JP5082624B2 - Stencil printing machine - Google Patents

Description

  The present invention relates to a stencil printing apparatus capable of performing double-sided printing on the front and back surfaces of a sheet, and more specifically, a master as a stencil sheet in which a first image and a second image are made side by side within the length of one plate. The present invention relates to a stencil printing apparatus that performs printing by winding paper around the outer peripheral surface of a printing drum and automatically re-feeding under a single printing drum configuration.

A heat-sensitive digital stencil printing apparatus is known, in which a perforated master is wound on a rotatable plate cylinder having a structure in which a mesh screen made of resin or metal mesh is wound around a porous support cylinder. Then, ink is supplied from the ink supply member provided inside the plate cylinder, the ink is oozed out from the plate cylinder opening part and the master punching part, and the paper is continuously pressed to the plate cylinder side by a press roller or the like. And printing.
The stencil master used here has a laminate structure in which a thermoplastic resin film and a Japanese paper fiber or synthetic fiber of a porous support, or a mixture of Japanese paper and synthetic fiber are bonded together. The master wound around the plate cylinder is brought into contact with the heating element of the thermal head to form a perforated plate according to the original image, and the master perforated portion oozes ink passing through the plate cylinder opening. Printing on paper.
In JP-A-6-48014 (Patent Document 1), ink is extruded from a stencil printing base paper, transferred onto an ink receptor, and further transferred onto a printing medium to be printed. A stencil printing apparatus capable of transferring an appropriate amount of ink is disclosed.

  The opening portion of the porous cylindrical plate cylinder used in such a conventional stencil printing apparatus is set in accordance with the maximum paper to be printed. For example, when A3 paper is the maximum paper, the opening length is about 420 mm. In the case of small size paper, a printing cylinder is used, and there are a lot of blank parts that are not used for printing, and there is a disadvantage that the master is wasted together with ink that is attached to the master and discarded. . Japanese Patent Application Laid-Open No. 64-24783 (Japanese Patent No. 2625437) (Patent Document 2) discloses a pre-made heat-sensitive stencil sheet which is detected in accordance with the size of a sheet set in a paper feeding unit and drawn out according to the size. A stencil printing apparatus is disclosed in which the cutting length of the paper is changed and adjusted, thereby eliminating wasteful consumption of the base paper when forming a printed matter having a small size.

  By the way, in order to reduce the consumption of printing paper, duplex printing has been performed in which printing is performed on both the front and back sides of printing paper. In such double-sided printing, in general, the printing sheets stacked on the sheet feeding unit are separated and fed one by one, and after printing on one side, the printed sheets discharged and stacked on the discharge tray are again printed. A method has been proposed in which the paper is turned upside down and fed, and the other side is printed. In this double-sided printing method, printing in the same process is performed twice, which increases the printing time and necessitates the work of neatly aligning printing paper that has already been printed on one side and setting it again in the paper feed unit. It was very troublesome to be.

In order to cope with this situation, a double-sided printing device has been proposed that allows two printing drums to face each other and simultaneously print on both sides with a single pass (single paper transport). When printing, there are restrictions such as the need to wind an unprocessed master to prevent ink transfer from the printing drum on one side to the back of the printing paper, and the master is wasted and the operation is troublesome. There was a problem.
Therefore, it is desired to propose a device that can print on both sides in one pass by printing with two plate cylinders facing each other. However, the size of the device is increased, and when printing on one side, the printing from one plate cylinder is required. In order to prevent ink transfer, there is a restriction such as winding a plate-free master. Under such conditions, the master is unnecessarily consumed and the operation is troublesome.

Therefore, a method has been attempted in which the plate cylinder surface is divided into two, and the printing is performed on both sides by reversing the paper with respect to the front and rear plate surfaces while the pressing means is continuously pressed against the plate cylinder.
For example, in Japanese Patent Laid-Open No. 2003-200355 (Patent Document 3), a master in which a first image and a second image are arranged in the conveyance direction of printing paper within a length of one plate is used as a printing drum. While winding around the outer peripheral surface and controlling the pressing timing of the press roller against the printing drum, the printing paper with the surface printed thereon is guided to the refeeding means by the discharge direction switching means, and the peripheral surface of the press roller by the refeeding means A double-sided printing apparatus has been proposed in which the paper is reversed and fed again, and after the back side printing is finished, the paper is discharged.

In this method, the printing paper that has been printed on one side is in contact with the surface of the press roller for paper re-feeding in a state where the ink has not been sufficiently dried. The paper tends to get dirty. In order to suppress ink adhesion to the press roller, a cleaning roller for cleaning the surface of the press roller is provided.
When performing such double-sided printing, it is necessary to transport the surface-printed printing paper again to the refeeding means by the discharge direction switching means. As a sheet conveying unit in the sheet re-feeding unit and a conveying unit used for normal sheet discharge, for example, as disclosed in JP-A-60-148864 (Patent Document 4), a belt is provided between rollers. A paper discharge transport device is used that is stretched and transported while being sucked by a fan, etc., whereby the paper is reversed and re-fed along the peripheral surface of the press roller, or sent to a paper discharge tray. Yes.

JP-A-6-48014 JP-A 64-24783 JP 2003-200355 A JP-A-60-148864

However, when performing double-sided printing, the paper after single-sided printing that has been peeled off from the plate cylinder and sucked and transported by the transport means is affected by the size of the image, the deviation of the image, unevenness of the air pressure due to the waist of the paper or the peeling fan, etc. As a result, peeling from the plate cylinder becomes non-uniform. As a result, when the sheet is conveyed in a slightly skewed state, the pressing means remains in a state skewed with respect to the conveying direction. It will be sent to. In such a case, an image position shift (referred to as a vertical registration) in the transport direction of the second surface printed in reverse may be large.
In addition, since printing is performed while continuously reversing the front and back with a single plate cylinder, it is difficult to operate by changing only the image position on the reversal side to the direction orthogonal to the transport direction. There is a problem.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a stencil printing apparatus that can prevent image position deviation on the second surface by moving an image in a direction orthogonal to the sheet conveying direction by a sheet conveying device of a refeed unit. To do.

In order to achieve the above object, in the first aspect of the present invention, the master in which the first image for front side printing and the second image for back side printing are arranged side by side within the length of one plate by the plate making means. Is wound around the outer peripheral surface of a porous cylindrical plate cylinder supported so as to be rotatable about its own central axis, and is substantially front and rear of the plate cylinder by a pressing member which is relatively movable toward and away from the plate cylinder. One-side printing is performed by pressing the sheet against the first surface divided into two, and the sheet is reversed by a refeeding means disposed below the plate cylinder, and the reversed sheet is applied to the second surface of the plate cylinder. in the stencil printing device for performing side printed was pressed by the pressing member, the sheet conveying device of the re-feeding means transporting the pair of guide members and the sheet for regulating a position in a direction orthogonal to the conveying direction of the sheet A conveyor belt stretched around a pair of conveyor rollers A mechanism for moving the pair of guide members toward and away from each other in a direction perpendicular to the sheet conveyance in order to move the print image position of the second surface with respect to the sheet in a direction orthogonal to the sheet conveyance; A mechanism that inclines the conveyor belt with respect to the conveyance direction by moving one of the pair of conveyance rollers in a direction perpendicular to the sheet conveyance direction, and the guide member movement mechanism and the conveyance according to an image position setting value A stencil printing apparatus characterized by drivingly controlling a roller moving mechanism .

According to a second aspect of the present invention, in the stencil printing apparatus according to the first aspect , one pivot member of each of the pair of transport rollers and each guide member are formed to be connectable via an interlocking member, and the one transport At least one of the pair of guide members is switched and held in the same direction in conjunction with the switching in the direction orthogonal to the sheet conveyance direction by the roller.

According to the first aspect of the present invention, the guide member that regulates the side edge portion of the sheet that is sucked and conveyed by the sheet conveyance device, and the conveyance belt that is controlled to be slightly inclined according to the image position setting value. Even if the sheet is placed in a skewed state during conveyance , the sheet can be conveyed while being moved in the direction of the side wall of the guide member so that the sheet can be corrected straightly with respect to the traveling direction of the sheet. Therefore, deterioration of the vertical registration of the paper is prevented, and in particular, the image movement in the direction orthogonal to the paper conveyance direction on the second surface can be easily performed.

According to the invention described in claim 2, since the interlocking member switches at least one of the pair of guide members in the same direction in accordance with the switching of the pair of transport rollers in the direction orthogonal to the one transport direction, The operation of tilting the belt and moving and conveying the sheet obliquely can be easily performed with a simple structure.

FIG. 1 shows a stencil printing apparatus adopting an embodiment of the present invention. The stencil printing apparatus includes a printing unit 120, a plate making unit 130, a paper feeding unit 140, a plate discharging unit 150, a paper discharging unit 160, an image reading unit 170, a pressing unit 180, a refeeding unit 190, a switching member 23, and the like. ing. As will be described later, the paper refeeding unit 190 includes a paper refeeding guide unit 200, a transport device lower portion 55 as a paper transport device, and a guide unit 240.
The printing unit 120 disposed almost at the center of the apparatus main body 100 includes a plate cylinder 1 that forms a printing drum and a press roller 15 as a pressing unit 180. The plate cylinder 1 is rotatably supported by the apparatus main body 100 and is driven to rotate by a plate cylinder driving means (not shown). The plate cylinder 1 has an openable / closable clamper 7 on its outer peripheral surface, and a divided pre-made master 8 (see FIG. 3) made by the plate making unit 130 is wound around the outer peripheral surface of the plate cylinder 1 during double-sided printing. Be dressed. The divided plate-making master 8 is formed with a first plate-making image (first surface 8A image) corresponding to the front surface image and a second plate-making image (second surface 8B image) corresponding to the back surface image. A plate making portion 8C is formed between 8A and the second surface 8B.

On the plate cylinder 1, the divided plate-making master 8 has a first plate-making image 8A in the front surface area e1 shown in FIG. 1, a second plate-making image 8B in the same back surface region e2, and a non-plate-making part 8C in the same intermediate region e3. Each is wound to correspond. A rotary encoder (not shown) for detecting the position of the plate cylinder 1 is provided in the vicinity of the outer peripheral surface of the plate cylinder 1.
On the upper left side of the plate cylinder 1, a plate making unit 130 for making the master 8 based on image information is disposed. In the plate making section 130, the master 8 is wound as a master roll 8a, and the roll core 8b is rotatably supported by holder means (not shown).
The master 8 is pressed against a platen roller 9 rotatably supported by a plate making side plate (not shown) by a thermal head 10 having innumerable heating elements. The platen roller 9 is driven to rotate clockwise by a stepping motor (not shown), so that the master 8 is fed out from the master roll 8a.

The thermal head 10 is urged toward the platen roller 9 by a material such as a spring portion (not shown). On the downstream side of the platen roller 9 in the master conveyance direction, a conveyance roller pair 12 is provided that is rotatably supported in a state where the plate-making side plates (not shown) are pressed against each other. The conveying roller pair 12 is set at a speed slightly higher than the peripheral speed of the platen roller 9, and applies an appropriate tension to the master 8 while sliding with the master 8.
A cutter 11 is provided on the upstream side of the pair of conveying rollers 12 to cut the master 8 made into a plate to an appropriate length. The cutter 11 is a guillotine type composed of an upper blade 11a and a lower blade 11b. The cutter may be a rotary blade moving type or the like. A master guide plate 13 that is fixed between plate making side plates (not shown) and guides the tip of the master 8 is provided. These constitute the plate making unit 130.

An image reading unit 170 is disposed on the upper part of the apparatus main body. The image reading unit 170 focuses a contact glass (not shown), a pressure plate (not shown) provided so as to be able to come in contact with and away from the contact glass, a reflection mirror and a fluorescent lamp (not shown) that scan and read a document image, and a scanned image, respectively. The lens includes a lens (not shown), an image sensor (not shown) that processes a focused image, and the like.
The image information of the document read by the image reading unit 170 is sent to a control unit (not shown) (for example, a main controller of the duplex printing apparatus). Based on this image information, the thermal head 10 of the plate making unit 130 is driven by the control means, and the heating element is energized to carry out the heat perforation plate making. A control unit (not shown) inputs a command for normal single-sided printing or double-sided printing by an operator through an operation panel (not shown) at an appropriate time.

The plate cylinder 1 has a configuration in which a plurality of layers of resin or metal mesh mesh screens are wound on the outer peripheral surface of a porous support cylindrical body, and is rotatably supported by an ink pipe 5 as a support shaft (not shown). It is fixed to the flange. The plate cylinder 1 is driven to rotate clockwise by a driving force transmitted from a driving source (not shown) by a driving transmission means (gear or the like) (not shown).
Inside the plate cylinder 1, there is provided an ink roller 2 in which an ink roller shaft is rotatably supported by a side plate (not shown) fixed to the ink pipe 5, and the ink roller 2 is provided with a drive transmission means (gear not shown). , A belt or the like) and is rotated in the same direction in synchronization with the plate cylinder 1. A doctor roller 3 is provided with a slight gap from the outer peripheral surface of the ink roller 2, and the ink in the ink reservoir 4 formed in the wedge-shaped space between the ink roller 2 and the doctor roller 3 by the doctor roller 3 is transferred to the ink roller 2. Is supplied to the outer surface of the film in a thin film.

The ink in the ink reservoir 4 is sucked from an ink pack or the like provided outside the plate cylinder 1 by an ink supply device (not shown) and supplied dropwise from a supply hole 5 a of the ink pipe 5.
The plate cylinder 1 has an opening 1a through which ink can pass and a non-opening 1b. On the surface of the non-opening portion 1b, a stage 6 made of a magnetic material is provided in a state parallel to the rotation center line of the plate cylinder 1. A clamper shaft 7a is rotatably supported in parallel with the stage 6, and the clamper 7 is integrally fixed to the clamper shaft 7a. The clamper 7 is opened and closed at a predetermined position by an opening / closing device (not shown).
The plate cylinder 1 is provided integrally with an ink pack or the like in its own axial direction with respect to the apparatus main body 100, that is, is detachably provided as one unit. It is provided so that movement can be adjusted.
On the lower side of the plate cylinder 1, a pressing means 180 that can freely contact and separate from the plate cylinder 1 is disposed.

As shown in FIG. 2, the pressing means 180 includes an arm shaft 16 a that is rotatably supported by a device body side plate (not shown), a press roller 16 fixed to one end of the arm shaft 16 a, and a press roller 16. And a press roller 15 as a pressing member that rotatably supports the shaft portion.
As shown in FIG. 2, a rotatable cam follower 160 is provided on the lower end side with respect to the arm shaft 16 a of the arm 210. The cam follower 160 is urged so as to come into contact with a plurality of cams 211 rotatably supported by an apparatus main body side plate (not shown) by a spring 212 or the like. The plurality of cams 211 rotate in synchronization with the plate cylinder 1 by driving means (not shown), and function to bring the press roller 15 into contact with or separate from the plate cylinder 1 at a predetermined position.
Here, a method is adopted in which a plurality of cams 210 are switched and the pressing range is switched as in the first surface 8A, the second surface 8B, and the whole. The press roller 15 is rotationally driven in a direction opposite to the plate cylinder 1 at substantially the same peripheral speed as the plate cylinder 1. That is, the printing pressure range by the press roller 15 is switched by a cam as in the method described in Patent Document 3 described above.

  As shown in FIG. 2, a refeed resist roller 17 is disposed below the press roller 15. The roller-shaped refeed resist roller 17 is rotatably supported on a support shaft 17a, and the support shaft 17a is attached to one end of a swing arm 220 as a refeed resist support member. The swinging arm 220 having a substantially square shape is supported by a support shaft 220a fixed to the arm 16 so that the bent portion can swing freely. At the other end of the swing arm 220, a plunger 231 of a solenoid 230 attached to the arm 16 via a bracket (not shown) and one end are fixed to the one arm 16 and the support shaft 220 a is centered with respect to the swing arm 220. In FIG. 2, the other end of the tension spring 232 for attaching a rotation biasing force in the counterclockwise direction is attached. With this configuration, the re-feeding registration roller 17 occupies the press contact position indicated by the solid line in FIG. 2, which presses the peripheral surface thereof against the peripheral surface of the press roller 15 with a predetermined press contact force when the solenoid 230 is operated. When the operation is released, the peripheral surface of the tension spring 232 is separated from the peripheral surface of the press roller 15 by the urging force of the tension spring 232, and occupies a separation position indicated by a two-dot chain line in FIG. The re-feed resist contact / separation mechanism 235 is configured by the solenoid 230 and the tension spring 232.

As shown in FIGS. 1 and 2, a roller guide plate 18 that is curved close to the surface of the press roller 15 is provided on the right side of the press roller 15. The surface of the roller guide plate 18 is coated with Teflon (registered trademark) resin or the like having a low friction coefficient in order to reduce the resistance of the printing paper during conveyance (during re-feeding).
The outer surface of the press roller 15 is uniformly formed with glass beads or the like used for preventing smearing of printed matter by an offset printing machine or the like, and is contacted with the surface of the plate cylinder 1 or printed later. The contamination of the image surface of the paper 45 due to ink or the like is reduced as much as possible.

  As shown in FIG. 1, a paper feeding device 35 as a feeding unit is disposed on the right side of the press roller 15. The paper feeding device 35 includes a paper feeding tray 36 that stacks and stores paper 45 as recording media, a paper feeding roller 37 that separates and feeds the stacked printing paper 45 one by one, and printing that is separated and fed. A registration roller pair 14 is provided that conveys the paper 45 toward a printing nip portion between the plate cylinder 1 and the press roller 15 at a predetermined timing.

  As shown in FIG. 1, on the left side of the plate cylinder 1, a peeling claw 26 that is rotatably supported in the vicinity of the plate cylinder 1 and compressed air is blown onto the surface of the plate cylinder 1 to peel off the paper 45. A peeling fan 27 is provided. Under the peeling claw 26, a paper discharge conveying device 38 constituting the discharge means 160 is provided. The paper discharge conveying device 38 is rotatably supported between the apparatus main body side plates (not shown), and is provided with a front discharge roller 19 and a rear discharge roller 20 that are driven to rotate counterclockwise by a drive device (not shown). A paper discharge belt 21 wound around the paper rollers and a suction fan 22 that sucks the paper 45 onto the surface of the paper discharge belt 21 are provided.

A switching guide plate 23 serving as a switching member is fixed between the paper discharge conveyance device 38 and the press roller 15 on a shaft that is rotatably supported by a housing side plate (not shown). The switching guide plate 23 is swung (vertically moved) at a predetermined position by a driving means (solenoid, stepping motor, etc.) not shown. Usually, it is held at the position shown in FIG.
Here, a discharge tray 123 on which the discharged sheets 45 are stacked is arranged on the left side of the discharge conveyance device 38.
As shown in FIGS. 1 and 2, a paper refeeding unit 190 is provided at the lower part of the paper discharge transport device 38. The paper refeeding unit 190 includes a paper refeeding guide unit 200, a transport device lower part 55 as a paper transport device, and a guide unit 240.

As shown in FIG. 2, the paper refeeding guide unit 200 is provided on the upper portion of the lower part 55 of the transport device, and the single-sided (front surface) printed paper 45 </ b> A switched to the refeeding unit 190 by the switching guide plate 23. The sheet 45 </ b> A is set in a state in which the sheet can be temporarily held (refer to FIG. 4) and guided to the lower part 55 of the conveying device, so that the sheet can be re-fed to the lower part 55 of the conveying device.
Here, as shown in FIG. 2, the refeed guide means 200 includes a moving guide 81 that temporarily holds the leading end of the printing paper 45A that has been printed on one side, and a belt feed mechanism that reciprocates the moving guide 81. And a reciprocating drive mechanism 82 (represented schematically by a two-dot chain line in FIG. 2).
The moving guide 81 has a moving bracket 83 driven (reciprocated) by a reciprocating driving mechanism 82, and a holding member 84 provided on the moving bracket 83 in a direction orthogonal to the feeding direction of the printing paper 45A.

The holding member 84 clamps the front end of the front surface printed paper 45A at a moving position P1 (indicated by a two-dot chain line in FIG. 2) as a first position in the vicinity of the printing nip, and is lower than the moving position P1. It reaches an initial position P2 (shown by a solid line in FIG. 2) as a second position in the vicinity of the upstream side of the paper feeding means 56, and, for example, as shown in FIG. Then, a function as a sheet clamping means is provided.
Such a holding member 84 sandwiches the front end portion of the front surface printed paper 45A and holds the front end portion of the front surface printed paper 45A. A clamp claw 84c that can be freely opened and closed, a torsion coil spring (not shown) that biases the free end of the clamp claw 84c against the upper surface of the clamping table 84a, and a back side of the paper surface of the clamp shaft 84d that is integrated with the clamp claw 84c. A fixed release lever 84f extending vertically, a movement position P1 for releasing the release lever 84f, and vertical stoppers 84s1 and 84s2 at the initial position P2 are configured.

Here, a pair of protrusions 83a are integrally formed on both side ends of the sandwiching base 84a, and these are guides for the device body side plate pair (a part of which is shown in a rectangular shape with a two-dot chain line in FIG. 2). The groove 85 is loosely fitted. A mounting portion 86 is integrally provided at a lower portion of the moving bracket 83 on the back side of the drawing surface, and is connected to a feed belt Bt on the reciprocating drive mechanism 82 side.
When the movement guide 81 occupies the movement position P1 (see FIGS. 2 and 3), the integral release lever 84f comes into contact with the upper stopper St1 via the clamp pawl 84c and the clamp shaft 84d and is temporarily released. After that, when it is separated from the upper stopper St1, it can operate so as to pinch the front end portion of the surface-printed paper 45A. When the movement guide 81 reaches the initial position P2 (see FIGS. 2 and 4), the release lever 84f integrated with the clamp pawl 84c is brought into contact with the lower stopper St2 to be released, and the front surface printed paper 45A is moved downward. Guide on the lower part 55.

As shown in FIG. 2, a lower conveying device 55 and a guide unit 240 are provided below the refeed guide unit 200.
The lower part 55 of the transport device is endlessly wound around the right transport roller right 40, the left transport roller left 41, and the pair of left and right transport rollers as viewed from the front side of the main body (front view in FIG. 1). And a suction fan 43 that sucks the printing paper 45 on the surface of the conveyor belt 42.
The lower part 55 of the conveying device includes a substantially rectangular casing 551, and the casing 551 is supported so as to be slidable with respect to the main body side plate (not shown) via the rotation shaft 411 of the conveying roller left 41. Protruding pins 553 (see FIG. 6) on the left and right side walls on the sliding end side of the casing 551 are engaged with the elongated holes 161 of the pair of left and right arms 16. As a result, the conveying device lower portion 55 is interlocked with the contact / separation operation of the press roller 15 with respect to the plate cylinder 1, that is, interlocked with the arm 16, and the conveying roller right 40 is moved up and down around the rotation shaft 411 of the conveying roller left 41 Swing (movement) can be switched in the direction.

As shown in FIG. 5, an input gear 56 is fixed to one end of the rotation shaft 411 of the transport roller left 41, and a rotational force from a drive source (not shown) is transmitted to the end via a gear train 57. Yes. As a result, the conveyor belt 42 is intermittently driven at a predetermined timing.
As shown in FIG. 6, a guide portion 240 is attached to the casing 551 of the lower conveying device 55. The guide part 240 supports the front and rear guides 50 and 51 having an L-shaped cross section located on the front side and the back side of the lower part 55 of the transport device as viewed from the operator side, and the guide front and rear parts 50 and 51 are slidably supported on the casing 551. The guide recesses 552 and 553 at the front and rear positions, the rack front and rear 501 and 511 which extend below the guide front and rear 50 and 51 and bend and extend opposite to each other, and the rack front and rear 501 and 511 and the middle part of each other And a drive source 53 (see FIG. 2) composed of a reduction gear and a drive motor for driving the change gear 52. Here, using a rack and pinion mechanism comprising rack front and rear 501 and 511 and a switching gear 52 that meshes with each other, position adjustment in a direction perpendicular to the conveyance direction F of the sheet 45A, that is, on the sheet 45A by the second surface 8B. The image position will be adjusted.

As shown in FIG. 6, the switching gear 52 that meshes with the connected rack front and rear 501 and 511 in the center rotates in the forward and reverse directions, so that the guide front and rear 50 and 51 are switched in the approaching and detaching directions by equal amounts. Has become free.
Face plates (not shown) are provided between the transport belt 42 and the rack front and rear 501 and 511, and do not affect the suction state or the movement range of the guide front and rear 50 and 51, the rotation and movement of the transport rollers 40 and 41, and the like. In this way, the opening is provided in the necessary part.

As shown in FIG. 6, the transport roller right 40 is formed such that the rotation shaft 401 is movable by a predetermined amount in the axial direction by a driving means 70 including a reduction gear 701 and a step motor 702. The amount of movement of the transport roller right 40 is input to the operation panel (not shown) by inputting a value corresponding to the image position in the direction A perpendicular to the transport direction (traveling direction) F to the second surface 8B. , 51 in conjunction with the movement.
For example, in FIG. 7, assuming that the image is input so as to move 5 mm to the back side, the front and rear guides 50 and 51 open 5 mm to the left and right, the conveyance roller right 40 also moves about 5 mm in the arrow → direction, and the conveyance belt 42 It is controlled so as to be inclined to the front side (right side in FIG. 7). Conversely, for example, in FIG. 8, assuming that the image is input so as to move 5 mm to the front side (front side), the front and rear guides 50 and 51 and the conveyance roller right 40 also move about 5 mm in the direction of the arrow → 42 is controlled to be inclined to the rear side (left side in FIG. 8).

The printing operation of the stencil printing apparatus based on the above configuration will be described.
The duplex printing mode is selected, and the guide front and rear 50 and 51 are appropriately moved and set in accordance with the size of the stacked paper 45. The conveyance roller right 40 is also held at the initial position (solid line position in FIG. 6). When it is determined by a paper feed tray sensor (not shown) that compatible paper 45 is loaded, a start signal (such as a start button is pressed) after a document is set on the image reading unit 170. As a result, the plate cylinder 1 is rotated by a drive motor (not shown). For example, as shown by a broken line in FIG. 1, the used master 8 ′ is peeled off from the surface of the plate cylinder 1 by the plate discharging unit 150 and discarded. Is done.

The plate cylinder 1 rotates and stops until the clamper 7 is in a position almost directly above. When the plate cylinder 1 is stopped, the clamper shaft 7a is rotated by an unillustrated opening / closing device, whereby the clamper 7 is opened and a plate feeding standby state is entered.
The document is sent to the image reading unit 170, and first image information of the document is first taken into a control unit (not shown), and the heating element of the thermal head 10 is energized in a pulsed manner according to the first image information. . The thermal head 10 operates in the main scanning direction, and a stepping motor (not shown) rotates to convey the master 8 in the sub-scanning direction by the platen roller 9, and plate making of the front half of the thermal film of the master 8 is started.

When the front end of the master 8 is guided between the stage 6 and the clamper 7 by the master guide plate 13 and it is determined that the front end of the master 8 has reached the clamper 7 from the number of steps of the stepping motor (not shown), the opening / closing device (not shown) The clamper 7 is closed and the leading end portion of the master 8 is clamped, and the plate cylinder 1 resumes rotation at a speed substantially the same as the master conveyance speed, and the master 8 thus made is wound.
If it is determined from the number of steps of a stepping motor (not shown) that the plate making of the image on the first surface 8A (see FIG. 3) has been completed, the platen roller 9 and the conveying roller pair 12 are stopped, and the next second image is displayed. It becomes a plate making standby state. Next, the original is automatically or reset on the original reading unit, and the original is sent to the original reading unit in the same manner as described above by a start signal (such as pressing the start button again), and the plate making of the remaining second surface 8B is performed. The same is done.

If it is determined from the number of steps of the stepping motor (not shown) that the plate-making of the image on the second surface 8B (see FIG. 3) has been completed, the cutter 11 operates to cut the master 8 and the platen roller 9 stops. Then, the rear end of the cut master 8 is pulled out, and the winding around the plate cylinder 1 is completed.
When the winding of the master 8 around the plate cylinder 1 is completed, only one sheet 45 is fed out by the paper feed roller 37 and is timed by the registration roller pair 14 to perform printing between the plate cylinder 1 and the press roller 15. It is conveyed toward the nip part.
When the paper detection means (not shown) detects the entry of the printing paper 45, the locking means (not shown) is released, and the cam follower 160 moves to the concave portion of the cam 211 along with the rotation of the cam 211.

As a result, the press roller 15 continuously presses the printing paper 45 against the plate cylinder 1 by the urging spring 212, and printing is started to fill the image on the first surface 8 </ b> A of the master 8 with ink. In parallel with this operation, when the clamper 7 of the plate cylinder 1 passes, the switching guide plate 23 is rotated counterclockwise as shown in FIG. It stops at the position where it is guided to the paper means 56.
At this time, the movement guide 81 also moves obliquely upward from the standby position (initial position P2) toward the movement position P1 so as to sandwich the leading end portion of the printing paper 45. At this time, as shown in FIG. 2, the release lever 84f rides on the upper stopper St1, and the clamp pawl 84c rotates in the clockwise direction and stops and waits.
When the moving guide 81 stops, the printing paper 45A is peeled from the plate cylinder 1 by the switching guide plate 23 and the peeling fan 27, guided to the lower surface of the clamping base 84a, and inserted into the gap between the clamping claw 84c.

When the leading end of the printing paper 45A is inserted, the movement guide 81 starts to move to the initial position P2 at almost the same speed as the conveyance speed of the printing paper 45, and the release lever 84f is disengaged from the upper stopper St1. The clamping claw 84c is rotated counterclockwise by the torsion coil spring that does not hold, and sandwiches the leading end of the printing paper 45A. As shown in FIG. 5, the leading end of the printing paper 45A is fixed downward (initial position P2). ).
In response to the switching operation of the cam 211, the press roller 15 is pressed within the range of the first image, and then separated from the plate cylinder 1 to return to the initial position and stop (see FIG. 5). The sheet 45A is conveyed by the movement guide 81, and when the movement guide 81 stops at the initial position P2, as shown in FIG. 2, the release lever 84f contacts the lower stopper 84s1, and the clamp pawl 84c rotates clockwise. It is released by doing.

The switching guide plate 23 is controlled to rotate clockwise when the rear end of the sheet 45 passes and to return to the initial position shown in FIGS.
The sheet 45A is sucked and fixed to the conveying belt 42 by the suction fan 43 of the conveying means 55, and the conveying belt 42 rotates in the clockwise direction so that the end surface of the printing sheet 45A is close to the nip portion between the press roller 15 and the roller 17. Transport to position and stop.
At this time, the side edge portion of the paper 45 is conveyed while the skew state is corrected by the front and back guide plates 50 and 51.

Here, if it is determined that the next rotation of the plate cylinder 1 has reached the position corresponding to the position of the second surface 8B, the conveyance belt 42 rotates clockwise again at approximately the same speed as the speed of the plate cylinder 1. Then, the conveyance of the paper 45A on which the first surface 8A is printed is started.
At this time, the press roller 15 is also controlled to be pressed at a position corresponding only to the second surface 8B by the action of the cam 211.
The sheet 45 </ b> A is inserted into the nip portion between the press roller 15 and the roller roller 17, guided by the curved roller guide plate 18 while being sandwiched, and conveyed toward the nip portion between the plate cylinder 1 and the press roller 15.
The sheet 45A is pressed against the plate cylinder 1 by the press roller 15, and printing is performed to fill the second surface 8B with ink. The sheet 45 </ b> A is separated from the plate cylinder 1 by the sheet discharge claw 26 and the separation fan 27 that are close to and separated from the plate cylinder 1, sucked and conveyed by the sheet discharge belt 21, and discharged to the sheet discharge tray 123.

Next, a case where the print image position is changed with reference to the discharged paper 45 will be described.
The image movement in the direction orthogonal to the conveyance direction F of the first surface 8A can be performed by moving a plate cylinder support unit (not shown) that supports the plate cylinder 1 in the axial direction of the plate cylinder 1.
The movement of the first surface 8A in the transport direction F (paper traveling direction) is performed by changing the transport timing of the paper 45 by an input operation on an operation panel (not shown).
If the image movement in the direction orthogonal to the conveyance direction F of the second surface 8B is on the front (front) side, the image moves as shown in FIGS. At this time, the movement amount of the second surface 8B is set in consideration of the movement amount of the plate cylinder 1 set on the first surface 8A.

  The sheet 45 </ b> A on the second surface 8 </ b> B is conveyed while being gradually moved in a direction in contact with the side surfaces of the guide front and rear 50, 51 by the inclined conveyance belt 42, until the sheet 45 </ b> A approaches the nip portion between the roller 17 and the press roller 15. Correction is made by contacting the side surfaces of the front and rear guides 50 and 51. Thereafter, after the trial printing by the operator, the set number of sheets is printed or the set number of sheets is printed as it is.

As described above, in the stencil printing apparatus shown in FIG. 1, the front and rear guides 50 and 51 (guides) that restrict the movement of the side edge of the sheet 45A that is sucked and transported by the transport device lower part 55 in the direction perpendicular to the transport direction F. Member) is provided, and even when the paper 45A is placed in a skewed state during conveyance, it is conveyed while being moved in the direction of the side walls of the guide front and rear 50, 51 by the slightly inclined conveyance belt 42. The skew of the sheet 45A can be corrected to the movement state in the transport direction F.
As described above, the sheet 45A can be corrected straight in the transport direction F, so that the vertical registration of the sheet is prevented from deteriorating, and the image position of the second surface 8B is shifted. Can be avoided.

  Furthermore, in the conventional apparatus, the first surface 8A and the second surface 8B are sequentially used in a state where the press roller is continuously pressed against a single plate cylinder, so that the plate is printed during printing of the first surface 8A. Although it was difficult to move the second surface 8B of the cylinder, in the stencil printing apparatus, the width in which the front of the front and rear transport rollers 40 and 41 is orthogonal to the transport direction F of the paper 45 according to the image position setting value. Since the configuration is such that the conveyance belt 42 of the sheet conveying apparatus is tilted with respect to the conveying direction F by moving the sheet 45A in the direction, and the sheet 45A is moved and conveyed obliquely so as to be aligned. The image can be easily moved in the direction orthogonal to the conveyance direction F of the 8B paper.

Here, in the stencil printing apparatus of FIG. 1, only the front of the front and rear of the transport rollers 40 and 41 is switched to the width direction perpendicular to the transport direction, but only the rear of the front and rear of the transport roller is orthogonal to the transport direction depending on the case. Switching movement in the width direction may be performed, and the front and rear transport rollers 40 and 41 may be switched and moved in the width direction relatively. In these cases as well, substantially the same effect as the stencil printing apparatus of FIG. 1 can be obtained.
Further, in the stencil printing apparatus of FIG. 1, the front and rear guides 50 and 51 for regulating the edge of the paper are switched according to the image position setting value, and the transport rollers 40 and 41 are moved in the same manner to move the transport belt 42. Since the sheet is moved and conveyed obliquely and aligned, the image movement in the direction perpendicular to the conveyance direction F of the sheet 45A on the second surface 8B can be reliably and easily performed.

Further, since the rack and pinion mechanism is used to operate the front and rear guides 50 and 51 (guide members) for regulating the side edge of the paper in the stencil printing apparatus of FIG. 1, the front and rear guides 50 and 51 (guide members) can be easily operated. ) In the direction orthogonal to the transport direction F, that is, the image position on the sheet 45A can be adjusted.
A second embodiment will be described with reference to FIG.
FIG. 9 shows a transport device lower portion 55a employed in the stencil printing apparatus according to the second embodiment of the present invention.

The conveying device lower part 55a has the same configuration as that of the stencil printing apparatus of FIG. 1 except for the other components other than the conveying device lower part 55 in the first embodiment, and therefore, the redundant description other than the conveying device lower part 55a is omitted.
The transport device lower portion 55 has a transport roller right 40 at the front, a transport roller left 41 at the rear in the transport direction F of the paper 45, a transport belt 42 as an endless belt wound around these rollers, A suction fan 43 for sucking the printing paper 45 is provided on the surface of the conveyor belt 42. The lower part 55 of the conveying device has a substantially rectangular casing 551, a rotation shaft 411 of the conveying roller left 41 supported so as to be slidable with respect to a main body side plate (not shown), and a sliding end side of the casing 551 between the pair of left and right arms 16. An ejecting pin 553 that engages with the elongated hole 161 is provided, and in conjunction with the arm 16, the conveying roller right 40 is swung in the vertical direction about the rotation shaft 411 of the conveying roller left 41 as a fulcrum. Further, a rotational force from a drive source (not shown) is transmitted via a gear train 57 to the rotation shaft 411 of the conveyance roller left 41.

A guide portion 240a different from the guide portion 240 in the first embodiment is attached to the casing 551a of the transport device lower portion 55a.
This guide portion 240 supports L-shaped guide front and rear 50, 51 positioned on the front side and the back side of the lower part 55a of the transport device as viewed from the operator side, and supports the guide front and rear 50, 51 slidably on the casing 551a. The guide recesses 552 and 553 at the front and rear positions, the interlocking members front and rear 502 and 512 that extend below the guide front and rear 50 and 51, bend and extend so that the respective pressing portions face each other, and the conveyance roller right 40 And a slider 60 that is rotatably held in the center of the rotary shaft 401 in the axial direction.
The slider 60 is pivotally supported by the rotary shaft 401 and is linked in the axial direction, an extension portion 602 extending rearward in the conveying direction F therefrom, and the pressing portions 503 and 513 at the tip of the extension portion. And a locking portion 603 that is disposed in the space and selectively presses the pressing portion.

  The front and rear interlocking members 502 and 512 are formed such that pressing portions 503 and 513 facing each other can be brought into contact with the stopper members 61 and 62, and are urged toward each other by a return spring (not shown). Therefore, the pressing portions 503 and 513 come into contact with the stopper members 61 and 62, respectively, at the time of steady operation, and at this time, the guide front and rear 50 and 51 integral with the interlocking members front and rear 502 and 512 are substantially center guide positions which are reference home positions. Held at P0. In addition, it is pressed by the pressing portions 503 and 513 of the slider 60 on the right side of the transport roller 40 and is linked to the same direction and perpendicular to the transport direction F, that is, approaching and leaving the other front and rear guides 50 and 51 facing each other. Switching movement in the direction is free.

  As a result, the transport device lower portion 55a in the second embodiment cooperates with the attached guide portion 240a even if the paper 45 is placed in a skewed state during transport, as in the first embodiment. Since the belt is moved while being moved in the direction of the side walls of the guide front and rear 50, 51 by the slightly inclined conveyance belt, it can be corrected straightly with respect to the conveyance direction of the sheet. Deterioration of the vertical resist, which is misaligned in the conveyance direction, is prevented, and problems such as misalignment of the image position on the second surface do not occur.

  According to the stencil printing apparatus of FIG. 9 as described above, one of the front and rear guides 50 and 51, in which the interlocking member 60 is a pair of guide members, is moved in accordance with the switching in the direction orthogonal to the transport direction F of the transport roller front 40. Since switching is performed in conjunction with the direction, the operation of tilting the transport belt 42 and moving and transporting the paper 45A obliquely can be easily performed with a simple structure.

1 is a schematic front view of a stencil printing apparatus according to a first embodiment of the present invention. FIG. 2 is an enlarged schematic front view of main parts of a refeeding unit and its peripheral members of the stencil printing apparatus of FIG. 1. It is the schematic of the master used with the stencil printing apparatus of FIG. It is a schematic front view which shows the state which the movement guide of the stencil printing apparatus of FIG. 1 located in the movement position. FIG. 2 is a schematic front view showing a state in which a movement guide of the stencil printing apparatus of FIG. 1 holds a printing sheet on which single-side printing has been performed and reaches an initial position. It is a schematic plan view explaining the function in the conveyance apparatus lower part of the stencil printing apparatus of FIG. It is the schematic explaining the 1st switching function in the conveyance apparatus lower part of the stencil printing apparatus of FIG. It is the schematic explaining the 2nd switching function in the conveyance apparatus lower part of the stencil printing apparatus of FIG. It is a general | schematic top view of the stencil printing apparatus in the 2nd Embodiment of this invention.

Explanation of symbols

1 Plate cylinder 8 Master 15 Press roller (pressing means)
23 Switching member 42 Conveying belt 50, 51 Guide member 55 Conveying device lower part (paper conveying device)
DESCRIPTION OF SYMBOLS 120 Printing part 130 Plate making means 150 Plate discharging part 190 Refeeding means 200 Refeeding guide means 240 Guide part a1 1st surface a2 2nd surface

Claims (2)

Porous material that is supported by a plate making means so that the master, in which the first image for front surface printing and the second image for back surface printing are arranged side by side within the length of one plate, is rotatable about its own central axis. Single-sided printing is performed by winding a sheet on the outer peripheral surface of a cylindrical plate cylinder and pressing a sheet on a first surface that is divided into two substantially front and rear sides of the plate cylinder by a pressing member that is relatively movable toward and away from the plate cylinder. In the stencil printing apparatus for performing the other side printing by reversing the paper by a refeeding means disposed below the plate cylinder and pressing the reversed paper against the second surface of the plate cylinder by the pressing member,
The sheet feeding device of the refeeding means includes a pair of guide members that regulate positions in a direction orthogonal to the sheet feeding direction and a conveyor belt that is stretched between a pair of feeding rollers that feed the sheet in the feeding direction. And a mechanism for moving the pair of guide members toward and away from each other in a direction perpendicular to the sheet conveyance in order to move the print image position of the second surface with respect to the sheet in a direction orthogonal to the sheet conveyance; A mechanism that inclines the conveyor belt with respect to the conveyance direction by moving one of the pair of conveyance rollers in a direction perpendicular to the sheet conveyance direction, and the guide member movement mechanism and the mechanism according to an image position setting value A stencil printing apparatus characterized by drivingly controlling a conveyance roller moving mechanism . In the stencil printing apparatus according to claim 1 ,
One pivot member of each of the pair of conveyance rollers and each guide member are formed to be connectable via an interlocking member, and in conjunction with switching to a direction orthogonal to the sheet conveyance direction by the one conveyance roller, The stencil printing apparatus according to claim 1, wherein at least one of the pair of guide members is switched and held in the same direction .

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