JP4221038B2 - Stencil printing machine - Google Patents

Description

  The present invention relates to control of a stencil printing apparatus, and more particularly to control for reducing consumption of a master and ink.

  Conventionally, digital thermal stencil printing is known as a simple printing method. This is achieved by bringing a thermal head in which fine heating elements are arranged in a row into contact with a heat-sensitive stencil master (hereinafter referred to as “master”) and conveying the master by a platen roller or the like while energizing the heating elements in pulses. Thus, after making a perforated image based on image information on the master by hot-melt perforation, the master that has been perforated is wound around a porous cylindrical plate cylinder, and the printing paper is printed by a pressing member such as a press roller. By pressing against the outer peripheral surface of the cylinder, ink is oozed out from the opening portion of the plate cylinder and the perforation portion of the master, and this ink is transferred to the printing paper to obtain a printed image.

  The plate cylinder described above has an opening portion through which ink oozes and a non-opening portion in which a clamper, a stage portion, and the like that sandwich the tip of the master are arranged, and the length of the opening portion is printed. Is set according to the maximum size of the paper to be printed. For example, in a stencil printing apparatus capable of printing a maximum A3 size paper, the length of the opening is about 420 mm.

  In the stencil printing apparatus described above, after the printing is completed and the original is changed, when performing the next printing, the user presses the plate making start key to release the used master from the plate cylinder, The master newly made by the plate making means is configured to be automatically wound around the plate cylinder. This is because when the used master is peeled off from the plate cylinder immediately after the printing is finished, the outer peripheral surface of the plate cylinder is left exposed to the atmosphere until a new plate-making master is wound before the next printing. If this state is left for a long time, the ink remaining on the outer peripheral surface of the plate cylinder and the perforated portion evaporates, and when the next plate is printed, the replenishment of ink to the master is hindered and good printing is performed. In some cases, the used master is wound on the outer peripheral surface of the plate cylinder to prevent drying of the outer peripheral surface of the plate cylinder.

  Therefore, as the master used in the above-described stencil printing apparatus, a master having a length of 420 mm + α is required to cover the entire opening portion and allow for the clamping length of the clamper and the press roller contact position. However, when A4 size printed matter is obtained with this stencil printing device, about half of the master becomes a blank portion that is not used for printing, and the amount of ink attached to the master and discarded increases the cost. There is a problem that it will.

  To solve this problem, prepare a plurality of plate cylinders with different opening lengths for each paper size, replace the plate cylinders according to the desired size of printed matter, and open the hole lengths of the installed plate cylinders. A technique is known that cuts the master made in accordance with the thickness and reduces the consumption of the master.

JP-A 64-24783

  However, in the above-described technique, it is troublesome to attach and detach a plurality of plate cylinders, and it is necessary to prepare a plate cylinder corresponding to the paper size and ink type, particularly when performing multicolor printing. However, the number of plate cylinders is enormous, resulting in a significant increase in cost and a problem of occupying a large space as a storage place for the plate cylinders.

  Therefore, a plate cylinder having a large opening length is used, the length of the master to be wound is cut according to the size of the printing paper to be used, and there is no master when a short master is wound. A technique for controlling the pressing range of the pressing member so that the pressing member does not press the opening portion of the printing cylinder is disclosed in, for example, “Patent Document 1”. In this technique, a printing cylinder on which a short master is wound is disclosed. Is left unattended, there is a risk that the outer peripheral surface of the plate cylinder will dry out, resulting in loss of paper at the start of printing the next plate. Especially when left outside the machine, dust etc. may adhere to the opening of the plate cylinder, and during the printing of the next plate, the passage of ink in the part where the dust is attached is obstructed, There was a problem that white spots occurred in the printed image.

  An object of the present invention is to provide a stencil printing apparatus capable of solving the above problems and obtaining a good printed matter while reducing the consumption of the master and ink without increasing the cost.

First aspect of the present invention, a plate cylinder having an opening on its outer peripheral surface is supported by a rotating self-standing on the housing, a plate making unit for stencil making and conveying and cutting the master, and away with respect to the outer peripheral surface In a stencil printing apparatus having a pressing member provided freely, the plate making means and a control means for controlling the operation of the pressing member, and the first plate making printing mode for performing the first plate making printing operation as the plate making printing mode or A switching means for switching to any one of the second prepress printing modes for performing the second prepress printing operation, an original reading means for reading an original image, and an automatic separating / conveying apparatus for automatically feeding originals one by one to the original reading means; ; and a document reading unit having a document length detection means for detecting the length of the document is provided in the automatic separating and conveying apparatus, the control means, as the master when the first plate printing mode is selected When the second plate-making printing mode is selected, the master is controlled so that a plate having a length that covers all of the opening portions qualitatively and the master is wound around the outer peripheral surface is selected. The plate making means having an arbitrary length shorter than the opening portion and controlling the plate making means to wind the master around the outer peripheral surface, and the outer circumference of the pressing member according to the arbitrary length The control means switches the switching means based on the length of the original detected by the original length detecting means when controlling the contact range to the surface and performing the reading operation of the original, and the automatic separation conveyance A first original reading by the original reading means using the apparatus and a second original reading by the original reading means not using the automatic separation / conveyance device can be selected. Control means switches the switching means to the first plate printing mode, said control means only for the last document when the first document reading, characterized in that switches the switching means to the first plate printing mode.

According to a second aspect of the present invention, in the stencil printing apparatus according to the first aspect, when the reading operation of a plurality of originals is further performed by the first original reading, the control means changes the switching means for each predetermined number of plates. Switching to the first plate-making printing mode is characterized.

  According to the present invention, a master that substantially covers all of the opening portions of the plate cylinder and a master that covers a part of the opening portions are arbitrarily made, and the pressing member according to the length of each master. The range of contact with the outer peripheral surface of the plate cylinder can be controlled, so that the master and the ink absorbed by the master are suppressed by making the master according to the length of the original and performing printing. By making a master plate that substantially covers all of the apertures and performing printing, the evaporation of ink from the inside of the plate cylinder and the solidification of the ink in the apertures can be prevented to suppress the occurrence of paper loss. it can.

  Further, by notifying the operator that the part of the opening is an exposed plate cylinder, the ink stain inside the casing or the plate cylinder is left unattended when the plate cylinder is removed. It is possible to prevent the occurrence of problems such as ink evaporation and solidification caused by.

  In addition, by notifying the operator that the master and the printing paper are not aligned, it is possible to prevent the occurrence of damaged paper and the contamination of the press roller.

  Further, by preventing the plate cylinder from which a part of the opening portion is exposed from being easily removed from the casing, ink stains in the casing when the plate cylinder is removed or the plate It is possible to prevent the occurrence of problems such as ink evaporation and solidification caused by leaving the cylinder unattended.

  In addition, by notifying the operator that the master and the plate-making printing mode stored in the memory means are inconsistent, it is possible to prevent the occurrence of damaged paper and the contamination of the press roller.

  In addition, by restricting the operation of the paper feeding unit in a state where the master and the printing paper are not aligned, it is possible to prevent the occurrence of paper loss and the contamination of the press roller.

  In addition, printing can be performed by making a master corresponding to the size of the designated plate-making image area, and consumption of ink absorbed by the master and the master can be suppressed.

  In addition, printing can be performed by making a master according to the size of the original, and consumption of ink absorbed by the master and the master can be suppressed.

  In addition, when the first document is read, the master corresponding to the size of the document is made and printed, so that the consumption of ink absorbed by the master and the master can be suppressed, and when the second document is read, the plate cylinder is opened. By making a master plate that substantially covers all the hole portions and performing printing, even if the stencil printing apparatus is left for a long period of time after the printing is completed, it is possible to prevent problems such as ink evaporation and solidification.

  In addition, since only the final document is a master that substantially covers all the opening portions of the plate cylinder, even if the stencil printing apparatus is left for a long period of time after printing, problems such as ink evaporation and solidification may occur. Can be prevented.

  In addition, a master that substantially covers all the opening portions of the plate cylinder is made every predetermined number of plates, so that dust that adheres to the surface of the opening portions is adhered to the master and discarded periodically. And a good printed matter can be obtained.

  FIG. 1 is a schematic front view of a stencil printing apparatus 1 that employs an embodiment of the present invention. In FIG. 1, a stencil printing apparatus 1 is mainly composed of a printing unit 2, a plate making unit 3, a paper feeding unit 4, a plate discharging unit 5, a paper discharging unit 6, a document reading unit 7, and the like.

As shown in FIG. 2, the printing unit 2 disposed in the center of the housing 18 mainly includes a plate cylinder 8, an ink supply unit 9, a press roller 10 as a pressing member, and the like.
The plate cylinder 8 mainly includes a pair of flanges 12 and 12 that are rotatably supported by a support shaft 11 that also serves as an ink supply pipe, and a porous support plate 8a that is wound around the outer peripheral surface of the flanges 12 and 12. 1 and is driven to rotate in the direction of the arrow in FIG. The support shaft 11 is supported at the front end portion 11a (see FIG. 5) by the side plate 18a (see FIG. 5) of the housing 18, and has a plurality of small holes for supplying ink to the ink supply means 9 on the surface. The flanges 12 and 12 are attached to the support shaft 11 via bearings (not shown).

  The porous support plate 8a formed of a stainless steel thin plate or the like has an opening portion and a non-opening portion, and a large number of openings 8b are formed in the opening portion. A stage portion 14 having a plane parallel to one generatrix of the plate cylinder 8 is disposed. An openable / closable clamper 15 is disposed on the upper surface of the stage unit 14. Further, on the outside of the porous support plate 8a, about 1 to 3 layers of mesh screens (not shown) woven with polyester or stainless fine wires are wound.

  An ink supply means 9 mainly composed of an ink roller 16, a doctor roller 17 and the like is disposed inside the plate cylinder 1 and below the support shaft 11. The ink roller 16 has a support shaft 16a rotatably supported on a pair of side plates (not shown) fixed on the support shaft 11 between the flanges 12 and 12, and the rotational force from the driving means 13 is applied to a gear, a belt, or the like. It is transmitted by the rotational force transmitting means and rotates in the same direction as the plate cylinder 8. The doctor roller 17 is rotatably supported between the side plates at a position where a slight gap is generated between the outer peripheral surface of the doctor roller and the outer peripheral surface of the ink roller 16. Are driven to rotate in the opposite direction. In the vicinity of the outer peripheral surfaces of the ink roller 16 and the doctor roller 17, the ink supplied from the support shaft 11 forms a wedge-shaped ink reservoir 17a.

  FIG. 3 shows driving means 13 for rotationally driving the plate cylinder 8, the ink roller 16 and the doctor roller 17. The driving means 13 is mainly composed of gears 19 and 20, a toothed pulley 21, a timing belt 22, a pinion gear 23, a stepping motor 24, and the like.

  A gear 19 is fixed to the outside of one flange 12 located on the back side of the apparatus. The gear 19 is attached around the support shaft 11 and has a hole 19a formed in a size not contacting the support shaft 11 in the center. A tip portion (not shown) of the support shaft 11 passes through the gear 19 and is supported by the side plate 18a.

  A gear 20 that meshes with the gear 19 is disposed in the vicinity of the gear 19. The gear 20 is fixed to the end of a support shaft 20a that is rotatably supported by the casing 18, and is on the support shaft 20a on the outer side (the side farther from the flange 12) than the position where the gear 20 is fixed. The toothed pulley 21 is fixed. The toothed pulley 21 is connected to a pinion gear 23 fixed to an output shaft end of a stepping motor 24 attached to the housing 18 by a timing belt 22. The operation of the stepping motor 24 is controlled by the control means 26 described later.

  With this configuration, the rotational force of the stepping motor 24 is transmitted, the flange 12 rotates about the support shaft 11, and the plate cylinder 8 is rotationally driven. A gear (not shown) is also attached to the inside of one flange 12, and the ink roller 16 and the doctor roller 17 are driven to rotate by transmitting a rotational force by a gear (not shown) meshing with the gear. The

  A dog 25 extending in the axial direction is fixed to the vicinity of the outer peripheral edge of the flange 12, and a home position sensor 27 is disposed on a circular track of the dog 25 that rotates as the flange 12 rotates. . The home position sensor 27 is attached to the housing 18 and outputs a signal toward the control means 26 when the dog 25 passes through the detection unit.

  As shown in FIG. 4, a handle 28 having a U-shape for carrying the plate cylinder 8 is attached outside the flanges 12 and 12 so as to straddle the plate cylinder 8 in the axial direction. The handle 28 is integrally formed of a main body 28a and side plates 28b and 28c, and the side plates 28b and 28c are attached to the support shaft 11, respectively.

  The main body 28a has rollers 28d and 28d at the end on the side plate 28b side, and engages the rails 28d and 28d with a rail member 29 attached to the side plate 18a of the housing 18 as shown in FIG. By doing so, the housing 18 is configured to be detachable. The plate cylinder 8 can be attached to and detached from the casing 18 only when the plate cylinder 8 is placed at the home position.

  The side plate 28b located on the back side of the apparatus has a distal end portion 11a of the support shaft 11 passing therethrough, and the distal end portion 11a is detachably supported by a positioning member 30 provided on the side plate 18a. An ink supply device 31 having an ink pack for replenishing ink to be supplied to the support shaft 11 is provided on the side plate 28c on the other flange 12 side located on the front side of the device.

  As shown in FIGS. 5 and 6, the casing 18 is provided with a withdrawal restriction means 32 for the plate cylinder 8 and a sensor 33 as a master length detection means. The withdrawal regulating means 32 is mainly composed of a solenoid 34, an arm 35, a tension spring 36, and the like.

  The solenoid 34 is attached to the side plate 18a via an attachment member (not shown), and its operation is controlled by the control means 26. The arm 35 is supported by a pin 35a planted on the side plate 18a in a swingable manner, and a plunger 34a of a solenoid 34 is attached to the free end side from the center thereof. The arm 35 is attached with the other end of a tension spring 36 having one end fixed to the side plate 18a.

  With this configuration, the removal restricting means 32 is engaged with the notch portion 11 b formed in the vicinity of the tip end portion 11 a of the support shaft 11 by the urging force of the tension spring 36 when the solenoid 34 is inoperative. 6 is positioned to regulate the removal of the plate cylinder 8 from the casing 18, and when the solenoid 34 is operated, the free end of the arm 35 and the notch 11b are disengaged. It is positioned at the position of the two-dot chain line in FIG. 6 to allow the plate cylinder 8 to be removed from the casing 18.

  A sensor 33, which is a reflection type sensor, is attached to the casing 18, and detects the presence or absence of a master from the difference in the amount of reflection on the outer peripheral surface of the plate cylinder 8, and the master when the plate cylinder 8 is rotated by a predetermined angle. The length of the wound master is detected from the presence or absence of. The sensor 33 is attached at a position where it does not interfere with obstacles such as the clamper 15 when the plate cylinder 8 rotates, and its output signal is input to the control means 26.

  A press roller 10 is disposed below the plate cylinder 8. As shown in FIG. 7, in the press roller 10, both ends of the support shaft 10a are rotatably supported between one ends of a pair of press roller arms 37, 37. Each press roller arm 37, 37 has the other end. Each is fixed to the support shaft 37a.

  In addition to the press roller arms 37, 37, a swing arm 38 having a rotatable cam follower 38a at one end is fixed to a support shaft 37a whose both ends are rotatably supported by the casing 18. The other end of the tension spring 39, one end of which is fixed to the casing 18, is attached to the swing arm 38, and a pivoting biasing force in the clockwise direction in FIG. 7 is applied to the support shaft 37a. . Further, the swing arm 38 is provided with a pin 38b that engages with a tip of a locking arm 44 described later.

  In the vicinity of the swing arm 38, a multistage cam 40 having four cam plates 40a, 40b, 40c, and 40d is disposed. Each cam plate 40a, 40b, 40c, 40d is fixed with a gap near one end of a support shaft 41 supported at both ends by the housing 18 and movably in the direction of the paper surface of FIG. The cam plate 40a, the cam plate 40b, the cam plate 40c, and the cam plate 40d are arranged in this order from the front side. As shown in FIG. 7, each of the cam plates 40a, 40b, 40c, and 40d has a base portion that is a disc concentric with the support shaft 41, and a convex portion having the same protruding amount. The shape is formed so that the convex portions of the cam plate 40b, the cam plate 40c, and the cam plate 40d increase in the circumferential direction with respect to the right edge of the convex portion of the cam plate 40a. As shown in FIG. 8, the multistage cam 40 is driven from the drive means 13 via a drive gear 42 attached to the support shaft 41 and a transmission gear 49 attached to a support shaft 48 rotatably supported by the housing 18. , And is rotationally driven in the direction indicated by the arrow in FIG.

  The press roller 10 moves to a position indicated by a solid line in FIG. 7 when any convex portion of each of the cam plates 40a, 40b, 40c, and 40d comes into contact with the cam follower 38a, and makes contact with any convex portion. When is released, it is pressed against the outer peripheral surface of the plate cylinder 8 by the urging force of the tension spring 39. At this time, the base of each cam plate 40a, 40b, 40c, 40d and the cam follower 38a are configured not to contact each other.

  The size of the convex portion of each cam plate 40a, 40b, 40c, 40d in the circumferential direction is such that the pressure contact range between the outer peripheral surface of the press roller 10 and the outer peripheral surface of the plate cylinder 8 is A3 vertical length, B4 vertical length, The lengths are set to correspond to the A4 vertical length and the B5 vertical length, respectively.

  As shown in FIG. 7, a locking arm 44 is disposed in the vicinity of the swing arm 38. The locking arm 44 having a distal end 44a formed in a bowl shape is supported at its base end so as to be swingable on a support shaft 44b. A plunger 45a of a solenoid 45 attached to the housing 18 and another end of a tension spring 46 attached to one end of the tension spring 46 are attached to the locking arm 44. When any of the convex portions of the cam plates 40a, 40b, 40c, and 40d is in contact with the cam follower 38a and the solenoid 45 is de-energized, the tip 44a is engaged with the pin 38b as shown in FIG. Thus, the press roller 10 is configured to hold the outer peripheral surface thereof in a state of being separated from the outer peripheral surface of the plate cylinder 8. The operation of the solenoid 45 is controlled by the control means 26.

  As shown in FIG. 8, a moving arm 43 and a step cam 47 are disposed near the lower portion of the support shaft 41. The movable arm 43 having a substantially L-shape is swingably supported by a support shaft 43c at its bent portion, and a roller 43a is rotatably attached to one end and a cam follower 43b is rotatably attached to the other end. . The other end of the tension spring 50 having one end attached to the housing 18 is attached to a portion between the other end of the moving arm 43 and the bent portion. A clockwise biasing force in FIG. 8 is applied to the center.

  The roller 43 a is disposed between the discs 41 a and 41 b that are fixed to each other in the middle of the support shaft 41, and the cam follower 43 b has an outer peripheral surface of the step cam 47 surrounded by the urging force of the tension spring 50. It is in contact with the surface. The interval between the discs 41a and 41b is set to be slightly larger than the diameter of the roller 43a.

  The step cam 47 has four cam portions 47 a, 47 b, 47 c, 47 d on its peripheral surface, and is fixed to a support shaft 51 that is rotatably supported by the housing 18. A gear 54 that meshes with a gear 53 attached to an output shaft of a stepping motor 52 attached to the housing 18 is attached to the support shaft 51, and the step cam 47 is moved by an arrow in FIG. Rotated in the direction. When the stepping motor 52 operates and the step cam 47 rotates, the moving arm 43 swings about the support shaft 43c, and the roller 43a pushes the disk 41a or the disk 41b, whereby the support shaft 41 is moved as shown in FIG. Move left and right. The operation of the stepping motor 52 is controlled by the control means 26.

  Each of the cam portions 47a, 47b, 47c, 47d is such that when the cam follower 43b and the cam portion 47a come into contact with each other, the cam follower 43b and the cam portion 47b come into contact with each other so that the cam plate 40a can be brought into contact with the cam follower 38a. The cam follower is arranged such that when the cam follower 43b comes into contact with the cam follower 47c, the cam plate 40c comes into a position where the cam follower 38a can come into contact with the cam follower 38a. The cam plate 40d is formed in such a shape that the support shaft 41 is moved so that the cam plate 40d can be brought into contact with the cam follower 38a when 43b and the cam portion 47d come into contact with each other.

  A plate making unit 3 as a plate making means is disposed on the upper right side of the printing unit 2. The plate making section 3 is mainly composed of a master storage means 55, a platen roller 56, a thermal head 57, a cutting means 58, a master conveying roller pair 59, 60 and the like.

  The master storage means 55 rotatably and detachably supports a core portion 62a of a master roll 62 obtained by winding a master 61 in which a thermoplastic resin film and a porous support are bonded together in a roll shape.

  A platen roller 56 and a thermal head 57 are disposed downstream of the master storage means 55 in the master transport direction. The platen roller 56 is rotatably supported on a side plate (not shown) of the housing 18 and is rotated by a stepping motor 63. The operation of the stepping motor 63 is controlled by the control means 26.

  A thermal head 57 having a large number of heat generating elements is attached to a side plate (not shown) of the casing 18, and is urged by an urging means (not shown) and pressed against the platen roller 56. The thermal head 57 selectively heats the heating element while making contact with the thermoplastic resin film surface of the master 61, and performs hot melt perforation plate-making on the master 61. The operation of the thermal head 57 is controlled by the control means 26.

  A cutting means 58 is disposed downstream of the platen roller 56 and the thermal head 57 in the master conveyance direction. The cutting means 58 composed of the fixed blade 58a and the movable blade 58b has a known configuration in which the movable blade 58b rotates with respect to the fixed blade 58a fixed to the side plate of the housing 18.

  A master transport roller pair 59, 60 and guide plates 64, 65 are disposed downstream of the cutting means 58 in the master transport direction. The master conveying roller pair 59, 60 includes driving rollers 59a, 60a that are driven to rotate synchronously by a driving unit (not shown), and driven rollers 59b, 60b that are pressed against the driving rollers 59a, 60a by a biasing unit (not shown). It is composed of

  A guide plate 64 is disposed between each of the master transport roller pairs 59 and 60, and a guide plate 65 is disposed downstream of the master transport roller pair 60 in the master transport direction. Each guide plate 64, 65 is fixed to the side plate of the housing 18, guides the master 61 conveyed by each master conveyance roller pair 59, 60, and guides the tip of the master 61 to the outer peripheral surface of the plate cylinder 8. To do.

  Below the plate making unit 3, a sheet feeding unit 4 as a sheet feeding unit is disposed. The paper feed unit 4 mainly includes a paper feed tray 66, a paper feed roller 67, a separation roller 68, a separation roller 69, a registration roller pair 70, and the like.

  A paper feed tray 66 on which a large number of printing sheets P are stacked is supported by the casing 18 so as to be movable up and down, and is moved up and down by a lifting means (not shown). The paper feed tray 66 is provided with four sensors 71a, 71b, 71c, 71d as paper length detecting means and a pair of side guides 72 for guiding the printing paper P. Output signals from the sensors 71a, 71b, 71c, 71d are output to the control means 26, and the control means 26 determines the size of the printing paper P based on the output signals from the sensors 71a, 71b, 71c, 71d. The side guide 72 has a well-known configuration that is movable in the paper width direction (direction perpendicular to the conveyance direction of the printing paper P).

  Above the sheet feed tray 66, a sheet feed roller 67, a separation roller 68, and a separation roller 69 each having a surface formed of a member having a high friction resistance are disposed. The paper feed roller 67 and the separation roller 68 are pressed against the printing paper P on the paper feed tray 66 with a predetermined pressure, and are driven by a common stepping motor 73 via a driving force transmission means (not shown) such as a gear or a belt. It is driven to rotate in the direction of the arrow. The separation roller 69 is in pressure contact with the separation roller 68 with a predetermined pressure, and is disposed so as to be intermittently rotatable in the same direction as the separation roller 68. The operation of the stepping motor 73 is controlled by the control means 26.

  A registration roller pair 70 is disposed on the downstream side of the separation roller 68 and the separation roller 69 in the conveyance direction of the printing paper. The registration roller pair 70 including the driving roller 70a and the driven roller 70b transmits the rotational driving force from the driving unit 13 by the driving force transmission unit such as a gear or a cam, so that the driving roller 70a rotates at a predetermined timing. The printing paper P is fed toward the printing unit 2 by the driven roller 70b pressed against the driving roller 70a.

  A plate discharging unit 5 is disposed on the upper left side of the printing unit 2. The plate discharging unit 5 is mainly composed of 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 discharging member 74 includes a driving roller 78, a driven roller 79, and an endless belt 80. When the driving roller 78 is driven to rotate in the clockwise direction in FIG. Move in the direction. The lower plate discharging member 75 includes a driving roller 81, a driven roller 82, and an endless belt 83, and a driving force of a driving unit (not shown) that rotationally drives the driving roller 78 is transmitted by a driving force transmission unit such as a gear or a belt. Thus, the drive roller 81 is rotationally driven in the counterclockwise direction in FIG. 1 to move the endless belt 83 in the arrow direction in the figure. Further, the lower plate discharging member 75 is movably provided by a moving means (not shown), and is selectively positioned at the position shown in FIG. 1 and the position where the outer peripheral surface of the drive roller 81 contacts the outer peripheral surface of the plate cylinder 8. The

  A plate removal box 76 for storing a used master therein is detachably attached to the housing 18. A compression plate 77 that pushes the used master carried by the upper plate removal member 74 and the lower plate removal member 75 into the plate release box 76 is supported by a lifting means (not shown) so as to be movable up and down. Move up and down between the dotted lines.

  A paper discharge unit 6 is disposed below the plate discharge unit 5. The paper discharge unit 6 mainly includes a peeling claw 84, a paper discharge conveying member 85, a paper discharge tray 86, and the like.

  The peeling claw 84 for peeling the printed printing paper P from the outer peripheral surface of the plate cylinder 8 is swingably supported on the side plate of the housing 18 by a support shaft 84a. Are selectively swung between a position close to the outer peripheral surface of the plate cylinder 8 and a position where the tip of the plate cylinder 8 does not interfere with an obstacle such as a clamper 15 that is moved by the rotation of the plate cylinder 8.

  The paper discharge conveyance member 85 mainly includes a driving roller 87, a driven roller 88, an endless belt 89, a suction fan 90, and the like. The drive roller 87 is rotatably supported by a unit side plate (not shown) and is driven to rotate by a drive means (not shown). The driven roller 88 is also rotatably supported on the same side plate, and a plurality of endless belts 89 having a plurality of openings are spanned between the driving roller 87 and the driven roller 88. A suction fan 90 is disposed below the driving roller 87, the driven roller 88 and the endless belt 89. The paper discharge transport member 85 sucks the print paper P onto the endless belt 89 by the suction force of the suction fan 90, and transports the print paper P in the direction of the arrow by the rotation of the drive roller 87.

  The paper discharge tray 86 on which the printed printing paper P conveyed by the paper discharge conveying member 85 is stacked has a pair of side fences 91 and end fences 92 that are movable in the paper width direction.

  A document reading unit 7 is disposed on the top of the housing 18. The document reading unit 7 guides the document receiving tray 94 on which the document 93 is stacked, the contact glass 95 on which the document 93 is placed, the document transport roller pair 96 and the document transport roller 97 that transport the document 93, and the document 93 that is transported. The guide plates 98 and 99, a plurality of document conveying belts 100 that convey the document 93 along the contact glass 95, the document tray 101 on which the scanned document 93 is stacked, and the above members other than the contact glass 95 are supported, and the contact glass is supported. 95, a lid 102 provided so as to be able to come in contact with and away from the camera 95, reflection mirrors 103 and 104 and a fluorescent lamp 105 for scanning and reading a document image, a lens 106 for focusing the scanned image, and processing the focused image It is mainly composed of an image sensor 107 such as a CCD.

  In the above configuration, the document receiving tray 94, the document conveying roller pair 96, the document conveying roller 97, the guide plates 98 and 99, the document conveying belt 100, the document tray 101, the automatic separating and conveying device 108, the contact glass 95, A document reading unit 132 is configured by the reflection mirrors 103 and 104, the fluorescent lamp 105, the lens 106, and the image sensor 107, and a document for detecting the length of the document to be conveyed between the plurality of document conveyance belts 100. A sensor 109 is provided as a length detection means.

  A sensor 109, which is a reflective sensor similar to the sensor 33, detects the presence / absence of the document 93 based on a difference in reflection amount on the contact glass 95. A signal from the sensor 109 is input to the control means 26, and the control means 26 determines the length of the original 93 based on this signal and the operation time of the original conveying belt 100. A sensor 131 that detects the document 93 remaining on the document tray 94 is disposed below the document tray 94. The sensor 131 outputs a signal to the control means 26 when the document 93 on the document tray 94 runs out.

  FIG. 9 shows the operation panel 110 of the stencil printing apparatus 1. An operation panel 110 disposed on the upper front side of the casing 18 and on the front side of the lid 102 has a plate making start key 111, a printing start key 112, a test printing key 113, a stop key 114, a numeric keypad 115, an upper surface thereof. Other known configurations such as a clear key 116, an enlargement / reduction key 117, a printing speed setting key 118, a display device 119 composed of a 7-segment LED, a display device 120 composed of an LCD, and an image area designation key 133 as a plate-making image area designation means. The first prepress printing mode in which the first prepress printing operation is performed without changing the master length regardless of the original size, or the second prepress printing operation in which the master length is changed in accordance with the original size (image size). A mode selection key 121 as a switching means for switching the plate-making printing mode to any one of the plate-making printing modes, a mode selection key A mode display means 122 composed of LEDs for displaying the plate-making printing mode selected by 21; a size selection key 123 for selecting the plate-making printing size when the plate-making printing mode selected by the mode selection key 121 is the second plate-making printing mode; A size display means 124 composed of LEDs for displaying the plate-making printing size selected by the size selection key 123, a buzzer 125 as an alarm means, and an alarm lamp 126 are provided.

  FIG. 10 shows a block diagram of the control means 26. The control means 26, which is a well-known microcomputer having a CPU, ROM, RAM, and the like disposed in the housing 18, is composed of a CPU 127, a RAM 128 as a memory means, and a ROM 129. The ROM 129 stores the master 61 in correspondence with the first plate-making printing mode (creates the master 61 corresponding to the A3-size printing paper P) and the second plate-making printing mode (corresponding to the B5, A4, B4-size printing paper P, respectively). In addition to the operation program of the plate making unit 3 in the creation of the master 61), the operation program of the entire stencil printing apparatus 1 is stored. The RAM 128 stores the plate making printing mode selected by the mode selection key 121. The RAM 128 is provided with a backup mechanism (not shown) so that the stored contents are not erased even when the main power of the stencil printing apparatus 1 is turned off.

  Based on the above configuration, the operation of the stencil printing apparatus 1 will be described below. First, the case where the reading operation of the document 93 is performed only by the document reading unit 132 without using the automatic separation / conveyance device 108 will be described.

  The operator opens the lid 102 upward and places the document 93 on the contact glass 95, and then closes the lid 102 again. Then, the platemaking conditions are set by various keys on the operation panel 110, the mode selection key 121 is pressed to select the platemaking printing mode, and then the platemaking start key 111 is pressed. Here, first, a case where the first plate-making printing mode is selected by turning on the “first” LED of the mode display unit 122 will be described.

  When the mode selection key 121 is pressed and the first plate-making printing mode is selected and then the plate-making start key 111 is pressed, the CPU 127 calls up the operation program for the first plate-making printing mode from the ROM 129 and also stores the first plate-making printing in the RAM 128. It is stored that the mode has been selected. The document reading unit 7 reads an image of the document 93 and sends the read signal to the control unit 26 as an image data signal.

In parallel with the reading operation in the document reading unit 7, the plate discharging unit 5 performs a plate discharging operation for peeling the used master 130 from the outer peripheral surface of the plate cylinder 8.
The plate cylinder 8 around which the used master 130 is wound on the outer peripheral surface is rotationally driven by a stepping motor 24 that is operated by an operation signal from the control means 26, and rotates clockwise in FIG. Then, the control means 26 confirms from the number of steps of the stepping motor 24 that the end of the used master 130 wound around the outer peripheral surface of the plate cylinder 8 has reached a predetermined discharge position corresponding to the drive roller 81. Then, an operation signal is sent from the control means 26 to the plate discharge drive circuit, and the moving means and drive means (not shown) are operated to rotate the drive rollers 78 and 81 and move the lower plate discharge member 75 to the plate cylinder 8 side. . After the outer peripheral surface of the drive roller 81 comes into contact with the used master 130, the plate cylinder 8 rotates again in the clockwise direction, and the used master 130 that is scooped up in contact with the drive roller 81 is connected to the lower plate discharging member 75. It is sandwiched between the upper plate removal member 74 and peeled off from the outer peripheral surface of the plate cylinder 8. The peeled used master 130 is transported by the lower plate discharging member 75 and the upper plate discharging member 74 and discarded in the plate discharging box 76, and then compressed by the compression plate 77.

In parallel with the reading operation in the document reading unit 7, in the printing unit 2, the control operation of the pressing range of the press roller 10 against the outer peripheral surface of the plate cylinder 8 is performed.
The control means 26 confirms the set plate-making printing mode and sends an operation signal to the stepping motor 52. Upon receiving the signal, the stepping motor 52 is driven to rotate clockwise in FIG. 8, and the step cam 47 rotates in the direction of the arrow in FIG. When the control means 26 determines that the step cam 47 has rotated to a position where the cam portion 47a contacts the cam follower 43b based on the number of steps of the stepping motor 52, the operation of the stepping motor 52 is stopped.

  When the cam follower 43b comes into contact with the cam portion 47a, the moving arm 43 is swung counterclockwise about the support shaft 43c, and the roller 43a comes into contact with the disc 41b along with this swinging, so that the support is supported. The shaft 41 is moved to the back side in FIG. 7 to position the multistage cam 40 at a position where the cam plate 40a and the cam follower 38a can come into contact with each other, which is the position shown in FIG. Simultaneously with the depression of the plate making start key 111, the energization of the solenoid 45 is cut off, and the tip 44a and the pin 38b are in an engaged state as shown in FIG. It is held in the state shown by the solid line in FIG.

  The plate cylinder 8 continues to rotate even after all the used master 130 is peeled off from the outer peripheral surface. When the plate cylinder 8 reaches the home position which is the predetermined plate feeding position shown in FIG. 1 and the dog 25 is detected by the home position sensor 27, a signal is output from the home position sensor 27 to the control means 26. . Receiving the signal from the home position sensor 27, the control means 26 sends a signal to the stepping motor 24 to stop its operation. When the plate cylinder 8 stops at the home position, an operation signal is sent from the control means 26 to an opening / closing means (not shown), the clamper 15 rotates in the clockwise direction in FIG. 2, and the plate cylinder 8 waits for the plate feed shown in FIG. The state is reached and the plate removal operation is completed.

  When the plate discharging operation is completed and the control operation of the pressing range of the press roller 10 is completed, the plate making operation is subsequently performed. When the plate cylinder 8 enters the plate feed standby state, the stepping motor 63 is actuated by the signal from the control means 26 to rotate the platen roller 56 and the drive rollers 59a and 60a to rotate. Master 61 is pulled out. When the control unit 26 confirms that the image forming area of the master 61 has reached a position corresponding to the heating element of the thermal head 57 based on the number of steps of the stepping motor 63, a signal is sent from the control unit 26 to read the document. Based on the image data signal sent from the unit 7, the heating elements of the thermal head 57 selectively generate heat, and a perforated plate-making image is formed on the surface of the thermoplastic resin film of the master 61.

  The master 61 is guided to the guide plates 64 and 65 and conveyed to the clamper 15 while forming a perforated plate making image. When the control means 26 determines that the leading edge of the master 61 has reached a predetermined position between the stage unit 14 and the clamper 15 based on the number of steps of the stepping motor 63, a signal is sent to an opening / closing means (not shown) to cause the clamper 15 to react. It rotates in the clockwise direction, and the stage portion 14 and the clamper 15 sandwich the tip of the master 61.

  Thereafter, a signal is sent from the control means 26 to the stepping motor 24, and the plate cylinder 8 is driven to rotate clockwise in FIG. 1 at the same peripheral speed as the conveyance speed of the master 61, and the master 61 is wound around the plate cylinder 8. Operation is performed. When the image data signal from the document reading unit 7 is interrupted, the operation of the thermal head 57 is stopped, and then the length of one plate capable of A3 size printing is made by plate making / conveying based on the number of steps of the stepping motor 63. When the control means 26 determines that it has been done, a signal is sent to the driving means (not shown) for driving the stepping motor 63 and the drive rollers 59a and 60a, and the rotation of the platen roller 56 and the drive rollers 59a and 60a is stopped. The movable blade 58b rotates and the master 61 is cut. The cut master 61 is pulled out by the rotation of the plate cylinder 8. When the plate cylinder 8 reaches the home position again and the dog 25 is detected by the home position sensor 27, the stepping motor 24 is operated by a command from the control means 26. Stop and complete the plate feeding operation.

Subsequent to the plate feeding operation, a plate printing operation is performed.
When the plate cylinder 8 stops at the home position, a signal is sent from the control means 26, and the driving means (not shown) of the stepping motor 24, the stepping motor 73, and the paper delivery / conveyance member 85 are operated, and the solenoid 45 is energized. The As a result, the plate cylinder 8 is driven to rotate at a low speed, and the paper feed roller 67, the separation roller 68, the drive roller 87, and the suction fan 90 are driven, and the holding state of the press roller 10 is released. Due to the rotation of the paper feed roller 67 and the separation roller 68, the topmost one of the printing papers P stacked on the paper feed tray 66 is drawn out, and the leading end thereof is added to the registration roller pair 70.

  The printing paper P is a driving force transmission means (not shown) at the timing when the leading end of the image area of the master 61 wound around the plate cylinder 8 reaches the position corresponding to the press roller 10 in the rotation direction of the plate cylinder 8. Is fed between the plate cylinder 8 and the press roller 10 by a registration roller pair 70 that rotates by receiving the rotational force from the plate roller 8. Further, in the multistage cam 40 that is rotated by receiving the rotational force from the driving means 13, the contact state between the convex portion of the cam plate 40a and the cam follower 38a is released almost simultaneously with the rotation of the registration roller pair 70, and the press The roller 10 presses the outer peripheral surface of the roller 10 against the outer peripheral surface of the plate cylinder 8 by the biasing force of the tension spring 39.

  The printing paper P fed from the registration roller pair 70 is pressed against the master 61 wound around the plate cylinder 8 by the press roller 10. By this pressing operation, the press roller 10, the printing paper P, the master 61, and the porous support plate 8a are brought into pressure contact with each other, and the ink supplied to the inner peripheral surface of the porous support plate 8a by the ink roller 16 is formed in the opening 8b and in the drawing. It exudes from the mesh screen not filled, fills the gap between the outer peripheral surface of the porous support plate 8 a and the master 61, and is transferred to the printing paper P through the perforated portion of the master 61. When the image is transferred to the printing paper P, the press contact with the printing paper P is finished, and the non-image area at the rear end of the master 61 and the outer peripheral surface of the press roller 10 are in pressure contact, the convex portion of the cam plate 40a and the cam follower 38a Then, the press roller arm 37 is swung counterclockwise in FIG. 7, and the press contact between the outer peripheral surface of the press roller 10 and the outer peripheral surface of the plate cylinder 8 is released.

  The printing paper P to which the ink has been transferred is peeled off from the outer peripheral surface of the plate cylinder 8 at the tip of the peeling claw 84 and falls downward, and is pulled leftward while being attracted to the upper surface of the endless belt 89 by the suction force of the suction fan 90. And is discharged onto a discharge tray 86. Thereafter, the plate cylinder 8 is again stopped at the home position, and the plate attaching operation is completed, and the stencil printing apparatus 1 enters a printing standby state.

  When the trial printing key 113 is pressed after the stencil printing apparatus 1 is in the print standby state, the topmost printing paper P on the paper feed tray 66 is fed to the paper feed roller 67 and While being pulled out by the separation roller 68 and added to the registration roller pair 70, a command is sent from the control means 26, the stepping motor 24 is operated, and the plate cylinder 8 is rotationally driven at a high speed. The registration roller pair 70 feeds the printing paper P between the plate cylinder 8 rotating at high speed and the press roller 10, and the fed printing paper P is wound around the plate cylinder 8 by the press roller 10. Then, the ink is transferred by being pressed by the master 61, and after a printed image is formed on the upper surface thereof, it is peeled off from the outer peripheral surface of the plate cylinder 8 by the peeling claw 84, transported to the left by the paper discharge transport member 85 and discharged. The paper is discharged onto the paper tray 86. The plate cylinder 8 is returned to the home position again to complete the trial printing operation.

  After confirming the density and position of the printed image by this trial printing, adjusting these with various keys on the operation panel 110 and performing the trial printing again, the number of prints is set on the display device 119 using the numeric keypad 115, and printing is performed. By setting the printing speed with the speed setting key 118 and pressing the print start key 112, the printing paper P is continuously sent from the paper supply unit 4 and the printing operation is performed. After the printing operation is completed, the plate cylinder 8 returns to the home position again.

Next, the case where the second plate-making printing mode is selected by turning on the “second” LED of the mode display unit 122 will be described.
The operator presses the mode selection key 121 to select the second prepress printing mode, and then presses the size selection key 123 to select the prepress printing size. Here, a case where the A4 size is selected by pressing the size selection key 123 twice to light “A4” of the size display means 124 will be described.

  When the mode selection key 121 and the size selection key 123 are sequentially pressed and the A4 size in the second plate-making printing mode is selected and then the plate-making start key 111 is pressed, the CPU 127 operates from the ROM 129 in the second plate-making printing mode A4 size. While calling the program, the RAM 128 stores that the second plate-making printing mode A4 size has been selected. The document reading unit 7 reads an image of an A4 size document 93 and sends the read signal to the control unit 26 as an image data signal.

  In parallel with the document reading operation, the plate discharging unit 5 performs the same plate discharging operation as described above, and the printing unit 2 performs the control operation of the pressing range of the press roller 10. The stepping motor 52 is actuated in response to a command from the control means 26, the step cam 47 is rotationally driven to a position where the cam portion 47c contacts the cam follower 43b, and the cam plate 40c and the cam follower 38a can contact each other. The multistage cam 40 is positioned. The plate cylinder 8 stops at the home position after all the used master 130 is peeled off from the outer peripheral surface, and the clamper 15 is released to enter a plate feed standby state.

  When the plate cylinder 8 enters the plate feeding standby state, a plate making operation is performed. The platen roller 56 and the driving rollers 59a and 60a are respectively driven to rotate, the master 61 is pulled out from the master roll 62, and the heating element of the thermal head 57 is energized to make the master 61. The master 61 thus made is sandwiched between the stage unit 14 and the clamper 15 and is wound around the outer peripheral surface of the plate cylinder 8 by the rotation of the plate cylinder 8. Then, if the control means 26 determines that the master 61 having a length of one plate capable of A4 size printing has been made and conveyed from the number of steps of the stepping motor 63, the stepping motor 63 and the drive rollers 59a, 60a The rotation is stopped and the movable blade 58b is rotated to cut the master 61. The cut master 61 is pulled out by the rotation of the plate cylinder 8, and the plate cylinder 8 is again stopped at the home position to complete the plate feeding operation.

  When the plate cylinder 8 stops at the home position, the uppermost sheet of printing paper P on the paper feed tray 66 is pulled out, and the leading end thereof is added to the registration roller pair 70. Then, the printing paper P is fed between the plate cylinder 8 and the press roller 10 at the same timing as in the first plate making printing mode. Further, the contact state between the convex portion of the cam plate 40 c and the cam follower 38 a is released substantially simultaneously with the rotation of the registration roller pair 70, and the outer peripheral surface of the press roller 10 is pressed against the outer peripheral surface of the plate cylinder 8.

  The printing paper P fed to the pair of registration rollers 70 is pressed by the master 61 wound around the plate cylinder 8 by the press roller 10 to transfer the print image. When the image is transferred to the printing paper P, the press contact with the printing paper P is finished, and the non-image area at the rear end of the master 61 and the outer peripheral surface of the press roller 10 are in pressure contact, the convex portion of the cam plate 40c and the cam follower 38a Then, the press roller arm 37 is swung counterclockwise in FIG. 7, and the press contact between the outer peripheral surface of the press roller 10 and the outer peripheral surface of the plate cylinder 8 is released.

  The printing paper P to which the print image has been transferred is peeled off from the outer peripheral surface of the plate cylinder 8 by the peeling claw 84, transported by the paper discharge transport member 85, and discharged onto the paper discharge tray 86. The plate cylinder 8 rotates again to the home position and stops, and the stencil printing apparatus 1 enters a print standby state.

  Thereafter, the trial printing key 113 is pressed to perform trial printing, and after adjusting the image state, the printing start key 112 is pressed, whereby the plate cylinder 8 rotates at a high speed and the printing paper P is continuously fed from the paper feeding unit 4. The printing operation is performed.

  Here, the attaching / detaching operation of the plate cylinder 8 with respect to the housing 18 in the stencil printing apparatus 1 will be described. The plate cylinder 8 is attached to and detached from the housing 18 at the time of ink color change or jam processing.

  When the plate cylinder 8 is removed from the casing 18, a door (not shown) provided on the front surface of the casing 18 is opened, and the main body 28a of the handle 28 shown in FIG. Achieved.

  At the time of removal, if the plate making printing mode stored in the RAM 128 is the first plate making printing mode, the plate cylinder 8 can be removed from the housing 18 without any problem. However, when the prepress printing mode stored in the RAM 128 is the second prepress printing mode, a command is sent from the control means 26 to the operation panel 110, the buzzer 125 is activated, the alarm lamp 126 is turned on, and the display device 120 is further turned on. A message indicating that a short master is wound is displayed to alert the operator. With such a configuration, the plate cylinder 8 around which the master 61 made in the second plate-making printing mode is wound, that is, the plate cylinder 8 in which a part of the opening 8b is not covered with the master 61 is easily enclosed. Evaporation and solidification of ink caused by preventing the ink from being removed from the body 18 and leaving the plate cylinder 8 with the ink holes inside the casing 18 exposed or the opening 8b exposed when the plate cylinder is removed. The occurrence of problems such as these can be prevented in advance.

  Further, in the stencil printing apparatus 1, when the buzzer 125 and the alarm lamp 126 are operated, the energization to the solenoid 34 shown in FIGS. 5 and 6 is cut off, and the arm 35 is engaged with the notch portion 11b, so that the casing 18 Therefore, the plate cylinder 8 cannot be removed. When the prepress printing mode is selected arbitrarily or automatically and the second prepress printing mode is stored in the RAM 128, the energization of the solenoid 34 is interrupted by a command from the control means 26.

  By providing such an extraction / removal restricting means 32, it is possible to more reliably prevent the occurrence of the above problems as compared with warnings by the buzzer 125, the alarm lamp 126, and the display means 120. The buzzer 125, the alarm lamp 126, and the removal restriction means 32 can be released by resetting the first plate-making printing mode and pressing the plate-making start key 111 or a key combination on the operation panel 110 (for example, a stop key). For example, the solenoid 34 may be programmed to be energized by pressing 114 twice and pressing the clear key 116.

Next, a case where the plate cylinder 8 is mounted on the casing 18 will be described. The mounting is performed in the reverse order of the removal.
The operator opens a door (not shown) of the casing 18, grasps the main body 28 a, engages each roller 28 d with the rail member 29, and pushes the plate cylinder 8. When the plate cylinder 8 is set at a predetermined position where the dog 25 is detected by the home position sensor 27 and a door (not shown) of the casing 18 is closed, a command is sent from the control means 26 to the stepping motor 24, and the plate When the barrel 8 rotates clockwise in FIG. 1 and the dog 25 is detected again by the home position sensor 27, the operation of the stepping motor 24 is stopped. When the plate cylinder 8 rotates, a signal from the sensor 33 is inputted to the control means 26, and the control means 26 detects the length of the master wound around the plate cylinder 8 based on this signal. To do.

  At the time of mounting, the control means 26 compares the detected master length with the length of the printing paper P on the paper feed tray 66, and if these do not correspond, the control means 26 controls the operation panel 110. Command is sent, the buzzer 125 is activated and the alarm lamp 126 is lit, and the display device 120 is displayed to indicate that the master and the printing paper are inconsistent to alert the operator. By adopting such a configuration, it is possible to prevent the occurrence of damaged paper and the contamination of the press roller due to the mismatch between the master and the printing paper.

  Further, the control means 26 compares the detected master length with the plate-making printing mode stored in the RAM 128, and even when these do not correspond, the buzzer 125 is operated and the alarm lamp 126 is turned on to display the display. The apparatus 120 is caused to display that the master and the plate-making printing mode are inconsistent.

  Further, the stencil printing apparatus 1 is configured such that the stepping motor 73 is deactivated by a command from the control means 26 when the buzzer 125 and the alarm lamp 126 are activated. Therefore, even if the printing start key 112 is pressed when the buzzer 125 and the alarm lamp 126 are operated, the stencil printing apparatus 1 does not operate. As a method for releasing the buzzer 125 and the alarm lamp 126, a simple method such as pressing the stop key 114 or the clear key 116 is desirable. This is because, for example, when an A3 size master is wound but only has an A4 size plate-making image, printing can be performed on A4 printing paper. This is to make it easier to cope with a case where a large-size master is wound around the hole to prevent drying of the hole.

Next, a case where the original 93 is read by the original reading unit 132 using the automatic separating and conveying apparatus 108 will be described.
The operator presses the plate making start key 111 after placing the document 93 on the document tray 94.

  When the plate-making start key 111 is pressed, the document transport roller pair 96, the document transport roller 97, and the document transport belt 100 are driven to rotate, and the document 93 on the document tray 94 is transported onto the contact glass 95 to display the document image. Read. The document 93 whose image has been read is transported by the document transport belt 100 and the document transport roller 97 and is discharged onto the document tray 101. When the original 93 is read, the conveyed original 93 is detected by the sensor 109, and the control unit 26 detects the size of the original 93 based on a signal from the sensor 109. Based on the detected size of the original 93, the control means 26 enters the first prepress printing mode when the size of the original 93 is A3, and the second prepress printing when the size of the original 93 is B4, A4, or B5. The plate-making printing mode is automatically switched to the mode, an operation program corresponding to the plate-making printing mode is read from the ROM 129, and the plate-making printing mode is stored in the RAM 128.

  When the plate making printing mode is set, the plate making operation, the plate feeding operation, and the plate attaching operation are performed after the plate discharging operation and the control operation of the pressing range of the press roller 10 are performed as described above, and the plate cylinder 8 is operated. Enters the print standby state. Then, after the trial printing key 113 is pressed and the trial printing is performed, the printing operation is performed by pressing the printing start key 112.

  In the above embodiment, the plate-making printing mode is automatically set by the signal from the sensor 109 when the automatic separation / conveying device 108 is used. However, the plate-making printing mode is automatically set on the operation panel 110 or manually set. It is also possible to employ a configuration in which a key for switching whether to perform or not, and the plate-making printing mode can be arbitrarily set regardless of the document size even when the automatic separation / conveyance device 108 is used.

  In the above-described embodiment, when the plate-making printing mode is switched manually or automatically, the first plate-making printing mode or the second plate-making printing mode is switched based on the size of the original 93. However, the image area designation key 133 and a known command are used. It is also possible to arbitrarily designate a plate making image area to be made from a manuscript image of a manuscript 93 using a sheet and switch the plate making printing mode manually or automatically in accordance with the length of the designated plate making image area. A technique for making a plate by designating an image area is disclosed in, for example, Japanese Patent Laid-Open No. 63-224468. Further, the prepress image area may be arbitrarily designated using a known digitizer or the like.

  Further, the size of the printing paper P is detected based on the signals from the sensors 71a, 71b, 71c, 71d, and the plate-making image area is determined from the image of the original 93 according to the detected size of the printing paper P. According to this, it is also possible to select a prepress printing mode, or to enlarge or reduce the image of the original 93 according to the detected size of the printing paper P and select the prepress printing mode accordingly. Of course it is possible.

  As a modification of the above-described embodiment, when the original 93 is read by the original reading unit 132 using the automatic separating and conveying apparatus 108, the plate-making printing mode is automatically set according to the size of the original 93 (plate-making image area). When the original 93 is read by the original reading means 132 without using the automatic separation / conveying device 108, a program for switching the plate-making printing mode to the first plate-making printing mode regardless of the size of the original 93 (plate-making image area). It may be adopted.

  With this configuration, the original 93 is read by the original reading unit 132 without using the automatic separating / conveying device 108 at the time of the plate making operation immediately before the end or immediately before the interruption. Since the master 61 wound around the plate cylinder 8 always covers the opening 8b, problems such as ink evaporation and solidification can be prevented even if the stencil printing apparatus 1 is left for a long period of time. .

  As another modification of the above-described embodiment, when a plurality of documents 93 are stacked on the document tray 94 and printing is performed, a plate-making printing mode corresponding to the size of the document 93 based on a signal from the sensor 109 is used. May be automatically set, and a program for setting the first plate-making printing mode to the last one-plate original 93 regardless of its size may be adopted. Confirmation that the document is the last one document can be confirmed by outputting a signal from the sensor 131 to the control means 26 at the time of document reading.

  With such a configuration, the master 61 wound around the plate cylinder 8 always covers the opening 8b at the end of printing or when printing is interrupted. Even if it is left as it is, it is possible to prevent problems such as ink evaporation and solidification.

  Furthermore, as another modification of the above-described embodiment, when a plurality of originals 93 are stacked on the original receiving tray 94 and printing is performed, plate-making printing corresponding to the size of the original 93 based on a signal from the sensor 109 is performed. A program that automatically sets the mode and sets the first plate making printing mode regardless of the size of the document 93 for each predetermined number of plates may be adopted.

  By adopting such a configuration, dust or the like adhering to the surface of the exposed porous support plate 8a having the openings 8b can be obtained by winding the master 61 covering all the openings 8b for each predetermined number of plates. Cleaning can be performed periodically in the form of being attached to the master 61 and discarded, and a good printed matter can be obtained.

  In the above embodiment, a press roller is used as the pressing member, but a configuration using an impression cylinder having the same diameter as the plate cylinder 8 may be used. In this case, the rocking motion of the impression cylinder can adopt a configuration using a cam or a solenoid, and as a control operation of the pressing range, a configuration using a multi-stage cam or an energization to the solenoid as in the above embodiment. The structure etc. which control time are mentioned.

  In the above embodiment, the pressing range of the pressing member is controlled using a multi-stage cam and a step cam. Instead, a configuration using a variable cam using a differential gear mechanism is adopted. Also good.

1 is a schematic front view of a main part of a stencil printing apparatus adopting an embodiment of the present invention. It is the schematic of the principal part of the printing part which shows one Embodiment of this invention. It is a perspective view of the principal part of a printing part which shows one Embodiment of this invention. It is a perspective view explaining the plate cylinder used for one Embodiment of this invention. It is a fragmentary sectional side view explaining the attachment or detachment mechanism of the plate cylinder used for one Embodiment of this invention. It is the schematic explaining the removal control means of the plate cylinder used for one Embodiment of this invention. It is the schematic explaining the rocking | fluctuation mechanism of the press member used for one Embodiment of this invention. It is the schematic explaining the press range variable mechanism of the press member used for one Embodiment of this invention. It is the schematic of the operation panel used for one Embodiment of this invention. It is a block diagram of the control means used for one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stencil printing apparatus 3 Plate making means (plate making part)
4 Paper feed means (paper feed unit)
7 Document reading means (document reading section)
8 Plate cylinder 8b Opening part (opening)
10 Pressing member (press roller)
18 Housing 26 Control means 32 Removal restriction means 33 Master length detection means (sensor)
61 Master 71a, 71b, 71c, 71d Paper length detection means (sensor)
93 Document 108 Automatic separation / conveyance device 109 Document length detection means (sensor)
121 switching means (mode selection key)
125 Alarm means (buzzer)
126 Alarm means (alarm lamp)
128 Memory means (RAM)
132 Document reading means 133 Plate-making image area designation means (image area designation key)
P Printing paper

Claims (2)

A plate cylinder having an opening on its outer peripheral surface is supported by a rotating self-standing on the housing, a plate making unit for stencil making and conveying and cutting the master, a pressing member provided to freely contact and separation with respect to the outer peripheral surface In a stencil printing apparatus having
Control means for controlling the operation of the plate making means and the pressing member, and the first plate making printing mode for performing the first plate making printing operation or the second plate making printing mode for performing the second plate making printing operation. Switching means for switching to any one of the above, an original reading means for reading an original image, an automatic separating / conveying apparatus for automatically feeding originals one by one to the original reading means, and a length of the original provided in the automatic separating / conveying apparatus An original reading unit provided with an original length detecting means ,
When the first plate-making printing mode is selected, the control means makes a plate having a length that covers substantially all of the opening as the master and winds the master around the outer peripheral surface. When the second plate-making printing mode is selected by controlling the plate-making means, the master makes a plate having an arbitrary length shorter than the opening and winds the master around the outer peripheral surface. The length of the original detected by the original length detecting means when the original is read by controlling the contact range of the pressing member to the outer peripheral surface according to the arbitrary length and controlling the original. On the basis of this, the control means switches the switching means, the first original reading by the original reading means using the automatic separating and conveying apparatus, and the original not using the automatic separating and conveying apparatus. The second original reading by the taking means can be selected, and the control means switches the switching means to the first plate-making printing mode at the time of the second original reading, and the final original at the time of the first original reading. Only the control means switches the switching means to a first plate-making printing mode . In the stencil printing apparatus according to claim 1,
A stencil printing apparatus , wherein when a plurality of originals are read in the first original reading, the control means switches the switching means to a first plate-making printing mode every predetermined number of plates .

Images