JP2006001135A - Printing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide printing equipment which enables performance of a platemaking operation without being aware of a copy size even in the case of double-side printing using a copy including that of a different size and enables prevention of a useless platemaking operation. <P>SOLUTION: A double-side cancellation mode wherein a double-side printing mode is canceled and the platemaking by a platemaking section is made undone and an automatic variable magnification mode wherein the magnification of a platemaking image made into a plate in the platemaking section is changed automatically to that of a prescribed size or a user set mode wherein an equipment user is made to set an arbitrary mode, can be set as the modes which function on the occasion when the double-side printing mode, wherein the double-side printing can be performed, is set. When the size of the copy having a copy image to be printed on both of the front and back sides of paper is a prescribed one, the platemaking image corresponding to the prescribed size is made into the plate in the platemaking section, and when the copy size is not a prescribed one, an operation corresponding to the double-side cancellation mode, the automatic variable magnification mode or the user set mode is performed in the platemaking section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing apparatus capable of printing on both sides of a sheet, and more particularly to a printing apparatus capable of good plate making and printing without worrying about the document size.

In the field of printing apparatuses, double-sided printing apparatuses that can automatically print on both sides of a sheet have been actively developed, and various types of double-sided printing apparatuses have been proposed. For example, a so-called two-sided continuous master for duplex printing in which plate-making images corresponding to a first document image and a second document image are arranged in a master having a length corresponding to one plate is used as an outer peripheral surface of a printing drum. Patent Document 1 discloses a printing apparatus that obtains a printed image by winding a sheet onto a double-sided printing master of the printing drum and pressing a sheet with a printing pressure member that can freely come into contact with the printing drum.
A printing drum mounted on a printing apparatus that performs double-sided printing has an outer peripheral surface length around which an A3 size master is wound, so that the master corresponds to the first and second original images. When making each plate-making image at once, plate-making images corresponding to two documents cannot be made unless they are A4 size or smaller. For this reason, when performing duplex printing, the document size is naturally limited to A4 size or smaller.
However, since there are various sizes of originals and the originals may be read in a mixed state in some cases, Patent Document 2 discloses an image data size to be output on the front side of the paper and an image to be output on the back side of the paper. An image processing apparatus is described that compares the data size and scales the image so as to correspond to one of the sizes. Patent Document 3 discloses a document size and a paper size when performing two-sided continuous printing. A printing apparatus for automatically scaling a plate-making image formed on a master has been proposed.

JP 2002-172839 A JP 2004-48531 A JP 2001-260512 A

In the printing apparatus and the image processing apparatus described in the above-mentioned patent document, the plate-making image and the image can be scaled according to the document size. However, when the document size when performing duplex printing is, for example, A3 size, In some cases, the A3 size may be used for making a double-sided printing.
It is an object of the present invention to provide a printing apparatus capable of performing plate making operation without being aware of the document size and preventing wasteful plate making operation even when performing duplex printing using a document including different sizes. Objective.

In order to solve the above-described problems and achieve the above object, the present invention provides a double-sided image in which plate-making images corresponding to the first document image and the second document image are arranged in a master having a length corresponding to one plate. A plate making unit capable of making a printing master, and a printing pressure member capable of making contact with and separating from a printing drum wound around an outer peripheral surface of a master for duplex printing made by the plate making unit, the paper on the printing drum As a mode that functions when a duplex printing mode capable of performing duplex printing is set in a printing apparatus capable of duplex printing, including a printing unit that obtains a printed image by being pressed against the master for duplex printing. Cancels the mode and cancels the double-sided cancellation mode in which the plate making by the plate making unit is not made, automatic scaling mode that automatically changes the plate making image made by the plate making unit to a predetermined size, or allows the user to set any mode User setting mode De are possible setting,
When the size of the document having each document image is a predetermined size, a plate-making image corresponding to the predetermined size is made by the plate-making unit, and when the document size is not the predetermined size, the duplex release mode and the automatic scaling mode are selected. Or it has the control means which performs the operation | movement corresponding to a user setting mode in a plate-making part.

  In the present invention, the arbitrary mode is a mode in which a forced plate making mode corresponding to the document size or a cancel mode in which plate making is not executed regardless of the document size is selected. The printing apparatus according to the present invention includes an image reading unit that reads an image of a document, and a document size detection unit that detects the size of the document that can be read by the image reading unit. The control unit is a document size detection unit. A document size is determined based on the detected document size information, and a plate making operation is executed by the plate making unit based on the document image read by the image reading unit. This is a so-called printing apparatus in which an image reading unit and a plate making unit are mounted on a printing apparatus, and enables processing by the printing apparatus alone.

  In the printing apparatus according to the present invention, each information of the document size, the first document image, and the second document image is information transmitted from an external device that can communicate with the printing apparatus main body, and the control unit includes the external device. The document size is determined based on the document size, the first document image, and the second document image information transmitted from, and the plate-making unit executes a plate-making operation. That is, the printing apparatus is connected to an information processing apparatus such as a personal computer or a portable terminal device, and receives and prints document image data processed by these information processing apparatuses.

  According to the present invention, as a mode that functions when a duplex printing mode capable of performing duplex printing is set, a duplex release mode that cancels the duplex printing mode and makes the plate making by the plate making unit unmade, When an automatic scaling mode for automatically scaling a plate-making image to be made to a predetermined size and a user setting mode for allowing an apparatus user to set an arbitrary mode can be set, and the size of a document having each document image is a predetermined size Control means for making a plate-making image corresponding to the predetermined size at the plate-making unit, and executing the plate-making corresponding to the double-side release mode, the automatic scaling mode or the user setting mode when the document size is not the predetermined size. Therefore, in the case of a document of a predetermined size, the plate-making unit normally performs the plate-making, and when it is not a document of the predetermined size, the plate-making is canceled or the document size Operations according to whether or the user setting mode is automatically zooming is performed by the stencil making section according. For this reason, even when performing double-sided printing using originals containing different sizes, it is possible to perform the plate making operation without being aware of the original size and to prevent useless plate making operations.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a printing apparatus capable of duplex printing (hereinafter referred to as “double-side printing apparatus”). The duplex printing apparatus includes a printing unit 2, a plate making unit 3, a paper feeding unit 4, a plate discharging unit 5, a paper discharging unit 6, an image reading unit 7, an auxiliary tray 8, a refeed unit 9, a switching member 10, and the like. Yes.

  The printing unit 2 disposed almost at the center of the printing apparatus main body 11 has a plate cylinder 12 as a printing drum and a press roller 13 as a printing pressure member. The plate cylinder 12 includes a pair of flanges (not shown) that are rotatably supported by a support shaft 14 that also serves as an ink supply pipe, a porous support plate (not shown) wound around the outer peripheral surface of each flange, and a porosity (not shown). It is mainly composed of a mesh screen (not shown) wound around the outer peripheral surface of the support plate, and is configured to be rotationally driven by the plate cylinder driving means 121 (see FIG. 6) and to be detachable from the printing apparatus main body 11. Has been. In the present embodiment, the plate cylinder 12 has a size capable of obtaining a maximum A3 size printed material during single-sided printing.

  An ink supply means 15 is disposed inside the plate cylinder 12. The ink supply means 15 includes a support shaft 14, an ink roller 16, a doctor roller 17, and the like. The ink roller 16 is rotatably supported between side plates (not shown) provided in the plate cylinder 12, and its peripheral surface is disposed in the vicinity of the inner peripheral surface of the plate cylinder 12. 12 is rotated in the same direction. The doctor roller 17 is also rotatably supported between the side plates, and the peripheral surface thereof is disposed in the vicinity of the peripheral surface of the ink roller 16 and is rotationally driven in a direction opposite to the plate cylinder 12 by a driving means (not shown). . A plurality of small holes are formed in the support shaft 14, and the ink supplied from the support shaft 14 is collected in a wedge-shaped space formed in the vicinity of the ink roller 16 and the doctor roller 17. A reservoir 18 is formed.

  On the outer peripheral surface of the plate cylinder 12, a stage portion (not shown) that forms a plane along one generatrix of the plate cylinder 12 is formed, and on this, the tip of the master is held on the outer peripheral surface of the plate cylinder 12. A clamper 19 is provided. The clamper 19 is opened and closed by opening / closing means (not shown) when the plate cylinder 12 is rotated to a predetermined position.

  A press roller 13 is disposed below the plate cylinder 12. The press roller 13 is configured by winding an elastic body such as rubber around a metal core 13 a and is provided to extend in the axial direction of the plate cylinder 12. As shown in FIG. 2, the press roller 13 is rotatably supported by a pair of arm members 20 serving as press roller support members at both ends of the core portion 13a. Each arm member 20 having an approximately L-shape is integrated by a swing shaft 21 attached to a portion near the bent portion, and the swing shaft 21 is rotatably supported by the printing apparatus main body 11. ing. In this embodiment, the press roller 13 is composed of a member having ink repellency such as polytetrafluoroethylene resin at least on the peripheral surface thereof.

  Between each arm member 20, in addition to the press roller 13, a refeed guide member 22, a refeed resist roller 23 as a refeed resist member, a refeed positioning member 24, a refeed transport member 25, and a cleaning A cleaning roller 26 and a guide plate 27 as members are provided.

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

  A refeed resist roller 23 is disposed below the press roller 13. The roller-shaped refeed resist roller 23 is rotatably supported by a support shaft 23a, and the support shaft 23a is attached to one end of a swing arm 32 as a refeed resist support member. The swinging arm 32 having a substantially square shape is supported by a support shaft 32a fixed between the arm members 20 so that the bent portion can swing freely. It is determined so that it is located in the substantially center part of the width direction of the press roller 13, and is located in the middle of the arrangement | positioning position of each roller 30. FIG. At the other end of the swing arm 32, a plunger 33a of a solenoid 33 attached to one arm member 20 via a bracket (not shown) and one end are fixed to the one arm member 20 and supported with respect to the swing arm 32. The other end of the tension spring 34 is attached to the shaft 32a to give a rotational biasing force in the counterclockwise direction in FIG. With this configuration, the re-feeding registration roller 23 occupies the press contact position indicated by the solid line in FIG. 2 that presses the peripheral surface thereof against the peripheral surface of the press roller 13 with a predetermined press contact force when the solenoid 33 is operated. When the operation is released, the peripheral surface is separated from the peripheral surface of the press roller 13 by the urging force of the tension spring 34 and occupies a separation position indicated by a two-dot chain line in FIG. The re-feeding resist contact / separation mechanism 40 is constituted by the solenoid 33 and the tension spring 34.

  A refeed positioning member 24 is disposed near the upper portion of the refeed resist roller 23. The sheet refeeding positioning member 24 is made of a plate material having an L-shaped cross section, and is formed so that the width thereof is substantially the same as the width of the press roller 13, and the bent end portion 24 a faces upward. The portion is fixed to each arm member 20. The refeed positioning member 24 has a notch (not shown) for preventing the refeed registration roller 23 from colliding with the swing.

  A refeed conveyance member 25 is disposed below the press roller 13 and to the left of the refeed positioning member 24. The refeed conveyance member 25 includes a conveyance member main body 35, a driving roller 36, a driven roller 37, an endless belt 38, a suction fan 39, and the like, and an auxiliary tray 8 is integrally provided on the upper surface thereof.

  The transport member main body 35, which is a housing whose upper surface is opened and whose width is slightly smaller than the interval between the arm members 20, has bearings (not shown) on both the upstream and downstream sides in the paper transport direction. Each bearing (not shown) rotatably supports the drive shaft 36a and the driven shaft 37a. Both ends of the drive shaft 36a pass through both side surfaces of the transport member main body 35, and the both ends penetrated are rotatably supported by bearing members (not shown) provided in the printing apparatus main body 11. A drive gear (not shown) is attached to one end of the drive shaft 36a, and the drive shaft 36a is rotationally driven by a conveying member drive motor 122 (see FIG. 6) provided in the printing apparatus main body 11. The driven shaft 37a is configured such that both ends thereof do not penetrate both side surfaces of the conveying member main body 35. Bosses 35a are integrally provided on both outer sides of the upstream end of the conveying member body 35 in the sheet conveying direction, and each boss 35a is fitted in a long hole (not shown) formed in each arm member 20, respectively. Has been. With this configuration, the transport member main body 35 is centered on the drive shaft 36a as each arm member 20 swings when the press roller 13 is brought into and out of contact with the plate cylinder 12 by a press roller contact / separation mechanism 55 described later. Rocking is possible.

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

A suction fan 39 is integrally attached to the lower surface of the conveying member main body 35, and the auxiliary tray 8 is integrally attached to the upper surface of the conveying member main body 35. The auxiliary tray 8 is formed with a plurality of openings (not shown) for allowing the endless belts 38 to face the sheet conveying surface, and a fence for receiving the sheet P being conveyed at the downstream end in the sheet conveying direction. 8a is integrally formed. A hole (not shown) is provided on the lower surface of the conveying member main body 35, which is a mounting surface of the suction fan 39, and the suction fan 39 is activated thereby to apply a negative pressure to the inside of the conveying member main body 35, which is a casing. The sheet P is sucked onto the upper surface of each endless belt 38 that is generated and moved. The suction force of the suction fan 39 and the frictional resistance of the endless belt 38 are determined between the sheet P and each endless belt 38 when the leading end of the sheet P comes into contact with the bent end 24a of the refeed positioning member 24. The strength is set so that slipping occurs.
The above-described refeed guide member 22, refeed resist roller 23, refeed positioning member 24, and refeed transport member 25 constitute a refeed unit 9.

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

  A guide plate 27 is disposed on the upper left side of the cleaning roller 26. Both ends of the guide plate 27, which is a plate material, are fixed to each arm member 20. The sheet P pressed against the plate cylinder 12 by the press roller 13 does not touch the cleaning roller 26 and is attached to the auxiliary tray 8. Guide you to head. The guide plate 27 is disposed at a position close to the peripheral surfaces of the press roller 13 and the cleaning roller 26.

  On the other end side of each arm member 20 opposite to the one end side where the press roller 13 is supported, rotatable cam followers 41 are arranged in such a manner as to face each other. In addition, the other end of the printing spring 42 having one end fixed to the printing apparatus main body 11 is attached in the vicinity of the position where the cam follower 41 of each arm member 20 is disposed. As a result, each arm member 20 is given a rotational biasing force in the clockwise direction in the drawing around the swing shaft 21.

  In the vicinity of the left side of each cam follower 41, a multistage cam 43 having three cam plates 43A, 43B, 43C is disposed. Each cam plate 43A, 43B, 43C is fixed to a cam shaft 44 supported at both ends by the printing apparatus main body 11 and movably in the paper surface direction of FIG. The cam plate 43B, the cam plate 43A, and the cam plate 43C are arranged in this order. Each of the cam plates 43A, 43B, and 43C has a base portion that is a disc concentric with the cam shaft 44 and a convex portion having the same protruding amount. As shown in FIG. 4, the multistage cam 43 is driven by a plate cylinder via a drive gear 45 attached to the cam shaft 44 and a transmission gear 47 attached to a support shaft 46 that is rotatably supported by the printing apparatus main body 11. The rotational force from the means 121 is transmitted, and it is driven to rotate in the clockwise direction in FIG.

  The press roller 13 occupies the separation position shown in FIG. 2 where the circumferential surface is separated from the circumferential surface of the plate cylinder 12 when any convex portion of each of the cam plates 43A, 43B, 43C comes into contact with the cam follower 41. When the contact between any of the convex portions and the cam follower 41 is released, the peripheral surface occupies the press contact position shown in FIG. 3 where the peripheral surface presses the peripheral surface of the plate cylinder 12 by the urging force of the printing pressure spring 42. Each of the cam plates 43A, 43B, and 43C is configured such that the base portion and the cam follower 41 do not come into contact with each other when the press roller 13 occupies the press contact position. The convex portions of the cam plates 43A, 43B, and 43C are such that the contact range between the press roller 13 and the plate cylinder 12 is a range in which the front surface region, the intermediate region, and the back surface region shown in FIG. Thus, the cam plate 43B is formed so as to be in the same range as the surface region, and the cam plate 43C is formed so as to be in the combined range of the downstream portion of the surface region, the intermediate region, and the back surface region. The intervals between the cam plates 43A, 43B, 43C are set to be sufficiently larger than the plate thickness of the arm member 20.

  In FIG. 2, press roller locking means (not shown) that prohibits the swinging of each arm member 20 in a state where the press roller 13 occupies the separated position is disposed near the right side of each arm member 20. A press roller locking means (not shown) has a solenoid (not shown), and a state of holding each arm member 20 and a state of releasing the holding are selectively switched by switching on / off of the solenoid (not shown). A solenoid (not shown) is operated in a state where the cam follower 41 is in contact with any one of the convex portions of the cam plates 43A, 43B, and 43C.

  As shown in FIG. 4, a moving arm 48 and a step cam 49 are disposed near the lower portion of the cam shaft 44. The moving arm 48 having a substantially L shape has a bent portion attached to a support shaft 48a that is rotatably supported by the printing apparatus main body 11. A roller 48b is provided at one end of the moving arm 48, and the other end is provided at the other end. Each cam follower 48c is rotatably attached. Furthermore, the other end of the tension spring 50 having one end attached to the printing apparatus main body 11 is attached to a portion between the other end of the moving arm 48 and the bent portion, and the moving arm 48 is centered on a support shaft 48a. Further, in the drawing, a rotational biasing force in the clockwise direction is applied.

  The roller 48 b is disposed between the discs 44 a and 44 b that are fixed to each other in the middle of the cam shaft 44, and the cam follower 48 c has its peripheral surface brought into contact with the peripheral surface of the step cam 49 by the biasing force of the tension spring 50. It is in contact. The interval between the discs 44a and 44b is set to be slightly larger than the diameter of the roller 48b.

  The step cam 49 has three cam portions 49 a, 49 b, 49 c on its peripheral surface, and is fixed to a support shaft 51 that is rotatably supported by the printing apparatus main body 11. A gear 54 that meshes with a gear 53 attached to an output shaft of a stepping motor 52 attached to the printing apparatus main body 11 is attached to the support shaft 51. By the operation of the stepping motor 52, the step cam 49 is shown in FIG. It is rotationally driven in the direction of the arrow. With this configuration, when the stepping motor 52 operates and the step cam 49 rotates, the moving arm 48 swings about the support shaft 48a, and the roller 48b pushes the disk 44a or the disk 44b so that the camshaft 44 is illustrated. 4 in the left-right direction.

  Each cam portion 49a, 49b, 49c is in contact with the cam follower 48c and the cam portion 49b so that the cam plate 43B is in a position where the cam follower 41 can come into contact with the cam follower 41 when the cam follower 48c and the cam portion 49a contact each other. When the cam follower 48c and the cam portion 49c come into contact with each other so that the cam plate 43A comes into contact with the cam follower 41, the cam shaft 44C comes into contact with the cam follower 41. Each is formed in a shape to be moved.

  The above-described cam follower 41, printing pressure spring 42, multi-stage cam 43, press roller locking means (not shown), moving arm 48, and step cam 49 constitute a press roller contact / separation mechanism 55. By the operation, the press roller 13 selectively occupies the separated position shown in FIG. 2 and the press contact position shown in FIG.

  On the left side of the contact position between the plate cylinder 12 and the press roller 13 and on the transport path of the paper P, a switching member 10 for switching the transport path of the paper P is disposed. The switching member 10 made of a plate material having substantially the same width as the plate cylinder 12 and the press roller 13 is fixed to a support shaft rotatably supported by the printing apparatus main body 11 at the downstream end in the paper conveyance direction. The upstream end of the sheet conveying direction formed with an acute cross section when the solenoid 123 (see FIG. 6) is activated is selected between a first position indicated by a solid line and a second position indicated by a two-dot chain line in FIG. Positioned. When the switching member 10 occupies the first position, the tip of the switching member 10 is close to the peripheral surface of the press roller 13 and does not interfere with the clamper 19 on the plate cylinder 12 and occupies the second position. The tip of the plate cylinder 12 is placed close to the peripheral surface of the plate cylinder 12. The paper P that has passed between the plate cylinder 12 and the press roller 13 is guided to the paper discharge unit 6 when the switching member 10 occupies the first position, and the switching member 10 occupies the second position. Sometimes it is guided to the auxiliary tray 8 through between the guide plate 27 and the guide plate 56 fixed to the printing apparatus main body 11.

  A plate making unit 3 is disposed in the upper right part of the printing apparatus main body 11. The plate making unit 3 includes a master holding member 57, a platen roller 58, a thermal head 59, a cutting means 60, a master stock unit 61, a tension roller pair 62, a reverse roller pair 63, and the like. The plate making unit 3 performs plate making on a master 64, which will be described later, and a first plate making image 65A corresponding to the first document image and a second plate making image 65B corresponding to the second document image as shown in FIG. Or a master plate having a third plate-making image 66A having an image amount area corresponding to two sides of the first plate-making image 65A and the second plate-making image 65B as shown in FIG. 5B. 66 is created. The first plate-making image 65A is formed at a position corresponding to the front surface region shown in FIG. 1 when the double-sided printing master 65 is wound on the outer peripheral surface of the plate cylinder 12, and the second plate-making image 65B is a back surface region. It is formed at the corresponding position.

  The master holding member 57 is provided on each pair of side plates (not shown) of the printing apparatus main body 11, and a master roll 64a formed by winding a master 64 in which a thermoplastic resin film and a porous support are bonded together into a roll shape. Both ends of the core part 64b are supported rotatably and detachably.

  A platen roller 58 provided on the left side of the master holding member 57 is rotatably supported on a side plate (not shown) of the printing apparatus main body 11 and is rotationally driven by a plate making driving means 124 (see FIG. 6) including a stepping motor. . A thermal head 59 having a large number of heat generating elements located below the platen roller 58 is attached to a side plate (not shown) of the printing apparatus main body 11, and the surface of the heat generating element is applied to the platen roller 58 by a biasing force of a biasing means (not shown). It is in pressure contact. The thermal head 59 selectively generates heat from the heating element while being in contact with the thermoplastic resin film surface of the master 64, and performs hot melt perforation plate making on the master 64.

  A cutting means 60 is disposed on the left side of the platen roller 58 and the thermal head 59. The cutting means 60 having a fixed blade 60a fixed to a frame (not shown) of the printing apparatus main body 11 and a movable blade 60b movably supported by the fixed blade 60a has a movable blade 60b with respect to the fixed blade 60a. This is a well-known configuration in which the master 64 is cut by rotating.

  A master stock section 61 is disposed below the cutting means 60 on the downstream side in the master conveyance direction. The master stock section 61, which is a space for temporarily storing the double-sided printing master 65 or the pre-printed master 66, is partitioned by a plurality of plate members, and a suction fan (not shown) is provided at the innermost portion. Has been. When this suction fan is operated, negative pressure is generated inside the master stock unit 61 that is a sealed space, and the master 65 for duplex printing or the master 66 that has been made by plate making is transported by the master stock unit 61. It is stored towards the innermost part.

  A tension roller pair 62 is disposed at a portion between the cutting means 60 and the master stock portion 61. A tension roller pair 62 composed of a driving roller 62a and a driven roller 62b that are rotatably supported by a side plate (not shown) of the printing apparatus main body 11, respectively, has a circumferential surface of the driving roller 62a. The master roller 64 is sandwiched and conveyed by the driving roller 62 a being rotationally driven by the plate-making driving means 124. The drive roller 62 a has a peripheral speed set slightly higher than the peripheral speed of the platen roller 58, and a torque limiter (not shown) is provided in the drive roller 62 a, and between the platen roller 58 and the tension roller pair 62. A predetermined tension is applied to the master 64.

  A reverse roller pair 63 including a driving roller 63a and a driven roller 63b that are rotatably supported by a side plate (not shown) of the printing apparatus main body 11 is disposed on the downstream side of the master stock unit 61 in the master conveyance direction. The reversing roller pair 63 sandwiches and conveys the master 64 by a driving roller 63a that is rotationally driven by the plate-making driving means 124 and a driven roller 63b that is pressed against the driving roller 63a by an urging means (not shown). A one-way clutch (not shown) is provided inside the driving roller 63a.

  A movable master guide plate (not shown) is disposed between the tension roller pair 62 and the reverse roller pair 63. The movable master guide plate is swingably supported by a support member (not shown), and a solenoid (not shown) moves the upper surface of the master 64 so that the master 64 enters the master stock unit 61. It is selectively positioned at a retracted position that does not obstruct.

A sheet feeding unit 4 is disposed below the plate making unit 3. The paper feed unit 4 includes a paper feed tray 67, a paper feed roller 68, a separation roller 69, a separation pad 70, a registration roller pair 71, and the like.
A paper feed tray 67 on which a large number of sheets P can be stacked is supported on the printing apparatus main body 11 so as to be movable up and down, and is moved up and down by a paper feed driving means 125 (see FIG. 6) including a lifting means. A pair of side fences 72 are provided on the upper surface of the paper feed tray 67 on which A3 size paper P can be placed vertically and supported by a rail member (not shown) so as to be movable in the paper width direction perpendicular to the paper transport direction. . A plurality of paper size detection sensors 73 for detecting the size of the stacked paper P are provided on the free end side of the paper feed tray 67.

  Above the paper feed tray 67, a paper feed roller 68 having a high frictional resistance member on the surface is disposed. The paper feed roller 68 is rotatably supported by a bracket (not shown) that is swingably supported by the printing apparatus main body 11. When the paper feed tray 67 is lifted by a lifting / lowering means (not shown), it is supplied with a predetermined pressure. The uppermost sheet P on the paper tray 67 is pressed against. The paper feed roller 68 is rotationally driven by the paper feed driving means 125.

  On the left side of the paper feed roller 68, a separation roller 69 and a separation pad 70 each having a high friction resistance member on the surface are disposed. The separation roller 69 is drivably coupled to the paper feed roller 68 via a timing belt 69a, and is driven to rotate in the same direction in synchronism with the rotation of the paper feed roller 68. The separation pad 70 is pressed against the separation roller 69 by a biasing force of a biasing means (not shown).

  A registration roller pair 71 is disposed on the left side of the separation roller 69 and the separation pad 70. The registration roller pair 71 including the driving roller 71a and the driven roller 71b transmits the rotational driving force from the plate cylinder driving unit 121 by a driving force transmitting unit (not shown) such as a gear or a cam, so that the driving roller 71a is connected to the plate cylinder. The paper P is rotated toward the printing unit 2 at a predetermined timing by a driven roller 71b that rotates at a predetermined timing synchronized with the driving roller 71a and is pressed against the driving roller 71a.

At the upper left of the printing unit 2, a plate discharging unit 5 is disposed. The plate discharging unit 5 includes an upper plate discharging member 74, a lower plate discharging member 75, a plate discharging box 76, a compression plate 77, and the like.
The upper plate removal member 74 has a drive roller 78, a driven roller 79, an endless belt 80, and the like, and the endless belt is driven by the drive roller 78 being rotated in the clockwise direction in the drawing by the plate discharge drive means 126 (see FIG. 6). 80 moves in the direction of the arrow in FIG. The lower plate removing member 75 has a driving roller 81, a driven roller 82, an endless belt 83, and the like, and transmits the driving force of the plate discharging driving means 126 that rotationally drives the driving roller 78 by a driving force transmitting means (not shown) such as a gear or a belt. As a result, the drive roller 81 is rotationally driven in the counterclockwise direction in the figure, whereby the endless belt 83 moves in the direction of the arrow in FIG. The lower plate removing member 75 is movably provided by a moving means (not shown) included in the plate driving means 126, and an endless belt 83 positioned on the outer peripheral surface of the driven roller 82 is located at the position shown in the figure. It selectively occupies a position in contact with the outer peripheral surface.

  A plate removal box 76 for storing a used master therein is provided detachably with respect to the printing apparatus main body 11. A compression plate 77 for pushing the used master carried by the upper plate removal member 74 and the lower plate removal member 75 into the plate discharge box 76 is supported by the printing apparatus main body 11 so as to be movable up and down, and is included in the plate discharge driving means 126. It is moved up and down by lifting means (not shown).

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

  A sheet conveying means 85 disposed below the peeling claw 84 and to the left of the switching member 10 includes a driving roller 87, a driven roller 88, an endless belt 89, a suction fan 90, and the like. A plurality of roller-shaped drive port-rollers 87 are attached at predetermined intervals to a support shaft 87a rotatably supported by the box-shaped unit side plate 200, and are integrally formed by a sheet drive means 127 (see FIG. 6). It is comprised so that it may be rotationally driven. A plurality of driven rollers 88 are also provided on a support shaft 88a rotatably supported by the box-shaped unit side plate 200 at regular intervals with each drive roller 87, and each drive roller 87 and each corresponding driven roller 88 corresponding thereto are provided. Endless belts 89 having a plurality of holes h are respectively wound around. A suction fan 90 is disposed below the driving roller 87, the driven roller 88, and the endless belt 89.

  A paper discharge tray 86 on which the paper P conveyed by the paper discharge conveyance member 85 is stacked is provided with one end fence 91 movable in the paper conveyance direction and a pair of side fences 92 movable in the paper width direction. And have.

  An image reading unit 7 is disposed on the upper part of the printing apparatus main body 9. The image reading unit 7 includes a contact glass 93 on which a document is placed, a pressure plate 94 provided so as to be able to come in contact with and away from the contact glass 93, reflection mirrors 95, 96, 97, 98 for scanning and reading a document image, and a fluorescent lamp. 99, a lens 100 for focusing a scanned document image, an image sensor 101 such as a CCD for processing the focused image, a plurality of document size detection sensors 102 as document size detection means for detecting the size of the document, An image memory 135 or the like for storing image data is provided, and the document image reading operation is performed by the operation of the reading drive unit 128 (see FIG. 6).

  As shown in FIG. 1, a dog 133 is attached to the outer surface of a flange (not shown) constituting the plate cylinder 12, and a home position sensor 134 attached to the printing apparatus main body 11 is arranged near the periphery of the plate cylinder 12. It is installed. The home position sensor 134 detects the dog 133 when the plate cylinder 12 occupies a position where the clamper 19 faces the press roller 13 and outputs a signal to the control means 129 described later.

  FIG. 7 shows an operation panel of the duplex printing apparatus. In the figure, an operation panel 103 provided on the upper front surface of the printing apparatus main body 11 has a plate making start key 104, a printing start key 105, a test printing key 106, a continuous key 107, a clear / stop key 108, a ten key 109, Enter key 110, program key 111, mode clear key 112, printing speed setting key 113, four-direction key 114, paper size setting key 115, paper thickness setting key 116, duplex printing key 117, simplex printing key 118, 7 segment LED Display device 119, LCD display device 120, and "mode setting key 1".

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

  The clear / stop key 108 is pressed when the operation of the duplex printing apparatus is stopped or when the numerical value is cleared, and the numeric keypad 109 is used for numerical value input. The enter key 110 is pressed when setting a numerical value or the like during various settings, the program key 111 is pressed when registering or calling an operation that is often performed, and the mode clear key 112 is cleared to initialize various modes. Pressed when returning to the state. The print speed setting key 113 is pressed when setting the print speed prior to the printing operation, and when it is desired to obtain a dark image or when the ambient temperature is low, the print speed is slow and a light image is desired. Or, when the ambient temperature is high, the printing speed is set fast. The four-way key 114 has an up key 114a, a down key 114b, a left key 114c, and a right key 114d, and is pressed when adjusting the image position when editing an image or when selecting a value or item when making various settings. Is done.

  The paper size setting key 115 is pressed when an arbitrary paper size is input, and the paper size input with the paper size setting key 115 has priority over the paper size detected by the paper size detection sensor 73. The paper thickness setting key 116 is pressed when inputting the thickness of the paper P prior to double-sided printing, and selects one of three types of “plain paper”, “thin paper”, and “thick paper” in this embodiment. It has a configuration.

  The duplex printing key 117 is pressed before the plate making start key 104 is pressed when the duplex printing apparatus performs the duplex printing operation, and when the duplex printing key 117 is pressed, the LED 117a disposed in the vicinity thereof is lit to inform the operator. It is displayed that the printer is in the duplex printing mode. Further, when the duplex printing key 117 is pressed, the input of the plate making start key 104 is rejected only after the thickness of the paper P to be used is input by the paper thickness setting key 116. Similarly to the double-sided printing key 117, the single-sided printing key 118 is pressed before the start key 104 is pressed when the double-sided printing apparatus performs the single-sided printing operation, and when the single-sided printing key 118 is pressed, the LED 118a disposed in the vicinity thereof. Lights up and the operator is informed that it is in single-sided printing mode. In the duplex printing apparatus, the LED 118a is lit in the initial state, and the single-sided printing mode is set.

  A display device 119 composed of a 7-segment LED mainly displays numbers such as the number of printed sheets. The display device 120 made up of an LCD has a hierarchical display structure. By pressing the selection setting keys 120a, 120b, 120c, and 120d provided below the display device 120, changing to various modes such as scaling and position adjustment is performed. In addition, the setting in each mode is possible. In addition to displaying the status of the duplex printing device and the warning content during duplex printing, the display device 120 displays alarms such as plate-making or ejection jam, paper feed or paper ejection jam, and supplies such as printing paper, master, and ink. A supply instruction or the like is also displayed.

  The mode setting key 1 sets a mode that functions when the duplex printing mode that enables duplex printing is set. The duplex setting mode cancels the duplex printing mode and sets the plate making by the plate making unit 3 to be unfinished. A double-sided release key 1A for setting a release mode, an automatic scaling mode key 1B for setting an automatic scaling mode for automatically scaling a plate-making image made by the plate-making unit 3 to a predetermined size, and an arbitrary mode set for the user of the apparatus And a user setting key 1C for setting a user setting mode to be performed. When the user setting key 1C is operated once, the forced plate making mode for causing the plate making unit 3 to execute the plate making corresponding to the detected document size is set. When the forced plate making mode is operated again during the setting, it is detected. A cancel mode in which plate making is not executed regardless of the document size is set. The set double-sided release mode, automatic magnifying mode, forced plate making mode, and cancel mode are displayed on the display device 120.

  FIG. 6 shows a block diagram of the control means used in the duplex printing apparatus. In the figure, the control means 129 is a known microcomputer having a CPU 130, ROM 131, and RAM 132 therein, and is provided inside the printing apparatus main body 11.

  Based on various signals from the operation panel 103, detection signals from various sensors provided in the printing apparatus main body 11, and an operation program called from the ROM 131, the CPU 130 performs printing unit 2, plate making unit 3, paper feeding unit 4, Actuation of solenoid 123 for actuating each of the driving means provided in the plate discharging unit 5 and the image reading unit 7, the re-feeding resist contact / separation mechanism 40 provided in the re-feeding unit 9, the conveying member driving motor 122, and the switching member 10. To control the operation of the entire duplex printing apparatus. The ROM 131 stores an operation program for the entire duplex printing apparatus, and this operation program is appropriately called by the CPU 130. The RAM 132 has a function of temporarily storing calculation results of the CPU 130, a function of storing data signals and on / off signals set and input from various keys and various sensors on the operation panel 103 as needed. The control unit 129 also grasps the position of the plate cylinder 12 based on a home position signal from the home position sensor 134 and a signal from an encoder (not shown) provided in the plate cylinder driving unit 121.

  The ROM 131 stores information on a predetermined size of a document and a program that is executed in the case of specific conditions at the time of duplex printing. When the document size is a predetermined size, the program causes the plate making unit 3 to make a plate-making image corresponding to the predetermined size, and when the document size is not the predetermined size, the double-side cancel mode, the automatic scaling mode or the user The plate making unit 3 executes an operation corresponding to the setting mode.

  Based on the above configuration, the operation of the duplex printing apparatus will be described. The operator loads the paper P to be used for printing on the paper feed tray 67, opens the pressure plate 94 and places a document to be printed on the contact glass 93, and then closes the pressure plate 94 again. Thereafter, after setting the plate making conditions with various keys on the operation panel 103, the duplex printing key 117 or the simplex printing key 118 is pressed to set the printing mode, and the plate making start key 104 is pressed. First, a case where the simplex printing key 118 is pressed to perform simplex printing will be described.

  The operator confirms the single-sided printing mode by turning on the LED 118a, and then presses the plate making start key 104. When the plate making start key 104 is pressed, a paper size detection signal is sent from the paper size detection sensor 73 and a document size detection signal is sent from the document size detection sensor 102 to the control means 129. Compare signals. At this time, if the paper size and the document size are the same, the image reading operation is immediately performed. If the paper size and the document size are different, the control unit 129 displays the fact on the display device 120 and pays attention to the operator. Prompt. When the paper size and the document size are different, enlargement or reduction may be automatically performed by a command from the control unit 129 so that the document size and the image size are matched.

  When the plate making start key 104 is pressed, the image reading unit 7 performs a document image reading operation. Reading of the document image is performed by reflecting the reflected light exposed by the fluorescent lamp 99 by each of the reflection mirrors 95, 96, 97, and 98. The read document image is focused by the lens 100 and then image sensor 101. And is photoelectrically converted. The photoelectrically converted electrical signal is input to an A / D converter (not shown) in the printing apparatus main body 11 and then stored in the image memory 135 as an image data signal.

  In parallel with the image reading operation in the image reading unit 7, the plate discharging unit 5 performs a plate discharging operation for peeling the used master from the outer peripheral surface of the plate cylinder 12. When the plate making start key 104 is pressed, the plate cylinder 12 starts rotating. When the plate cylinder 12 reaches the home position shown in FIG. 1, the dog 133 is detected by the home position sensor 134, and the home position sensor 134 controls the control means 129. A home position signal is sent to. Receiving the home position signal, the control means 129 measures the number of pulses generated by an encoder (not shown) based on the home position, and the tip of the used master wound around the outer peripheral surface of the plate cylinder 12 is connected to the driven roller 82. When it is determined that the predetermined plate discharging position corresponding to the endless belt 83 located on the outer peripheral surface has been reached, the operation of the plate cylinder driving unit 121 is stopped.

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

  In parallel with the plate removal operation, the plate making unit 3 performs the plate making operation. When the plate making start key 104 is pressed, the platen roller 58, the tension roller pair 62, and the reversing roller pair 63 are driven to rotate, and the master 64 is pulled out from the master roll 64a. At this time, a movable master guide plate (not shown) is positioned at the transport position. When the master 64 is pulled out and the image forming area reaches a position corresponding to the heat generating element of the thermal head 59, the image data signal stored in the image memory 135 is called after image processing is performed, not shown. The thermal head driver selectively heats each heating element of the thermal head 59, whereby the third plate-making image 66A is formed on the thermoplastic resin film surface of the master 64. When the master 64 is transported while making a plate and its leading end is sandwiched between the reverse roller pair 63, a movable master guide plate (not shown) is moved to the retracted position and the rotation of the reverse roller pair 63 is stopped.

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

  During the above-described plate making operation, when the plate discharging operation is completed and the duplex printing apparatus enters the plate feed standby state, the reverse roller pair 63 starts to rotate and the plate-making master 66 stored in the master stock unit 61 is released. It is transported toward the clamper 19. Then, when the leading end of the plate-making master 66 is transported to a predetermined position where it can be clamped by the clamper 19, an opening / closing means (not shown) is actuated to close the clamper 19, and the plate-making master 66 moves the tip of the plate cylinder 12. It is held on the outer peripheral surface.

  Thereafter, the plate cylinder 12 is intermittently rotated in the clockwise direction in FIG. 1, and the winding operation of the plate-making master 66 around the plate cylinder 12 is performed. At this time, the reversing roller pair 63 stops rotating, and the driving roller 63a is rotated along with the drawing-out master 66 being pulled out by a one-way clutch (not shown) provided therein. When the image data signal from the image memory 135 is interrupted, the operation of the thermal head 59 is stopped, and when the plate-making master 66 for one plate is conveyed, the platen roller 58, the tension roller pair 62, and the reverse roller pair 63 are turned on. Each of the rotations is stopped and the cutting means 60 is operated to cut the master-making master 66. The cut master 66 that has been cut is pulled out from the plate making unit 3 by the rotation of the plate cylinder 12, and the plate cylinder 12 rotates to the home position and stops, thereby completing the plate making operation and the plate feeding operation.

  The printing operation is performed following the plate feeding operation. When the plate cylinder 12 stops at the home position, the solenoid 123 is actuated and the switching member 10 is positioned at the first position. Then, the press roller locking means (not shown) is actuated and the stepping motor 52 is actuated to actuate the step cam. 49 is rotated, and the cam portion 49b is brought into contact with the cam follower 48c. As a result, the movable arm 48 is swung around the support shaft 48a, and the cam shaft 44 is moved to a position where the cam plate 43A can come into contact with the cam follower 41. Thereafter, the press roller locking means (not shown) is operated. Is released.

  Thereafter, the paper feed roller 68, the separation roller 69, the drive roller 87, and the suction fan 90 are each driven, and the plate cylinder 12 is driven to rotate in the clockwise direction in FIG. The uppermost sheet of the paper P is pulled out and the leading end thereof is held between the registration roller pair 71. Then, the drive roller 71a is driven at a predetermined timing when the image area leading end of the third plate-making image 66A in the plate cylinder rotation direction of the plate-making master 66 wound on the plate cylinder 12 reaches a position corresponding to the press roller 13. The paper P that is driven to rotate and pulled out is fed toward the space between the plate cylinder 12 and the press roller 13.

  In synchronism with the rotation of the plate cylinder 12, the press roller contacting / separating mechanism 55 rotates the cam shaft 44 and the multistage cam 43 provided integrally therewith, and can come into contact with the cam follower 41 as described above. The cam plate 43A moved to the position disengages the convex portion from the cam follower 41 at the predetermined timing. As a result, the press roller 13 has its peripheral surface pressed against the outer peripheral surface of the plate cylinder 12 by the urging force of the printing spring 42, and the paper P fed by the registration roller pair 71 is wound around the plate cylinder 12. Pressed by the master 66. By this pressing operation, the press roller 13, the sheet P, the master plate 66 and the plate cylinder 12 are pressed against each other, and the ink supplied to the inner peripheral surface of the plate cylinder 12 by the ink roller 16 oozes out from the opening of the plate cylinder 12. A perforated portion of the master 66 after being filled in a porous support plate (not shown) and a mesh screen (not shown) constituting the plate cylinder 12 and a porous support of the master master 66 wound around the plate cylinder 12. Then, it is transferred to the paper P and so-called printing is performed.

  The sheet P on which an image corresponding to the third plate-making image 66A is printed by printing is guided to the paper discharge conveyance member 85 by the switching member 10 occupying the first position, and the leading end portion thereof by the peeling claw 84. From the master plate 66 on the outer peripheral surface of the plate cylinder. The peeled paper P falls downward and is sent to the paper discharge conveyance member 85, and is conveyed leftward while being attracted to the upper surface of the endless belt 89 by the suction force of the suction fan 90, and on the paper discharge tray 86. To be discharged. Thereafter, the plate cylinder 12 is rotated again to the home position and stopped, and the plate printing operation is finished, and the duplex printing apparatus enters a print standby state.

  After the duplex printing apparatus is in the print standby state, when the print condition setting key 113 and various keys on the operation panel 103 are used to input print conditions and the test print key 106 is pressed, the test print is performed. When the trial printing key 106 is pressed, the plate cylinder 12 is driven to rotate at the set printing speed and one sheet P is fed from the sheet feeding unit 4. The fed paper P is temporarily stopped by the registration roller pair 71 and then fed at the same timing as that at the time of printing. The press roller 13 is pressed against the plate-making master 66 on the outer peripheral surface of the plate cylinder. The paper P on which the image has been printed is guided to the paper discharge unit 6 by the switching member 10, and then peeled off from the master-making master 66 on the outer peripheral surface of the plate cylinder by the peeling claw 84, and transported by the paper transporting member 85. The paper is discharged onto the paper discharge tray 86.

  When the position or density of the image is confirmed by the trial printing and the print start key 105 is pressed after the number of prints is input by the ten key 109, the paper P is continuously fed from the paper feeding unit 4 and the trial printing is performed. The printing operation is performed under the same conditions. When the set number of prints is consumed, the plate cylinder 12 stops at the home position, and the double-sided printing apparatus enters the print standby state again.

  Next, a description will be given of a case where double-sided printing is performed by pressing the double-sided printing key 117 with reference to a flowchart shown in FIG. In FIG. 8, the operator presses the duplex key 117 in step S1 to set the duplex printing mode. The setting of the duplex printing mode can be confirmed by turning on the LED 117a. In step S2, initial setting is executed. In the initial setting here, the duplex cancel mode 1A, automatic scaling mode key 1B or user setting key 1C is operated to set the duplex cancellation mode, automatic scaling mode or user setting mode, and the paper thickness setting key. 116 is pressed to set the thickness of the paper P to be used. In this duplex printing mode, if the paper thickness setting key 116 is not pressed, the input of the plate making start key 104 is rejected. If the plate making start key 104 is pressed without pressing the paper thickness setting key 116, the control is performed. The means 129 causes the display device 120 to display an indication that the sheet thickness should be set. In this embodiment, when the thickness of the paper P set by the paper thickness setting key 116 is “plain paper” or “thin paper”, the input of the plate making start key 104 is permitted and “thick paper” is set. In order to prevent the paper P from being jammed, the input of the plate making start key 104 is rejected, and the control means 129 displays a warning to the effect that the correct paper should be set on the display device 120. A paper P that is “plain paper” or “thin paper” is set on the paper feed tray 67, and a paper thickness based on the paper P shown in FIG. 7 is set by a paper thickness setting key 116.

  When the initial settings so far are completed and the plate making start key 104 is pressed in step S3, the document size detection information is sent from the document size sensor 102 to the control means 129, and the document image reading operation is performed in step S4. Executed. Here, the first original image is read by the image reading unit 7 as in the case of single-sided printing. The read original image is stored in the image memory 135 as the first image data signal. When the reading operation of the first original is completed and the image data signal is stored in the image memory 135, the control means 129 displays that the second original should be set on the display device 120. Make it. The operator opens the pressure plate 94 in accordance with this display, removes the first original from the contact glass 93, places the second original, and closes the pressure plate 94 again. When a sensor (not shown) detects that the pressure plate 94 is closed and another sensor (not shown) detects that there is a document on the contact glass 93, the reading operation of the second document is performed in the same manner as the first sheet. Is called. The read document image is stored in the image memory 135 as a second image data signal.

  In this embodiment, the reading operation of the original in the single-sided printing mode and the double-sided printing mode is configured such that the operator sets the original to be read on the contact glass 93 by opening and closing the pressure plate 94, but automatically using the ADF. A configuration in which a document is conveyed onto the contact glass 93 or a configuration in which image data is taken in from an external device (not shown) may be employed. Further, in the duplex printing mode, one original may be reversed and conveyed, and image data for two sheets may be acquired from the front and back surfaces.

  In step S5, it is determined whether or not the document image information read by the image reading unit 7 is a predetermined size (A4). Here, when the size of the document having the read document image is a predetermined size (A4), the process proceeds to step S6, and the duplex plate making operation corresponding to the A4 size document is executed. This double-side plate making operation will be described later. If the size of the document having the read document image is not the predetermined size (A4), the process proceeds to step S7, S10 or S12 depending on the mode specific to duplex printing set in the initial mode of step S2. In this embodiment, since the double-sided cancellation mode, automatic scaling mode, and user setting mode are determined in one flowchart, the determination step of the double-sided cancellation mode, automatic scaling mode, and user setting mode is provided. Therefore, for the sake of convenience, step S7 is set as a step for determining the presence / absence of double-sided release mode setting, step S10 is set as a step for determining automatic scaling mode setting, and step S12 is set as a step for determining whether there is user setting mode setting. It is not limited to the order.

  If it is determined in step S7 that the duplex release mode is set, the process proceeds to step S8, a warning message is displayed on the display device 120, the process proceeds to step S9, the plate making operation is canceled, and this control is finished. .

  If the double-side release mode is not set in step S7, the process proceeds to step S10 to determine another mode. Here, it is determined whether or not the automatic scaling mode is set. If the automatic scaling mode is set, the process proceeds to step S11, and the read original image is automatically changed to be an A4 size plate-making image. This control is finished by doubling and executing the plate making operation. For example, when the document size is smaller than A4, the original image is automatically scaled in the direction of enlargement so as to be A4 size, and when larger than A4, the document image is reduced in size to A4 size. Performs plate making operation with automatic scaling.

  If the automatic scaling mode is not set in step S10, the process proceeds to step S12 to set the user setting mode, and the process proceeds to step S13 to determine the contents of the user setting mode. If the forced prepress mode is set in step S13, the process proceeds to step S14, where the prepress operation corresponding to the original size of the read original image is executed, and this control is finished. If the forced plate making mode is not set, the process proceeds to step S15 to set the cancel mode, and the process proceeds to step S16 to cancel the plate making operation and this control is finished.

  In parallel with the image reading operation in the image reading unit 7, the plate discharging unit 5 performs the plate discharging operation in the same manner as in single-sided printing. The plate cylinder 12 from which the used master has been peeled off from the outer peripheral surface is stopped at the plate feeding standby position, and the clamper 19 is opened by an opening / closing means (not shown). In parallel with this plate removal operation, the plate making unit 3 performs a plate making operation.

  The plate making operation is performed in the same procedure as in the single-sided printing mode, but the first plate making image 65A and the second plate making image 65B are formed on the surface of the thermoplastic resin film of the master 64. At this time, the images 65A and 65B are made so that a predetermined blank portion S is provided between the first plate-making image 65A and the second plate-making image 65B as shown in FIG. The predetermined blank portion S is provided at a position corresponding to the intermediate region shown in FIG. 1 when the double-sided printing master 65 is wound on the outer peripheral surface of the plate cylinder 12. The double-sided printing master 65 on which the images 65A and 65B are formed is stored in the master stock unit 61, and is released by the operation of the reversing roller pair 63 when the plate removal operation is completed and the double-sided printing apparatus enters the plate feeding standby state. It is transported toward the clamper 19. Thereafter, the plate cylinder 12 is intermittently rotated as in the single-sided printing mode, and the double-sided printing master 65 is wound around the plate cylinder 12. When all the image data for two sheets is sent from the image memory 135, the cutting means 60 is activated to cut the double-sided printing master 65. The cut master for duplex printing 65 is pulled out from the plate making unit 3 by the rotation of the plate cylinder 12, and the plate cylinder 12 is stopped at the home position to complete the plate making operation and the plate feeding operation.

  The printing operation is performed following the plate feeding operation. When the plate cylinder 12 stops at the home position, the stepping motor 52 operates to rotate the step cam 49 and press roller locking means (not shown) to bring the cam portion 49a into contact with the cam follower 48c. As a result, the movable arm 48 is swung around the support shaft 48a and the cam shaft 44 is moved to a position where the cam plate 43B can come into contact with the cam follower 41. Is released.

  Thereafter, the paper feed roller 68, the separation roller 69, the drive rollers 36 and 87, and the suction fans 39 and 90 are driven, and the plate cylinder 12 is driven to rotate in the clockwise direction in FIG. 67. The first sheet P1 is pulled out from above 67, and its leading end is sandwiched between the registration roller pair 71. When the clamper 19 passes through the position corresponding to the switching member 10, the solenoid 123 is actuated to position the switching member 10 at the second position, and then the double-sided printing master 65 wound on the plate cylinder 12. When the driving roller 71a is rotationally driven at a predetermined timing when the image area leading end of the first plate-making image 65A in the plate cylinder rotation direction reaches a position corresponding to the press roller 13, the drawn paper P1 is extracted from the plate cylinder 12. And the press roller 13.

  The cam plate 43B moved to a position where it can come into contact with the cam follower 41 at the predetermined timing disengages its convex portion from the cam follower 41, and the press roller 13 presses the peripheral surface by the biasing force of the printing spring 42. Press contact with the outer peripheral surface of the body 12. As a result, the press roller 13, the paper P1, the first plate-making image 65A forming portion of the double-sided printing master 65, and the plate cylinder 12 are pressed against each other, and the ink supplied to the inner peripheral surface of the plate cylinder 12 by the ink roller 16 is the plate cylinder. The first plate-making image 65A is exuded after being filled in the porous support plate (not shown) and mesh screen (not shown) wound around the plate cylinder 12 and the porous support of the master 65 for double-sided printing. The portion of the double-sided printing master 65 where the first plate-making image 65A is formed is printed by being transferred to the paper P1 through the punching portion.

  The sheet P1, on which the image corresponding to the first plate-making image 65A is printed on the surface by printing, is peeled off from the double-sided printing master 65 on the outer peripheral surface of the plate cylinder by the leading end of the switching member 10, while The re-feeding means 9 is guided by the switching member 10 occupying the position 2. The sheet P 1 guided downward by the switching member 10 passes between the guide plates 27 and 56, has its tip abutted against the fence 8 a, and is placed on the auxiliary tray 8. The paper P1 transported on the auxiliary tray 8 is transported in the direction of the arrow in FIG. 1 while being held by the endless belt 38 by the suction force of the suction fan 39, and the leading edge (the rear edge at the time of printing the first plate-making image 65A). It abuts on the bent end 24a. At this time, since slip occurs between the paper P1 and the endless belt 38, the paper P1 is stopped in a state where the leading end thereof is in contact with the bent end portion 24a. A sensor (not shown) that detects when the leading edge of the paper P1 contacts the bent end 24a is provided, and when the sensor (not shown) detects the leading edge of the paper P1, the drive roller 36 and the suction fan 39 are operated. It is good also as a structure which stops.

  The plate cylinder 12 continues to rotate while the paper P1 is being guided on the auxiliary tray 8, and when the press roller 13 finishes contacting the surface area of the plate cylinder 12, the convex portion of the cam plate 43B becomes the cam follower 41. It occupies the separated position by contacting the Due to the function of the cam plate 43B, the back surface region of the plate cylinder 12 and the press roller 13 are not pressed against each other in the state where the paper P is not present, and ink transfer to the peripheral surface of the press roller 13 can be prevented. At this time, a press roller locking means (not shown) is operated to hold the press roller 13 in the separated position, and then the stepping motor 52 is operated to rotate the step cam 49 to bring the cam portion 49b into contact with the cam follower 48c. As a result, the moving arm 48 is swung around the support shaft 48a, and the cam shaft 44 is moved to a position where the cam plate 43A can be brought into contact with the cam follower 41.

  Almost simultaneously with the above-described operation, the paper feed roller 68 and the separation roller 69 are driven, the second paper P2 is drawn from the paper feed tray 67, and the leading end thereof is held between the registration roller pair 71. Then, the driving roller 71 a is rotationally driven at a predetermined timing similar to that described above, and the drawn paper P <b> 2 is fed toward the space between the plate cylinder 12 and the press roller 13.

  On the other hand, in the press roller contact / separation mechanism 55, when the cam shaft 44 rotates to a position where the convex portion of the moved cam plate 43A can come into contact with the cam follower 41, the operation of the press roller locking means (not shown) is released. At this time, the plate cylinder 12 rotating in synchronization with the camshaft 44 occupies a position where the non-opening portion, which is a portion other than the front surface region, the back surface region, and the intermediate region, faces the press roller 13. Further, the solenoid 123 is operated until the surface region of the plate cylinder 12 passes through the portion facing the press roller 13 and the clamper 19 occupies the position corresponding to the switching member 10 again, so that the switching member 10 is in the second state. It is displaced from the position to the first position.

  At a predetermined timing when the sheet P2 is fed by the pair of registration rollers 71, the cam plate 43A disengages the convex portion from the cam follower 41, so that the press roller 13 urges its peripheral surface by the urging force of the printing spring 42. 12 is pressed against the outer peripheral surface. As a result, the press roller 13, the paper P2, the first plate-making image 65A forming portion of the master for double-sided printing 65, and the plate cylinder 12 are pressed against each other, and the ink supplied to the inner peripheral surface of the plate cylinder 12 by the ink roller 16 is the plate cylinder. The image is transferred to the paper P2 through the 12 openings, a porous support plate (not shown), a mesh screen (not shown), and a perforated portion of the first platemaking image 65A.

  The paper P2 on which an image corresponding to the first plate-making image 65A is printed is guided to the paper discharge conveyance member 85 by the switching member 10 occupying the first position, and from the front end portion thereof by the peeling claw 84. It peels from the double-sided printing master 65 on the outer peripheral surface. The peeled paper P2 falls downward and is sent to the paper discharge conveying member 85 and then discharged onto the paper discharge tray 86.

  Further, after the sheet P2 is fed by the registration roller pair 71, the leading edge of the image area of the second plate-making image 65B in the plate cylinder rotation direction of the double-sided printing master 65 reaches a position corresponding to the press roller 13. The solenoid 33 is actuated at a predetermined timing which is slightly earlier, and the swing arm 32 is swung in the clockwise direction in FIG. 2 about the support shaft 32a. As a result, the re-feeding registration roller 23 is swung from the separation position to the press-contact position, and the paper P1 that is stopped with the leading end in contact with the bent end portion 24a contacts the plate cylinder 12 and rotates. The press roller 13 is in contact with the peripheral surface.

  The paper P1 brought into contact with the peripheral surface of the press roller 13 by the refeed resist roller 23 is conveyed downstream in the rotational direction by the rotational force of the press roller 13, and the paper guide plate 31 and the rollers 28, 29, 30 is conveyed toward the contact portion with the plate cylinder 12 in a state of being in close contact with the peripheral surface of the press roller 13. At this time, an image corresponding to the first plate-making image 65A is printed on the surface of the paper P1, but the paper P1 is brought into close contact with the peripheral surface of the press roller 13 by the action of the refeed guide member 22, so The sheet P1 in contact with the peripheral surface of the press roller 13 is not displaced, and occurrence of problems such as rubbing dirt or thickening of the image line is prevented. Then, after the rear end and the intermediate region of the paper P2 pass through the position corresponding to the press roller 13, the paper P1 is transferred to the plate cylinder 12 and the press roller at a timing when the leading end of the back surface region reaches the position corresponding to the press roller 13. 13 is sent to the abutting part.

  As a result, the press roller 13, the paper P1, the second plate-making image 65B forming portion of the double-sided printing master 65, and the plate cylinder 12 are pressed against each other, and the ink supplied to the inner peripheral surface of the plate cylinder 12 by the ink roller 16 is the plate cylinder. The second plate-making image 65B of the master for double-sided printing 65 is formed by being transferred to the paper P1 through the 12 openings, a porous support plate (not shown) and a mesh screen (not shown), and a perforation portion of the second plate-making image 65B. The part is printed.

  The paper P1 on which the image corresponding to the first plate-making image 65A is printed on the front surface and the image corresponding to the second plate-making image 65B is printed on the back surface is transferred to the paper discharge conveyance member 85 by the switching member 10 occupying the first position. And the peeling claw 84 peels from the front end portion of the double-sided printing master 65 on the outer peripheral surface of the plate cylinder. The peeled sheet P1 drops downward and is sent to the paper discharge conveying member 85 and then discharged onto the paper discharge tray 86. Thus, the printing operation of the master for double-sided printing 65 is completed, and the double-sided printing apparatus Is in a print standby state.

  At the time of the above-described printing, a predetermined blank portion S is provided between the first plate-making image 65A and the second plate-making image 65B of the double-sided printing master 65, and the double-sided printing master 65 is placed on the outer peripheral surface of the plate cylinder 12. Since the intermediate area is formed when the sheet P is wound, the rear end of the sheet P2 sent from the sheet feeding unit 4 and the leading end of the sheet P1 sent from the refeed unit 9 are prevented from overlapping. , Good printing can be done.

  When the trial printing key 106 is pressed after the printing conditions are input by the printing speed setting key 113 and various keys on the operation panel 103 after the duplex printing apparatus enters the printing standby state, the trial printing is performed. Even when the trial printing key 106 is pressed, the control means 129 displays a message to the effect that the paper thickness should be set on the display device 120. When “thick paper” is set, the input of the trial printing key 106 is performed. And a warning that the correct paper should be set is displayed on the display device 120.

  When the trial printing key 106 is pressed, the plate cylinder 12 is rotationally driven at a printing speed set after the cam shaft 44 is moved to a position where the cam plate 43B can come into contact with the cam follower 41 as in the case of printing. In addition, the switching member 10 is positioned at the second position as in the case of printing. After the rotation of the plate cylinder 12 is started, the first sheet P1 is fed from the sheet feeding unit 4, and the fed sheet P1 is temporarily stopped by the registration roller pair 71 and then fed at the same timing as the plate printing. The press roller 13 is pressed against the first plate-making image 65A of the double-sided printing master 65. The sheet P1 having an image corresponding to the first plate-making image 65A printed on the front surface is guided to the auxiliary tray 8 while being peeled off from the double-sided printing master 65 on the outer peripheral surface of the plate cylinder by the switching member 10. The sheet P1 conveyed on the auxiliary tray 8 is held in a state in which the leading end is in contact with the bent end portion 24a while being held on the endless belt 38 by the suction force of the suction fan 39.

  Thereafter, the press roller locking means (not shown) is operated to hold the press roller 13 in the separated position, and the cam shaft 44 is moved to a position where the step cam 49 rotates and the cam plate 43A can be brought into contact with the cam follower 41. After the movement, the operation of the press roller locking means (not shown) is released. The switching member 10 is displaced from the second position to the first position until the clamper 19 occupies a position corresponding to the switching member 10 again. Also, almost simultaneously with this operation, the second sheet P2 is fed from the sheet feeding unit 4, and the fed sheet P2 is temporarily stopped by the pair of registration rollers 71 and then sent to the printing unit 2 at the same timing as the sheet P1. It is sent toward.

  The fed paper P2 is pressed against the first plate-making image 65A of the double-sided printing master 65 by the oscillating press roller 13, and the paper P2 on which an image corresponding to the first plate-making image 65A is printed is the first paper P2. The switching member 10 occupying the position is guided to the paper discharge conveying member 85. The paper P2 is peeled off from the double-sided printing master 65 by the peeling claw 84, dropped downward, transported by the paper discharge transport member 85, and discharged onto the paper discharge tray 86.

  After the paper P2 is fed by the registration roller pair 71, the solenoid 33 is operated at the same timing as when the printing is performed, and the re-feeding registration roller 23 is displaced from the separation position to the press-contact position, and is temporarily stopped. P1 contacts the peripheral surface of the rotating press roller 13. The paper P <b> 1 is transported by the rotational force of the press roller 13, and is transported to the printing unit 2 while being in close contact with the peripheral surface of the press roller 13 by the refeed guide member 22.

  The conveyed paper P1 is pressed against the second plate-making image 65B of the double-sided printing master 65 by the swinging press roller 13, and the paper P1 on which images corresponding to the plate-making images 65A and 65B are printed on both sides is a switching member. 10 is guided to the paper discharge conveying member 85. Thereafter, the sheet P1 is peeled off from the double-sided printing master 65 by the peeling claw 84, transported by the paper discharge transport member 85, and discharged onto the paper discharge tray 86, thereby completing the test printing.

  When the position or density of the image is confirmed by trial printing and the print start key 105 is pressed after the number of prints is input by the ten key 109, a printing operation is performed. Even when the print start key 105 is pressed, the control means 129 displays a message to the effect that the paper thickness should be set on the display device 120. If “thick paper” is set, the print start key 105 is input. And a warning that the correct paper should be set is displayed on the display device 120. In the present embodiment, a case where N sheets are input as the number of prints will be described.

  When the print start key 105 is pressed, the printing speed is set after the cam shaft 44 is moved to a position where the cam plate 43B can come into contact with the cam follower 41 as in the case of printing and test printing. The plate cylinder 12 is driven to rotate, and the switching member 10 is positioned at the second position as in the case of plate printing and test printing. After the plate cylinder 12 starts to rotate, the first sheet P1 is fed from the sheet feeding unit 4, and the fed sheet P1 is temporarily stopped by the registration roller pair 71 and then fed at the same timing as in the trial printing. The The sheet P1 is pressed against the first plate-making image 65A of the double-sided printing master 65 by the press roller 13, whereby an image corresponding to the first plate-making image 65A is printed on the surface. The sheet P1 on which the image is printed is peeled and guided by the switching member 10 occupying the second position, conveyed onto the auxiliary tray 8, and stopped in a state where the leading end is in contact with the bent end 24a. .

  After that, the press roller locking means (not shown) is actuated to hold the press roller 13 in the separated position, and the cam shaft 44 is moved to a position where the cam plate 43A can come into contact with the cam follower 41. The operation of the press roller locking means is released. Almost simultaneously with this operation, the second sheet P2 is fed from the sheet feeding unit 4, and the sheet P2 is temporarily stopped by the registration roller pair 71 and then fed toward the printing unit 2 at the same timing as the sheet P1. Is done. The switching member 10 is positioned at the first position so as to avoid a collision with the clamper 19, and then is positioned again at the second position after passing the clamper 19.

  The fed paper P2 is pressed against the first plate-making image 65A of the master for double-sided printing 65 by the press roller 13, and after the image corresponding to the first plate-making image 65A is printed on the surface, it occupies the second position. Stripping is guided by the switching member 10 and conveyed onto the auxiliary tray 8. At this time, the solenoid 33 is actuated at the same timing as the trial printing, and the paper P1 retained on the auxiliary tray 8 is conveyed to the printing unit 2 by the rotational force of the press roller 13. After the rear end of the sheet P2 passes through the contact portion between the plate cylinder 12 and the press roller 13, the sheet P1 passes through a position where the intermediate area of the plate cylinder 12 faces the press roller 13, and the back area is the press roller. 13 is sent to an abutting portion between the plate cylinder 12 and the press roller 13 at a timing facing the plate 13, and is pressed against the second plate-making image 65B of the master for double-sided printing 65 by the press roller 13, whereby the second plate-making image is formed on the back surface thereof. An image corresponding to 65B is printed.

  During the above-described operation, the solenoid 123 is actuated immediately before the intermediate region of the plate cylinder 12 occupies the position facing the press roller 13, and the switching member 10 is displaced from the second position to the first position. As a result, the rear end of the sheet P2 guided by the switching member 10 is guided onto the auxiliary tray 8 through a slight gap between the lower surface 10a of the switching member 10 and the peripheral surface of the press roller 13. Subsequently, the leading edge of the conveyed paper P <b> 1 is guided to the paper discharge conveying member 85 along the upper surface 10 b of the switching member 10. The paper P <b> 1 is peeled off from the double-sided printing master 65 by the peeling claw 84, transported by the paper discharge transport member 85, and discharged onto the paper discharge tray 86.

  Thereafter, the third sheet P3 is fed from the sheet feeding unit 4, and the sheet P3 is temporarily stopped by the registration roller pair 71 and then fed toward the printing unit 2 at the same timing as the sheet P1. The switching member 10 is positioned at the first position so as to avoid a collision with the clamper 19, and is positioned again at the second position after passing the clamper 19. The fed paper P3 is guided on the auxiliary tray 8 by the switching member 10 after an image corresponding to the first plate-making image 65A is printed on the surface. Then, the solenoid 33 is actuated at a predetermined timing, and the paper P2 stopped on the auxiliary tray 8 is conveyed to the printing unit 2. The sheet P2 is sent to the contact portion between the plate cylinder 12 and the press roller 13 at the same timing as the above-described sheet P1, and an image corresponding to the second plate-making image 65B is printed on the back surface thereof. The switching member 10 is displaced from the second position to the first position at the same timing as described above, and the rear end of the sheet P3 has a slight gap between the lower surface 10a of the switching member 10 and the peripheral surface of the press roller 13. It is guided on the auxiliary tray 8 through. Following this, the leading edge of the paper P2 conveyed from the auxiliary tray 8 is guided to the paper discharge conveying member 85 along the upper surface 10b of the switching member 10, and the paper P2 is peeled off by the peeling claw 84 by the double-sided printing master 65. After being further peeled off, the sheet is conveyed by the sheet discharge conveying member 85 and discharged onto the sheet discharge tray 86.

  Thereafter, the same printing operation as described above is performed up to the (N-1) th sheet. Then, after the Nth sheet PN is fed from the sheet feeding unit 4 and an image corresponding to the first plate-making image 65A is printed on the surface and guided onto the auxiliary tray 8, the (N-1) th sheet When an image corresponding to the second plate-making image is printed on the back surface of the paper P (N-1) and discharged onto the paper discharge tray 86, the press roller locking means (not shown) is activated and the press roller 13 is moved. After the cam shaft 44 is moved to a position where the cam plate 43C can be brought into contact with the cam follower 41 while being held at the separated position, the operation of the press roller locking means (not shown) is released. At this time, the switching member 10 maintains the state of occupying the first position.

  Then, the cam follower 41 can be brought into contact with the cam follower 41 at a first timing earlier than the leading end of the image area of the second plate-making image 65B in the plate cylinder rotation direction of the double-sided printing master 65 reaching the position corresponding to the press roller 13. The cam plate 43 </ b> C moved to the position disengages its convex portion from the cam follower 41, and the press roller 13 presses the peripheral surface thereof against the outer peripheral surface of the plate cylinder 12 by the biasing force of the printing pressure spring 42. Thereafter, the solenoid 33 is activated at a second timing slightly earlier than the leading edge of the image area of the second plate-making image 65B in the plate cylinder rotation direction of the double-sided printing master 65 reaches the position corresponding to the press roller 13, and the oscillation is The moving arm 32 is swung clockwise around the support shaft 32a in FIG. As a result, the re-feeding registration roller 23 is swung from the separation position to the press-contact position, and the paper PN that has been stopped with the leading end in contact with the bent end portion 24a contacts the plate cylinder 12 and rotates. The press roller 13 is in contact with the peripheral surface.

  The sheet PN is sent to the contact portion between the plate cylinder 12 and the press roller 13 at the same timing as the sheet P1, and an image corresponding to the second plate-making image 65B is printed on the back surface thereof. The paper PN on which the image is printed is guided to the paper discharge conveyance member 85 along the upper surface 10b of the switching member 10, and is peeled off from the double-sided printing master 65 by the peeling claw 84 and then conveyed by the paper discharge conveyance member 85. The paper is discharged onto the paper discharge tray 86. Thereafter, when the press roller 13 finishes contact with the back surface region of the plate cylinder 12, the convex portion of the cam plate 43C comes into contact with the cam follower 41 to occupy the separated position. Due to the function of the cam plate 43C, the surface region of the plate cylinder 12 and the press roller 13 are not brought into pressure contact with each other in the absence of the paper P, and ink transfer to the peripheral surface of the press roller 13 can be prevented. At this time, the press roller locking means (not shown) is operated to hold the press roller 13 in the separated position, and then the plate cylinder 12 stops at the home position, and the duplex printing apparatus finishes the printing operation and enters the print standby state again. .

  According to the double-sided printing apparatus having such a configuration, during the setting of the double-sided printing mode, when the original is an original of a predetermined size (A4), the normal plate making operation is executed by the plate making unit 3. If the original size is not a predetermined size (A4) and the mode set at the initial setting is the duplex cancel mode, the plate making operation corresponding to the duplex printing is canceled and the automatic scaling mode is set. A plate-making image corresponding to the A4 size is uniformly formed by automatic scaling, and when the user setting mode is the forced plate-making mode, the plate-making operation corresponding to the detected document size is executed, and when the cancel mode is set, the plate-making operation is performed. Will be canceled. For this reason, even when performing double-sided printing using a document including different sizes, it is possible to perform the plate making operation without being aware of the document size and to prevent useless plate making operation.

  In the above embodiment, since the duplex printing apparatus includes the image reading unit 7 and the plurality of document detection sensors 102, the document image information and the document size information are read by the document detection sensor 102 and the image reading unit 7. However, it is not limited to such a form. For example, as shown in FIG. 9, a personal computer 200 as an external device is connected to the printing apparatus main body 11, and original image data, original size information, and the like are transmitted from the personal computer 200 to the control means 129. Even if the document size is determined based on the size and the plate-making operation is controlled by the plate-making unit 3 according to the result, the same effect as in the case of the image reading unit 7 can be obtained.

1 is a schematic front view of a double-sided printing apparatus showing one configuration example of the present invention. It is a schematic front view which shows the printing pressure member spaced apart from the plate cylinder outer peripheral surface shown in FIG. It is a schematic front view which shows the printing pressure member which contacted the plate cylinder outer peripheral surface shown in FIG. It is the schematic which shows the structure of a printing pressure member contacting / separating mechanism. (A) is the schematic explaining the master for double-sided printing, (b) is the schematic explaining the master-made master. It is a block diagram of the control means in this invention, and the structure connected to it. It is a partial expansion failure figure which shows one form of an operation panel. It is a flowchart which shows one form of control of the platemaking operation | movement concerning this invention. It is a schematic front view which shows the structure of the double-sided printing apparatus connected with the external terminal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Printing part 3 Plate making part 7 Image reading part 12 Printing drum 11 Printing apparatus main body 13 Printing pressure member 65 Master for double-sided printing 65A, 65B Plate-making image 102 Original size detection means 129 Control means 200 External apparatus P Paper

Claims (4)

A plate making unit capable of plate making a master for duplex printing in which plate making images corresponding to a first document image and a second document image are arranged in a master having a length of one plate;
The double-sided printing master made by the plate making unit is pressed against the printing drum wound around the outer peripheral surface, and the printed image is pressed against the master for double-sided printing on the printing drum. In a printing apparatus capable of double-sided printing comprising a printing unit for obtaining
As a mode that functions when a duplex printing mode capable of performing duplex printing is set, a duplex release mode that cancels the duplex printing mode and makes the plate making by the plate making unit unmade, and plate making made by the plate making unit An automatic scaling mode that automatically scales the image to a predetermined size or a user setting mode that allows the user to set an arbitrary mode can be set.
If the size of the document having each document image is a predetermined size, a plate-making image corresponding to the predetermined size is made by the plate-making unit, and if the document size is not a predetermined size, the duplex cancel mode, automatic A printing apparatus comprising control means for causing the plate making unit to execute an operation corresponding to a magnification change mode or a user setting mode. The printing apparatus according to claim 1.
The printing apparatus according to claim 1, wherein the arbitrary mode selects a forced plate-making mode corresponding to the document size or a cancel mode in which plate-making is not executed regardless of the document size. The printing apparatus according to claim 1 or 2,
An image reading unit that reads an image of the document, and a document size detection unit that detects a size of the document whose image is read by the image reading unit,
The control unit determines a document size based on the document size information detected by the document size detection unit, and causes the plate making unit to execute a plate making operation based on the document image read by the image reading unit. Printing device to do. The printing apparatus according to claim 1 or 2,
Each information of the document size, the first document image, and the second document image is information transmitted from an external device that can communicate with the printing apparatus main body.
The control means determines the document size based on the document size, the first document image, and the second document image information transmitted from the external device, and causes the plate-making unit to execute a plate-making operation. Printing device to do.

Images