JP5272222B2 - Printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer capable of suppressing the formation of a ghost image more reliably while cutting down ink consumption. <P>SOLUTION: The printer includes a plate making part 3 making a plate of a first plate-making image and a second plate-making image side by side to one plate 64 or making a plate of a third plate-making image having an image area of two face portions, and a printing part 2 carrying out printing on paper P by operating a pressure applying member 13 to contact with and separate from a printing cylinder 12 wound with the made plate. The printer comprises a double side printing function of printing the first and second plate-making images, a single side selective printing function of printing one of the images, and a single side printing function of printing the third plate-making image. The printer has a storage means for storing a plate-making image area, and a measuring means for measuring an elapsed time after the end of printing. Whether the elapsed time measured by the measuring means has passed a predetermined set time is determined, and when the elapsed time has passed the set time, the operation of the plate making part 3 is controlled to carry out plate-making while limiting it to areas other than the plate-making area stored in the storage means in plate-making carried out after the lapse of the set time. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a printing apparatus capable of making a first plate-making image and a second plate-making image on a single plate.

As a simple printing method, a digital thermal stencil printing apparatus is well known. In such a stencil printing device, the film surface of the master serving as a plate is brought into contact with a thermal head in which fine heating elements constituting the plate making unit are arranged in a row, and the heating elements are conveyed while being energized in pulses. The outer peripheral surface of a printing drum comprising a perforated master made by perforation according to image information, and comprising a porous cylindrical support and a mesh screen layer that is a resin or metal fiber network And press the paper against the plate cylinder with a pressing member such as a press roller through the pre-made master, and transfer the ink that has oozed out through the drum opening and the perforated part of the pre-made master to the paper. And printing is performed.
In such a stencil printing apparatus, ink is always consumed in the perforated portion of the pre-printed master, that is, in the image forming portion, but in the non-image forming portion where no image is formed without being perforated. Therefore, a large amount of ink is accumulated in the non-image forming portion as compared with the image forming portion where ink is always consumed. During printing in this state, the non-image forming part is squeezed between the press roller and ink roller and receives the pressing force. It will be better.
When printing is finished, a new document is set, the next master is punched and engraved, and when the next master is wound around the plate cylinder, the image forming part of the next master is the previous master. If it is mounted over the non-image forming part, the ink in that part will ooze out due to the highly fluidized ink accumulated in the non-image forming part of the previous master making master. For example, in the case of black and white printing, the image forming portion of the previous master making master has an image density, and the black and white printing portion is reversed to become a ghost image.
Therefore, in Patent Document 1, by uniformly rotating the printing drum in a state in which a roller or a blade member is in contact with the outer peripheral surface or the inner peripheral surface of the printing drum, the ink with high fluidity of the printing drum can be obtained. In order to reduce the ghost image.

Japanese Patent No. 3143281

In Patent Document 1, since the printing drum is rotated in a state where the roller and the blade member are in contact with each other in order to make the ink which is no longer consumed and has high fluidity, the ink is removed by the roller and the blade member. Will be consumed by adhering to the pre-printed master which is pushed out of the drum inner peripheral surface and discarded.
In addition, when using a roller or blade member to make the ink uniform, there is a difference in the state of the ink where the plate-making image was and where it was not, so it takes a lot of time to make the ink uniform. In some cases, the generation of ghost images may not be sufficiently suppressed.
An object of the present invention is to propose a printing apparatus that can suppress generation of a ghost image more reliably while suppressing consumption of ink.

  In order to achieve the above-described object, the first plate-making image and the second plate-making image are arranged side by side for one plate according to the present invention, or two sides of the first plate-making image and the second plate-making image. A plate-making portion for making a third plate-making image having the image area; and a printing pressure member is brought into contact with and separated from a printing drum wound around an outer peripheral surface of the plate made by the plate-making portion, A double-sided printing unit having a printing unit that performs printing on a sheet conveyed between a printing drum and a printing pressure member, and printing a first plate-making image and a second plate-making image successively on different sides of the sheet; A printing function, a single-sided selective printing function for selecting one of the first plate-making image and the second plate-making image and printing on one side of the paper, and a plate on which only the third plate-making image is made on one side of the paper For printing devices with a single-sided printing function, the image area of the platemaking performed on the plate A storage unit for storing, a measuring unit for measuring an elapsed time after completion of printing using the plate, and determining whether or not an elapsed time measured by the measuring unit has passed a preset set time; When the time has passed, it has a control means for controlling the operation of the plate making section so that the plate making is performed only in the area other than the plate making area stored in the storage means at the time of the plate making performed after the set time elapses. It is characterized by. With such a configuration, the plate-making image formed on the new plate is not located in the area of the printing drum where the ink image at the time of printing using the previous plate-making image remains.

  In the printing apparatus according to the present invention, the control unit applies a printing pressure only to an area other than the plate-making area stored in the storage unit before starting the plate-making operation at the time of plate-making executed after the set time has elapsed. And controlling the operation of the drive source of the printing drum so that the printing drum is rotated a plurality of times in a state where the printing drum is applied with the printing pressure. It is characterized by that.

The printing apparatus according to the present invention has an input means for inputting the print set number of sheets, and the control means executes the print set number of sheets to be executed after the set time input from the input means has elapsed. The operation of the printing unit is controlled so as to execute the printing of the minimum number of printed sheets when the number of printed sheets is not reached .

  According to the present invention, when the elapsed time after the end of printing measured by the measuring unit exceeds a preset setting time, the plate-making area stored in the storage unit at the time of plate-making executed after the set time has elapsed. Since the plate-making is performed only in the other area, the plate-making image formed on the new plate is not located in the area of the printing drum where the ink image at the time of printing using the previous plate-making image remains. For this reason, at the time of printing with a new plate, the ink image at the time of the previous printing is not printed, and the occurrence of an afterimage (ghost) can be prevented. Further, since the ink of the printing drum is not made uniform with a roller, a blade or the like as in the prior art, the amount of ink deposited on the plate and discarded can be reduced, and the ink consumption can be reduced.

  According to the present invention, the printing drum is applied in a state where the printing pressure is applied only to the area other than the plate making area stored in the storage means before the start of the plate making operation at the time of the plate making executed after the set time elapses. By rotating the printing drum multiple times, the remaining ink from the previous printing is mixed with other inks by the rotation of the printing drum, so that the ink can be made uniform. The amount can be reduced and ink consumption can be reduced.

  According to the present invention, when the set number of prints at the time of printing executed after the set time input from the input unit has not reached the preset minimum number of prints, the minimum number of prints is printed. Regardless of the number of prints entered, the print drum rotates by the preset minimum number of prints, so the remaining ink from the previous printing is mixed with other inks by the rotation of the print drum, making the ink uniform Therefore, as in the prior art, the amount of ink deposited on the plate and discarded can be reduced, and the ink consumption can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The printing apparatus according to the present embodiment employs the same mechanical configuration as the double-sided printing apparatus 1 described in Japanese Patent No. 3940036. Hereinafter, the basic configuration and operation of the double-sided printing apparatus 1 will be described on the assumption that the detailed configuration takes into account the description in Japanese Patent No. 3940036.

  A double-sided printing apparatus 1 shown in FIG. 1 includes a printing unit 2, a plate making unit 3, a paper feeding unit 4, a plate discharging unit 5, a paper discharging unit 6, an image reading unit 7, an auxiliary tray 8, a refeed unit 9, and a switching member 10. Etc. The printing unit 2 is disposed substantially at the center of the apparatus main body 11 and includes a plate cylinder 12 serving as a printing drum and a press roller 13 serving as a printing pressure member.

  The double-sided printing apparatus 1 is a plate-making device that forms a plate in which a first plate-making image 65A and a second plate-making image 65B as shown in FIG. A double-sided printing function for continuously printing the first plate-making image 65A and the second plate-making image 65B using the completed master 65, the first plate-making image 65A and the second plate-making image as shown in FIG. FIG. 7A shows a single-sided printing function for printing on one side of the paper P using the master-making master 66 that is a plate where only the third plate-making image 66A having an image area for two sides with the image 65B is made. Single-sided selective printing that prints on one side of the paper P using a master-making master 67 that is a plate on which the first plate-making image 65A as shown in FIG. 7 or the second plate-making image 65B as shown in FIG. It has a function.

  The plate cylinder 12 includes a pair of end plates (not shown) 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 end plate, and not shown. It is mainly composed of a mesh screen (not shown) wound around the outer peripheral surface of the porous support plate, and is rotationally driven by a plate cylinder driving means 121 (see FIG. 9) serving as a driving source. In this 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 in which an ink supply hole is formed, a well-known ink roller 16 and a doctor roller 17, and the ink supplied from the support shaft 14 is close to the ink roller 16 and the doctor roller 17. The ink reservoir 18 is formed by accumulating in a wedge-shaped space formed in the section.

  On the outer peripheral surface of the plate cylinder 12, a stage portion 19 a that forms a plane along one generatrix of the plate cylinder 12 is formed. On the outer surface of the plate cylinder 12, a master 64 serving as a later-described plate is formed. A clamper 19b is provided to hold the tip.

  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 so as 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 at both ends of the core portion 13 a. Each arm member 20 having a substantially 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 apparatus main body 11. Yes. In this embodiment, at least the peripheral surface of the press roller 13 is constituted by a member having ink repellency such as polytetrafluoroethylene resin. Between the arm members 20, in addition to the press roller 13, a refeed guide member 22, a refeed resist roller 23, a refeed positioning member 24, a refeed transport unit 25, a cleaning roller 26, a guide plate 27, and the like. Is 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-shaped rollers 28, 29, and 30, and a paper guide plate 31 formed in a curved shape for allowing the surface-printed paper PA 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 the corresponding support shaft 28 a, 29 a, 30 a with a predetermined interval over substantially the entire width of the press roller 13.

  The paper guide plate 31 is disposed at a position away from the peripheral surface of the press roller 13 by a predetermined distance that is smaller than the radius of each of the rollers 28, 29, 30, and both ends thereof are fixed to the arm members 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 is configured to bring the peripheral surfaces of the rollers 28, 29, and 30 into contact with the peripheral surface of the press roller 13. A plurality of openings (not shown) are formed.

  A re-feeding registration roller 23 is disposed below the press roller 13. The re-feeding registration roller 23 is rotatably supported by the support shaft 23 a, and the support shaft 23 a is attached to one end of the swing arm 32. The swing 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. Is positioned substantially at the center in the width direction of the press roller 13 and is positioned in the middle of the positions where the rollers 30 are disposed.

  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, which presses the peripheral surface 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 of the tension spring 34 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.

  A refeed conveyance unit 25 is disposed on the lower left side of the press roller 13. The refeed conveyance unit 25 includes a conveyance unit main body 35, a driving roller 36, a driven roller 37, an endless belt 38 as a sheet conveyance member, a suction fan 39, and the like. Have.

  The transport unit 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, is not shown on both side surfaces upstream and downstream in the paper transport direction. Each of the bearings (not shown) rotatably supports the drive shaft 36a and the driven shaft 37a. Both ends of the drive shaft 36a penetrate both side surfaces of the conveying member main body 35, and both the penetrated both end portions are rotatably supported by a bearing member (not shown) provided in the 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 transport unit drive motor 122 (see FIG. 9) provided in the apparatus main body 11. The driven shaft 37a is configured such that both end portions thereof do not penetrate both side surfaces of the transport unit body 35.

  Bosses 35a are integrally provided on both outer sides of the upstream end of the transport unit body 35 in the paper transport 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 unit 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 drive rollers 36 are integrally attached to the drive shaft 36a, and predetermined intervals are provided between the drive rollers 36, respectively. A 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 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 frictional resistance member is moved in the direction indicated by the arrow in FIG. 2 when the drive shaft 36 a is rotationally driven by the transport unit drive motor 122.

  A suction fan 39 is integrally attached to the lower surface of the transport unit main body 35, and the auxiliary tray 8 is integrally attached to the upper surface of the transport unit main body 35. As shown in FIG. 3, the auxiliary tray 8 is configured such that a part of the circumferential surface of each of the rollers 36 and 37 faces the sheet conveying surface, and the auxiliary tray 8 is disposed on both sides of each endless belt 38 on the sheet conveying surface. A plurality of apertures 8b are formed, and two end fences 8a for receiving one end of the surface-printed paper PA sent from the printing unit 2 are integrally provided at the downstream end of the paper conveyance direction. It has been.

  At the upstream end of the auxiliary tray 8 in the paper conveyance direction, refeeding is performed to temporarily stop the other end of the front-side printed paper PA re-feeded to the printing unit 2 by the re-feed conveyance unit 25 at a fixed position. A paper positioning member 24 is provided. In this embodiment, two re-feeding positioning members 24 are provided and are integrally attached to the auxiliary tray 8 respectively. The auxiliary tray 8 is provided with a sensor 8c as a surface printed paper detection member that detects that the other end of the surface printed paper PA has approached the refeed positioning member 24. The sensor 8c outputs a signal to a control unit 129 (see FIG. 9) described later when the other end of the front surface printed paper PA is detected.

A hole (not shown) is provided on the lower surface of the transport unit main body 35, which is a mounting surface of the suction fan 39, and the suction fan 39 is operated thereby to apply a negative pressure to the interior of the transport unit main body 35, which is a housing. The surface-printed paper PA 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 force of the endless belt 38 are determined between the surface-printed paper PA and each endless belt 38 when the other end of the surface-printed paper PA comes into contact with the refeed positioning member 24. Each is set to a strength that causes slippage between them.
The auxiliary tray 8, the refeed guide member 22, the refeed registration roller 23, the refeed positioning member 24, and the refeed transport unit 25 constitute the refeed unit 9.

  A cleaning roller 26 that cleans the peripheral surface of the press roller 13 is disposed in the vicinity of the press roller 13 and above the refeed conveyance unit 25. The cleaning roller 26 having substantially the same width as that of the press roller 13 has at least a surface 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 press roller by a biasing means (not shown) provided in the long hole. The peripheral surface is constantly 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 the arm members 20, so that the surface-printed paper PA fed from the printing unit 2 does not touch the cleaning roller 26 and faces the auxiliary tray 8. To guide. The guide plate 27 is disposed at a position close to each peripheral surface 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 so as to face each other. Further, the other end of the printing spring 42 having one end fixed to the 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, and 43C is fixed to a cam shaft 44 supported at both ends by the apparatus main body 11 and movably in the paper surface direction of FIG. The 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 has plate cylinder driving means via a drive gear 45 attached to the camshaft 44 and a transmission gear 47 attached to a support shaft 46 rotatably supported by the apparatus body 11. The rotational force from 121 is transmitted, and it is rotated in the clockwise direction in FIG.

  The press roller 13 occupies a separation position shown in FIG. 2 in which 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, and 43C comes into contact with the cam follower 41. When the contact between any one of the convex portions and the cam follower 41 is released, the peripheral surface occupies the press contact position shown in FIG. 5 where the peripheral surface presses the peripheral surface of the plate cylinder 12 by the biasing force of the printing pressure spring 42. Each of the cam plates 43A, 43B, and 43C is configured so that the base and the cam follower 41 do not come into contact when the press roller 13 occupies the press contact position. The shape of the convex portions of the cam plates 43A, 43B, and 43C is such that the contact range between the press roller 13 and the plate cylinder 12 is a range in which all of 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.

  2, in the vicinity of the right side of each arm member 20, press roller locking means (not shown) that prohibits the swing of each arm member 20 in a state where the press roller 13 occupies the separated position is disposed. . The press roller locking means (not shown) has a solenoid (not shown), and the state of holding each arm member 20 and the state of releasing the holding are selectively switched by switching on and off 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 rotatably supported by the 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 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 the support shaft 48a. In the figure, a rotational biasing force in the clockwise direction is applied.

  The roller 48b is disposed between the discs 44a and 44b fixed in the middle of the camshaft 44, and the cam follower 48c has its peripheral surface brought into contact with the peripheral surface of the step cam 49 by the urging 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 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 apparatus main body 11 is attached to the support shaft 51. It is rotationally driven in the direction. With this configuration, when the stepping motor 52 is actuated to rotate the step cam 49, 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, the printing pressure spring 42, the multistage cam 43, the press roller locking means (not shown), the moving arm 48, and the 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. A 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 apparatus main body 11 at the downstream end in the sheet conveying direction, and is a solenoid. 123 (see FIG. 9) is activated, and the upstream end portion in the sheet conveyance direction formed with an acute cross section is selectively used as a first position indicated by a solid line and a second position indicated by a two-dot chain line in FIG. Is 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 at the position where it does not interfere with the clamper 19b 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 surface-printed paper PA 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 is in the second position. Is guided to the auxiliary tray 8 through the space between the guide plate 27 and the guide plate 56 fixed to the apparatus main body 11.

  As shown in FIG. 1, a plate making unit 3 is disposed in the upper right part of the apparatus main body 11. The plate making section 3 includes a master holding member 57, a platen roller 58, a thermal head 59, a cutting means 60, a master stock section 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 plate making master 65 having a first plate making image 65A and a second plate making image 65B as shown in FIG. 6A, FIG. The master making master 66 having the third plate making image 66A as shown in FIG. 7 or the plate making with the first plate making image 65A or the second plate making image 65B shown in FIGS. 7 (a) and 7 (b). A completed master 67 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 pre-printed 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. And corresponding positions. Each of the master holding members 57 is provided on a pair of side plates (not shown) of the plate making unit 3, 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 plate making unit 3 and is rotationally driven by plate making drive means 124 (see FIG. 9) including a stepping motor. A thermal head 59 positioned below the platen roller 58 and having a large number of heating elements is also attached to a side plate (not shown) of the plate-making unit 3, and the heating element surface is pressed against the platen roller 58 by a biasing force of a biasing means (not shown). Has been. 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. In the cutting means 60 having a fixed blade 60a fixed to a frame (not shown) of the plate making unit 3 and a movable blade 60b supported by the fixed blade 60a, the movable blade 60b rotates relative to the fixed blade 60a. This is a well-known configuration for cutting the master 64 by moving.

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

  A tension roller pair 62 is disposed at a portion between the cutting means 60 and the master stock portion 61. The tension roller pair 62 composed of a driving roller 62a and a driven roller 62b that are rotatably supported by a side plate (not shown) of the plate-making unit 3 respectively has a circumferential surface of the driving roller 62a that is driven by an urging means (not shown). The master roller 64 is sandwiched and conveyed by the driving roller 62a being rotationally driven by the plate-making driving means 124 (see FIG. 9). 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.

On the downstream side of the master stock unit 61 in the master conveyance direction, 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 plate making unit 3 is disposed. 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 670, 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 670 on which a large number of sheets P can be stacked on the upper surface is supported by the 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. 9) including an elevating means. A pair of side fences 72 supported by a rail member (not shown) so as to be movable in the paper width direction perpendicular to the paper transport direction are provided on the upper surface of the paper feed tray 670 on which A3 size paper P can be placed vertically. . A plurality of paper size detection sensors 73 that detect the size of the stacked paper P are provided on the free end side of the paper feed tray 670.

  A paper feed roller 68 is disposed above the paper feed tray 670. The paper feed roller 68 is rotatably supported by a bracket (not shown) that is swingably supported by the apparatus main body 11. When the paper feed tray 670 is lifted by lifting means (not shown), paper is fed with a predetermined pressure contact force. The uppermost sheet P on the tray 670 is pressed against. The paper feed roller 68 is rotationally driven by a paper feed driving means 125 (see FIG. 9). A separation roller 69 and a separation pad 70 are disposed on the left side of the paper feed roller 68. The separation roller 69 is drivingly connected to the paper feed roller 68 via a timing belt 69a, and is driven to rotate in the same direction in synchronization with the rotation of the paper feed roller 68. The separation pad 70 is pressed against the separation roller 69 by 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. 12, the paper P is fed toward the printing unit 2 at a predetermined timing by a driven roller 71 b that rotates at a predetermined timing in synchronization with the driven roller 71 and is in pressure contact with the driving roller 71 a.

  A plate discharging unit 5 is disposed on the upper left side of the printing unit 2. The plate discharging unit 5 includes an upper plate discharging member 74, a lower plate discharging member 75, a plate discharging box 76, a compression plate 77, and the like. The upper plate removal member 74 includes a 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. 9). 80 moves in the direction of the arrow in FIG. The lower plate removing member 75 includes 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 arrow direction in FIG. The lower plate removing member 75 is movably provided by a moving means (not shown) included in the plate discharging driving means 126, and an endless belt 83 positioned on the outer peripheral surface of the driven roller 82 is positioned at the position shown in the drawing and the outer peripheral surface of the plate cylinder 12. And selectively occupy the position where it abuts.

  A plate removal box 76 for storing the used master 64 c therein is provided detachably with respect to the apparatus main body 11. A compression plate 77 for pushing the used master 64c carried by the upper plate removal member 74 and the lower plate removal member 75 into the plate release box 76 is supported by the apparatus main body 11 so as to be movable up and down, and is included in the plate discharge drive 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 transport unit 85, a paper discharge tray 86, and the like.
A plurality of peeling claws 84 are arranged in the width direction of the plate cylinder 12, and are respectively integrally attached to a support shaft that is swingably supported by the apparatus main body 11. The plurality of peeling claws 84 are swung by a claw rocking means (not shown), and the tips of the peeling claws 84 are located close to the peripheral surface of the plate cylinder 12 and the tips of the plates 84 avoid the obstacles such as the clamper 19b. 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 paper discharge conveyance unit 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-like drive rollers 87 are attached to a support shaft (not shown) rotatably supported on a unit side plate (not shown) at a predetermined interval, and each is integrally rotated by a paper discharge drive means 127 (see FIG. 9). Is done. A plurality of driven rollers 88 are also provided on a support shaft (not shown) rotatably supported on the same side plate at equal intervals with each drive roller 87, and an endless belt 89 is provided for each drive roller 87 and each corresponding driven roller 88 corresponding thereto. Each is over. A suction fan 90 is disposed below the driving roller 87, the driven roller 88, and the endless belt 89. The paper discharge transport unit 85 sucks the paper P onto each endless belt 89 by the suction force of the suction fan 90, and transports the printed paper PB in the direction of the arrow in FIG. A paper discharge tray 86 on which the printed paper PB conveyed by the paper discharge conveyance unit 85 is stacked is provided with one end fence 91 movable in the paper conveyance direction and a pair of side fences movable in the paper width direction. 92.

  An image reading unit 7 is disposed on the upper part of the apparatus main body 11. The image reading unit 7 includes a contact glass 93 on which a document is placed, a pressure plate 94 provided so as to be able to come in contact with and away from the contact glass 93, reflection mirrors 95, 96, 97, 98 for scanning and reading a document image, and a fluorescent lamp. 99, a lens 100 for 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 for detecting the size of the document, and an image for storing the read image data The document image reading operation is performed by the operation of the reading drive unit 128 (see FIG. 9).

  As shown in FIG. 1, a dog 133 is attached to the outer surface of an end plate (not shown) constituting the plate cylinder 12, and a home position sensor 134 attached to the 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 b faces the press roller 13, and outputs a signal to the control means 129 described later.

  FIG. 8 shows an operation panel of the duplex printing apparatus 1. In the figure, an operation panel 103 provided on the upper front surface of the apparatus main body 11 has a plate making start key 104, a print start key 105, a clear / stop key 108, a numeric key 109 serving as an input means, a security mode setting key 110, Plate making position setting keys 111 and 112 serving as plate making image position setting means, a double-sided printing key 117, a single-sided printing key 118, a display device 119 including a 7-segment LED, a display device 120 including an LCD, and the like.

  The plate making start key 104 is pressed when the duplex printing apparatus 1 performs the plate making operation. When the plate making start key 104 is pressed, the plate making operation is performed after the plate discharging operation and the document reading operation are performed. The operation is performed and the duplex printing apparatus 1 enters a print standby state. The print start key 105 is pressed when the double-sided printing apparatus 1 performs a printing operation. The printing operation is performed when the double-sided printing apparatus 1 is in a print standby state and various printing conditions are set and then the print start key 105 is pressed. Done. The clear / stop key 108 is pressed when the operation of the duplex printing apparatus 1 is stopped or when the numerical value is cleared, and the numeric keypad 109 is used for numerical value input.

  The duplex printing key 117 is pressed before the plate making start key 104 is pressed when the duplex printing apparatus 1 performs the duplex printing operation. When the duplex printing key 117 is pressed, the LED 117a disposed in the vicinity thereof is lit. The operator is in the duplex printing mode. Similarly to the duplex printing key 117, the simplex printing key 118 is pressed before the start key 104 is pressed when the duplex printing apparatus 1 performs the simplex printing operation or the simplex selection printing operation. The LED 118a arranged in the vicinity is lit and the operator is informed that it is in the single-sided printing mode. In the duplex printing apparatus 1, 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. As shown in the figure, the display device 120 composed of an LCD displays the state of the double-sided printing device 1 such as “can be made / printed”, alarms such as plate-making or discharge jam, paper feed or paper discharge jam, and printing. Supply instructions for supplies such as paper, master and ink are also displayed.

  The security mode setting key 110 has a configuration unique to the present invention. When the operator presses the security mode setting key 110, the control unit 129 sets the security mode and executes the contents of the security mode to be described later. The prepress position setting keys 111 and 112 select either the first prepress image area 67A or the second prepress image area 67B shown in FIG. 10, and the first prepress image 65A or the second prepress image area 67B is selected in the selected area. The master making master 67 on which any of the two master making images 65B is made is used for printing in the single-sided selective printing mode using the master making master 67. The single-sided selective printing mode is set in the control means 129 when the single-sided printing key 116 is operated and the plate-making position setting key 111 or the plate-making position setting key 112 is operated. The plate making position setting key 111 is operated when forming a plate making image in the first plate making image area 67A and the plate making position setting key 112 is formed in the second plate making image area 67B.

  FIG. 9 shows a block diagram of the control means 129 used in the duplex printing apparatus 1. 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 apparatus main body 11. The control unit 129 is connected to a timer 113 serving as a measuring unit and a storage unit 114 that stores an image area of the plate making performed by the plate making unit 3.

  The CPU 130 is based on various signals from the operation panel 103, detection signals from various sensors provided in the apparatus main body 11, and an operation program called from the ROM 131, the printing unit 2, the plate making unit 3, the paper feeding unit 4, and the discharge plate. Operation of the drive unit provided in the unit 5, the paper discharge unit 6, the image reading unit 7, the solenoid 33 provided in the refeed unit 9, the conveying member drive motor 122, the operation of the solenoid 123 that operates the switching member 10, and the like. To control the operation of the entire duplex printing apparatus 1. The ROM 131 stores a single-sided printing mode, a double-sided printing mode, a single-sided selective printing mode which is an operation program for the entire duplex printing apparatus 1, a security mode which is a mode peculiar to the present invention, a set time Т and a predetermined rotation speed N of the plate cylinder 12. These programs and various setting values are appropriately called by the CPU 130. The RAM 132 temporarily stores the calculation result of the CPU 130 and the measurement result of the timer 113, the 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, etc. have. 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.

  Next, the contents of the security mode will be described. When the security mode is set by operating the security mode setting key 110, the control unit 129 operates the timer 113 after the end of printing when the security mode is set, and measures the elapsed time Т1. Then, it is determined whether or not the measured elapsed time Т1 has passed a preset set time Т, and if the set time Т has passed, it is stored in the storage means 114 at the time of plate making executed after the set time has elapsed. The operation of the plate making unit 3 is controlled so that plate making is performed only in an area other than the plate making area, and before the plate making operation at the time of plate making executed after the set time Т elapses, the storage means 114 is stored. The press roller contact / separation operation is controlled by controlling the operation of the press roller contact / separation mechanism 55 so as to apply the printing pressure only to the area other than the stored plate making area. The operation of the plate cylinder driving means 121 is controlled so that the plate cylinder 12 is rotated a plurality of times, that is, by a predetermined number of rotations N, while the printing pressure is applied to 12. The determination after the end of printing is made by counting the number of printed sheets corresponding to the set number of input prints, and determining that the number of printed sheets has been reached.

Next, the operation of the double-sided printing apparatus 1 will be described based on the above configuration. The operator loads the paper P to be used for printing on the paper feed tray 670, 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.
(Single-sided printing operation)
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 each signal. At this time, if the paper size and the document size are the same, the image reading operation is immediately performed. If the paper size and the document size are different, the control unit 129 displays the fact on the display device 120 and pays attention to the operator. Prompt.

  When the plate making start key 104 is pressed, the image reading unit 7 performs a document image reading operation. The document image read by the reading operation is converged by the lens 100 and then incident on the image sensor 101 to be photoelectrically converted. The The photoelectrically converted electrical signal is input to an A / D converter (not shown) in the 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. In the plate discharging operation, when the plate making start key 104 is pressed, the plate cylinder 12 starts to rotate. 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. A home position signal is sent to the control means 129. Receiving the home position signal, the control means 129 measures the number of pulses generated by an encoder (not shown) based on this 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 12 stops at a predetermined plate discharge position, the plate cylinder driving unit 121 and the plate discharge driving unit 126 are operated to rotate the plate cylinder 12 and operate the plate discharging unit 5 to be used from the outer peripheral surface of the plate cylinder 12. The used master 64 c is removed and placed in the plate removal box 76, and compressed by the compression plate 77.

  Even after all the used master 64c is peeled off from the outer peripheral surface of the plate cylinder 12, the plate cylinder 12 continues to rotate, and the clamper 19b 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 19b, and the duplex printing apparatus 1 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 reverse roller pair 63 are driven to rotate, and the master 64 is pulled out from the master roll 64a. At this time, a movable master guide plate (not shown) is positioned at the transport position. When the master 64 is pulled out and the image forming area reaches a position corresponding to the heat generating element of the thermal head 59, the image data signal stored in the image memory 135 is called after image processing is performed, 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 conveyed while being made and its tip is sandwiched between the reverse roller pair 63, a movable master guide plate (not shown) is moved to the retracted position and the rotation of the reverse roller pair 63 is stopped.

  The platen roller 58 and the tension roller pair 62 continue to rotate even after the rotation of the reversing roller pair 63 is stopped, and the plate-making master 66 made by the thermal head 59 is stored in the master stock unit 61. When the pair of reversing rollers 63 is stopped, a suction fan (not shown) provided in the master stock unit 61 is operated, and the pre-made master 66 is stored in the master stock unit 61 well 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 1 enters the plate feed standby state, the plate making master 66 stored in the master stock unit 61 is rotated by the reversing roller pair 63 being rotated. It is transported between the part 19a and the opened clamper 19b. When the leading end of the master 66 has been transported to a predetermined position where it can be clamped by the clamper 19b, an opening / closing means (not shown) is actuated to close the clamper 19b. The master 66 has its leading end moved to the stage 19a. And the clamper 19b are held on the outer peripheral surface of the plate cylinder 12.

  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. Then, when the image data signal from the image memory 135 is interrupted, the operation of the thermal head 59 is stopped, and when the plate-making master 66 for one plate is conveyed, the platen roller 58, the tension roller pair 62, and the reverse roller pair 63 are turned on. Each of the rotations is stopped and the cutting means 60 is operated to cut the master-making master 66. The cut master 66 that has been cut is pulled out from the plate making unit 3 by the rotation of the 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 is stopped at the home position, the solenoid 123 is actuated to position the switching member 10 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 be brought into contact with the cam follower 41, and then 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 driven, and the plate cylinder 12 is rotated at a low speed in the clockwise direction of FIG. 1 and loaded on the paper feed tray 670. The uppermost sheet of the paper P is pulled out and the leading end is sandwiched between the registration roller pair 71. Then, the drive roller 71a is driven at a predetermined timing when the leading end of the image area 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 between the plate cylinder 12 and the press roller 13.

  In synchronization 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 brought into pressure contact with the outer peripheral surface of the plate cylinder 12 by the urging force of the printing spring 42, and the sheet 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 paper P, the master plate master 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 unit 85 by the switching member 10 that has become the printed sheet PB and occupies the first position. Then, the peeling claw 84 peels from the plate-making master 66 on the outer peripheral surface of the plate cylinder from the tip portion. The peeled printed paper PB falls downward and is sent to the paper discharge transport unit 85, and is transported to the left while being attracted to the upper surface of the endless belt 89 by the suction force of the suction fan 90, and is discharged to the paper discharge tray. 86 is 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 1 enters a print standby state.

After the duplex printing apparatus 1 enters the print standby state, when the print condition is input using the various keys on the operation panel 103 and the set number of prints is input using the numeric keypad 109, the print start key 105 is pressed. The sheet P is continuously driven and the sheet P is continuously 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 for printing. The press roller 13 is pressed against the plate-making master 66 on the outer peripheral surface of the plate cylinder. The printed paper PB 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 plate-making master 66 on the outer peripheral surface of the plate cylinder by the peeling claw 84 and transported by the paper transport unit 85. Then, the paper is discharged onto the paper discharge tray 86. Such single-sided printing operation is continued until the set number of printed sheets is consumed, and when the number of printed sheets is consumed, the plate cylinder 12 is stopped at the home position, and the duplex printing apparatus 1 is again in a print standby state.
(Double-sided printing operation)
Next, a case where duplex printing is performed by pressing the duplex printing key 117 will be described. The operator confirms that the duplex printing mode is in effect by turning on the LED 117a, and then presses the plate making start key 104. When the plate making start key 104 is pressed, a paper size detection signal and a document size detection signal are sent from the sensors 73 and 102 to the control means 129 as in the case of single-sided printing, and the control means 129 receives the input signals. Compare. In the present embodiment, since the maximum paper size that can be printed by the plate cylinder 12 is A3 size, the paper size that can be used in duplex printing is up to A4 landscape orientation. As a result of comparing the document size and the paper size, if both sizes are the same, the image reading operation is immediately performed. If the two sizes are different, the control unit 129 displays a message to that effect on the display device 120 as a warning. Call attention to the operator. When the paper size and the document size are different, a configuration in which enlargement or reduction is automatically performed according to a command from the control unit 129 to match the document size and the image size, and the display device 120 is configured to reduce or reduce the size of the image data. It is good also as a structure which displays the procedure, such as rotation, and assists an operator's operation. When the paper size exceeds A4 landscape, the control unit 129 may display on the display device 120 a message that prohibits double-sided printing and prompts single-sided printing.

  When the plate making start key 104 is pressed, the image reading unit 7 reads the first original image 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 original reading operation 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. Alternatively, the document may be transported onto the contact glass 93, or the image data may be captured from an external device (not shown). Further, in the duplex printing mode, one original may be reversed and conveyed, and image data for two sheets may be acquired from the front and back surfaces.

  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 64c has been peeled off from the outer peripheral surface stops at the plate supply standby position, and the clamper 19b 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 master 64 forms the first plate-making image 65A and the second plate-making image 65B on the surface of the thermoplastic resin film. At this time, the images 65A and 65B are made between the first plate-making image 65A and the second plate-making image 65B so that a predetermined blank portion S is provided 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 master-making master 65 is wound on the outer peripheral surface of the plate cylinder 12.

  The master-making master 65 on which the images 65A and 65B are formed is stored in the master stock unit 61. When the plate-removing operation is completed and the duplex printing apparatus 1 enters the plate-feed standby state, the plate-making master 65 has been made by the operation of the reverse roller pair 63. The master 65 is transported between the stage portion 19a and the open clamper 19b. Thereafter, the plate cylinder 12 is intermittently rotated in the same manner as in the single-sided printing mode, and the plate-making master 65 is wound around the plate cylinder 12. When all the two pieces of image data are sent from the image memory 135, the cutting means 60 is activated to cut the master-making master 65. The cut master 65 that has been cut is pulled out of the plate making unit 3 by the rotation of the plate cylinder 12, and the plate cylinder 12 stops at the home position, 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 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 be brought 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 respectively driven, and the plate cylinder 12 is rotationally driven in the clockwise direction in FIG. The first sheet P is pulled out from above 670 and its leading end is sandwiched between the registration roller pair 71. When the clamper 19b passes the position corresponding to the switching member 10, the solenoid 123 is operated to position the switching member 10 at the second position, and then the plate of the pre-made master 65 wound on the plate cylinder 12 is used. When the driving roller 71a is rotationally driven at a predetermined timing when the leading end of the image area of the first plate-making image 65A in the cylinder rotation direction reaches a position corresponding to the press roller 13, the first sheet P drawn out is The sheet is fed between 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 first sheet P, the first plate-making image 65A forming portion of the plate-making master 65, and the plate cylinder 12 are pressed against each other and supplied to the inner peripheral surface of the plate cylinder 12 by the ink roller 16. After the ink oozes out from the opening of the plate cylinder 12 and is filled in the porous support plate (not shown) and mesh screen (not shown) wound around the plate cylinder 12 and the porous support body of the master 65 that has been made, the first The plate-making image 65A is transferred to the first sheet P through the punching portion, and the portion of the master-making master 65 where the first plate-making image 65A is formed is printed.

  An image corresponding to the first plate-making image 65A is printed on the surface by printing and the first sheet P which becomes the surface-printed sheet PA is formed on the outer periphery of the plate cylinder from one end by the tip of the switching member 10. While being peeled off from the master-making master 65, it is guided to the paper re-feeding means 9 by the switching member 10 occupying the second position. The surface-printed paper PA guided downward by the switching member 10 passes between the guide plates 27 and 56, has one end abutting against the end fence 8 a, and is placed on the auxiliary tray 8. The surface-printed paper PA conveyed on the auxiliary tray 8 is conveyed 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 other end (when the first plate-making image 65A is printed). The rear end of the sheet is brought into contact with the refeed positioning member 24. At this time, the sensor 8c detects the other end of the surface-printed paper PA, and a detection signal from the sensor 8c is output to the control unit 129, so that a command is sent from the control unit 129 and the drive roller 36 and the suction unit are sucked. The operation of the fan 39 is stopped.

  The plate cylinder 12 continues to rotate while the first sheet P is being guided on the auxiliary tray 8, and the press roller 13 protrudes from the cam plate 43B when it finishes contacting the surface area of the plate cylinder 12. The portion is in contact with the cam follower 41 and occupies the separated position. 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 in 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, 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.

  Further, the paper feed roller 68 and the separation roller 69 are driven almost simultaneously with the above-described operation, and the second sheet P is drawn from the paper feed tray 670 and the leading end thereof is sandwiched between the registration roller pair 71. Then, the driving roller 71a is rotationally driven at the same predetermined timing as described above, and the drawn second sheet P is fed 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 19b again occupies the position corresponding to the switching member 10, and the switching member 10 is moved to the second state. It is displaced from the position to the first position.

  At a predetermined timing when the second sheet P is fed by the registration roller pair 71, the cam plate 43 A disengages the convex portion from the cam follower 41, so that the press roller 13 is rotated by the biasing force of the printing pressure spring 42. The surface is brought into pressure contact with the outer peripheral surface of the plate cylinder 12. As a result, the press roller 13, the second sheet P, the first plate-making image 65A forming portion of the plate-making master 65, and the plate cylinder 12 are pressed against each other and supplied to the inner peripheral surface of the plate cylinder 12 by the ink roller 16. Ink is transferred onto the second sheet P through the opening of the plate cylinder 12, a porous support plate (not shown), a mesh screen (not shown), and a perforated portion of the first plate-making image 65A.

  The second sheet P, which has been printed with an image corresponding to the first plate-making image 65A and becomes the printed sheet PB, is guided to the sheet discharge conveyance unit 85 by the switching member 10 occupying the first position. The peeling claw 84 peels from one end of the master plate 65 on the outer peripheral surface of the plate cylinder. The printed paper PB which has been peeled off falls downward and is sent to the paper discharge transport unit 85 and then discharged onto the paper discharge tray 86.

  In addition, after the second sheet P is fed by the registration roller pair 71, the image area leading end of the second plate-making image 65 B in the plate cylinder rotation direction of the plate-making master 65 is at a position corresponding to the press roller 13. The solenoid 33 is actuated at a predetermined timing which is slightly earlier than the arrival, and the swing arm 32 is swung in the clockwise direction in FIG. 2 about the support shaft 32a. As a result, the re-feed registration roller 23 is swung from the separation position to the press-contact position, and the front-side printed paper PA that has been stopped with the other end in contact with the re-feed positioning member 24 contacts the plate cylinder 12. It is in contact with the peripheral surface of the press roller 13 that is in contact with and is rotated.

  The surface-printed paper PA brought into contact with the peripheral surface of the press roller 13 by the re-feeding registration roller 23 is conveyed to the downstream side in the rotational direction by the rotational force of the press roller 13, and the paper guide plate 31 and each roller 28. , 29, 30 are conveyed toward the contact portion with the plate cylinder 12 in close contact with the peripheral surface of the press roller 13. At this time, an image corresponding to the first plate-making image 65 A is printed on the surface of the surface-printed paper PA, but the surface-printed paper PA is applied to the peripheral surface of the press roller 13 by the operation of the refeed guide member 22. Since they are in close contact with each other, the surface-printed paper PA once in contact with the peripheral surface of the press roller 13 is not displaced, and the occurrence of problems such as rubbing dirt or thickening of the image line is prevented. Then, after the rear end and the intermediate area of the second sheet P pass through the position corresponding to the press roller 13, the front surface printed sheet PA is reached at the timing when the leading end of the back area reaches the position corresponding to the press roller 13. Is fed into the contact portion between the plate cylinder 12 and the press roller 13.

  Thus, the press roller 13, the surface-printed paper PA, the second plate-making image 65B forming portion of the plate-making master 65, and the plate cylinder 12 are in pressure contact with each other, and the ink supplied to the inner peripheral surface of the plate cylinder 12 by the ink roller 16 Is transferred to the back surface of the surface-printed paper PA through the opening of the plate cylinder 12, a porous support plate (not shown) and a mesh screen (not shown), and a perforated portion of the second plate-making image 65B. Printing of the portion where the second plate-making image 65B is formed is performed.

  An image corresponding to the first plate-making image 65A is printed on the front surface, and an image corresponding to the second plate-making image 65B is printed on the back surface. The occupying switching member 10 guides the sheet to the paper discharge conveyance unit 85, and the peeling claw 84 peels from the plate-making master 65 on the outer periphery of the plate cylinder from one end thereof. The peeled printed paper PB is dropped downward and sent to the paper discharge transport unit 85 and then discharged onto the paper discharge tray 86. Thus, the plate-making operation of the master master 65 is completed, and double-sided printing is performed. The apparatus 1 enters a print standby state.

  At the time of the above-described plate-making, a predetermined blank portion S is provided between the first plate-making image 65A and the second plate-making image 65B of the plate-making master 65, and the plate-making master 65 is on the outer peripheral surface of the plate cylinder 12. Since the intermediate area is formed when the paper is wound on the paper, the rear end of the second paper P sent from the paper supply unit 4 and the front end of the front surface printed paper PA sent from the refeed means 9 Is prevented from being polymerized, and good printing can be performed. Further, when the surface-printed paper PA is re-feeded from the re-feeding means 9, the ink from the surface-printed paper PA is re-applied to the surface of the press roller 13 by contacting the printing surface of the surface-printed paper PA. However, since the peripheral surface of the press roller 13 has ink repellency and the cleaning roller 26 cleans the peripheral surface of the press roller 13, the amount of retransfer ink from the surface-printed paper PA to the peripheral surface of the press roller 13 And the removal of the retransfer ink from the peripheral surface of the press roller 13 is promoted, and the retransfer of the ink from the press roller 13 to the back surface of the paper P can be prevented during the following printing.

  After the duplex printing apparatus 1 enters the print standby state, printing conditions are input using various keys on the operation panel 103, and when the print start key 105 is pressed after the set number of prints is input using the numeric keypad 109, the printing operation is performed. Done. Here, 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 plate printing. Similarly, the switching member 10 is positioned at the second position. After rotation of the plate cylinder 12 is started, the first sheet P is fed from the sheet feeding unit 4, and the fed first sheet P is temporarily stopped by the registration roller pair 71 and is the same as that at the time of printing. The sheet is fed at the timing and is pressed against the first plate-making image 65 A of the plate-making master 65 by the press roller 13. The first sheet P, which has been printed with an image corresponding to the first plate-making image 65A on the surface to become a surface-printed sheet PA, is being peeled off from the plate-making master 65 on the outer peripheral surface of the plate cylinder by the switching member 10. Guided to the auxiliary tray 8. The surface-printed paper PA conveyed on the auxiliary tray 8 is held in a state where the other end is in contact with the refeed positioning member 24 while being held on the endless belt 38 by the suction force of the suction fan 39.

  Thereafter, a press roller locking means (not shown) is actuated to hold the press roller 13 in the separated position, and the cam cam 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 19b occupies a position corresponding to the switching member 10 again. At the same time as this operation, the second sheet P is fed from the sheet feeding unit 4, and the fed second sheet P is temporarily stopped by the registration roller pair 71 and then the first sheet. The paper is fed toward the printing unit 2 at the same timing as P.

  The fed second sheet P is pressed against the first plate-making image 65A of the plate-making master 65 by the oscillating press roller 13, and an image corresponding to the first plate-making image 65A is printed on the surface. The second paper P that has become the finished paper PB is guided to the paper discharge transport unit 85 by the switching member 10 occupying the first position. The printed paper PB is peeled off from the plate-making master 65 by the peeling claw 84, falls downward, is transported by the paper discharge transport unit 85, and is discharged onto the paper discharge tray 86.

  After the second sheet P is fed by the registration roller pair 71, the solenoid 33 is actuated at the same timing as that at the time of printing, and the re-feeding registration roller 23 is displaced from the separation position to the press-contact position, so that the auxiliary tray 8, the surface-printed paper PA that has been temporarily stopped is brought into contact with the peripheral surface of the rotating press roller 13. The surface-printed paper PA 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 front-side printed paper PA is brought into pressure contact with the second plate-making image 65B of the plate-making master 65 by the oscillating press roller 13, and an image corresponding to the second plate-making image 65B is transferred to the back surface thereof. The first sheet P, which has been printed on both sides with images corresponding to the plate-making images 65A and 65B to become a printed sheet PB, is guided by the switching member 10 to the discharge conveyance unit 85. Thereafter, the printed paper PB is peeled off from the plate-making master 65 by the peeling claw 84, transported by the paper discharge transport unit 85, and discharged onto the paper discharge tray 86.

  Thereafter, the third sheet P is fed from the sheet feeding unit 4, and the third sheet P is temporarily stopped by the registration roller pair 71 and then printed at the same timing as the first and second sheets P. It is fed toward part 2. The switching member 10 is positioned at the first position to avoid a collision with the clamper 19b, and is positioned again at the second position after passing through the clamper 19b. The fed third sheet P is printed on the front surface with an image corresponding to the first plate-making image 65 </ b> A to become a surface-printed sheet PA, and is then guided onto the auxiliary tray 8 by the switching member 10. Then, the solenoid 33 is actuated at a predetermined timing, and the second surface-printed paper PA stopped on the auxiliary tray 8 is conveyed to the printing unit 2.

  The second front-side printed paper PA is sent to the contact portion between the plate cylinder 12 and the press roller 13 at the same timing as the first front-side printed paper PA, and corresponds to the second plate-making image 65B on the back side. The printed image is printed and becomes the second printed paper PB. 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 (the other end) of the third surface printed paper PA is the lower surface 10a of the switching member 10 and the press roller 13. It is guided on the auxiliary tray 8 through a slight gap between the peripheral surface and the peripheral surface. Following this, the leading end (one end) of the second printed sheet PB conveyed from the auxiliary tray 8 is guided along the upper surface 10b of the switching member 10 to the paper discharge conveying unit 85. The printed paper PB of the eyes is peeled off from the master-making master 65 by the peeling claw 84, then transported by the paper discharge transport unit 85, and discharged onto the paper discharge tray 86.

  Thereafter, the same printing operation as described above is performed up to the (N-1) th sheet. Then, the Nth sheet P is fed from the sheet feeding unit 4 and an image corresponding to the first plate-making image 65A is printed on the surface thereof, and guided to the auxiliary tray 8 as the Nth sheet printed paper PA. After that, an image corresponding to the second plate-making image is printed on the back surface of the (N-1) th front printed sheet PA, and the discharge tray is used as the (N-1) th printed sheet PB. When ejected onto 86, the press roller locking means (not shown) is actuated to hold the press roller 13 in the separated position, and the cam shaft 44 moves to a position where the cam plate 43C can be brought into contact with the cam follower 41. Thereafter, 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.

  The cam follower 41 can be brought into contact with the cam follower 41 at the 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 plate-making master 65 reaches the position corresponding to the press roller 13. The cam plate 43 </ b> C moved to the position disengages the 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 operated and swung at a second timing slightly earlier than the leading end of the image area of the second plate-making image 65B in the plate cylinder rotation direction of the plate-making master 65 reaches a position corresponding to the press roller 13. The 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 N-th surface printed paper PA that has been stopped with the other end in contact with the re-feeding positioning member 24 is printed on the plate. The press roller 13 is brought into contact with the peripheral surface of the press roller 13 that is in contact with the cylinder 12 and is driven to rotate.

  The N-th surface printed paper PA is sent to the contact portion between the plate cylinder 12 and the press roller 13 at the same timing as the first surface-printed paper PA, and corresponds to the second plate-making image 65B on the back surface thereof. The printed image is printed and becomes the Nth printed paper PB. The N-th printed paper PB is guided to the paper discharge transport unit 85 along the upper surface 10b of the switching member 10, and is transported by the paper discharge transport unit 85 after being peeled off from the master master 65 by the peeling claw 84, 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 pressed against 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 actuated 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 1 finishes the printing operation and enters the print standby state again. Become.

According to this double-sided printing apparatus 1, at the time of single-sided printing, the plate-making unit 3 creates a plate-making master 66, winds it around the plate cylinder 12, feeds the paper P from the paper feed unit 4, and presses it. 13 is pressed against the plate cylinder 12 so that one-side printing can be performed in the same manner as in a normal stencil printing apparatus without using the master 64 wastefully. Further, at the time of double-sided printing, the plate-making unit 3 creates a plate-made master 65 and winds it on the plate cylinder 12, feeds the first sheet P from the paper feed unit 4, and this surface is pressed by the press roller 13. After being brought into pressure contact with the plate cylinder 12, it is discharged onto the auxiliary tray 8, and a second sheet P is fed from the paper feed unit 4, and this surface is brought into pressure contact with the plate cylinder 12 by the press roller 13, and then the auxiliary tray 8. The sheet is discharged upward, and the first surface-printed paper PA is reversely fed by the re-feeding means 9, and the back surface is pressed against the plate cylinder 12 by the press roller 13. Therefore, both the front image and the back image printed on the paper P are formed by the ink transferred from the plate cylinder 12 by the press roller 13, and a good double-sided printed product can be obtained.
(Single-sided selective printing)
When the single-sided printing key 118 is pressed and the setting key 111 or the setting key 112 is pressed, the single-sided selection printing mode is set. 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 unit 129. In this embodiment, it is assumed that the document size and the paper size are set to A4, and the setting key 112 is operated to set the position of the platemaking image in the second platemaking image area.

  An A4 size original image read by the reading operation of the image reading unit 7 is incident on the image sensor 101, photoelectrically converted, input to the A / D converter, and then stored in the image memory 135 as an image data signal. The

  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 in the same manner as in single-sided printing. After all the used masters 64c are peeled off from the outer peripheral surface of the plate cylinder 12, the plate cylinder 12 rotates to a predetermined plate supply standby position and stops, and enters a plate supply standby state.

  In parallel with the plate removal operation, the plate making unit 3 performs the plate making operation. Here, the platen roller 58, the tension roller pair 62, and the reverse roller pair 63 are driven to rotate, the master 64 is pulled out from the master roll 64a, and the second plate-making image area is located at a position corresponding to the heating element of the thermal head 59. When it reaches, the image data signal stored in the image memory 135 is called after the image processing is performed, and a thermal head driver (not shown) selectively heats each heating element of the thermal head 59 to thereby generate the master 64. A second plate-making image 66A is formed on the surface of the thermoplastic resin film. When the plate-making master 67 on which the second plate-making image 66A is formed is conveyed to the plate cylinder 12 in the plate-feed standby state, and the tip portion is conveyed to a predetermined position where it can be clamped by the clamper 19b, the clamper 19b is held between the stage portion 19a and the clamper 19b and held on the outer peripheral surface of the plate cylinder 12.

  Thereafter, the plate cylinder 12 is intermittently rotated in the clockwise direction in FIG. 1, and the winding operation of the plate-making master 67 around the plate cylinder 12 is performed. 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 67 for one plate is conveyed, the platen roller 58, the tension roller pair 62, and the reverse roller pair 63 are turned on. The rotation is stopped and the cutting means 60 is operated to cut the master-making master 67. The cut master-making master 67 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 is stopped at the home position, the solenoid 123 is actuated to position the switching member 10 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 be brought into contact with the cam follower 41, and then 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 driven, and the plate cylinder 12 is rotated at a low speed in the clockwise direction of FIG. 1 and loaded on the paper feed tray 670. The uppermost sheet of the paper P is pulled out and the leading end is sandwiched between the registration roller pair 71. The driving roller 71a is driven at a predetermined timing when the image area leading end of the second plate-making image 65B in the plate-cylinder rotation direction of the plate-making master 67 wound on the plate cylinder 12 reaches a position corresponding to the press roller 13. Is rotated, and the drawn paper P is fed between the plate cylinder 12 and the press roller 13.

  In synchronization 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 43AC 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 brought into pressure contact with the outer peripheral surface of the plate cylinder 12 by the urging force of the printing spring 42, and the sheet 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 paper P, the master plate master 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 67 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 67 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 second plate-making image 65B is printed by printing is guided to the paper discharge conveyance unit 85 by the switching member 10 that has become the printed sheet PB and occupies the first position. Then, the peeling claw 84 peels from the plate-making master 66 on the outer peripheral surface of the plate cylinder from the tip portion. The peeled printed paper PB is transported to the left via the paper ejection transport unit 85 and is ejected onto the paper ejection tray 86. 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 1 enters a print standby state.

  After the duplex printing apparatus 1 enters the print standby state, when the print condition is input using the various keys on the operation panel 103 and the set number of prints is input using the ten key 109 and then the print start key 105 is pressed, simplex printing is performed. Printing is performed in the same process. This single-sided selective printing is continued until the set number of prints is consumed, and when the number of printed sheets is consumed, the plate cylinder 12 stops at the home position, and the double-sided printing apparatus 1 enters the print standby state again.

  In this embodiment, the plate-making image is formed in the second plate-making image area 67B in single-sided selective printing, but the plate-making image may be formed in the first plate-making image area 67A. In this case, the plate-making image to be made may be either the first or the second plate-making image.

(Security mode)
Next, the operation and control when the security mode is set will be described using the flowchart shown in FIG.

  For example, in step S1, when the operator presses the security mode setting key 110 when setting single-sided selective printing, the control unit 129 sets the security mode, and here, normal single-sided selective printing is performed as described above. The difference between the case where the security mode is set and the case where the security mode is not set is that the position of the plate-making image made in the single-sided selective printing is stored in the storage unit 114 in step S2 and after the single-sided selective printing is finished in step S3. In step S4, the timer 113 is operated to measure the elapsed time Т1.

  In step S5, it is determined whether or not the measured elapsed time Т1 has passed a preset time Т. This set time Т is a time during which the fluidity of the ink accumulated on the inner peripheral surface and the opening of the plate cylinder 12 becomes high. In step S5, when the elapsed time Т1 has passed the set time Т, only for areas other than the plate making area stored in the storage means 114 before the plate making executed after the set time has passed in step S6. The operation of the press roller contact / separation mechanism 55 is controlled so as to apply the printing pressure to control the contact / separation operation of the press roller 13, and the plate cylinder driving means 121 for rotating the plate cylinder 12 by a predetermined rotational speed N in step S 7. Actuate. The predetermined rotational speed N is a rotational speed corresponding to a time during which the ink whose fluidity has increased after a predetermined time T can be mixed with the other ink in the plate cylinder 12 and uniformized.

  That is, when the plate-making image area stored in the storage unit 114 is the second plate-making image area 67B as shown in FIG. 10B, the area 67C shown in FIG. For this reason, the press roller locking means (not shown) and the stepping motor 52 are operated to rotate the step cam 49 and bring the cam portion 49b 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 be brought into contact with the cam follower 41. Is released, the press roller 13 comes into pressure contact with the region 67C. For this reason, the press roller 13 applies a printing pressure to the non-plate-making area (67C) of the plate-making master 67 wound around the plate cylinder 12, so that ink does not adhere to the press roller 13 and the plate cylinder 12 Ink is pushed back inside. The pushed-back ink is mixed with other inks as the plate cylinder 12 rotates, so that the ink can be made uniform in the plate cylinder 12. The predetermined rotation speed N and the speed for rotating the plate cylinder 12 may be the same as the normal printing speed, or may be rotated at a low speed as in the plate feeding.

  Such contact / separation operation of the press roller 12 is interlocked with the rotation of the plate cylinder 12, and when the plate cylinder 12 rotates by a predetermined number of revolutions N in step S8, the plate cylinder 12 is stopped and the press roller 13 is operated in step S9. The printing pressure is released and the printer enters a standby state.

  In step S10, when the plate making start key 104 is pressed and turned on to execute a new plate making, a new plate making is executed in an area other than the plate making area stored in the storage means 114 in step S11. That is, if the plate-making image area stored in the storage unit 114 is the second plate-making image area 67B as shown in FIG. 10B, afterimages are likely to occur if new printing is performed using this area. Therefore, a new plate making is performed on the first plate making image area 67A which is not the second plate making image area. Specifically, when the plate making start key 104 is pressed in step S9, a new plate making is performed in the first plate making image area 67A, not in the second plate making image area 67B which becomes the afterimage generation area of the master 64 in step S11. In step S12, the plate feeding operation and the plate attaching operation are performed as described above.

  When the set number of prints is input with the numeric keypad 109 in step S13 and the print start key 105 is pressed in step S14, a new plate-making master 67 in which a plate-making image is made in the first plate-making image area 67A in step S15. When printing for the set number of prints is completed in step S16, the printing operation is stopped in step S17, and this control is finished.

  As described above, according to the present embodiment, the printing pressure is applied only to the area other than the plate making area stored in the storage unit 114 before the start of the plate making operation at the time of plate making executed after the set time has elapsed. In this state, the plate cylinder 12 rotates a predetermined number of times, so that the ink remaining after the previous printing is mixed with other inks by the rotation of the plate cylinder 12 to make the ink uniform. For this reason, as in the prior art, the amount of ink deposited on the plate and discarded can be reduced, and the ink consumption can be reduced.

  Further, when the elapsed time T1 after the end of printing measured by the timer 113 exceeds a preset set time T, when the plate making is executed after the set time elapses, other than the plate making area stored in the storage unit 114 Since the plate-making is performed only in the region, the plate-making image made on the new plate is not located in the region of the plate cylinder 12 where the ink image at the time of printing using the previous plate-making image remains. For this reason, at the time of printing by the master-making master 67 newly made in step S11, the ink image at the previous printing is not printed, and the occurrence of an afterimage (ghost) can be prevented. Further, since the ink of the plate cylinder 12 is not made uniform with a roller or a blade as in the prior art, the amount of ink that adheres to the discarded master and is discarded can be reduced, and the ink consumption can be reduced.

  In the present embodiment, the set number of prints to be printed is input with the numeric keypad 109 in step S13 during printing using the plate-making master 67 obtained by a new plate-making operation performed after a predetermined time has elapsed. If it is less, the plate cylinder 12 will rotate less. Therefore, if the minimum print number N is set in advance in the ROM 131 of the control means 129 and the print setting number input in step S12 is less than the minimum print number N preset in step S22, step The process may proceed to S23 to execute printing of the minimum number N of prints.

  In such a control mode, the rotation of the plate cylinder 12 is ensured by the minimum number N of prints regardless of the set number input with the ten key 109, and the rotation of the plate cylinder 12 causes the previous printing to be performed. Since the residual ink can be mixed with other inks to make the ink uniform, the amount of ink deposited on the master and discarded can be reduced as in the prior art, and the ink consumption can be reduced.

1 is a schematic front view of a double-sided printing apparatus to which an embodiment of the present invention can be applied. It is a schematic front view explaining the press roller spaced apart from the press roller contacting / separating mechanism and plate cylinder outer peripheral surface used for one embodiment of this invention. FIG. 2 is a schematic plan view illustrating a sheet refeeding conveyance unit used in one embodiment of the present invention and a sheet receiving plate used in the first embodiment. It is a schematic side view explaining the press roller contacting / separating mechanism used for one embodiment of the present invention. It is a schematic front view explaining the press roller which contacted the press roller contact / separation mechanism and plate cylinder outer peripheral surface used for one embodiment of this invention. (A) is a schematic diagram illustrating a divided master-making master used in an embodiment of the present invention, and (b) is a schematic diagram illustrating a master-made master during single-sided printing. (A) is a schematic diagram for explaining a pre-made master in which a first plate-making image is made, and (b) is a schematic diagram for explaining a pre-made master in which a second plate-making image is made. It is the schematic which shows the operation panel used for one embodiment of this invention. It is a block diagram of the control means used for one embodiment of the present invention. (A) is the schematic explaining the 1st platemaking image area on a master, (b) is the schematic explaining the 2nd platemaking image area on a master. It is a flowchart which shows the control content at the time of the security mode which is the characteristic content of this invention. It is a flowchart which shows the content which changed a part of control content at the time of the security mode shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Duplex printing apparatus 2 Printing part 3 Plate making part 12 Printing drum 13 Printing pressure member 64 Plate 65A 1st plate making image 65B 2nd plate making image 66A 3rd plate making image 67A 1st plate making image area 67B 2nd plate making image Area 67A First plate-making image area 67B Second plate-making image area 109 Input means 113 Measuring means 114 Storage means 129 Control means P Paper T1 Elapsed time T Set time

Claims (3)

Plate making for making a plate making image by arranging the first plate making image and the second plate making image side by side for one plate, or making a third plate making image having image areas for two sides of the first plate making image and the second plate making image. And a sheet conveyed between the printing drum and the printing pressure member by moving the printing pressure member on and away from the printing drum wound around the outer peripheral surface of the plate made by the plate making unit. A double-sided printing function for successively printing a first plate-making image and a second plate-making image on different sides of the paper, and a first plate-making image and a second plate-making image. In a printing apparatus provided with a single-sided selection printing function for printing on one side of a sheet by selecting any of the above, a single-sided printing function for printing on one side of a sheet using a plate on which only a third plate-making image is made,
Storage means for storing an image area of the plate making performed on the plate;
Measuring means for measuring the elapsed time after completion of printing using the plate;
It is determined whether or not the elapsed time measured by the measuring means has passed a preset set time, and when the preset time has passed, it is stored in the storage means at the time of plate making executed after the set time has elapsed. A printing apparatus comprising control means for controlling the operation of the plate-making unit so as to perform plate-making only in an area other than the plate-making area.   The control means applies the printing pressure only to an area other than the plate making area stored in the storage means before the start of the plate making operation at the time of plate making executed after the set time elapses. Control the operation of the drive source of the printing drum so that the printing drum is rotated a plurality of times in a state where the printing drum is rotated by the printing pressure member while the printing pressure is applied to the printing drum. The printing apparatus according to claim 1. An input means for inputting the set number of prints;
The control unit executes printing of the minimum number of prints when the set number of prints at the time of printing executed after the set time input from the input unit is less than a preset minimum number of prints. The printing apparatus according to claim 1, wherein the operation of the printing unit is controlled .

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