and the printing drum 12 are pressed against each other, and the ink supplied to the inner peripheral surface of the printing drum 12 by the ink roller 16 oozes out from the opening of the printing drum 12. A perforated portion of the pre-printed master 66 after filling the porous support of the pre-made master 66 wound around the printing drum 12 and the opening portion of the plate cylinder constituting the printing drum 12 and a mesh screen (not shown). Then, it is transferred to the paper P and so-called printing is performed. Thereafter, the locking means 180 is operated at a predetermined timing, and the press roller 13 is held again in the non-printing position.

  The sheet P on which the printing image corresponding to the one-side plate-making image 66A is formed by printing is passed over the switching member 10 occupying the first position, and the front end portion thereof is blown by the peeling claw 84 and the peeling fan 141. From the master plate 66 on the outer peripheral surface of the plate cylinder. The peeled paper P falls downward and is sent to the paper discharge conveyance means 85, and is conveyed to the left while being attracted to the upper surface of the endless belt 89 by the suction force of the suction fan 90, and on the paper discharge tray 86. To be discharged. Thereafter, the printing drum 12 rotates again to the home position and stops, and after the plate making operation is finished, the duplex printing apparatus 1 enters a printing standby state. The operation of the peeling fan 141 is stopped when a predetermined time has elapsed from the start of rotation of the paper feed roller 68 and the separation roller 69.

  After the duplex printing apparatus 1 enters the print standby state, the trial printing is performed when the trial printing key 106 is pressed after inputting the printing conditions using the printing speed setting key 113 and various keys on the operation panel 103. When the trial printing key 106 is pressed, the peeling fan 141 is operated to rotate the printing drum 12 at the set printing speed and to feed one sheet P from the sheet feeding unit 4. The fed paper P is temporarily stopped by the registration roller pair 71 and then fed at the same timing as that for printing. The press roller 13 is pressed against the plate-making master 66 on the outer peripheral surface of the plate cylinder. After passing over the switching member 10, the paper P on which the printed image is formed is peeled off from the pre-made master 66 on the outer peripheral surface of the plate cylinder by the blowing air from the peeling claw and the peeling fan 141, and conveyed by the paper discharge conveying means 85. Are discharged onto the paper discharge tray 86. The operation of the peeling fan 141 is stopped when a predetermined time has elapsed from the start of rotation of the paper feed roller 68 and the separation roller 69.

  When the position or density of the image is confirmed by trial printing and the print start key 105 is pressed after the number of prints is input by the ten key 109, the peeling fan 141 operates and the paper P is continuously fed from the paper supply unit 4. The printing operation is performed under the same conditions as the trial printing. Also at this time, the paper P on which the printed image is formed passes over the switching member 10, and is then peeled off from the master 66 on the outer peripheral surface of the plate cylinder by the air from the peeling claw and the peeling fan 141, and the paper discharge conveying means. The sheet is conveyed by 85 and discharged onto the sheet discharge tray 86. When the set number of prints (predetermined number) has been consumed, the printing drum 12 stops at the home position, and the duplex printing apparatus 1 enters the print standby state again. The operation of the peeling fan 141 is stopped when a predetermined time has elapsed from the start of rotation of the paper feed roller 68 and the separation roller 69 for feeding the last paper P.

  When the leading edge of the paper P is not detected by the paper sensor within a predetermined time counted by the timer of the control means 200, the control means 200 is located upstream of the registration roller pair 71 or the paper conveyance direction Xa. Then, it is determined that the paper P is in a staying state due to a jam or the like, and the solenoid 181 of the locking means 180 is turned off to keep the press roller 13 held at the non-printing position as shown in FIG. As a result, the press roller 13 occupies the printing position in spite of the absence of the paper P, so that the press roller 13 comes into contact with the one-side printing plate making image 66A in the plate making master 66 on the printing drum 12. It is possible to prevent the outer peripheral surface of the ink from being soiled with ink. At this time, the peeling fan 141 is also stopped, and unnecessary power consumption is prevented. Such a control operation is the same in a continuous paper feeding operation at the time of double-sided printing, and will not be described below. It should be noted that a sheet detection means corresponding to such a sheet sensor is placed on the conveyance path so as to detect the leading edge and trailing edge of the surface printed sheet that is held on the outer peripheral surface of the press roller 13 and conveyed to the printing nip N. It may be arranged.

  Next, the operation when performing duplex printing will be described. First, for example, a case where the double-sided printing apparatus 1 has a configuration that does not require a plate-making operation and there is no plate-printing operation will be described. The operator presses the duplex printing key 117 to set the duplex printing mode, and then confirms that the duplex printing mode is set by turning on the LED 117a. Next, the operator presses the print start key 105 after inputting the number of prints with the ten key 109. In the operation example of this embodiment, a case where N sheets are input as the number of prints will be described. Before and after this operation, the operator sets the paper P on the paper feed tray 67 and then presses the plate making start key 104. Then, a start signal is generated in the same way as in the single-sided printing mode, and this is input to the control means 200.

  As in the single-sided printing mode, a paper size detection signal and a document size detection signal are sent from the sensors 73 and 102 to the control unit 200, and the control unit 200 compares the input signals. In the present embodiment, since the maximum paper size that can be printed by the printing drum 12 during single-sided printing is A3 size, the paper size that can be used during double-sided printing is up to A4 landscape.

  As a result of comparing the document size and the paper size, if both sizes are the same, the image reading operation is immediately performed. If the two sizes are different, the control unit 200 displays a warning on the display device 120 as a warning. Call attention to the operator. When the paper size and the document size are different, a configuration in which enlargement or reduction is automatically performed by a command from the control unit 200 to match the document size and the image size, and the display device 120 reduces the size of the document or the size of the image data. It is good also as a structure which displays the procedure, such as rotation, and assists an operator's operation. When the paper size exceeds A4 landscape orientation, the control unit 200 displays on the display device 120 a message that prohibits double-sided printing and prompts single-sided printing.

  On the other hand, when the plate making start key 104 is pressed, it is determined in the printing pressure range variable means 55 whether or not the pressure release cam 43b for the first first print is selected. If the pressure release cam 43b is selected, that is, if the pressure release cam 43b occupies a position facing the cam follower 41, the process proceeds to the next process (the plate discharging process in step S3). When the pressure release cam 43b is not selected, the control means 200 controls the drive of the motor 53 of the printing pressure range varying means 55 while referring to the signal from the cam home position 54 to the cam follower 41 of each printing pressure arm 20. The slide member 51 is moved so that the contacting pressure release cam becomes the pressure release cam 43b. The control means 200 determines that the pressure release cam 43b occupies a position facing the cam follower 41 from the signal from the cam home position sensor 54 and the number of pulses (or the number of steps) supplied to the motor 53 (step S1). , Step S2 and step S7).

  In parallel with the switching operation to the pressure release cam 43b in the printing pressure range variable means 55 described above, first, the plate discharging operation in the plate discharging unit 5 is performed in the same manner as in the single-sided printing mode, and from the outer peripheral surface. The printing drum 12 from which the used master has been peeled is stopped at the plate feeding standby position, and the clamper 19 is opened by an opening / closing means (not shown). In parallel with this plate removal operation, the image reading unit 7 performs a document image reading operation. In the original image reading operation, the first original image for front side printing is read in the same manner as in the single-sided printing mode. Information relating to the read document image is stored in the image memory 135 as the first image data signal. When the reading operation of the first original image is completed and the image data signal is stored in the image memory 135, the control means 200 reads “Set the second original for back side printing on the display device 120. "Is displayed. The operator opens the pressure plate 94 in accordance with this display, removes the first original from the contact glass 93, places the second original, and closes the pressure plate 94 again. When a sensor (not shown) detects that the pressure plate 94 is closed and another sensor (not shown) detects that there is a document on the contact glass 93, two sheets for back side printing are printed in the same manner as the first page for front side printing. The reading operation of the eye original is performed. Information relating to the read document image is stored in the image memory 135 as a second image data signal.

  In this embodiment, the reading operation of the original image in the single-sided printing mode and the double-sided printing mode is configured such that the operator sets the original to be read on the contact glass 93 by opening and closing the pressure plate 94. A document may be automatically conveyed onto the contact glass 93 using a document feeder, or may be configured to take in image data from an external device (not shown). Further, in the duplex printing mode, one original may be reversed and conveyed, and image data for two sheets may be acquired from the front and back surfaces. As a configuration for capturing image data from an external device, for example, the duplex printing apparatus 1 and a personal computer (hereinafter referred to as “PC”) are connected via a signal line and a personal computer controller, etc., and created and output on a personal computer. An example of capturing the digital image data is given.

  In part with the reading operation of the original image in the image reading unit 7, the plate making unit 3 performs the plate making operation. The plate-making operation is performed in the same procedure as in the single-sided printing mode, but a front plate-making image 65A and a back-side plate-making image 65B as shown in FIG. At this time, the images 65A and 65B are formed between the front plate making image 65A and the back plate making image 65B so that a predetermined intermediate unmade region 65S is provided as shown in FIG. The predetermined intermediate plate making area 65S is provided at a position corresponding to the intermediate area 12S shown in FIG. 1 when the divided plate-making master 65 is wound on the outer peripheral surface of the printing drum 12.

  The divided master-making master 65 on which the images 65A and 65B are formed is stored in the master stock unit 61, and is released by the operation of the reversing roller pair 63 when the plate discharging operation is completed and the duplex printing apparatus 1 enters the plate feeding standby state. It is conveyed toward the clamper 19 that is being used. Thereafter, the printing drum 12 is intermittently rotated in the same manner as in the single-sided printing mode, and the divided plate-making master 65 is wound around the printing drum 12. When all the two pieces of image data are sent from the image memory 135, the cutting means 60 is activated and the divided master-making master 65 is cut. The cut master plate 65 is pulled out from the plate making unit 3 by the rotation of the printing drum 12, and the printing drum 12 is stopped at the home position to complete the plate making operation and the plate feeding operation. Although the description will be mixed, during the plate feeding operation as in the above-described single-sided printing mode, the solenoid 181 of the locking means 180 remains off and the press roller 13 is moved from the outer peripheral surface of the printing drum 12 to the non-printing position. (See step S3 to step S6).

  Next, in step S8, it is determined whether or not a printing operation is performed. In this operation example, the printing operation is not performed, and thus the process proceeds to step S9. After the printing drum 12 is stopped at the home position, when the printing drum 12 is driven to rotate in the direction R at the set printing speed, the peeling fan is activated in synchronization with the rotation of the printing drum 12 and the paper feeding is performed. The paper P is sent out from the paper feed tray 67 at a predetermined timing by the roller 68, and further, the paper P is separated one by one by the cooperative action of the separation roller 69 and the separation pad 70 toward the registration roller pair 71. The leading edge of the first sheet P1 is abutted against the nip portion of the registration roller pair 71 and stopped. This state is indicated by a sheet P3 in FIG. In FIG. 1, symbols P1, P2, and P3 represent the state of the paper P in the process of being fed or discharged during double-sided printing, and one sheet corresponding to the paper feed / discharge order of the paper P The second, third and third images are shown. When the clamper 19 passes the position corresponding to the switching member 10, the solenoid 123 is actuated to position the switching member 10 at the second position, and then the divided plate-making master 65 wound on the printing drum 12 is moved. When the driving roller 71a is rotationally driven at a predetermined timing when the leading edge of the image area 65A in the direction R reaches the position corresponding to the press roller 13, the drawn first sheet P1 is a printing drum. 12 and the press roller 13.

  Thus, the fact that the leading edge of the first sheet P is fed between the printing drum 12 and the press roller 13 is detected by the sheet sensor within a predetermined time counted by the timer of the control means 200. Then, the locking means 180 is actuated by a command from the control means 200. Thereby, the holding state in the non-printing position of the press roller 13 shown in FIG. 2 is released.

  At the predetermined timing, the pressure release cam 43b that has been moved to a position where it can come into contact with the cam follower 41 disengages its large diameter portion from the cam follower 41, and the press roller 13 rotates its circumference by the biasing force of the printing pressure spring 42. The surface is pressed against the outer peripheral surface of the printing drum 12. As a result, a printing nip portion N is formed between the outer peripheral surface of the printing drum 12 and the outer peripheral surface of the press roller 13, and the surface plate making of the press roller 13, the first sheet P 1, and the divided plate-making master 65. The image 65A forming portion and the printing drum 12 are pressed against each other, and the ink supplied to the inner peripheral surface of the printing drum 12 by the ink roller 16 oozes out from the opening of the printing drum 12 and is wound around the printing drum 12. Of the master plate 65, the mesh screen (not shown), and the porous support of the divided master plate master 65, and then transferred to the paper P1 through the perforated portion of the front plate master image 65A. Image formation / printing corresponding to the surface plate-making image 65A is performed, and the surface image is formed on the paper P1.

  At this time, the printing pressure range variable means 55 is switched to the “pressure release cam 43b for the first printing first sheet”, and the printing pressure range pattern I shown in FIG. 5 is selected as the printing pressure range. The portion corresponding to the backside plate-making image 65B is not image-formed, and the outer peripheral surface of the press roller 13 is not stained with ink.

  The surface-printed paper P1 on which the surface image corresponding to the surface plate-making image 65A has been printed on the surface thereof has been subjected to divided plate-making on the outer peripheral surface of the printing drum 12 from the leading edge of the switching member 10 and the blowing fan 141. While being peeled off from the master 65, it is guided to the paper re-feeding means 9 by the switching member 10 occupying the second position. The surface-printed paper P1 guided downward by the switching member 10 is guided through the guide plates 27 and 56 while abutting the front end thereof against the end fence 8a to land on the refeed tray 8. Placed. The surface-printed paper P1 transported onto the refeed tray 8 is transported in the direction of the arrow (right) in FIG. 1 while being held by the endless belt 38 by the suction force of the suction fan 39, and the leading edge (front plate-making image 65A). The rear end at the time of printing corresponding to is stopped by hitting the stopper portion 24a and placed in a standby state. At this time, since the suction force of the suction fan 39 is relatively weak as described above, slippage occurs between the surface-printed paper P1 and the endless belt 38 without causing paper buckling or bending due to excessive transport force. Then, the front surface printed paper P1 is stopped and waited with the front end thereof in contact with the stopper portion 24a (see Step S9 to Step S11).

  A sensor (not shown) that detects when the leading edge of the front surface printed paper P1 contacts the stopper portion 24a is provided. When the sensor (not illustrated) detects the leading edge of the front surface printed paper P1, the driving roller 36 and The operation of the suction fan 39 may be stopped. The front surface printed paper P2 in FIG. 1 shows a stationary state of the first front surface printed paper P1 whose front end abuts against the stopper portion 24a.

  The printing drum 12 continues to rotate while the front-side printed paper P1 is being guided onto the refeed tray 8, and the pressure release cam when the press roller 13 finishes contacting the surface area 12A of the printing drum 12. The large diameter portion 43b abuts on the cam follower 41 to occupy the non-printing position. By the action of the pressure release cam 43b, the back surface area 12B of the printing drum 12 and the press roller 13 do not come into pressure contact with each other in the absence of the paper P, and the ink is transferred to the outer peripheral surface of the press roller 13 as described above. Can be prevented.

  Here, after the locking means 180 is actuated to hold the press roller 13 in the non-printing position, the printing drum 12 is rotated at a low speed while resting on the paper feeding / printing operation, and the printing pressure range is variable in accordance with the timing. The means 55 is actuated to perform an operation of switching from the “pressure release cam 43b for the first first printing” to the “pressure release cam 43a for continuous duplex printing”. Specifically, by using the portion A of the pressure release cam 43b, the slide member 51 is moved at high speed so that the pressure release cam 43a faces the cam follower 41 by the rotational drive of the motor 53 (step S12 and step S12). (See S13).

  On the other hand, the solenoid 33 is actuated at a predetermined timing that is slightly earlier than the leading edge of the image area of the back-side plate-making image 65B in the direction R of the divided plate-making master 65 reaches the position corresponding to the press roller 13, FIG. 3 is swung in the clockwise direction in FIG. 3 about the support shaft 32a. As a result, the re-feeding registration roller 23 is swung from the separation position to the press-contacting position, so that one sheet is stopped / standby on the re-feeding tray 8 with its leading end in contact with the stopper portion 24a. As will be described later, the first front surface printed paper on the refeed tray 8 follows the rear end of the second paper P2 fed from the paper feeding unit 4 as will be described later. P1 is pushed up and brought into contact with the peripheral surface of the press roller 13 that is in pressure contact with the printing drum 12 and is driven to rotate away from the stopper portion 24a, and is driven to rotate at the same peripheral speed as the peripheral speed of the printing drum 12. After the transport force is applied to the downstream side in the rotational direction by the rotational force of the press roller 13, and the rear end and the intermediate region of the second surface printed paper P <b> 2 pass the position corresponding to the press roller 13. The printing drum 12 At the timing when the front end of the surface region 12B reaches a position corresponding to the press roller 13, the printing nip portion N is in close contact with the outer peripheral surface of the press roller 13 by the paper guide plate 31 and the rollers 28, 29, 30. It is conveyed to.

  In other words, the first surface-printed paper P1 has a position where the intermediate region 12S of the printing drum 12 faces the press roller 13 after the trailing edge of the second paper P2 has passed through the printing nip N. It passes through the printing nip N between the printing drum 12 and the press roller 13 at a timing when the rear surface region 12B passes through and faces the press roller 13. At this time, since the printing pressure range is selected and set by the press roller 13 by the “pressure releasing cam 43a for continuous double-sided printing”, the printing pressure range can be brought into contact with the cam follower 41 at a predetermined timing. The pressure release cam 43a that has been moved to a certain position has its large diameter portion separated from the cam follower 41, and the press roller 13 presses the peripheral surface thereof against the outer peripheral surface of the printing drum 12 by the biasing force of the printing pressure spring 42. A printing nip portion N is formed between the outer peripheral surface of the printing drum 12 and the outer peripheral surface of the press roller 13.

  Further, at this time, an image corresponding to the surface plate-making image 65A is printed on the surface of the first surface-printed paper P1, but the paper P1 is moved to the outer periphery of the press roller 13 by the function of the refeed guide member 22. Since the sheet P1 is in close contact with the surface, the paper P1 once in contact with the outer peripheral surface of the press roller 13 is not displaced, and the occurrence of problems such as rubbing dirt or thickening of the image line is prevented.

  The first surface-printed paper P1 passes through a refeed reverse path formed by the refeed means 9, the press roller 13, the refeed resist roller 23, the rollers 28, 29, and 30, and the paper guide plate 31. It is reversed by being conveyed. Therefore, the first surface-printed paper P1 is in an inverted state, that is, the printed image forming surface of the first surface-printed paper P1 is the back surface (lower surface), and the front surface (upper surface) is the unprinted surface. In this state, it is fed into a printing nip N between the printing drum 12 and the press roller 13.

  As a result, the press roller 13, the front surface of the first surface-printed paper P1, the back plate-making image 65B forming part of the divided plate-making master 65, and the printing drum 12 are pressed against each other, and the inner periphery of the printing drum 12 is formed by the ink roller 16. The ink supplied to the front surface is transferred to the front surface of the first front surface printed paper P1 through the opening of the printing drum 12 and the perforated portion of the rear surface plate-making image 65B, and the back surface plate-making of the divided plate-making master 65. Printing corresponding to the image 65B, that is, a back side printed image (hereinafter simply referred to as “back side image”) is formed, and double sided printing is performed.

  In this way, as shown in FIG. 5, the press roller 13 causes the second sheet P2 and the first surface printed sheet P1 conveyed continuously to the rear end of the sheet P2 to be printed on the printing drum 12. By continuously pressing the front plate making image 65A and the back plate making image 65B in the divided plate making master 65, image formation / printing corresponding to the front plate making image 65A is performed on the second sheet P2. Image formation / printing corresponding to the back plate making image 65B is performed on the front surface (the upper surface which is an unprinted surface and corresponding to the back surface before being reversed) of the first front surface printed paper P1.

  Although the description is mixed, the feeding operation of the second sheet P2 is performed as follows. That is, the paper feed roller 68 and the separation roller 69 are driven, the second sheet P2 for normal duplex printing is drawn from the paper feed tray 67, and the front end of the paper P2 is brought into contact with the nip portion of the registration roller pair 71 and stopped. The Then, the driving roller 71a is rotationally driven at the same timing as that of the first sheet P1, and the drawn sheet P2 is fed between the printing drum 12 and the press roller 13. The switching member 10 is positioned at the first position so as to avoid a collision with the clamper 19, and then is positioned again at the second position after passing the clamper 19.

  Thus, the fact that the leading edge of the second sheet P is fed between the printing drum 12 and the press roller 13 is detected by the sheet sensor within a predetermined time counted by the timer of the control means 200. Then, the locking means 180 is actuated by a command from the control means 200. Thereby, the holding state in the non-printing position of the press roller 13 shown in FIG. 2 is released.

  The second sheet P2 is subjected to the detailed operation described above, and after image formation / printing corresponding to the front plate-making image 65A is performed, the printing drum is blown by blowing from the switching member 10 and the peeling fan 141 that occupy the second position. 12 is peeled and guided from the divided master-making master 65 on 12, and is conveyed onto the refeed tray 8. During the above-described operation, the switching member 10 is displaced from the second position to the first position by operating the solenoid 123 immediately before the intermediate region 12S of the printing drum 12 occupies the position facing the press roller 13. . As a result, the rear end of the second surface-printed paper P2 guided by the switching member 10 passes through a slight gap between the lower surface 10a of the switching member 10 and the outer peripheral surface of the press roller 13. When guided on the paper feed tray 8, the front image corresponding to the front plate-making image 65A conveyed next to the rear end of the paper P2 is provided on the back surface, and the back image corresponding to the back plate-making image 65B is provided on the front surface. The leading end of the printed first double-sided printed paper P1 is guided to the paper discharge conveying means 85 along the upper surface 10b of the switching member 10, and is blown from the leading end portion by the air blow from the peeling claw 84 and the peeling fan 141. It is peeled off from the divided plate-making master 65 on the outer peripheral surface of the printing drum 12. The first double-side printed paper P1 is peeled off from the divided plate-making master 65 by air blow from the peeling claw 84 and the peeling fan 141, and then is moved and rotated in the direction of the arrow in FIG. It is sucked and held on 89 and conveyed, and is discharged onto a discharge tray 86. In FIG. 1, a first double-sided printed paper P1 indicated by reference numeral P1 is in a state where the first double-sided printed paper P1 is attracted and held on the endless belt 89 and conveyed. Represents the state of being discharged and stacked on the discharge tray 86, respectively.

  Hereinafter, both the third sheet P3 fed from the sheet feeding unit 4 and the fourth sheet P4 or the (N-1) th sheet P (N-1) are printed on both sides as described above. The operation is continuously performed (see step S14 to step S19).

  The last N sheets PN of the predetermined number N, which is the number of prints set with the numeric keypad 109, is fed from the sheet feeding unit 4, and the surface image corresponding to the surface plate-making image 65A is printed on the surface and printed again. It is guided and conveyed onto the paper feed tray 8. On the other hand, the (N−1) -th surface printed paper P (N−1) waiting on the refeed tray 8 is reversed and re-fed toward the print nip portion N as described above. Then, the back side image corresponding to the back side plate-making image 65B is printed on the front side and printed on both sides, and then discharged onto the paper discharge tray 86. Immediately after this, the locking means 180 is activated and the press roller 13 is held in the non-printing position. At the same time, the printing drum 12 pauses the paper feeding / printing operation and also re-feeds / transports from the paper refeeding tray 8 and rotates at a low speed. The means 55 is operated to perform an operation of switching from the “pressure releasing cam 43a for continuous duplex printing” to the “pressure releasing cam 43c for the first sheet at the end of printing”. Specifically, by using the portion B of the pressure release cam 43a, the slide member 51 is moved at high speed so that the pressure release cam 43c faces the cam follower 41 by the rotational drive of the motor 53 (step S20 to step S20). (See S22). At this time, the switching member 10 occupies the first position.

  Then, the pressure release cam 43c moved to a position where it can come into contact with the cam follower 41 at an earlier timing than the front end of the image area of the back plate making image 65B in the divided plate making master 65 reaches the position corresponding to the press roller 13. The large diameter portion is separated from the cam follower 41, and the press roller 13 presses the peripheral surface thereof against the outer peripheral surface of the printing drum 12 by the urging force of the printing pressure spring 42. Thereafter, the solenoid 33 is actuated at a slightly earlier timing than the leading edge of the image area of the back plate making image 65B in the divided plate making master 65 reaches the position corresponding to the press roller 13, and the swing arm 32 is centered on the support shaft 32a. 2 is swung clockwise in FIG. As a result, the re-feeding registration roller 23 is swung from the separation position to the press-contact position, and the last printed surface sheet PN that has been stopped in a state where the leading end is in contact with the stopper portion 24 a contacts the printing drum 12. The press roller 13 is in contact with the outer peripheral surface of the press roller 13 that is driven and rotated.

  The last printed sheet PN at the end of printing is sent to the printing nip portion N between the printing drum 12 and the press roller 13 at the same timing as the sheet P1, and the back surface (unprinted surface) corresponding to the back plate-making image 65B. The image is printed. The double-side printed paper PN on which the front image and the back image are formed is guided to the paper discharge conveying means 85 along the upper surface 10b of the switching member 10, and the divided pre-made master 65 is blown by the air from the peeling claw 84 and the peeling fan 141. After being further peeled off, the paper is transported by the paper discharge transport means 85 and discharged onto the paper discharge tray 86. After that, the press roller 13 occupies the non-printing position by the large diameter portion of the pressure release cam 43c coming into contact with the cam follower 41 when the contact with the back surface region 12B of the printing drum 12 is finished. As described above, the printing pressure range is switched to the pressure release cam 43c for the first sheet at the end of printing, and the printing pressure range pattern II is selected. The surface region 12A and the press roller 13 are not pressed against each other, a surface image corresponding to the surface plate-making image 65A is not formed, and the outer peripheral surface of the press roller 13 is not stained with ink. At this time, the locking means 180 is activated and the press roller 13 is held in the non-printing position, and then the printing drum 12 is stopped at the home position, and the duplex printing apparatus 1 finishes a predetermined number of job printing operations. Then, the print standby state is entered again (see step S23 to step S25). The operation of the peeling fan 141 is stopped when a predetermined time elapses from the start of rotation of the paper feed roller 68 and the separation roller 69 for feeding the last printed surface PN.

  Here, the peelability from the master 64 of the paper P pressed by the master 64 wound around the printing drum 12 is lower toward the upstream side in the direction R near the printing nip portion N. Therefore, in the switching member 10 and the peeling claw 84, the switching member 10 is more disadvantageous for peeling.

  Therefore, the strength of the air blown by the peeling fan 141 is different depending on whether the peeling member performing the peeling operation is the switching member 10 or the peeling claw 84, and the direction R of the switching member 10 and the peeling claw 84 is different. The strength of the air blow when performing the peeling operation with the switching member 10 located on the upstream side in FIG. 6 is stronger than the strength of the air blowing when performing the peeling operation with the peeling claw 84 located on the downstream side in the direction R. Increase air volume. Thereby, the peeling operation | movement by the switching member 10 disadvantageous to peeling is performed favorably. Hereinafter, for convenience of explanation, the strength of the air blow when the peeling operation is performed with the peeling claw 84 is referred to as a first strength, and the strength of the air blow when the peeling operation is performed with the switching member 10 is referred to as a second strength.

In this way, the amount of air blown by the peeling fan 141 is switched at the time of double-sided printing in which the switching member 10 and the peeling claw 84 are sequentially switched for peeling of the paper P, and at the time of single-sided printing, the paper P is peeled off. Since only the peeling claw 84 is used, the strength of the blowing is maintained at the first strength.
Accordingly, the sheet peeling apparatus 150 performs a peeling operation on the master-making master 66 on which one plate-making image is formed along the direction R, and the peeling mode in which the strength of the air blow is constant at the first strength and the direction R. And a peeling mode in which the strength of the air blowing is switched between the first strength and the second strength. When the former mode is the first peeling mode and the latter mode is the second peeling mode, the first peeling mode is a mode used for single-sided printing, and the second peeling mode is a mode used for double-sided printing. It has become. The timing of switching the air flow rate is the timing when the solenoid 123 is energized in order to selectively position the switching member 10 between the first position and the second position. As a result, the strength of the air blowing is set as required, so that the energy required for driving the peeling fan 141 is suppressed and the noise generated by the air blowing is suppressed while ensuring the peeling performance of the paper P. .

  However, in double-sided printing, in addition to the switching member 10 among the switching member 10 and the peeling claw 84, which are a plurality of peeling members, the switching member 10 located upstream in the direction R is used for the peeling operation. The mode may be a mode in which the strength of the air blowing is maintained at the second strength. In this case, the strength of the airflow is maintained at the first strength during single-sided printing, and the strength of the airflow is maintained at the second strength during double-sided printing. In this way, there is an advantage that the control is simplified, and it is effective when there is a delay in the responsiveness of the peeling operation by switching the air flow rate.

  In addition, since each configuration is densely arranged around the printing nip portion N, in the present embodiment, the disposition position of the air blowing means 140 is a position farther from the printing nip portion N than the switching member 10 and the peeling claw 84. Among the switching member 10 and the peeling claw 84, air is blown from the downstream side in the direction R further than the peeling position of the paper P by the peeling claw 84 located on the downstream side in the direction R. Therefore, the separation operation by blowing is less likely to act at the separation position of the paper P by the switching member 10 located on the upstream side in the direction R among the switching member 10 and the separation claw 84. Therefore, increasing the amount of blown air when performing the peeling operation with the switching member 10 is also suitable for increasing the amount of blown air on the side where the peeling operation by blowing is less likely to act, and making the peeling operation more reliable.

  Next, when the plate printing is first performed after the plate-making and feeding, and when the operation is temporarily stopped and image confirmation is performed, or when only one test printing is performed, the above-described normal duplex printing operation is performed. The following operations and controls are performed which are slightly different (see step S8 yes to step S33).

  The first printing sheet P1 printed from the sheet feeding unit 4 (hereinafter sometimes simply referred to as “sheet P1”) is the same as the first sheet feeding operation in the normal duplex printing. In the non-printing position of the press roller 13 by the positioning operation of the switching member 10 to the second position and the operation of the locking means 180 when the clamper 19 passes the position corresponding to the switching member 10. After the operation of releasing the holding state, the driving roller 71a is moved at a predetermined timing when the leading edge of the image area 65A of the surface prepress image 65A in the divided prepress master 65 on the printing drum 12 reaches a position corresponding to the press roller 13. By being driven to rotate, the first sheet P1 is fed between the printing drum 12 and the press roller 13.

  At this time, the printing pressure range variable means 55 has already been switched to the pressure release cam 43b for the first sheet for printing, and the printing pressure range pattern I shown in FIG. 5 is selected. At a predetermined timing, the pressure release cam 43b that has been moved to a position where it can come into contact with the cam follower 41 disengages its large diameter portion from the cam follower 41, and the press roller 13 has its peripheral surface by the biasing force of the printing pressure spring 42. Is brought into pressure contact with the outer peripheral surface of the printing drum 12. As a result, a printing nip portion N is formed between the outer peripheral surface of the printing drum 12 and the outer peripheral surface of the press roller 13, and the surface plate making of the press roller 13, the first sheet P 1, and the divided plate-making master 65. When the image 65A forming portion and the printing drum 12 are pressed against each other, the ink supplied to the inner peripheral surface of the printing drum 12 by the ink roller 16 oozes out from the opening of the printing drum 12 and is wound around the printing drum 12. The plate cylinder (not shown), the mesh screen (not shown), and the porous support of the divided plate-making master 65 are filled, and then transferred to the paper P1 through the perforated portion of the surface plate-making image 65A to correspond to the surface plate-making image 65A. The image formation / printing of the portion is performed.

  At this time, as described above, since the printing pressure range pattern I shown in FIG. 5 is selected as the printing pressure range, the portion corresponding to the back plate-making image 65B is not imaged, and the outer peripheral surface of the press roller 13 is the ink. It will not get dirty.

  The surface-printed paper P1 on which the surface image corresponding to the surface plate-making image 65A is printed is guided to the re-feeding means 9 by the same detailed operation as described above by the switching member 10 and the peeling fan 141. The surface-printed paper P1 guided downward by the switching member 10 is landed and placed on the refeed tray 8 by the same detailed operation as described above, and further, as described above by the refeed transport means 25. With this detailed operation, the front end (the rear end at the time of printing corresponding to the front plate-making image 65A) abuts against the stopper portion 24a and is stopped and positioned (see step S26 to step S28).

  Here, after the locking means 180 is actuated to hold the press roller 13 in the non-printing position, the printing drum 12 is rotated at a low speed while resting on the paper feeding / printing operation, and the printing pressure range is variable in accordance with the timing. The means 55 is actuated to perform an operation of switching from “the first pressure canceling cam 43b for the first sheet” to “the last pressure canceling cam 43c for the first sheet” (see Step S29 and Step S30).

  Next, the solenoid 33 is actuated at a predetermined timing sent to the printing nip portion N without performing the sheet feeding operation of the second sheet P2 from the sheet feeding unit 4, so that it is temporarily placed on the refeed tray 8. The front-side printed paper P1 that is on standby undergoes the same detailed operation as described above, and the outer surface of the printing drum 12 and the outer surface of the press roller 13 are reversed while being turned upside down by the rotational force of the press roller 13 at the same timing. It is transported between. At this time, as the printing pressure range, the printing pressure range pattern II by the press roller 13 is selected by the “pressure release cam 43c for the first sheet at the end of printing”, and therefore, the printing pressure range can be brought into contact with the cam follower 41 at a predetermined timing. The pressure release cam 43c moved to the position disengages its large diameter portion from the cam follower 41, and the press roller 13 presses the peripheral surface thereof against the outer peripheral surface of the printing drum 12 by the biasing force of the printing spring 42. As a result, a printing nip portion N is formed between the outer peripheral surface of the printing drum 12 and the outer peripheral surface of the press roller 13, and the surface (the non-surface image forming surface of the press roller 13 and the surface printed paper P1) The ink supplied to the inner peripheral surface of the printing drum 12 by the ink roller 16 by the press contact between the rear plate-making image 65 </ b> B forming portion of the divided plate-making master 65 and the printing drum 12. Are transferred to the front-side printed paper P1 through the same detailed operation as described above, and image formation / printing of a portion corresponding to the backside plate-making image 65B is performed. At this time, the switching member 10 occupies the first position as described above. Thus, the double-sided printed paper P1 having the back side image corresponding to the back side plate-making image 65B printed on its front side (upper side) is guided to the paper discharge conveying means 85 along the upper side 10b of the switching member 10, and the peeling claw 84 and After being peeled off from the divided master-making master 65 by air blow from the peeling fan 141, it is transported by the paper discharge transport means 85 and discharged onto the paper discharge tray 86. This double-sided printed paper P1 becomes a printing material.

  As described above, since the pressure release cam 43c for the first sheet at the end of printing is selected as the printing pressure range, the surface region 12A of the printing drum 12 and the press roller 13 are in pressure contact with each other in the absence of the paper P. In other words, a surface print image corresponding to the surface plate-making image 65A is not formed, and the outer peripheral surface of the press roller 13 is not stained with ink or the like (see Steps S31 to S33).

  Thereafter, the printing drum 12 further rotates at a low speed, and the printing pressure range varying means 55 is operated at the same time, and the printing pressure range is changed from the “pressure release cam 43c for the first sheet at the end of printing” to “continuous”. When switching to the “pressure releasing cam 43a for double-sided printing”, the printing pressure range pattern III is selected and set, and when performing continuous double-sided printing similar to the above, the process proceeds to step S9, where trial printing or the like is performed. For example, the instruction waits in step S35 (see step S34).

  According to such a printing operation or trial printing operation in the double-sided printing mode, only one printed matter printed on both sides can be discharged to the paper discharge tray 86 of the paper discharge unit 6, In this case, there is no need to make a useless printed material in which only a single-sided image is printed in printing and trial printing, and the outer peripheral surface of the press roller 13 is not stained with ink. .

  Here, if the intensity of the air blown by the peeling fan 141 during the printing operation is maintained at the second strength while the switching member 10 occupies the second position, FIG. As already described with reference, the master 64 may be wrinkled with respect to the printing drum 12.

  That is, in the double-sided printing apparatus 1, with reference to FIG. 12, during double-sided printing, the plate making operation of the part corresponding to the surface plate-making image 65 A of the divided plate-making master 65 is performed in the first rotation of the printing drum 12. After the printing pressure by the press roller 13 is released, the printing pressure by the press roller 13 in the third rotation of the printing drum 12 that performs the printing operation of the portion corresponding to the backside plate-making image 65B of the divided plate-making master 65 is changed. Before the start, the part corresponding to the back side plate making image 65B of the divided plate making master 65, that is, the part not subjected to plate printing, receives air blown by the peeling fan 141 with the rotation in the direction R. Go through the area.

  Therefore, at the time of this passage, the portion of the divided plate-made master 65 corresponding to the back-side plate-making image 65B that has not been subjected to printing, that is, the portion that is not yet in close contact with the printing drum 12 is blown by blowing. In this state, the divided master-making master 65 sticks to the viscous printing drum 12, specifically, the surface of the mesh screen due to adhesion of ink.

  If the divided plate-making master 65 is stuck in such a state, the divided plate-making master 65 is pressed against the printing drum 12 by the press roller 13 in a state in which the divided plate-making master 65 is disturbed in the subsequent printing. If printing is performed in a state of being wound around the drum 12, an abnormal image is repeatedly printed especially on the back image.

  Therefore, the air blown toward the printing drum 12, and the strength of the air blown by the blowing means 140 on the portion of the divided master-making master 65 that has not been subjected to printing, i.e., the portion not pressed against the printing drum 12, is: Control is performed so as to be weaker than the intensity of air blowing by the air blowing means 140 on the part of the divided master-making master 65 where the printing is performed, that is, the part pressed against the printing drum 12. As a result, the strength of the air blowing is set as needed, so that the energy required for driving the peeling fan 141 is suppressed while the separation performance of the paper P is secured, and the noise generated by the air blowing is suppressed, Also, the printing is performed well.

  When performing the printing operation of the portion corresponding to the surface plate-making image 65A of the divided plate-making master 65, it is the switching member 10 that peels the paper P from the divided plate-making master 65, and the strength of the air blowing is the second. Since it is strength, the strength of the air blow to the unpressed portion of the divided master-making master 65 is made weaker than the second strength. If the strength of the blast in this case is the third strength, the third strength is not only weaker than the second strength, but also weaker than the first strength, and the disturbance of the divided master-making master 65 is suppressed as much as possible. It is like that. In FIG. 12, “Strong” corresponds to the second strength, “Medium” corresponds to the first strength, and “Weak” corresponds to the third strength of the peeling fan air flow.

  The timing for switching from “strong” to “weak” and the timing for switching from “strong” to “medium” are both when the press roller 13 is released from holding the surface of the printing drum 12. This is the timing at which separation starts from the portion corresponding to the image 65A, and this timing is measured by a timer based on the timing at which the dog 133 is detected by the home position sensor 134. If the printing pressure range pattern can be switched, the second rotation of the printing drum may not be idle.

  However, if the advantages of the above-mentioned plate printing are not so much desired, the printing range pattern III shown in FIG. 5 is selected and set in the same manner as in the normal single-side printing operation. A printing operation may be performed, and in this case, it is not necessary to control the strength of the air blowing.

  In the above description, the duplex printing apparatus 1 performs printing using the divided master making master 65 when performing duplex printing. However, the duplex printing apparatus 1 uses the split master making master 65 to perform high-speed printing. You may have the mode which performs. In the high-speed printing mode, printing is performed on a plurality of sheets P for each rotation of the printing drum 12. The number of sheets P is two corresponding to the number of images to be made on the divided master-making master 65. In the high-speed printing mode, printing with the front plate-making image 65A and printing with the back-side plate-making image 65B are alternately performed. Therefore, in consideration of the case where the front side plate-making image 65A and the back side plate-making image 65B are different from each other, it is assumed that the double-sided printing apparatus 1 has two paper discharge paths. One of these systems has a peeling claw 84, a paper discharge conveying means 85, a paper discharge tray 86, etc., and the other system can have the same configuration as the one system. It is. The peeling member provided in the other system is a second peeling claw (not shown) having the same configuration as that of the peeling claw 84, and in the direction R, on the downstream side of the peeling claw 84, from the divided master plate 65 to the sheet P Shall be peeled off.

  As described above, the double-sided printing apparatus 1 uses a sheet peeling apparatus including a plurality of peeling members 84 and the second peeling claws in the high-speed printing mode. Incidentally, in correspondence with having two systems of paper discharge paths, two systems of paper feed paths up to the registration roller pair 71 may be provided. In this case, the configuration of the other system up to the registration roller pair 71 can be the same as the configuration of the paper feed tray 67, the paper feed roller 68, the separation roller 69, and the separation pad 70. In contrast to the high-speed printing mode, a mode in which printing is performed on one sheet of paper P per rotation of the printing drum 12 using the master-making master 66 is referred to as a normal printing mode. In the normal printing mode, a peeling operation using any one of the peeling claw 84 and the second peeling claw is performed. The operation panel 103 is provided with a configuration for selecting a high-speed print mode such as a high-speed print mode key (not shown), and the control unit 200 recognizes whether the high-speed print mode or the normal print mode is selected. And

  In the above-described embodiment, the first peeling mode in which the peeling operation is performed with the peeling claw 84 that is one peeling member for the plate-making master 66 on which the single-side plate-making image 66A that is one plate-making image is formed along the direction R is , A peeling nail 84 that is a mode used for single-sided printing and is a plurality of peeling members for the divided plate-making master 65 in which a front plate-making image 65A and a back-side plate-making image 65B are formed along the direction R. The second peeling mode in which the second peeling nail sequentially performs the peeling operation is a mode used for double-sided printing. When the double-sided printing mode is provided, the double-sided printing mode is also a mode corresponding to the second peeling mode. Become.

  The strength of the air blow by the air blowing means 140 is when the peeling operation is performed by the peeling claw 84 positioned upstream in the direction R among the peeling claw 84 and the second peeling claw used in the normal printing mode and the duplex printing mode. Increase the strength of. The strength of the air blow when performing the peeling operation with the peeling claw 84 is the second strength as described above, but the strength of the air blowing when performing the peeling operation with the second peeling claw is the fourth strength. Then, the fourth strength is weaker than the second strength. As a result, the strength of the air blowing is set as required, so that the energy required for driving the peeling fan 141 is suppressed and the noise generated by the air blowing is suppressed while ensuring the peeling performance of the paper P. . The fourth strength is stronger than the third strength.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments. Unless specifically limited in the above description, the present invention described in the claims is not limited. Various modifications and changes are possible within the scope of the gist.

  For example, in the above-described embodiment, the paper peeling device is used in a printing device capable of double-sided printing, but the paper peeling device according to the present invention can also be applied to a printing device capable of only single-sided printing. . In this case, the refeed unit 9 and the like are omitted, and the configuration of the printing apparatus is simplified. However, a plurality of peeling members are provided, such as a printing apparatus having a high-speed printing mode.

  If there are a plurality of peeling members, the number is not limited to the above-mentioned number, and is determined according to, for example, the maximum number of images made on the stencil sheet wound around the plate cylinder. The maximum number of images is not limited to two and may be three or more. The strength of the air blow by the air blowing means is preferably stronger as the peeling member that performs the paper peeling operation is located upstream in the rotation direction of the plate cylinder, but at least the peeling member that is at the most upstream in the rotation direction of the plate cylinder It is sufficient that the strength of the air blow when performing the sheet peeling operation is stronger than the strength of the air blowing when the peeling member located on the most downstream side in the rotation direction of the plate cylinder performs the sheet peeling operation.

  When there are a plurality of plate-making images wound around the plate cylinder, printing is started from the plate-making image on the upstream side in the direction R instead of starting from the plate-making image on the downstream side in the direction R as described above. You may do it.

  The structure which has a pump for performing ventilation may be sufficient as a ventilation means. In the high-speed printing mode, the rotational speed of the plate cylinder may be made faster than that in the normal printing mode, such as double the normal printing mode.

  The printing apparatus may be provided with a plurality of plate cylinders, or may perform color printing using a plurality of plate cylinders, for example. The pressing means may be an impression cylinder instead of a press roller.

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

1 is a front view showing an outline of a printing apparatus to which the present invention is applied. FIG. 2 is a partial cross-sectional front view showing a press roller separated from the outer peripheral surface of a plate cylinder in the printing apparatus shown in FIG. 1. It is a partial cross section front view which shows the press roller which contacted the plate cylinder outer peripheral surface in the printing apparatus shown in FIG. It is a schematic front view for demonstrating the shape of the pressure release cam used for the printing apparatus shown in FIG. 1, and those phase relationships. FIG. 2 is a diagram for developing and explaining three printing pressure range patterns that are applied corresponding to a divided master-making master on a printing drum used in the printing apparatus shown in FIG. 1. FIG. 5 is a partial cross-sectional side view of the main part of the printing pressure range varying means used in the printing apparatus shown in FIG. 1 when the pressure release cam shown in FIG. 4 is viewed from the right side. FIG. 2 is a plan view of a divided master making master used in the printing apparatus shown in FIG. 1. FIG. 2 is a plan view of a master for making a plate used in the printing apparatus shown in FIG. 1. It is a top view of the operation panel used for the printing apparatus shown in FIG. FIG. 2 is a block diagram illustrating a control unit provided in the printing apparatus illustrated in FIG. 1 and a part of a configuration controlled thereby. 3 is a flowchart illustrating an operation sequence of the printing apparatus illustrated in FIG. 1. FIG. 2 is a timing chart showing the intensity of air blowing by the air blowing means provided in the printing apparatus shown in FIG. 1 and the timing of the change. It is a schematic front view which shows that the malfunction has arisen in the stencil paper wound by the plate cylinder in the conventional printing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing apparatus 10, 84 Peeling member 12 Plate cylinder 64, 65, 66 Stencil base paper 140 Blowing means 150 Paper peeling apparatus P, P1, P1 ', P2, P3 Paper R Direction of rotation of plate cylinder

Claims (10)

A paper peeling device that performs a peeling operation for peeling a paper pressed by a stencil sheet wound around a rotating plate cylinder from the stencil sheet,
A plurality of strip members disposed along the rotational direction of the plate cylinder, and a stripping member that performs the stripping operation by entering between the stencil sheet and the paper;
In a sheet peeling apparatus having a blowing means for blowing air toward the plate cylinder in order to perform the peeling operation,
A paper peeling device that increases the strength of the air blow by the blower when the peeling operation is performed by the peeling member positioned upstream in the rotation direction among the plurality of peeling members. The sheet peeling apparatus according to claim 1,
The paper peeling is characterized in that the strength of air blown by the air blowing means is weakened against the portion of the stencil sheet not pressed against the plate cylinder rather than the strength against the portion pressed against the plate cylinder. apparatus. The sheet peeling apparatus according to claim 1 or 2,
A first peeling mode for performing the peeling operation on the stencil sheet on which one plate-making image is formed along the rotation direction, and a plurality of the stencil sheets on which a plurality of plate-making images are formed along the rotation direction. And a second peeling mode in which the peeling operation is performed by sequentially using the peeling members. In the paper peeling apparatus according to claim 3,
A sheet peeling apparatus, wherein the first peeling mode is a mode used for single-sided printing, and the second peeling mode is a mode used for double-sided printing. In the paper peeling apparatus according to claim 3 or 4,
The first peeling mode is a mode used for normal printing in which printing is performed on one sheet per rotation of the plate cylinder, and the second peeling mode is performed on a plurality of sheets per rotation of the plate cylinder. A sheet peeling apparatus characterized by being in a mode used for high-speed printing for printing. A paper peeling device that performs a peeling operation for peeling a paper pressed by a stencil sheet wound around a rotating plate cylinder from the stencil sheet,
A plurality of strip members disposed along the rotational direction of the plate cylinder, and a stripping member that performs the stripping operation by entering between the stencil sheet and the paper;
In a sheet peeling apparatus having a blowing means for blowing air toward the plate cylinder in order to perform the peeling operation,
When the peeling operation is performed on the stencil sheet on which a plurality of plate-making images are formed along the rotation direction, the strength of the air blown by the blowing unit is set to the strength of the stencil sheet against the portion of the stencil sheet that has been pressed against the plate cylinder. A sheet peeling device that weakens the strength of the plate cylinder against the unpressed portion. A paper peeling method for performing a peeling operation for peeling the paper pressed by the stencil paper wound around the rotating plate cylinder from the stencil paper,
A plurality of strip members disposed along the rotational direction of the plate cylinder, and a stripping member that performs the stripping operation by entering between the stencil sheet and the paper;
In a paper peeling method using air blowing means for blowing air toward the plate cylinder to perform the peeling operation,
A paper peeling method in which the strength of air blown by the blower is increased as the peeling member performing the peeling operation is positioned upstream in the rotation direction. A paper peeling method for performing a peeling operation for peeling the paper pressed by the stencil paper wound around the rotating plate cylinder from the stencil paper,
A plurality of strip members disposed along the rotational direction of the plate cylinder, and a stripping member that performs the stripping operation by entering between the stencil sheet and the paper;
In a paper peeling method using air blowing means for blowing air toward the plate cylinder to perform the peeling operation,
When the peeling operation is performed on the stencil sheet on which a plurality of plate-making images are formed along the rotation direction, the strength of the air blown by the blowing unit is set to the strength of the stencil sheet against the portion of the stencil sheet that has been pressed against the plate cylinder. A sheet peeling method that weakens the strength of a portion that is not pressed against the plate cylinder.   A printing apparatus using the paper peeling apparatus according to claim 1 or the paper peeling method according to claim 7 or 8.   A printing method using the paper peeling device according to any one of claims 1 to 6, the paper peeling method according to claim 7 or 8, or the printing device according to claim 9.

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