JP5044842B2 - Abutting member, printing apparatus and printing method - Google Patents

Description

  The present invention relates to a configuration for avoiding a sheet such as a sheet from being wound around a pressing body such as a press roller, a printing apparatus having the structure, and a printing method using the printing apparatus.

  Conventionally, as described in [Patent Document 1], it has a pressing body such as a press roller for pressing the sheet against the stencil sheet on the plate cylinder, and the sheet is pressed against the stencil sheet by the pressing body. At this time, there is known a printing apparatus that performs printing by attaching ink oozed from a stencil sheet to a sheet.

JP 2003-200355 A

  However, such a printing apparatus has a problem that the sheet pressed against the stencil sheet on the plate cylinder by the pressing body is caught in the pressing body and the sheet is jammed or clogged.

  Such a problem is, for example, as described in [Patent Document 1], a peeling claw that enters between a stencil sheet on a plate cylinder and a sheet pressed against the stencil sheet and peels the sheet from the stencil sheet. It is likely to occur in an apparatus provided with a means called a peeling fan that blows air between a stencil sheet on a plate cylinder and a sheet pressed against the stencil sheet to release the sheet from the stencil sheet. . This is because the sheet peeled from the stencil sheet may be caught in the pressing body.

  The peeling claw and the peeling fan are attached to the stencil sheet on the plate cylinder by the ink leached from the stencil sheet toward the sheet, and the sheet from the stencil sheet It is provided in order to cope with the problem of roll-up in which the sheet is not peeled off and the sheet is not discharged out of the printing apparatus.

  As such a printing apparatus, a printing apparatus capable of performing double-sided printing is known. Such a double-sided printing apparatus includes a plurality of plate cylinders and pressing bodies, and enables double-sided printing by printing on each surface of the sheet at the facing portion between each plate cylinder and the pressing body. In addition, as described in [Patent Document 1], after printing is performed on one side of the sheet at the facing portion between the plate cylinder and the pressing body, the sheet is reversed and conveyed to the same facing portion. One having a sheet feeding means is known.

  In these double-sided printing apparatuses, the above-mentioned problem occurs at each facing portion, but in the latter double-sided printing apparatus, such a problem is particularly likely to occur. Although it is also described in [Patent Document 1], a double-sided printing apparatus having a refeeding unit generally has the above-described peeling claw and peeling fan for guiding a sheet printed on one side to the refeeding unit. In addition, a guide member is provided, and the sheet guided to the sheet re-feeding unit by the guide member may be caught in the pressing body.

  The direction in which the sheet is guided by the guide member is closer to the position where the pressing body is disposed than the direction in which the sheet is guided by the peeling claw or the peeling fan. This is more likely to occur than the roll-up of the sheet discharged out of the printing apparatus by the peeling fan.

  An object of the present invention is to provide a configuration for preventing or suppressing a sheet such as a sheet from being wound around a pressing body such as a press roller, a printing apparatus having the structure, and a printing method using the printing apparatus.

In order to achieve the above object, the invention described in claim 1 is characterized in that when the pressing body for pressing the sheet against the stencil sheet on the plate cylinder presses the sheet against the stencil sheet on the plate cylinder, A flexible member that comes into contact with the pressing body on the downstream side of the facing portion between the pressing body and the plate cylinder in the sheet conveyance direction so as to prohibit the sheet from entering between them . A contact member having

According to a second aspect of the invention, the contact member according to claim 1, wherein the flexible member is characterized by being rotatably supported the abutment member body.

A third aspect of the present invention is a printing apparatus having the contact member according to the first or second aspect .

According to a fourth aspect of the present invention, there is provided a printing method for performing printing using the printing apparatus according to the third aspect .

According to the present invention, when a pressing body for pressing the sheet against the stencil sheet on the plate cylinder presses the sheet against the stencil sheet on the plate cylinder, the sheet is prohibited from entering between the pressing body. in, it abuts against the same pressing member on the downstream side of the portion facing the same pressing member and the plate cylinder in the conveying direction of the sheet, since the contact member having a flexible member in contact with the same pressing member, the pressing member The flexible member abuts against the pressing body along the shape of the pressing body while suppressing the burden on the sheet, so that the abutting member enters between the front end of the sheet and the pressing body, and the sheet wraps around the pressing body. This can be prevented or suppressed, and a contact member that can prevent jamming of the sheet can be provided.

  If the flexible member is rotatably supported by the abutting member body, the flexible member rotates in response to the displacement of the pressing body while suppressing the load on the pressing body. It is possible to prevent or suppress the contact member from entering between the front end of the sheet and the pressing body and moving the sheet around the pressing body by moving and contacting the pressing body along the shape of the pressing body. In addition, it is possible to provide a contact member that can prevent a sheet jam or the like.

  Since the present invention is in a printing apparatus having such an abutting member, it has an abutting member that exhibits the above-described effects, and the abutting member enters between the leading end of the sheet and the pressing body, so that the sheet becomes the pressing body. It is possible to provide a highly reliable printing apparatus that can prevent or suppress winding and prevent sheet jamming and the like.

  Since the present invention is in a printing method for performing printing using such a printing apparatus, it is possible to prevent or suppress the contact member from entering between the leading end of the sheet and the pressing body and winding the sheet around the pressing body. In addition, it is possible to provide a highly reliable printing method capable of preventing sheet jamming and the like.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention including examples will be described with reference to the drawings. In the present embodiment, components such as members and components having the same function, shape, and the like are described with the same reference numerals, and the description thereof will be omitted. In order to simplify the drawings and the description, even components that are to be represented in the drawings may be omitted as appropriate without being specifically described in the drawings.

  With reference to FIG. 1, an overall configuration of a double-sided stencil printing apparatus 200 as an example of a double-sided printing apparatus that is a printing apparatus to which the present invention is applied will be described. As shown in FIG. 1, the double-sided stencil printing apparatus 200 is disposed at the upper left side of FIG. 1 and makes a master 8 wound in a roll shape, and is disposed at a substantially central portion in FIG. A plate cylinder 1 that winds a master 8 (hereinafter referred to as a “plate-making master 8”) around the outer peripheral surface, and an outer peripheral surface of the plate cylinder 1 can be freely contacted and separated. A printing unit 16 having a press roller 21 or the like as a pressing body that presses a sheet 36 as a sheet, and a used master 8 on the plate cylinder 1 disposed to face the plate making unit 15 with the plate cylinder 1 interposed therebetween are peeled and discharged. A plate discharging unit 17 that is disposed below the plate discharging unit 17, a sheet feeding unit 30 that feeds a sheet 36 on a sheet feeding tray 35 serving as a sheet feeding table toward the printing unit 16, and the sheet feeding unit 30. A sheet 3 that is disposed and printed under the plate-making unit 15 so as to face it. The are and a discharge portion 19 for discharging the sheet discharge tray 172 as a paper receiving tray and peeled from the plate cylinder 1.

  In addition, the double-sided stencil printing apparatus 200 reprints the surface-printed paper 36 on which the printing image is formed on the front surface, which is one side, in the printing unit 16 in order to print on the back surface, which is the other side. A sheet refeeding unit 201 that conveys the sheet to the unit 16, a peeling guide 46 as a guide unit that guides the surface printed sheet 36 to the sheet refeeding unit 201, and a surface printed sheet that is guided to the sheet refeeding unit 201 by the peeling guide 46. The fixed guide 202 as a contact member that is in contact with the press roller 21 so as to prohibit the entry of the 36 between the press roller 21 and the paper discharge conveying means 47 constituting a part of the paper discharge unit 19. And have.

  The sheet refeeding means 201 is a sheet receiving 45 that is a sheet refeeding tray serving as a lower conveyance device as a sheet refeeding storage means for temporarily placing and storing the surface printed sheet 36, and the surface printed sheet 36 as a sheet. A sheet holding unit 60 that conveys the sheet to the receiver 45 and a refeed unit 49 that re-feeds the surface-printed sheet 36 stored in the sheet receiver 45 toward the printing unit 16 are provided.

  Although not shown, the double-sided stencil printing apparatus 200 is arranged on the upper part of the printing apparatus main body in which the plate cylinder 1, the plate-making unit 15 and the plate discharging unit 17 are arranged, and double-sided stencil printing. A control device as control means for controlling the overall operation of the apparatus 200, and an operation panel as input means for performing predetermined operations on the double-sided stencil printing apparatus 200, such as inputting predetermined information to the control apparatus. It has.

  The plate making unit 15 performs plate making on the master 8, and as shown in FIG. 2, the first for surface printing along the rotation direction of the plate cylinder 1 (the direction along the paper transport direction X and the master transport direction X 1). A divided plate-making master 8X having a plate-making image 8A (hereinafter referred to as “front-side plate-making image 8A”) and a second plate-making image 8B for back-side printing (hereinafter referred to as “back-side plate-making image 8B”); As shown in the figure, a third plate-making image 8YA (hereinafter referred to as “single-side plate-making image 8YA”) having an image amount area corresponding to two sides of the front-side plate-making image 8A and the back-side plate-making image 8B along the rotation direction of the plate cylinder 1 is shown. And a function / configuration for producing a pre-made master 8Y. The front plate-making image 8A is formed at a position corresponding to the surface region 1A shown in FIG. 1 when the divided plate-making master 8X is wound on the outer peripheral surface of the plate cylinder 1, and the back plate-making image 8B is the same as the back surface region 1B. And corresponding positions.

  In FIG. 1, FIG. 2, etc., the master making master 8 </ b> Y is indicated with parentheses to distinguish it from the divided master making master 8 </ b> X. In FIG. 2, the area range of the single-side plate-making image 8YA formed on the plate-making master 8Y is indicated by a two-dot chain line, and the boundary line of the same area range in the master transport direction X1 is the solid line of the front-side plate-making image 8A and the back-side plate-making image 8B. Because of the overlap, the area range is shown to be slightly larger. However, the area range of the single-side plate-making image 8YA is a front-side plate-making image 8A, a back-side plate-making image 8B, and an unfinished blank area that is located between them. This is the entire range including the plate making area 8C. In FIG. 2, the front plate making image 8A, the back plate making image 8B, the intermediate non-plate making region 8C, and the single-side plate making image 8YA are drawn out of scale, and in particular, the intermediate non-plate making region 8C is drawn in an exaggerated manner. It is.

  As illustrated in FIG. 1, the plate making unit 15 performs plate making by heating a master support member 8 c as a master support unit that supports the master 8 so that the master 8 can be fed out in the master transport direction X <b> 1, and according to image information. A thermal head 11, a platen roller 9 as a master conveying means for conveying the thermal head 11 while rotating the master 8 downstream in the master conveyance direction X 1 while pressing the master 8 against the thermal head 11, and a master conveyed by the platen roller 9 8 is applied between the platen roller 9 and the pair of conveying rollers 13 as a master conveying unit that conveys 8 to the downstream side in the master conveying direction X1 while applying an appropriate tension. The master plate 8 is conveyed by a cutter 12, a platen roller 9, and a conveying roller pair 13 that cut the master plate 8 to a predetermined length. The leading edge of the stencil 8 have; and a master guide plate 14 or the like for guiding the clamper 7 was expanded on the plate cylinder 1 as described below.

  The master 8 has a continuous sheet shape and is wound around a synthetic resin roll core 8b to form a master roll 8a. The roll core 8 b protrudes from both end faces of the master roll 8 a and is formed longer than the width of the master 8. In the master roll 8a, the roll cores 8b on both ends are rotatably supported by the master support member 8c in a counterclockwise direction, and are detachable from the master support member 8c. Both ends of the master support member 8c are attached and fixed to a pair of plate making side plates (not shown) disposed on the left and right sides of the plate making unit 15 along the master transport direction X1. Therefore, the master 8 is supported by the master support member 8c so that it can be fed out from the master roll 8a in the master transport direction X1.

  The master 8 has a laminated structure in which, for example, a thermoplastic resin film having a thickness of 1 to 2 μm and a porous support made of synthetic fiber or the like are bonded together. In addition, the master is not limited to this, for example, a paste obtained by bonding a porous support made of Japanese paper fiber or a mixture of Japanese paper fiber and synthetic fiber and a thermoplastic resin film, or a so-called substantially thermoplastic material. A master made only of a resin film is also used.

  The thermal head 11 extends in parallel to the platen roller shaft of the platen roller 9 and the front side and the back side of the paper surface of FIG. 1, and is provided by a contact / separation mechanism including a cam and a spring member (not shown). The platen roller 9 can be contacted and separated via the master 8. The thermal head 11 is urged by the spring member so as to contact the platen roller 9. In the main scanning direction of the thermal head 11, a large number of heat generating elements (not shown) are disposed at portions that contact the platen roller 9 via the master 8. The thermal head 11 passes through an A / D conversion unit and an image signal processing unit (not shown) and the above-described heat generation based on a digital image signal processed and sent out by a plate making control device and a thermal head drive circuit (both not shown). By selectively heating the element, it has a well-known function as a plate making means for selectively heating, melting, punching and making the master 8.

  The platen roller 9 is formed integrally with the platen roller shaft through a metal cored bar. The platen roller 9 is rotatable clockwise because both end portions of the platen roller shaft are rotatably supported by the plate-making side plate pair. The platen roller 9 is connected to a master transport motor 10 as a master transport driving means via a rotation transmission member (not shown) such as a timing belt and a gear, and is thereby driven to rotate clockwise. The master transport motor 10 is composed of, for example, a stepping motor. As described above, when the platen roller 9 is driven to rotate clockwise by the master conveyance motor 10, the master 8 is pulled out from the master roll 8a.

  The conveying roller pair 13 is provided with an appropriate pressing force applied by an urging means such as a spring and pressed against each other, and both end portions of each roller shaft are rotatably supported by the plate making side plate pair. Thus, they can rotate in opposite directions. The conveyance roller pair 13 is set to rotate at a peripheral speed (conveyance speed) slightly faster than the peripheral speed (conveyance speed) of the platen roller 9 by the rotation transmission member including the master conveyance motor 10. Appropriate front tension is applied to the master 8 while sliding between the two.

  The cutter 12 is a known guillotine type that includes a fixed blade 12b and a movable blade 12a. The cutter 12 is not limited to the guillotine type, and a rotary blade moving type in which the movable blade moves while rotating in the master width direction perpendicular to the master transport direction X1 may be used.

  The plate cylinder 1 has a two-layer structure of a porous cylindrical support cylinder and a mesh screen (not shown) made of a resin or metal mesh wound around a plurality of layers so as to cover the outer periphery of the support cylinder. The plate cylinder 1 is provided with a printable opening 1a (hereinafter sometimes referred to as an “image forming region”) in which a large number of ink-permeable holes are formed, a clamper 7 and the like, and is non-printable. Non-opening portions (hereinafter sometimes referred to as “non-image forming regions”) are formed along the rotation direction of the plate cylinder 1 indicated by arrows in FIG. The image forming area includes a first image area 1A (hereinafter referred to as “front surface area 1A”), an intermediate area 1C, and a second image area 1B (hereinafter referred to as “back surface area 1B”) in the plate cylinder 1 in FIG. ”) At least.

  The plate cylinder 1 is wound and fixed around an outer peripheral portion of an end plate flange (not shown), and is rotatably supported around a support shaft 5 that also serves as an ink pipe 5 described later. The size of the plate cylinder 1 is a size that can be printed on an A3 size paper 36 at the maximum during single-sided printing to obtain an A3 size printed matter, that is, a single master plate 8 of A3 size can be wound. The outer peripheral diameter is set to 180 mm (the outer peripheral length of the plate cylinder 1 is about 565 mm), and the width direction (rotation center axis direction) is set to 350 mm.

  The plate cylinder 1 is connected to a main motor 20 as a plate cylinder driving means via a drive transmission means such as a gear or a belt (not shown), and is driven to rotate in the direction of the arrow (clockwise) in FIG. The As the main motor 20, for example, a control DC motor is used. The output shaft of the main motor 20 is provided with an optical rotary encoder (not shown) and a plate cylinder sensor (not shown) that generates a pulse by cooperating with the rotary encoder. This plate cylinder sensor is composed of a transmissive optical sensor, and is used for controlling the rotational speed (printing speed) of the plate cylinder 1 and determining the rotational position.

  The plate cylinder 1 is rotatably supported by a side plate (not shown), and the rotational driving force of the main motor 20 is transmitted by a drive transmission means such as a gear (not shown) so that the arrow in the figure is synchronized with the plate cylinder 1. Between the ink roller 2 which is driven to rotate in the direction (clockwise) and contacts the inner peripheral surface of the plate cylinder 1 to supply ink, and the ink roller 2 which is arranged in parallel with the ink roller 2 with a slight gap. A doctor roller 3 for forming an ink reservoir 4 having a wedge-shaped cross section and an ink pipe 5 for supplying ink to the ink reservoir 4 are disposed. The ink roller 2, the doctor roller 3, and the ink pipe 5 constitute an ink supply means. In this embodiment, the ink supply means is a single one. The ink in the ink reservoir 4 is sucked by an ink pump (not shown) from an ink pack (not shown) provided outside the plate cylinder 1, supplied from the supply hole of the ink pipe 5, and kneaded. The ink in the ink reservoir 4 is supplied as a thin film on the outer peripheral surface of the ink roller 2 while being measured by the doctor roller 3, and further, the outer peripheral surface of the ink roller 2 comes into contact with the peripheral surface of the support cylinder in the plate cylinder 1. It is supplied to the opening 1 a portion of the plate cylinder 1.

  A part of the plate cylinder 1 on the outer peripheral surface of the non-opening portion includes a ferromagnetic stage 6 provided along one bus bar of the plate cylinder 1 and clamper shafts provided on both side ends of the stage 6. And a clamper 7 having a rubber magnet that is pivotably attached to the flat portion of the stage 6 and can be opened and closed. The clamper 7 is opened and closed at a predetermined position by an opening and closing device (not shown) provided on the main body frame side. The plate cylinder 1 is stopped in a state in which the clamper 7 is located almost directly as shown in FIG. The plate cylinder 1 is configured as a plate cylinder unit integrally formed with the ink pack, the ink pump, and the like, and is detachable in the axial direction of the ink pipe 5 with respect to the main body frame of the double-sided stencil printing apparatus 200. It has become.

  In FIG. 1, a sheet feed motor 37 and a registration motor of the sheet feeding unit 30 are detected by detecting the rotational position of the plate cylinder 1 on the end plate flange of the plate cylinder 1 on the back side of the paper surface and the main body frame side in the vicinity of the end plate flange. The component which gives the start (start) and trigger information to 41 is arranged. That is, on the outer wall of the end plate flange on the back side of the plate cylinder 1, a sheet feeding start light shielding plate and a resist start light shielding plate (not shown) are spaced apart from each other on the same circumference of the plate cylinder 1. Each is attached at a predetermined position, and a sheet feeding registration sensor (not shown) is attached to the main body frame side in the vicinity of the light shielding plates.

  In the present embodiment, the home position (initial position) of the plate cylinder 1 receives the leading end portion of the divided plate-making master 8X and the plate-making master 8Y conveyed from the plate-making unit 15 with the clamper 7 positioned substantially directly above. It is set to the same position as the plate feeding standby position, which is the holding position. A light shielding plate for home position (not shown) for detecting the home position of the plate cylinder 1 is attached to a predetermined position of the outer wall of the end plate flange on the back side of the plate cylinder 1. A home position sensor (not shown) is attached to the main body frame side in the vicinity of the home position light shielding plate so as to face the home position light shielding plate of the plate cylinder 1 and sandwich it. The home position sensor is a transmissive optical sensor. The plate cylinder sensor, the paper feed registration sensor, and the home position sensor constitute a plate cylinder position detection sensor as plate cylinder position detection means for detecting the rotational position of the plate cylinder 1.

  The refeed means 49 is a press roller 21 that holds the surface-printed paper 36 on its outer peripheral surface and rotates and conveys it to the plate cylinder 1, a refeed resist roller 51, a roller guide plate 50, a stopper 203, It is mainly composed of a re-feed sensor as a surface-printed paper detection means (not shown).

The press roller 21 is disposed near the lower part of the outer peripheral surface of the plate cylinder 1 facing the ink roller 2. The press roller 21 is configured by integrally fixing an elastic body to a metal press roller shaft 21 a and is provided to extend in the axial direction of the plate cylinder 1. The press roller 21 is formed so that its lateral width is the same as that of the master 8 that covers the opening 1a of the plate cylinder 1 or a length that is slightly wider than that. The press roller 21 has a pair of printing pressure arms 22 (not shown on the front side of the paper surface) as pressing means support members disposed on the front side and the back side of the paper surface via both ends of the press roller shaft 21a. ) Is supported rotatably.
Each printing pressure arm 22 is integrated by an arm shaft 22a and a connection reinforcing member (not shown). The arm shaft 22a is supported between a pair of housing side plates (not shown) fixed on the main body frame side via a bearing (not shown) so as to be rotatable by a predetermined angle.

  The press roller 21 is formed of an elastic material having oil resistance, such as nitrile rubber (NBR) or silicone rubber (Q), and at least the outer peripheral surface of the rubber is prevented from being stained with an offset printing device or the like. The glass beads used in the above are uniformly arranged, or the outer peripheral surface of the press roller 21 is smoothed with a film having ink repellency and oil resistance such as fluoro rubber (FKM) and polytetrafluoroethylene resin. It may be coated on the surface. As a result, the contamination due to swelling and ink adhesion caused by contact with the ink on the printed image surface side of the surface-printed paper 36 is minimized when contacting the divided master-making master 8X or the master-making master 8Y on the plate cylinder 1. It is made to become.

  The press roller 21 applies the unprinted sheet 36 and the surface-printed sheet 36 to the divided plate-making master 8X and the plate-making master 8Y on the plate cylinder 1 by a printing pressure range varying means (not shown) and each printing pressure arm 22 which will be described later. It is configured to be freely displaceable between a printing position shown in FIG. 1 to be pressed and a non-printing position (also an initial position) shown in FIG. 6 away from this printing position.

  The press roller 21 is rotationally driven by a press roller rotation driving unit as a pressing unit driving unit (not shown). The press roller rotation drive means includes a press roller drive motor as a drive means for driving the press roller 21 in a direction opposite to the rotation direction of the plate cylinder 1 at a circumferential speed substantially the same as the circumferential speed of the plate cylinder 1, and a press roller drive. It is mainly comprised from the driving force transmission means which transmits the rotational driving force of a motor to the press roller 21. FIG.

  The press roller 21 is a press roller drive motor in accordance with the timing when the unprinted paper 36, the front surface printed paper 36, or the single-side printed paper 36 is pressed against the divided master 8X or the master 8Y on the plate cylinder 1. Is driven to rotate. The operation of the press roller drive motor is controlled by a control device. Since the press roller 21 is rotationally driven by the press roller drive motor at a substantially same peripheral speed as the peripheral speed of the plate cylinder 1, it is possible to obtain a good printed matter with no print image positional deviation.

  In addition to the press roller 21, a refeed resist roller 51 as a refeed resist member, a roller guide plate 50 as a feed guide member, and the like are disposed between the printing pressure arms 22. The re-feeding registration roller 51 is located below the press roller 21, and in the state shown in FIG. 1, its outer peripheral surface is pressed against the outer peripheral surface of the press roller 21 by a driving means (not shown). In the state shown, the outer peripheral surface is separated from the outer peripheral surface of the press roller 21. The re-feeding registration roller 51 is pressed against the press roller 21 to hold the front end portion of the surface-printed paper 36 stored in the paper receiver 45 between the press roller 21 and the press roller 21. The front end of the surface-printed paper 36 is transported to the plate cylinder 1 at a predetermined timing by the rotation of the press roller 21 when it contacts with the plate cylinder 1. The re-feeding registration roller 51 is composed of a plurality of rollers divided in a skewered manner, and is formed integrally with the shaft 51a. The re-feeding registration roller 51 has both ends of a shaft 51a supported between the printing pressure arms 22 so as to be rotatable and displaceable. It rotates following the opposite direction.

  The roller guide plate 50 has a function of guiding the surface-printed paper 36 conveyed by the rotational force of the press roller 21 toward the plate cylinder 1 while abutting on the outer peripheral surface of the press roller 21. The roller guide plate 50 has a curved partial cylindrical shape centered on the press roller shaft 21a in order to guide the surface-printed paper 36 along the outer peripheral surface of the press roller 21. Are fixed between the printing pressure arms 22. The guide surface side of the surface-printed paper 36 in the roller guide plate 50 is coated with a film having a low coefficient of friction with respect to the surface-printed paper 36 and having ink repellency and oil resistance such as polytetrafluoroethylene resin. ing.

  The stopper 203 is in contact with the front end of the front surface printed paper 36 that has been conveyed from the paper receiver 45 and stored on the paper receiver 45 to regulate its position. The stopper 203 is fixed between the printing pressure arms 22 and has a slit (not shown) that allows the re-feeding registration roller 51 to be displaced. The surface-printed paper 36 whose leading edge is regulated by the stopper 203 is formed between the press roller 21 and the refeeding registration roller 51 when the refeeding registration roller 51 is displaced upward and rotates in contact with the press roller 21. The leading end is sandwiched between them and conveyed toward the plate cylinder 1.

Next, the configuration around the printing pressure range variable means that determines the printing pressure range of the press roller 21 will be described in detail. In this embodiment, as shown in FIG. 1 and FIG. 2, as a first printing pressure range pattern that applies printing pressure only to the surface area 1A corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1. And a printing pressure range pattern II as a second printing pressure range pattern that applies printing pressure only to the back surface area 1B corresponding to the back plate making image 8B in the divided plate-making master 8X on the plate cylinder 1. And a printing pressure range pattern as a third printing pressure range pattern for applying a printing pressure from the front surface region 1A to the back surface region 1B corresponding to the single-side plate-making image 8YA in the plate-making master 8Y on the plate cylinder 1. One of at least three printing pressure range patterns with III can be selectively switched.
The printing pressure range variable means has a configuration / function for displacing the press roller 21 between the printing position and the non-printing position, and selectively switches one of these three printing pressure range patterns. The printing pressure range varying means may be called a press roller contacting / separating mechanism as pressing means contacting / separating means.

The printing pressure range variable means includes an arm shaft 22a, printing arm pairs 22, 22, a pair of cam followers (not shown), a pair of printing springs (not shown), a plurality of sets of printing pressure cams (not shown), solenoids (not shown), and the like. This is a well-known configuration.
Each cam follower is rotatably held by each printing pressure arm 22. Each printing spring is locked between each printing arm 22 and a housing side plate (not shown), and always presses the press roller 21 in a direction in which it is pressed against the outer peripheral surface of the plate cylinder 1. Each printing pressure cam is rotatably supported on the case side plate near each cam follower, and is connected to the main motor 20 via a drive transmission means such as a belt or a gear (not shown), and is synchronized with the rotation of the plate cylinder 1. And is designed to rotate. The cam follower is urged by a printing pressure spring 25 so as to always come into contact with the printing pressure cam.

  The printing cam is composed of, for example, a plate cam in which a small-diameter portion (concave portion) and a large-diameter portion (convex portion) are formed. The shape is different. The large diameter portion of the printing pressure cam is pressed against the cam follower against the urging force of the printing pressure spring, so that the printing pressure by the press roller 21 is turned off / released. A printing pressure cam that engages with the cam follower is switched by a solenoid or the like according to the three printing pressure range patterns.

  FIG. 2 is an expanded view of the printing pressure range of the press roller 21 for easy understanding. In FIG. 2, an area portion of the front plate-making image 8A and an area portion of the back-side plate-making image 8B are formed on the divided plate-making master 8X wound around the opening 1a on the plate cylinder 1 (not shown in FIG. 2). In addition, there is an unfinished blank intermediate unfinished area 8C between them. Here, the leading side of the divided plate-making master 8X, which is also referred to as the leading edge blank portion sandwiched and fixed by the clamper 7 of the plate cylinder 1 (not shown in FIG. 2), is the left end side.

  The printing pressure range pattern for normal printing including single-sided printing is as shown in III. That is, the printing pressure range pattern III is applied to one side of the prepressed master 8Y by applying a printing pressure from the area portion of the front plate making image 8A to the area portion of the back plate making image 8B through the intermediate non-plate making area 8C. The printing cam is rotated so that the small diameter portion of the predetermined printing cam faces the cam follower so that the paper 36 is continuously pressed against the plate-making image 8YA.

  At the time of surface printing, the printing pressure range pattern I is printed, and the printing is performed so that the small diameter portion of a predetermined printing pressure cam faces the cam follower so as to be printed corresponding to the area portion of the surface plate-making image 8A. The pressure cam is driven to rotate, and then the solenoid is controlled to be turned on / off so that the large diameter portion of the predetermined printing pressure cam abuts the cam follower so that the printing pressure is released in the intermediate unmade region 8C. .

  At the time of printing on the back side, the printing pressure range pattern II is obtained, and the large-diameter portion of a predetermined printing pressure cam abuts on the cam follower so that the printing pressure is released in the region of the first front plate-making image 8A. The solenoid is controlled to be turned on / off, and then the printing cam is rotationally driven so that the small diameter portion of the predetermined printing pressure cam faces the cam follower.

  The above can be summarized as follows. That is, a printing pressure range pattern I as a first printing pressure range pattern that applies printing pressure only to the surface region 1A corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1, and on the plate cylinder 1 In the divided plate-making master 8X, a printing pressure range pattern II as a second printing pressure range pattern that applies a printing pressure only to the back surface area 1B corresponding to the back surface plate-making image 8B, and the back surface area 1B continuously from the front surface area 1A. 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. A mechanism for selectively switching one of these three printing pressure range patterns is the above-described printing pressure range varying means.

  As shown in FIG. 1, the paper discharge conveying means 47 is disposed on the left side of the plate cylinder 1. The paper discharge conveying means 47 includes a paper discharge roller rear 84 as a drive roller integrally provided on a drive shaft 85 rotatably supported between a pair of casing side plates (not shown), and a paper more than the drive shaft 85. A discharge roller front 86 as a driven roller integrally provided on a driven shaft 87 disposed on the upstream side in the transport direction X and in the vicinity of the peeling guide 46, a discharge roller rear 84, and a discharge roller front 86. A sheet 36 having a surface printed thereon, wound on and stretched between the two, and a sheet 36 having both sides printed or discharged from a nip portion N as an image forming unit which is a pressure contact portion between the plate cylinder 1 and the press roller 21 A discharge belt 88 formed with a plurality of holes for air suction as an endless belt that holds and conveys one of the printed sheets 36, and a drive force such as a gear or a belt is transmitted to the drive shaft 85. Connected through means A belt driving motor 90 as a belt driving means for rotating the paper discharge belt 88 through the rotation drive of the post-roller 84, and the surface printed paper 36 discharged and conveyed from the nip portion N toward the paper discharge belt 88. A single suction fan 89 for sucking and holding either one of the double-sided printed paper 36 or the single-sided printed paper 36 on the upper surface of the paper discharge belt 88 by sucking air from the plurality of holes 88. It is mainly composed.

The paper discharge roller rear 84 and the paper discharge roller front 86 are divided into skewers and formed of toothed rollers, and are formed of a high friction material having oil resistance (ink corrosion resistance) such as nitrile rubber (NBR). However, a resin or the like may be used as long as the material has such properties. The paper discharge belt 88 is formed of a toothed belt, and is wound around and stretched between a paper discharge roller rear 84 and a paper discharge roller front 86 each of which is divided into a plurality of skewers. The discharge belt 88 is formed of, for example, nitrile rubber (NBR) or silicone rubber (Q), which is an oil-resistant elastic body, in order to be held and conveyed in contact with the printed image surface side of the surface-printed paper 36. At least the outer peripheral surface of the rubber is smoothly coated with a film having ink repellency and oil resistance such as fluoro rubber (FKM) and polytetrafluoroethylene resin. The suction fan 89 incorporates a fan drive motor as fan drive means. Hereinafter, for the sake of simplicity, the “fan driving motor” is sometimes simply referred to as “suction fan 89”.
The paper discharge belt 88 is rotated by the operation of the belt drive motor 90 based on a command signal from the control device.

  The peeling guide 46 is disposed on the upstream side in the paper transport direction X from the paper discharge belt 88, and rotates about a predetermined angle about a shaft 46a on the downstream side in the paper transport direction X. The peeling guide 46 has a thin plate shape with a sharp tip. The peeling guide 46 is rotated by driving means such as a solenoid and a stepping motor (not shown), and when the press roller 21 occupies the printing position, the tip rotates toward the plate cylinder 1 side. When the press roller 21 occupies the non-printing position, the tip rotates toward the press roller 21 side. The peeling guide 46 also serves as a peeling means for peeling the surface-printed paper 36 printed at the nip portion N from the plate cylinder 1 when the tip rotates toward the plate cylinder 1 side.

  The plate removal unit 17 includes an upper plate removal member 160, a lower plate removal member 161, a plate removal box 162, a compression plate 163, and the like. The upper plate removal member 160 includes a driving roller 164, a driven roller 165, an endless belt 166, and the like. The endless belt 166 moves in the direction of the arrow in FIG. 1 when the driving roller 164 is rotationally driven in the clockwise direction in FIG. 1 by a plate discharging driving means including a plate discharging motor (not shown). The lower plate removal member 161 includes a driving roller 167, a driven roller 168, an endless belt 169, and the like. The driving roller 167 is driven to rotate in the clockwise direction in FIG. 1 by transmitting the driving force of the above-mentioned plate discharging motor that rotates the driving roller 164 by driving force transmitting means (not shown) such as a gear or a belt. The endless belt 169 moves in the direction of the arrow in FIG. Further, the lower plate discharging member 161 is movably provided by a moving unit (not shown) included in the plate discharging driving unit, and an endless belt 169 positioned on the outer peripheral surface of the driven roller 168 and a position shown in the drawing is provided on the plate cylinder 1. It selectively occupies a position in contact with the outer peripheral surface.

  The plate removal box 162 stores a used master therein and is detachably attached to the main body frame. The compression plate 163 is supported by the main body frame so as to be movable up and down so as to push the used master carried by the upper plate removal member 160 and the lower plate removal member 161 into the plate release box 162, and is included in the plate drive means. It is moved up and down by lifting means (not shown) including a lifting motor.

  The plate ejection box 162 stores a used master therein and is detachably attached to the printing apparatus main body. The compression plate 163 is supported by the main body frame so as to be movable up and down so as to push the used master carried by the upper plate removal member 160 and the lower plate removal member 161 into the plate release box 162, and is included in the plate drive means. It is moved up and down by lifting means (not shown) including a lifting motor. The control target driving means of the plate discharging unit 17 including the plate discharging motor, the moving unit, and the lifting motor of the plate discharging unit 17 is collectively referred to as a plate discharging driving unit.

  As shown in FIG. 1, the paper feed unit 30 includes a paper feed tray 35 that serves as a tray that can be lifted up and down by stacking paper 36 on which image formation, that is, printing, can be lifted, and an outer peripheral surface of the plate cylinder 1. A registration roller pair 31 serving as a registration unit that feeds the paper 36 at a timing described later between the press roller 21 and a sheet 36 on the paper feed tray 35 and contacting a nip portion of the registration roller pair 31. A sheet feeding roller 33 and a separating member 34 as sheet feeding means for separating and conveying the sheets 36 one by one, a sheet size detecting means for detecting the sheet size of the sheet 36, and the like.

  The top of the stacked paper 36 is always placed in the paper feed tray 35 by a drive device (not shown) provided with a paper feed tray lifting / lowering motor (not shown) for moving the paper feed tray 35 up and down and a wire type lifting mechanism. Maintains a state in which the paper 36 contacts with a pressing force within a range in which the paper 36 can be transported in association with increase / decrease of the paper 36 so as to come into contact with the paper feed roller 33 with a predetermined pressing force (pressing force capable of transporting the paper 36). While moving up and down. The paper feed tray 35 has a structure in which many paper types and paper sizes can be used, and a stencil printing apparatus capable of stacking 500 sheets or more with paper 36 of paper size A3 (vertical) or A4, for example. It has a structure suitable for.

  The paper feed roller 33 is formed integrally with a metal paper feed roller shaft 33a, and one end of the paper feed roller shaft 33a is rotatably supported by the casing side plate. The surface of the paper feed roller 33 is formed of at least a high friction resistance member such as rubber. The paper feed roller shaft 33a is connected to the paper feed motor 37 via a one-way clutch (not shown) for rotating the paper feed roller 33 so as to transport the paper 36 only in the paper transport direction X and rotating only clockwise. ing. The separation member 34 has a member called a separation pad that is made of rubber or resin having a high coefficient of friction with respect to the paper 36 and that can contact the paper feed roller 33. This separation pad is urged in a direction to be pressed against the paper feed roller 33 by a compression spring (not shown) as urging means.

The paper feed motor 37 is composed of, for example, a stepping motor as a motor driven by pulse input.
A registration motor 41 is connected to the shaft 31 c of the lower roller constituting the registration roller pair 31. The registration motor 41 is composed of, for example, a stepping motor as a motor driven by pulse input.

  In FIG. 1, the leading and trailing ends of the sheet 36 fed from the registration roller pair 31 are detected in the sheet conveyance path XA from the nip portion between the plate cylinder 1 and the press roller 21 to the nip portion of the registration roller pair 31. A paper detection sensor 32 as a paper detection means is provided. In the paper detection sensor 32, the paper 36 stays in the paper transport path XA on the upstream side of the arrangement position of the paper detection sensor 32 (position where the leading edge of the paper 36 can be detected) (jamming or the like occurs). It also has a function to detect. The paper detection sensor 32 is a reflective optical sensor having a light emitting unit and a light receiving unit.

  The control target drive means of the paper feed unit 30 including the paper feed tray lifting / lowering motor, the paper feed motor 37, and the registration motor 41 of the paper feed unit 30 is generally referred to as a paper feed drive unit. The paper feed driving means for rotationally driving the paper feed roller 33 is not limited to the paper feed motor 37 and the like, and the rotational driving force from the main motor 20 is supplied by a driving force transmission means (not shown) such as a gear or a cam. It may be configured to be driven to rotate at a predetermined timing synchronized with the plate cylinder 1. Similarly, the registration driving means for rotationally driving the registration roller pair 31 is not limited to the registration motor 41 or the like, and the rotational driving force from the main motor 20 is transmitted by a driving force transmission means (not shown) such as a gear or a cam. The sheet 36 may be fed at a predetermined timing toward the nip N between the plate cylinder 1 and the press roller 21.

  As shown in FIG. 1, the paper discharge unit 19 is provided so as to be close to the outer peripheral surface of the plate cylinder 1, and a peeling claw 170 for peeling the single-side printed paper 36 from the plate-making master 8 </ b> Y on the plate cylinder 1. A separation fan 171 for blowing air between the front end portion of the single-sided printed paper 36 separated by the claw 170 and the plate cylinder 1 to assist the separation action by the separation claw 170, a paper discharge conveying means 47, a paper discharge Mainly composed of a tray 172.

  The peeling claw 170 is provided in the vicinity of the downstream in the printing nip portion N formed when the press roller 21 is in pressure contact with the outer peripheral surface of the plate cylinder 1. The peeling claw 170 is pre-processed on the plate cylinder 1 in the vicinity of the outer peripheral surface of the plate cylinder 1 by a peeling claw displacing means (not shown) provided with a cam and a spring that are rotationally driven in synchronization with the rotation of the plate cylinder 1. Between the peeling position for forcibly peeling the single-side printed paper 36 from the master 8Y and the non-peeling position to avoid contact with the clamper 7 disposition portion protruding from the outer peripheral surface of the plate cylinder 1 apart from the peeling position. It is configured to be freely displaceable. The peeling fan 171 has a built-in fan drive motor that rotationally drives the peeling fan.

The operation panel is for instructing the double-sided stencil printing apparatus 200 to perform a predetermined operation or the like.
The operation panel 173 has a plate making start key, a printing start key, a clear / stop key, a numeric keypad, an enter key, a printing speed setting key, a double-sided printing key, a single-sided printing key, a display device including an LCD (liquid crystal display device), etc. have.

The plate making start key is pressed when causing the double-sided stencil printing apparatus 200 to perform the plate making operation. When the plate making start key is pressed, the plate making operation is performed after the plate discharging operation and the document reading operation are performed. Operation is performed.
The print start key is pressed when causing the double-sided stencil printing apparatus 200 to perform a printing operation.
The clear / stop key is pressed when the operation of the double-sided stencil printing apparatus 200 is stopped or when the number is cleared.
The numeric keypad is used for numerical input.
The enter key is pressed when setting a numerical value or the like during various settings.
The print speed setting key is pressed when setting the print speed prior to the printing operation.

The double-sided printing key and the single-sided printing key are pressed before pressing the plate-making start key when the double-sided stencil printing apparatus 200 performs the double-sided printing operation and the single-sided printing operation, respectively.
The display device displays the status of the double-sided stencil printing apparatus 200 such as “can be made / printed”, warnings such as plate-making or discharge jam, paper feed or paper discharge jam, paper, master, ink, etc. A supply instruction for the supply is also displayed.

Control according to each mode and each setting is performed by a control device to be described later.
In addition to the operation panel, external input means such as a personal computer can be connected to the double-sided stencil printing apparatus 200 as input means for inputting predetermined information to the control device. When the input means is connected, it is possible to input all the information input through the operation panel described above. Further, it is also possible to input image data to be formed, that is, image data to be printed by such input means. Note that when such input means can be connected to the double-sided stencil printing apparatus 200, the operation panel is not necessarily required.

  The control device has a function and configuration as a control unit that mainly controls the document reading operation, the plate making operation, the paper feeding operation, and the printing operation of the double-sided stencil printing apparatus 200. The control device includes a CPU (central processing unit) (not shown), an I / O (input / output) port, a ROM (read only storage device), a RAM (read / write storage device), a timer with a battery, and the like. A microcomputer having a configuration connected by a signal bus is provided, and based on various signals from an operation panel, detection signals from various sensors, and an operation program called from a ROM, a printing unit 16, a plate making unit 15, paper feeding The operation of the image forming unit 30, the plate discharging unit 17, the paper discharge unit 19, and the image reading unit is controlled to control the operation of the entire duplex stencil printing apparatus 200.

  The ROM stores an operation program for the entire double-sided stencil printing apparatus 200, necessary data, and the like, and this operation program is appropriately called by the CPU. The RAM has a function of temporarily storing calculation results of the CPU, a function of storing data signals and ON / OFF signals set and input from various keys and various sensors on the operation panel as needed.

  As shown in FIG. 1, the paper receiver 45 is disposed below the paper discharge conveying means 47. The paper receiver 45 is disposed in the vicinity of the conveyance roller rear 154 integrally provided on the drive shaft 155 that is rotatably supported between the pair of casing side plates and the re-feeding registration roller 51. Further, a front roller 156 as a driven roller provided integrally with the driven shaft 157, and a rear roller 154 and a front roller 156 are wound and stretched so as to hold and convey the surface-printed paper 36. A conveying belt 158 formed with a plurality of holes (not shown) for sucking air as an endless belt, and connected to the drive shaft 155 via a driving force transmission means such as a gear or a belt, via the rotational drive of the rear 154 of the conveying roller. A belt driving motor 150 as a belt driving means for rotationally driving the conveying belt 158 and the surface-printed paper 36 by sucking air from a plurality of holes to convey the conveying belt 15. And a suction fan 159 for causing the suction-held on the upper surface.

  The paper receiver 45 also engages with the front surface printed paper 36 to prevent the front surface printed paper 36 from skewing on the paper receiver 45, and forms a part of the refeed means 49. The sheet receiving base 45 around the drive shaft 155 so that the re-feed sensor, the front 156 of the transport roller and the transport belt 158 wound around the re-feed sensor are always positioned in the vicinity of the re-feed resist roller 51. Displacement means for sliding and a face plate (not shown) disposed inside the conveyor belt 158 are provided.

  The conveyance roller rear 154 and the conveyance roller front 156 are divided into skewers and formed of toothed rollers, and are formed of a high friction material having oil resistance (ink corrosion resistance) such as nitrile rubber (NBR). However, any material having such properties may be a resin or the like. The conveyance belt 158 is a toothed belt, and a plurality of belts are wound and stretched between a conveyance roller 154 and a conveyance roller front 156, which are divided into skewers. The conveyor belt 158 is formed of an elastic body having oil resistance, such as nitrile rubber (NBR) or silicone rubber (Q), and at least the outer peripheral surface of the rubber has fluorine rubber (FKM) or polytetrafluoroethylene. A film having ink repellency and oil resistance, such as resin, is smoothly coated. The suction fan 159 includes a fan drive motor as a fan drive means. Hereinafter, the “fan drive motor” is sometimes simply referred to as “suction fan 159” for the sake of simplicity.

The conveyor belt 158 is rotated in opposite directions by the belt drive motor 150 that is intermittently driven at a predetermined timing based on a command signal from the control device, when receiving the front surface printed paper 36 and when feeding it. It is like that.
The face plate has a shape that does not hinder the rotation of the conveyance roller rear 154 and the conveyance roller front 156 and the suction by the suction fan 159, and the width direction of the roller guides 59 a and 59 b and the movement plates 152 a and 152 b described later. A notch is formed to allow displacement to the.

  The re-feed sensor detects the front-side printed paper 36 when the front-side printed paper 36 is conveyed to the paper receiver 45 by the paper holding means 60. The paper re-feed sensor is disposed in the vicinity of the paper re-feeding registration roller 51 on the paper receiver 45 and detects the front and rear ends of the front surface printed paper 36.

  The displacing means swings the paper tray 45 about the drive shaft 155, and always re-feeds the front of the transport roller 156 and the transport belt 158 wound around the re-feeding registration roller 51 regardless of the vertical movement of the re-feeding registration roller 51. The paper tray 45 is driven so as to be positioned in the vicinity of the paper registration roller 51.

  As shown in FIGS. 1 and 6, the paper holding means 60 is located above the paper receiving tray 45, and has a paper holding member 64, a clamp shaft 64 a rotatably supported by the paper holding member 64, A clamp claw 64b supported by the clamp shaft 64a, a biasing spring (not shown) that biases the tip of the clamp claw 64b to contact the paper holding member 64, and the paper holding member 64 in the first position shown in FIG. And a support member (not shown) that is movably supported between the paper holding position as the second position shown in FIG. 6 and the paper holding member 64 that reciprocates between the paper holding position and the standby position. Driving means (not shown).

  The clamp shaft 64a extends in the direction perpendicular to the paper surface in FIG. 1, and a plurality of clamp claws 64b are arranged in the same direction. The clamp claw 64b is inclined with respect to the paper holding member 64, and is inclined with respect to the moving direction of the front surface printed paper 36 guided to the paper re-feeding means 201 by the peeling guide 46. , The front end of the same surface printed paper 36 is sandwiched between the paper holding member 64.

  The clamp shaft 64a integrally has a lever (not shown) that contacts a release member (not shown) at the standby position at the standby position. When the lever comes into contact with the release member, the clamp pawl 64 resists the biasing force of the biasing spring. The front end of 64b is separated from the paper holding member, and the surface-printed paper 36 having the front end sandwiched between the clamp claw 64b and the paper ear cigarette b material 64 is released.

  The paper holding member 64, the clamp shaft 64a, the clamp pawl 64b, the urging spring, and the release member sandwich and hold the front end of the front surface printed paper 36 at the paper holding position and hold the front end of the front surface printed paper 36 at the standby position. A sheet leading end clamping member to be opened is configured. The home position of the sheet holding member 64 is a standby position, and normally occupies the standby position.

  The driving means is controlled by the control device, and when the front surface printing is performed in the double-sided printing mode, the sheet is held when the press roller 21 occupies the printing position and the leading end of the peeling guide 46 rotates toward the plate cylinder 1 side. The surface-printed paper 36 is moved from the standby position to the paper holding position until the press roller 21 occupies the non-printing position and the leading end of the peeling guide 46 rotates toward the press roller 21 side. The sheet holding member 64 is displaced to the standby position at substantially the same speed as the speed fed from the nip portion N between 1 and the press roller 21.

  To eliminate the skew of the front surface printed paper 36 by the skew prevention means 151, the clamp pawl 64 b opens the front end of the front surface printed paper 36, and the front surface printed paper 36 falls toward the paper receiver 45, and the conveying belt 158. The sheet holding member 64 moves from the sheet holding position toward the standby position and conveys the surface-printed sheet 36 depending on the strength of the clamping force by the clamp claws 64b. Is done.

  The fixed guide 202 is arranged on the downstream side of the nip portion N in the paper transport direction X with the tip thereof facing the nip portion N. The fixed guide 202 has a main body 204 fixed to the main body frame, and a distal end portion 205 as a contact portion supported by the main body 204 and capable of contacting the press roller 21.

  As shown in FIG. 1, the fixed guide 202 has a leading end only when it occupies the printing position, that is, when the press roller 21 is displaced toward the plate cylinder 1 to press the paper 36 against the master 8 on the plate cylinder 1. When 205 is in contact with the press roller 21 and occupies a position away from the plate cylinder 1 such as a non-printing position as shown in FIG. 6, it occupies a fixed position away from the press roller 21.

The main body 204 is configured by a metal plate.
The distal end portion 205 is a sheet-like flexible member made of a flexible resin such as polyethylene and having a base portion attached to the upper surface side of the main body 204. The reason why the front end portion 205 is disposed on the upper surface side of the main body 204 is to prevent the front end of the paper 36 from coming into contact with the joint portion between the front end portion 205 and the main body 204.

  The tip portion 205 has a thickness of 0.1 to 0.4 mm, and has flexibility depending not only on the material but also on the thickness. The material of the leading end portion 205 is preferably a material having low solid resistance and conductivity so as not to be charged with static electricity due to friction with the paper 36.

  As shown in FIG. 4, the end portion 205 on the right side of the front end portion 205 on the side in contact with the press roller 21 is tapered toward the end portion side, and the tip portion 205 becomes a tapered shape. Thus, the leading edge of the paper 36 is prevented or suppressed from being abutted.

  Since the leading end portion 205 has such a configuration, when the press roller 21 occupies the printing position, the leading end portion 205 closely contacts the press roller 21 so that the paper 36 does not enter. Accordingly, the surface printed paper 36 guided to the refeeding means 201 by the peeling guide 46 between the fixed guide 202 and the press roller 21 is prevented or suppressed, and the surface printed paper applied to the press roller 21 is prevented. It is prevented or suppressed that 36 is wound around.

  The separation guide 46 needs to change the conveyance path of the paper 36 upstream of the separation claw 170 and the separation fan 171 in the paper conveyance direction X. The surface-printed paper 36 guided to the re-feeding means 201 by the peeling guide 46 moves closer to the press roller 21 by that amount than the nail 170 and the peeling fan 171. That is, the paper 36 is likely to be caught by the press roller 21 as compared with a normal printing apparatus.

  However, since the fixed guide 202 is disposed, the surface-printed paper 36 guided to the refeed unit 201 by the peeling guide 46 enters between the fixed guide 202 and the press roller 21 as described above. This is prevented or suppressed, and the surface-printed paper 36 applied to the press roller 21 is prevented or suppressed from being wound.

  As shown in FIG. 6, when the peeling guide 46 is rotated toward the press roller 21, the leading end of the peeling guide 46 is positioned upstream of the leading end of the fixed guide 202 in the paper transport direction X. However, the leading end of the fixed guide 202 is moved upstream in the sheet conveying direction X in a range where no defective conveyance of the sheet 36 occurs so that the leading end of the sheet 36 is scooped up earlier than the peeling guide 46 by the fixed guide 202. You may arrange | position so that it may be located.

  The peeling claw 170 and the peeling fan 171 are first peeled off from the master 8 on the plate cylinder 1 in order to discharge the paper 36 printed at the nip portion N to the outside of the printing apparatus main body. The peeling guide 46 is a plate cylinder for conveying the paper 36 printed on one side in the nip N to the nip N and printing on the other side of the paper 36. The 2nd peeling means for peeling from the master 8 on 1 is comprised.

  Further, the front end portion 205 comes into contact with the press roller 21, but since the glass beads are disposed on the outer peripheral surface of the press roller 21, the wear of the press roller 21 due to the contact with the front end portion 205 is reduced. In addition, since the dirt adhered to the fixed guide 202 is hardly transferred and difficult to be stained, the dirt is less likely to be reattached to the surface-printed paper 36. As described above, the surface treatment with the glass beads or the like of the press roller 21 also has a function as a wear-resistant process against the contact of the fixed guide 202.

  As shown in FIG. 5, the fixed guide 202 may have a configuration in which the distal end portion 205 is rotatably supported by the main body 204. The fixed guide 202 having this configuration is provided integrally with the main body 204 and has a shaft 206 that rotatably supports the base portion of the distal end portion 205. Thereby, the front end portion 205 flexibly follows the displacement of the press roller 21, and it is better that the surface-printed paper 36 guided to the refeed unit 201 by the peeling guide 46 enters between the press roller 21. To prevent or suppress.

  In this configuration, the tip end 205 may always be in contact with the press roller 21 by adjusting the rotation angle of the tip 205 by the shaft 206. When the leading end 205 is always in contact with the press roller 21, the wear of the leading end 205 is likely to proceed, but the entrance of the paper 36 is further prevented or suppressed. When the distal end portion 205 is rotatably supported by the main body 204, the followability of the distal end portion 205 with respect to the press roller 21 is good, and therefore the distal end portion 205 is not necessarily a flexible member.

  Based on the above-described configuration, the operation including the operation procedure of the double-sided stencil printing apparatus 200 in this embodiment will be described. Since this operation is performed under the control of the control device, a command from the control device is used when explaining detailed operations such as activation, operation, and stop of actuators (control target drive means) such as various motors and various solenoids. Alternatively, expressions based on the command signal are omitted as much as possible.

  (Operation Example 1) First, an operation example 1 in which the single-sided printing mode is set and single-sided printing is performed will be described. The operation example 1 is substantially the same as the operation of performing single-sided printing with a conventional stencil printing apparatus, and uses the printing pressure range pattern III. In the first operation example, in order to facilitate understanding of each operation, the A3 size is used as the master size, and the A3 size is used as the document size and the paper size. Note that the continuous mode is not set and image position adjustment is not performed.

  The user stacks A3 size paper 36 as a paper size used for printing on the paper feed tray 35, sets a document on the image reading unit, sets plate making conditions with various keys on the operation panel, and then performs single-sided printing. Press the key to set the single-sided printing mode, press the plate making start key, and press the plate making start key.

  A start signal is generated by depressing a plate making start key, and when a start signal is input to the control device, a series of operations from discharging to discharging are automatically performed. Prior to this, when the paper feed tray lifting / lowering motor is turned on, the paper feed tray 35 is raised, and the uppermost paper 36 comes into contact with the paper feed roller 33 to turn on a paper feed position detection sensor (not shown). When it is determined by the control device that the uppermost sheet 36 is ready to be fed by the detection, the sheet feeding device 30 enters a sheet feeding standby state.

  First, in the plate removal unit 17, a plate removal operation for peeling the used master from the outer peripheral surface of the plate cylinder 1 is performed. When the plate making start key is pressed, the plate cylinder 1 starts to rotate, and when the plate cylinder 1 reaches the home position where the clamper 7 is almost directly above, a home position signal is sent from the home position sensor to the control device. . Upon receiving the home position signal, the control device measures the number of pulses generated by the encoder (not shown) with the home position as a base point, and the tip of the used master wound around the outer peripheral surface of the plate cylinder 1 is the driven roller 168. When it is determined that the predetermined plate discharging position corresponding to the endless belt 169 located on the outer peripheral surface has been reached, the operation of the main motor 20 is stopped.

  When the main motor 20 is stopped and the plate cylinder 1 is stopped at a predetermined plate discharging position, the main motor 20 and the plate discharging driving means are operated to rotate the drive rollers 164 and 167, and the lower plate discharging member 161 is moved to the plate cylinder. The endless belt 169 that moves to the first side and is positioned on the outer peripheral surface of the driven roller 168 contacts the used master. Then, the used master scooped up from the outer peripheral surface of the plate cylinder 1 by the rotation of the plate cylinder 1 and the movement of the endless belt 169 is nipped and conveyed by the lower plate discharging member 161 and the upper plate discharging member 160 to be outer periphery of the plate cylinder 1. It peels from the surface. The peeled used master is discarded in the discharge box 162 and then compressed by the compression plate 163. Even after all the used masters are peeled off from the outer peripheral surface, the plate cylinder 1 continues to rotate, and stops until the clamper 7 rotates to a predetermined plate feed standby position located substantially directly above. When the plate cylinder 1 stops at the plate feeding standby position, an opening / closing device (not shown) is operated to open the clamper 7, and the double-sided stencil printing apparatus 200 enters a plate feeding standby state.

  In parallel with the plate removal operation, a document image reading operation is performed by the image reading unit. Reading of an original image is performed optically and photoelectrically converted. The photoelectrically converted electrical signal is A / D converted and then transmitted as image information to a thermal head driving circuit.

  In parallel with the plate discharging operation and the image reading operation, the plate making unit 15 performs the plate making operation. That is, a digital image signal for controlling the heat generation of the heat generating elements of the thermal head 11 is transmitted to the thermal head 11 via a plate making control device and a thermal head driving circuit (not shown). As a result, the plurality of heating elements of the thermal head 11 are energized in a pulsed manner in the main scanning direction to selectively generate heat, and the master transport motor 10 is driven to rotate, whereby the platen roller 9 and the transport roller pair. 13 starts to rotate, and the thermoplastic resin film portion of the master 8 is selectively heated and punched according to image information while the master 8 is pulled out from the master roll 8a and is transported in the master transport direction X1.

  Then, the leading end of the master-made master 8Y is inserted between the clampers 7 that are guided by the master guide plate 14 and expanded with respect to the stage 6, and the number of steps of the master transport motor 10 reaches a certain set value, When it is determined that the front end of the master-making master 8Y has reached between the stage 6 and the clamper 7, the clamper 7 is closed by the opening / closing device, and the front-end of the master-making master 8Y is between the stage 6 and the clamper 7. Adsorbed and supported by

  After clamping the front end of the master 8Y, the plate cylinder 1 resumes rotating at a peripheral speed substantially the same as the master transport speed by the rotation of the main motor 20, and the master 8Y is subjected to the platen roller 9 and the transport roller pair 13. Is fed to be wound around the outer peripheral surface of the plate cylinder 1. When it is determined that the plate making to the master 8 and the carrying of the set amount of the plate-making master 8Y have been completed by the rotation driving of the master carrying motor 10 by a predetermined number of steps, the cutter 12 is operated to cut the plate-making master 8Y. At the same time, the rotation of the platen roller 9 and the conveyance roller pair 13 is stopped by stopping the rotation of the master conveyance motor 10.

  Then, when the rear end of the cut master 8Y is drawn out of the plate making unit 15 by the rotation of the plate cylinder 1 and completely wound around the outer peripheral surface of the plate cylinder 1, the plate master 1 has been made. When the winding of the master 8Y is finished, the plate feeding operation is finished. When the winding of the plate-making master 8Y around the plate cylinder 1 is completed, the plate cylinder 1 starts to rotate at a predetermined peripheral speed in the direction of the arrow shown in FIG. Is done. Until the leading edge of the paper 36 crosses / passes the paper detection sensor 32, in other words, until the leading edge of the paper 36 is detected to be on by the paper detection sensor 32, the printing pressure range variable means is in an inoperative state. Thus, the press roller 21 is held at a non-printing position, that is, at an initial position separated from the outer peripheral surface of the plate cylinder 1.

  When the plate cylinder 1 rotates at a low speed in the direction of the arrow, first, the sheet feeding start shading plate is engaged with the sheet feeding registration sensor, so that the sheet feeding registration sensor is turned on to generate a sheet feeding start signal. The signal is a trigger to activate the paper feed motor 37 (start rotation driving). When the paper feed motor 37 is operated, the paper feed roller shaft 33a and the paper feed roller 33 rotate clockwise, so that the uppermost paper 36 on the paper feed tray 35 in contact with the paper feed roller 33 is While being conveyed, the sheet is separated into one sheet by the cooperative action with the separating member 34 and fed toward the nip portion of the registration roller pair 31 on the downstream side in the sheet conveying direction X.

  Next, the plate cylinder 1 further rotates in the direction of the arrow in FIG. 1 and the resist start light-shielding plate engages with the paper feed resist sensor, so that the paper feed resist sensor is turned on and a resist start signal is generated. The registration motor 41 is activated (starts rotational driving) with the signal as a trigger. The registration motor 41 is activated at a predetermined timing when the leading edge of the image area of the single-side plate-making image 8YA in the plate cylinder rotation direction of the plate-making master 8Y wound on the plate cylinder 1 reaches a position corresponding to the press roller 21. It is set to be the timing. When the registration motor 41 is operated, the shaft 31c rotates counterclockwise, so that the sheet 36 that is in contact with and waiting at the nip portion of the registration roller pair 31 is nipped between the plate cylinder 1 and the press roller 21. It is sent out toward part N.

  Next, the leading edge of the paper 36 fed by the registration roller pair 31 is normally entered, that is, the leading edge of the paper 36 is within a predetermined time (or a predetermined power supplied to the registration motor 41) counted by the timer. This signal is input to the control device when the paper detection sensor 32 detects the ON state within the number of pulses. Based on the detection signal of the leading edge of the paper 36 from the paper detection sensor 32 and the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor, the control device operates the printing pressure range variable means.

  The press roller 21 has a sheet on the front end margin that is slightly to the left of the single-side plate-making image 8YA of the plate-making master 8Y whose outer peripheral surface is wound on the surface region 1A or the back surface region 1B of the plate cylinder 1 shown in FIG. 36 is pressed to be displaced to a printing position where printing pressure is applied. At the same time, the press roller drive motor rotates the press roller 21 at a substantially same peripheral speed as the peripheral speed of the plate cylinder 1, so that the press roller 21 rotates in the direction opposite to the rotation direction of the plate cylinder 1. By continuously pressing the paper 36 against the upper master 8Y, so-called printing is performed so that the master 8Y comes into close contact with the outer peripheral surface of the plate cylinder 1 and is filled with ink. In this printing, stencil printing is performed by the ink oozing from the opening portion of the opening 1a of the plate cylinder 1 to the punching portion of the master 8Y and transferred to the surface of the paper 36.

  At this time, the ink roller 2 also rotates in the same direction as the rotation direction of the plate cylinder 1. The ink in the ink reservoir 4 is attached to the surface of the ink roller 2 by the rotation of the ink roller 2, and the amount of the ink is regulated when passing through the gap between the ink roller 2 and the doctor roller 3. Supplied.

In this way, plate printing corresponding to the single-side plate-making image 8YA in the plate-making master 8Y on the plate cylinder 1 is performed, and the plate cylinder 1 is further rotated in the rear end margin portion slightly to the right of the rear end of the single-side plate-making image 8YA. The printing pressure application state by the press roller 21 is released.
When the plate cylinder 1 rotates in the direction of the arrow in FIG. 1 and the clamper 7 reaches the vicinity of the press roller 21 in pressure contact with the plate cylinder 1, the press roller 21 protrudes outward from the outer peripheral surface of the plate cylinder 1. It is separated from the clamper 7 and the interference between the press roller 21 and the clamper 7 is avoided.

  The single-sided printed paper 36 thus subjected to plate printing is further conveyed by the rotation of the plate cylinder 1 in the direction of the arrow in FIG. 1 while being pressed by the press roller 21, and the leading end of the single-sided printed paper 36 is the plate cylinder 1. The separation claw 170 and the separation fan 171 approaching the outer peripheral surface of the sheet are surely separated from the plate-making master 8Y on the plate cylinder 1 by the blowing air, and the separated single-side printed sheet 36 falls downward and is discharged and conveyed. The sheet 47 is conveyed to the downstream side in the sheet conveyance direction X while being attracted and held by the suction force of the suction fan 89 on the upper surface of the sheet discharge belt 88 rotated counterclockwise, and is transferred to the sheet discharge tray 172. Discharged.

  At this time, since the fixed guide 202 is in contact with the press roller 21, the surface-printed paper 36 guided to the paper discharge conveyance unit 47 by the peeling guide 46 enters between the fixed guide 202 and the press roller 21. This is prevented or suppressed, and the surface-printed paper 36 applied to the press roller 21 is prevented or suppressed from being wound and the paper is discharged well.

  When the plate cylinder 1 makes approximately three quarters of a turn from when the press roller 21 contacts the outer peripheral surface of the plate cylinder 1, the press roller 21 returns to a non-printing position away from the outer peripheral surface of the plate cylinder 1. While being held, the plate cylinder 1 rotates again to the home position and stops, and after the plate making operation is finished, the double-sided stencil printing apparatus 200 enters a printing standby state.

  Further, during paper feeding or plate-making, the platen roller 9 and the conveying roller pair 13 resume rotation, and the leading end of the cut master 8 is sent toward the nip portion of the conveying roller pair 13. If it is determined from the number of pulses of the master transport motor 10 that the tip of the cut master 8 has reached the nip portion of the transport roller pair 13 and has been sandwiched, the rotation of the platen roller 9 and the transport roller pair 13 stops, and the next It will be in the state of waiting for plate making in preparation for plate making.

  After the duplex stencil printing apparatus 200 enters the print standby state, when the print start key is pressed after the number of prints is input by the numeric keypad, the paper 36 is continuously fed from the paper supply unit 30 and the printing operation is performed. Done. When the set number of prints (predetermined number) has been consumed, the plate cylinder 1 stops at the home position, and the double-sided stencil printing apparatus 200 enters the print standby state again.

  (Operation Example 2) Next, an operation example 2 in which the duplex printing mode is set and duplex printing is performed will be described. In this operation example 2, the printing pressure range pattern I and the printing pressure range pattern II are used. In operation example 2, in order to facilitate understanding of each operation, a master size of A3 is used, and a document size and a paper size of A4 are used. Hereinafter, the points different from the operation example 1 will be mainly described.

  The user loads A4 size paper 36 as the paper size used for printing on the paper feed tray 35, sets the first A4 size original for front side printing on the image reading unit, and performs various operations on the operation panel. After the plate making conditions are set with the keys, the duplex printing key is pressed to set the duplex printing mode and the plate making start key is pressed.

  When the plate making start key is pressed, a series of operations from discharging to discharging are automatically performed as in the first operation example. Similarly to the first operation example, when the control unit determines that the uppermost sheet 36 of the sheet feeding tray 35 is ready to be fed, the sheet feeding unit 30 enters a sheet feeding standby state. After the plate removal operation similar to Operation Example 1 is performed, the plate cylinder 1 from which all used masters have been peeled off from the outer peripheral surface is stopped at the plate feed standby position as in Operation Example 1, and is opened and closed (not shown) The clamper 7 is opened by the device. In part in parallel with this plate removal operation, the image reading unit performs the reading operation of the first original image for front surface printing in the same manner as in Operation Example 1, and transmits the image data signal to the thermal head driving circuit.

  In part in parallel with the plate discharging operation and the image reading operation, the plate making unit 15 performs plate making by the thermal head 11 as in the first operation example, and the master roll 8a to the master 8 are rotated by the rotation of the platen roller 9 and the conveying roller pair 13. The thermoplastic resin film portion of the master 8 is selectively heated and perforated according to image information while being transported in the master transport direction X1 while being pulled out, and a surface plate-making image 8A for surface printing is formed in the first half portion of the master 8. Is formed (see the divided master-making master 8X shown in FIG. 2).

  Then, the leading end of the divided prepress master 8X is inserted between the clampers 7 which are guided by the master guide plate 14 and expanded with respect to the stage 6, and the number of steps of the master transport motor 10 reaches a certain set value. When it is determined that the leading end of the divided plate-making master 8X has reached between the stage 6 and the clamper 7, the clamper 7 is closed by the opening / closing device, and the leading end of the divided plate-making master 8X is moved to the stage 6 and the clamper 7. Adsorbed and held between.

  After clamping the front end of the divided plate-making master 8X, the plate cylinder 1 resumes rotating at the same peripheral speed as the master conveyance speed by the rotation drive of the main motor 20, so that the divided plate-making master 8X becomes the platen roller 9 and the conveyance roller. The plate 13 is conveyed so as to be wound around the outer peripheral surface of the plate cylinder 1 and fed. When the controller determines that the plate making of the surface plate making image 8A of the divided plate making master 8X shown in FIG. 2 is completed by the number of steps of the master carrying motor 10, the platen roller 9, the carrying roller pair 13, and the plate cylinder are determined. The rotation of No. 1 stops, and a plate-making standby state for plate-making of the back-side plate making image 8B for back-side printing in the next divided plate-making master 8X is entered.

  Next, when the user sets a second A4 size original for back side printing on the image reading unit and presses the plate making start key again, the image reading unit reads the second original image for back side printing. Is performed in the same manner as that for the first original, and the image data signal is transmitted to the thermal head drive circuit. In the plate making unit 15, plate making is performed by the thermal head 11 as in the case of the first document, and the platen roller 9 and the carry roller pair 13 are rotated by the master carrying motor 10 being rotated again. While the master 8 is pulled out from the master roll 8a and transported in the master transport direction X1, the thermoplastic resin film portion of the master 8 is selectively heated and punched according to the image information, and the back surface of the master 8 is back. A back side plate-making image 8B for printing is formed (see FIG. 2).

  At this time, the plate cylinder 1 resumes rotating at a circumferential speed substantially the same as the master conveyance speed, so that the latter half of the divided plate-making master 8X is wound around the outer circumferential surface of the plate cylinder 1 while being drawn out from the plate-making section 15. To go. Then, when the control device determines that the last plate making image 8B of the divided plate-making master 8X has been completed by the number of steps of the master transport motor 10, the cutter 12 operates and the divided plate-making master 8X. The platen roller 9 and the conveying roller pair 13 stop rotating, and the rear end of the divided plate-making master 8X for one plate cut by the rotation of the plate cylinder 1 is in the plate making unit 15. Is completely drawn out, and the winding / plate feeding operation of the divided plate-making master 8X to the plate cylinder 1 is completed.

  When the winding of the divided plate-making master 8X around the plate cylinder 1 is completed, the plate cylinder 1 starts to rotate at a predetermined peripheral speed (usually a low speed for printing), thereby supplying paper for printing. The printing process is started. Similar to the first operation example, the press roller 21 is held in the non-printing position until the leading edge of the paper 36 is detected to be on by the paper detection sensor 32.

  As the plate cylinder 1 rotates in the direction of the arrow, first, the paper feed motor 37 is activated in the same manner as in the operation example 1 by engaging the paper feed start shading plate with the paper feed registration sensor. When the paper feed motor 37 is operated, the uppermost first sheet 36 on the paper feed tray 35 in contact with the paper feed roller 33 is separated while being conveyed through the same operation as in the first operation example. The sheets are separated into a single sheet by the cooperative action with the member 34 and fed toward the nip portion of the registration roller pair 31. After the leading edge of the sheet 36 thus fed comes into contact with the nip portion of the registration roller pair 31, the sheet 36 is held in a state where a predetermined curved deflection is formed at the leading end portion of the sheet 36. Next, when the plate cylinder 1 further rotates in the direction of the arrow in FIG. 1 and the registration start light-shielding plate engages with the paper feeding registration sensor, the registration motor 41 is started in the same manner as in the first operation example. When the registration motor 41 is operated, the sheet 36 that has been waiting in contact with the nip portion of the registration roller pair 31 is directed between the plate cylinder 1 and the press roller 21 at a predetermined timing similar to that in the first operation example. Sent out. At this time, as in the operation example 1, the approach of the leading edge of the paper 36 fed by the registration roller pair 31 is normally detected by the paper detection sensor 32.

Next, on the basis of the detection signal at the leading edge of the sheet 36 from the sheet detection sensor 32 and the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor, the control device operates the printing pressure range variable means as in the first operation example. .
As a result, as shown in FIG. 2, the press roller 21 has a slightly smaller outer surface than the surface plate-making image 8A of the divided plate-making master 8X wound on the surface region 1A of the plate cylinder 1 shown in FIG. The sheet 36 is pressed against the left end margin and displaced to a printing position where printing pressure is applied (see printing pressure ON timing by the press roller 21 in the printing pressure range pattern I shown in FIG. 2). At the same time, the press roller drive motor rotates the press roller 21 at a substantially same peripheral speed as the peripheral speed of the plate cylinder 1, so that the press roller 21 rotates in the direction opposite to the rotation direction of the plate cylinder 1. In order to bring the surface plate-making image 8A of the divided plate-making master 8X into close contact with the outer peripheral surface of the plate cylinder 1 and to fill it with ink by continuously pressing the paper 36 against the surface plate-making image 8A portion of the upper plate-making master 8X. The so-called versioning is performed. In this printing, ink oozes out from the opening portion of the opening 1a of the plate cylinder 1 to the perforated portion of the surface plate-making image 8A in the divided plate-making master 8X, and is transferred to the surface of the paper 36, thereby making stencil printing. Is done.

At this time, the ink roller 2 also rotates in the same direction as the rotation direction of the plate cylinder 1. The ink in the ink reservoir 4 is attached to the surface of the ink roller 2 by the rotation of the ink roller 2, and the amount of the ink is regulated when passing through the gap between the ink roller 2 and the doctor roller 3. Supplied.
Further, the sheet receiving unit 45 occupies the position shown in FIG. 1 and is held and stopped by oscillating and displacing counterclockwise around the drive shaft 155 by the displacing means, and the sheet holding member 64 is shown in FIG. It is displaced to the paper holding position.

  Thus, plate printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 is performed. The front end portion of the surface-printed paper 36 that has been subjected to plate printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 is blown by the air from the peeling claw 170, the peeling guide 46, and the peeling fan 171. It is reliably peeled off from the divided plate-making master 8X on the plate cylinder 1.

  The surface-printed paper 36 peeled from the divided master-making master 8X on the plate cylinder 1 is guided to the paper refeeding means 201 by the peeling guide 46. At this time, since the fixed guide 202 is in contact with the press roller 21, the surface-printed paper 36 guided to the refeed unit 201 by the peeling guide 46 enters between the fixed guide 202 and the press roller 21. This is prevented or suppressed, and the surface-printed paper 36 applied to the press roller 21 is prevented or suppressed from being wound.

  The front end of the surface-printed paper 36 guided to the re-feeding means 201 along the upper surface of the fixed guide without being caught by the press roller 21 by the fixed guide 202 is pinched by the paper holding means 60, and the paper is held in this state. The member 64 is displaced toward the standby position. When the paper holding member 64 occupies the standby position, the front end of the front surface-printed paper 36 is released, and the front surface-printed paper 36 drops toward the conveyance belt 158 and is sucked, but the front surface-printed paper 36 skews When the conveyor belt 158 is adsorbed, the posture is corrected to be substantially straight with respect to the traveling direction until the conveyance belt 158 is sucked, and the skew feeding is corrected by the skew feeding preventing means 151.

When the vicinity of the rear end of the surface prepress image 8A reaches the rotational position corresponding to the printing nip portion N due to the rotation of the plate cylinder 1, the control device, based on the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor, The press roller 21 is held in a state where it is separated from the printing position and occupies a substantially non-printing position.
At this time, when the swing motor 96 of the displacing means is driven, the sheet receiver 45 is swung clockwise with the drive shaft 155 as a fulcrum, thereby occupying the position shown in FIG.

When the rear end of the front surface printed paper 36 passes the re-feed sensor and the front end of the front surface printed paper 36 is restricted by the stopper 203, the rotational driving of the belt drive motor 150 is stopped.
When it is determined that the plate cylinder 1 has reached the predetermined position, the belt drive motor 90 is driven again, and the conveyor belt 158 is rotated counterclockwise at a linear speed substantially the same as the peripheral speed of the plate cylinder 1.

  At the same time, the press roller drive motor is driven to rotate, whereby the press roller 21 is rotated counterclockwise, and the refeed resist roller 51 is displaced upward so as to contact the press roller 21. Thus, the front end of the surface-printed paper 36 regulated by the stopper 203 is sandwiched between the press roller 21 that rotates counterclockwise and the re-feeding registration roller 51 that rotates clockwise following this. However, the plate cylinder 1 and the press roller 21 are guided by the roller guide plate 50 so as to be conveyed along the outer peripheral surface of the press roller 21 at a substantially same peripheral speed as that of the plate cylinder 1. The paper is conveyed while being turned upside down toward the nip portion N formed by the pressure contact.

  In parallel with this conveyance, when the predetermined rotation position of the plate cylinder 1, that is, the vicinity of the front end of the back plate-making image 8B on the divided plate-making master 8X on the plate cylinder 1 reaches the rotation position corresponding to the nip portion N, the press roller No. 21 is a printing pressure by pressing the back surface of the surface-printed paper 36 against the leading edge portion slightly left of the back plate-making image 8B of the divided plate-making master 8X whose outer peripheral surface is wound on the back surface region 1B of the plate cylinder 1. Is displaced to a printing position for applying printing, and double-sided printing for printing is performed (see printing pressure ON timing by the press roller 21 in the printing pressure range pattern II shown in FIG. 2).

  In this way, the double-sided printed paper 36 for printing on which double-sided printing has been performed corresponding to the backside plate-making image 8B in the divided pre-made master 8X on the plate cylinder 1 is the same as the discharge operation of the single-sided printed paper 36. The double-sided printed paper 36 that has been peeled off from the divided master-making master 8X on the plate cylinder 1 by the air from the peeling claw 170 and the peeling fan 171 whose front end approaches the outer peripheral surface of the plate cylinder 1 is peeled off. The paper falls to the lower side and is sent to the paper discharge conveyance unit 47, and is conveyed to the downstream side in the paper conveyance direction X while being attracted and held by the suction force of the suction fan 89 on the upper surface of the paper discharge belt 88. To be discharged.

  At this time, since the fixed guide 202 is in contact with the press roller 21, the surface-printed paper 36 guided to the paper discharge conveyance unit 47 by the peeling guide 46 enters between the fixed guide 202 and the press roller 21. This is prevented or suppressed, and the surface-printed paper 36 applied to the press roller 21 is prevented or suppressed from being wound and the paper is discharged well.

  Since the double-sided printed paper 36 printed by printing is always in a substantially straight posture on the paper receiver 45 with respect to the traveling direction, the position where the printing is performed by the front plate making image 8A and the back plate making. The position where printing is performed by the image 8B is exactly the same, and there is no image position shift.

  On the other hand, when the plate cylinder 1 makes approximately three quarters of a turn from when the press roller 21 contacts the outer peripheral surface of the plate cylinder 1, the press roller 21 returns to a non-printing position away from the outer peripheral surface of the plate cylinder 1. The plate cylinder 1 is again rotated to the home position and stopped. After the plate setting operation is completed, the duplex stencil printing apparatus 200 enters a printing standby state for the next regular duplex printing.

  After the duplex stencil printing apparatus 200 enters the print standby state, when the print start key is pressed after the number of prints is input by the numeric keypad, the paper 36 is continuously fed from the paper supply unit 30 and the printing operation is performed. Done. When the set number of prints (predetermined number) has been consumed, the plate cylinder 1 stops at the home position, and the double-sided stencil printing apparatus 200 enters the print standby state again.

  In the normal regular duplex printing operation, the set number of duplex printings is performed every two rotations of the plate cylinder 1, and the odd number of rotations of the plate cylinder 1 corresponds to the surface plate-making image 8A of the divided plate-making master 8X. When printing is performed evenly by the plate cylinder 1, back side printing corresponding to the back side plate making image 8B of the divided plate-making master 8X is performed in this order.

  When the plate cylinder 1 rotates at an odd number, the surface-printed paper 36 peeled from the divided master-making master 8X on the plate cylinder 1 is guided to the paper re-feeding means 201 by the peeling guide 46, but the fixed guide 202 is pressed by the press roller 21. , The surface printed sheet 36 guided to the sheet refeeding unit 201 by the peeling guide 46 is prevented or suppressed from entering between the fixed guide 202 and the press roller 21, and the press roller 21. It is prevented or suppressed that the surface-printed paper 36 is wound and wound.

  Even when the plate cylinder 1 rotates evenly, the fixed guide 202 is in contact with the press roller 21, so that the surface printing is guided between the fixed guide 202 and the press roller 21 to the paper discharge conveying means 47 by the peeling guide 46. The entrance of the used paper 36 is prevented or suppressed, and the surface-printed paper 36 applied to the press roller 21 is prevented or suppressed from being wound and the paper is discharged satisfactorily.

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

For example, when the contact member does not occupy a fixed position but is configured to keep the contact member in contact with the pressing body, the entire contact member is displaced together with the pressing body. May be.
The printing apparatus to which the present invention is applied may be not only a double-sided printing apparatus but also a single-sided printing apparatus, and a plurality of plate cylinders may be provided. For example, color printing is performed using a plurality of plate cylinders. It may be a thing. The pressing body may be an impression cylinder instead of a press roller.
As a sheet used for printing, in addition to plain paper generally used for copying or the like, cardboard, cardboard, cardboard, recording media such as envelopes, and printing media can be used.

  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.

It is a front view which shows the outline of the contact member to which this invention is applied, and a printing apparatus provided with the same. FIG. 2 is a diagram for developing and explaining three printing pressure range patterns applied corresponding to a master on a plate cylinder used in the printing apparatus shown in FIG. 1. It is a top view of the contact member shown in FIG. It is a sectional side view of the flexible member with which the contact member shown in FIG. 1 is equipped. It is a side view which shows the structure by which the flexible member with which the contact member is provided is supported by the contact member so that rotation is possible. It is a front view of another state of the printing apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate cylinder 8, 8Y, 8X Stencil paper 21 Press body 36 Sheet 46 Guide means 201 Refeeding means 202 Contact member 204 Contact member main body 205 Flexible member, contact part N Opposite of press body and plate cylinder Part X Sheet transport direction

Claims (4)

When the pressing body for pressing the sheet against the stencil sheet on the plate cylinder presses the sheet against the stencil sheet on the plate cylinder, the sheet is prevented from entering between the pressing body. An abutting member having a flexible member that abuts against the pressing body on the downstream side of the facing portion between the pressing body and the plate cylinder in the conveying direction. The contact member according to claim 1,
The contact member, wherein the flexible member is rotatably supported by the contact member main body . A printing apparatus comprising the contact member according to claim 1. A printing method for performing printing using the printing apparatus according to claim 3.

Images