Stencil two-sided printing device

Abstract

To reduce transfer contamination of a sheet and reduce a time up to first print sheet discharge of double-sided printing to reduce a printing time.SOLUTION: A platemaking part 4 that performs platemaking for first side printing and platemaking for second side printing is made to wait at a middle position 4C of both drums. Subsequently to the end of deployment of printing data on a first side, a control part 13 successively performs printing rate calculation of the first side, deployment of printing data on a second side, printing rate calculation of the second side, and determination of printing order of the first side and the second side. On the other hand, simultaneously with the printing rate calculation of the first side, platemaking of the first side is started in the platemaking part 4. When a printing rate of the first side is lower than a printing rate of the second side, control is performed so as to attach the plate to a first drum 5a, then, perform the platemaking of the second side and attaching the plate to a second drum 7a, and perform double-sided printing. When the printing rate of the first side is higher than the printing rate of the second side, control is performed so as to attach the plate to the second drum 7a, and then, perform the platemaking of the first side and attaching the plate to the first drum 5a.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a stencil double-sided printing apparatus that reduces transfer stains on paper while shortening the time until the first print paper for double-sided printing is discharged, thereby shortening the printing time.

Background Art

[0002] Conventionally, a stencil master (hereinafter referred to as a "master") is made based on image data obtained by scanning a document with an image reading device or image data transmitted from an external terminal such as a PC (personal computer), and this made master is wound around a printing drum. There is known a stencil printing apparatus that exudes ink from inside the drum in a state where the made master and paper serving as a recording medium are pressed against each other, and prints the image made on the master on the paper.

[0003] Patent Document 1 discloses a double-sided printing apparatus that prints on the first side of paper and then reverses the paper to print on the second side. In this double-sided printing apparatus, when reducing transfer stains, the side with the lower printing rate is printed first as the first side, and the side with the higher printing rate is printed as the second side.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when attempting to apply the technology of Patent Document 1 to a stencil double-sided printing machine, it is necessary to perform plate-making and plate-mounting processes on two drums. If plate-making is performed after determining the printing rate for both sides, it takes time until the first print paper is discharged, and there has been a demand to shorten this time.

[0006] In addition, in a stencil double-sided printing machine, there is one plate-making unit for plate-making and plate mounting on two drums, and plate-making and plate mounting on each drum are performed by moving this unit relative to the two drums. However, when the plate-making unit is on the side opposite to the drum on which plate mounting is first performed, additional time is required to move the plate-making unit, and there has been a demand to improve this situation.

[0007] The present invention has been made in view of such problems, and an object of the present invention is to provide a stencil double-sided printing apparatus that can reduce the transfer stain of paper, shorten the time until the first print paper for double-sided printing is discharged, and shorten the printing time.

Means for Solving the Problems

[0008] To achieve the above object, the stencil double-sided printing apparatus according to the present invention is characterized in that in a stencil double-sided printing apparatus that reverses the paper printed on the first side by the first drum and prints the second side by the second drum, a plate-making unit for plate-making for printing the first side and plate-making for printing the second side is made to standby at an intermediate position between the two drums, subsequent to the completion of the development of the print data for the first side, the calculation of the printing rate for the first side, the development of the print data for the second side, the calculation of the printing rate for the second side, and the determination of the printing order for the first side and the second side are sequentially performed. Meanwhile, plate-making for the first side is started by the plate-making unit simultaneously with the calculation of the printing rate for the first side, when the printing rate for the first side is lower than the printing rate for the second side, after the determination of the printing order, the plate-making unit is moved to the first drum, the stencil master paper for the first side that has been plate-made is mounted on the first drum, and then plate-making for the second side and mounting on the second drum are performed, and control is performed so as to perform double-sided printing, when the printing rate for the first side is higher than the printing rate for the second side, after the determination of the printing order, the plate-making unit is moved to the second drum, the stencil master paper for the second side that has been plate-made is mounted on the second drum, and then plate-making for the first side and mounting on the first drum are performed.

Effects of the Invention

[0009] According to the characteristics of the stencil double-sided printing apparatus according to the present invention, it is possible to reduce the transfer stain of the paper and shorten the printing time by shortening the time until the first print paper for double-sided printing is discharged.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components throughout the drawings are denoted by the same or equivalent reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Also, there are portions where the dimensional relationships and ratios are different between the drawings.

[0012] Also, the embodiments shown below are examples of apparatuses for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the arrangement of each component part as follows. The technical idea of the present invention can be variously modified within the scope of the claims.

[0013] [Configuration of the Stencil Printing Apparatus] First, the configuration of a stencil printing apparatus 1 according to an embodiment of the present invention will be described with reference to FIG. 1 or FIG. 2.

[0014] As shown in FIG. 1, the stencil printing apparatus 1 includes an image reading unit 2, a paper feeding unit 3, a plate making unit 4, a first printing unit 5, an inversion storage unit 6, a second printing unit 7, a first layout unit 8, a second layout unit 9, a paper discharging unit 10, an operation setting unit 11, and a control unit 13.

[0015] The image reading unit 2 is provided at the upper part of the stencil printing apparatus 1. Although not shown, it includes a contact glass on which an original is placed, a cover that is provided so as to be able to come into contact with and separate from the contact glass, a scanning unit that scans the original placed on the contact glass, a lens that focuses the scanned image, and an image processing unit that processes the focused image. The image reading unit 2 optically reads an image from the original placed on the contact glass, generates data (printing data) obtained by binarizing the captured image data for each pixel, and outputs it to the control unit 13.

[0016] In addition, the image reading unit 2 includes an original size acquisition unit that reads the size of the original (such as A3, A4, B3, B4, etc.) and the orientation of the original.

[0017] The paper feeding unit 3 includes a paper feed tray 3a on which papers are stacked, a primary paper feed roll 3b that conveys only the topmost paper from the paper feed tray 3a, and a pair of secondary paper feed rolls 3c that convey the paper conveyed by the primary paper feed roll 3b to between a first drum 5a and a first press roller 5c of the first printing unit 5 described later at a predetermined timing in synchronization with the rotation of the first drum 5a.

[0018] The plate making unit (plate making unit) 4 is supported so as to be movable in the X direction in FIG. 1 by a rail not shown, and selectively moves to a plate making position 4B that supplies a master plate made for the first printing unit 5 and a plate making position 4A that supplies a master plate made for the second printing unit 7 under the control from the control unit 13. The plate making unit 4 makes a plate for the first drum 5a based on the printing data of the first side, and makes a plate for the second drum 7a based on the printing data of the second side.

[0019] In addition, before plate making, the plate making unit 4 moves to an intermediate position 4C in the X direction between the plate making position 4A and the plate making position 4B.

[0020] The first printing unit 5 includes a first drum 5a that rotates in the direction of the arrow in FIG. 1 by the driving force of the first main motor 5e, and a base paper clamping unit 5b that is provided on the outer peripheral surface of the first drum 5a and clamps the tip of the master.

[0021] Further, the first printing unit 5 includes a first reference position detection unit 5f that detects the reference position of the first drum 5a, and a first rotary encoder 5g that outputs a pulse signal at a fixed period in accordance with the rotation of the first main motor 5e. The rotation angle of the first drum 5a is detected by detecting the pulse signal of the first rotary encoder 5g based on the reference position signal detected by the first reference position detection unit 5f, and is output to the control unit 13.

[0022] Furthermore, the first printing unit 5 includes a conveyance belt 5d that conveys the paper to the reverse storage unit 6, and a first press roller 5c that is disposed at a position below the first drum 5a. The paper fed from the paper feeding unit 3 in synchronization with the rotation of the first drum 5a is pressed against the master printed on the first drum 5a by the first press roller 5c, so that the ink is extruded from the perforations of the master and the image is printed on the surface of the paper.

[0023] Then, the paper on which the image is printed by the pressure contact of the first press roller 5c with the first drum 5a is conveyed to the reverse storage unit 6 by an annular conveyance belt 5d whose both ends are wound around a pair of rotating shafts in the case of double-sided printing, and is conveyed to the subsequent second printing unit 7 by a first intermediate conveyance belt 10c described later in the case of single-sided printing.

[0024] The reverse storage unit 6 is arranged on the downstream side in the paper conveyance direction with respect to the first printing unit 5, and an annular reverse belt 6a formed in a porous structure is arranged in a semi-circular shape. This reverse belt 6a is wound around a semi-circular auxiliary member 6b and a pair of rollers 6c, 6d, and at least one of the pair of rollers 6c, 6d is rotationally driven by a drive motor (not shown). Further, a suction fan 6e for sucking the paper to the reverse belt 6a is provided on the back side of the reverse belt 6a. By this reverse storage unit 6, the front and back of the paper are reversed, and the paper is conveyed to the stacking table 6f.

[0025] Similar to the first printing unit 5, the second printing unit 7 includes a second drum 7a that rotates in the direction of the arrow in FIG. 1 by the driving force of a second main motor 7e, a paper clamp portion 7b provided on the outer peripheral surface of the second drum 7a for clamping the leading end of the second stencil paper, a second press roller 7c disposed below the second drum 7a, and a pair of secondary paper feed rolls 7d for conveying the paper reversed by the reverse storage unit 6 between the second drum 7a and the second press roller 7c in synchronization with the rotation of the second drum 7a.

[0026] Also, similar to the first printing unit 5, the second printing unit 7 includes a second reference position detection unit 7f for detecting the reference position of the second drum 7a, and a second rotary encoder 7g that outputs a pulse signal at a fixed period in response to the rotation of the second main motor 7e that drives the second drum 7a. The rotation angle of the second drum 7a is detected based on the reference position signal detected by the second reference position detection unit 7f by detecting the pulse signal of the second rotary encoder 7g and output to the control unit 13.

[0027] Then, similar to the first printing unit 5, the second printing unit 7 presses the paper fed from the pair of secondary paper feed rolls 7d in synchronization with the rotation of the second drum 7a against the master printed on the second drum 7a by the second press roller 7c, so that the ink is extruded from the perforations of the master and the image is printed on the back surface of the paper.

[0028] The first typesetting unit 8 peels off the master that has been unclamped from the outer peripheral surface of the first drum 5a of the first printing unit 5 described later from the first drum 5a, and stores the peeled-off master in a typesetting box (not shown). Similarly, the second typesetting unit 9 peels off the master that has been unclamped from the outer peripheral surface of the second drum 7a of the second printing unit 7 from the second drum 7a, and stores the peeled-off master in a typesetting box (not shown).

[0029] The paper discharge unit 10 includes a paper discharge belt 10a through which the printed paper is conveyed, a paper discharge table 10b on which the paper discharged from the paper discharge belt 10a is stacked, a first intermediate conveyance belt 10c that conveys the paper carried out from the first printing unit 5 without double-sided printing to the subsequent stage, a second intermediate conveyance belt 10d that conveys the papers stacked on the stacking table 6f one by one while sucking them, and a pair of rollers 10e that convey the paper conveyed by the second intermediate conveyance belt 10d to the second printing unit 7.

[0030] The operation setting unit 11 is provided above the stencil printing apparatus 1, and includes a pressure-sensitive or electrostatic transparent touch panel disposed in front of a liquid crystal display panel that displays various display screens, and various operation keys such as selection keys for inputting start / stop of plate making, printing, etc. and numeric keys for inputting the number of printed sheets, etc. The operation setting unit 11 outputs an operation signal based on an operation by the user while viewing the display content displayed on the liquid crystal display panel to the control unit 13.

[0031] The control unit 13 is composed of a processor such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), or an MPU (Micro-Processing Unit) having these functions, and performs drive control of each part constituting the stencil printing apparatus 1 according to an operation signal from the operation setting unit 11 and the like.

[0032] Further, before the plate making operation, the control unit 13 moves the plate making unit 4 to an intermediate position 4C between the first drum 5a for plate making for first-side printing and the second drum 7a for plate making for second-side printing and makes it standby.

[0033] After the development of the printing data for the first side is completed, the control unit 13 sequentially performs the calculation of the printing rate for the first side, the development of the printing data for the second side, the calculation of the printing rate for the second side, and the determination of the printing order for the first and second sides.

[0034] On the other hand, the control unit 13 causes the plate-making unit 4 to start plate-making for the first side simultaneously with the calculation of the printing rate for the first side.

[0035] When the printing rate of the first side is lower than that of the second side, after the determination of the printing order, the control unit 13 moves the plate-making unit 4 to the first drum 5a and mounts the plate-making completed master for the first side on the first drum 5a. Thereafter, the control unit 13 performs plate-making for the second side and mounting on the second drum 7a, and controls for double-sided printing.

[0036] When the printing rate of the first side is higher than that of the second side, after the determination of the printing order, the control unit 13 moves the plate-making unit 4 to the second drum 7a and mounts the plate-making completed master for the second side on the second drum 7a. Thereafter, the control unit 13 controls for performing plate-making for the first side and mounting on the first drum 5a.

[0037] [Operation of the stencil printing apparatus] FIG. 3(a) is a timing chart of the operation in the prior art for comparison, and FIG. 3(b) is a timing chart of the operation in the stencil printing apparatus according to an embodiment of the present invention.

[0038] In the prior art, after the previous printing is completed, the plate-making unit 4 is moved to the plate-making position 4B and waits.

[0039] Then, as shown in FIG. 3(a), at time t1, the control unit 13 develops the printing data for the first side, and at time t2, the control unit 13 executes the calculation of the printing rate for the first side.

[0040] At time t3, the control unit 13 develops the printing data for the second side, and at time t4, the control unit 13 executes the calculation of the printing rate for the second side.

[0041] The control unit 13 determines the printing order based on the calculation results of the printing rate calculation for the first side and the calculation results of the printing rate calculation for the second side. Here, it is determined to print the first side first and the second side later.

[0042] The control unit 13 performs plate making based on the determined printing order. Here, at time t6, the control unit 13 causes the plate making unit 4 to start plate making for the first side, and at time t7, the completed master is mounted on the first drum 5a.

[0043] At time t8, the control unit 13 moves the plate making unit 4 to the plate making position 4A. At time t9, the control unit 13 causes the plate making unit 4 to start plate making for the second side. At time t10, the completed master is mounted on the second drum 7a and is completed at time t11.

[0044] On the other hand, in the stencil printing apparatus 1 according to an embodiment of the present invention, when the previous printing is completed, the plate making unit 4 is moved to the intermediate position 4C and waits.

[0045] Then, as shown in FIG. 3(b), at time t21, the control unit 13 develops the printing data for the first side. Then, at time t22, the control unit 13 starts executing the printing rate calculation for the first side and causes the plate making unit 4 to start plate making for the first side.

[0046] The control unit 13 develops the printing data for the second side at time t23 and executes the printing rate calculation for the second side at time t24.

[0047] The control unit 13 determines the printing order based on the calculation results of the printing rate calculation for the first side and the calculation results of the printing rate calculation for the second side. Specifically, when the printing rate of the first side is lower than the printing rate of the second side, the second side is printed after the first side is printed. When the printing rate of the first side is higher than the printing rate of the second side, the first side is printed after the second side is printed.

[0048] The control unit 13 moves it to the plate-making unit 4 based on the determined printing order. Specifically, when printing the second side after printing the first side, the control unit 13 moves the plate-making unit 4 to the plate-making position 4B, and when printing the first side after printing the second side, the control unit 13 moves the plate-making unit 4 to the plate-making position 4A.

[0049] At time t27, plate the plate-made master onto the first drum 5a.

[0050] At time t28, the control unit 13 moves the plate-making unit 4 to the plate-making position 4A. At time t29, the control unit 13 starts plate-making for the second side in the plate-making unit 4. At time t30, plate the plate-made master onto the second drum 7a, and it is completed at time t31.

[0051] In this way, in the stencil printing apparatus 1 according to an embodiment of the present invention, the plate-making unit 4 that performs plate-making for the first-side printing and plate-making for the second-side printing is made to standby at the intermediate position 4C between the two drums. The control unit 13 sequentially performs the calculation of the printing rate for the first side following the completion of the expansion of the printing data for the first side, the expansion of the printing data for the second side, the calculation of the printing rate for the second side, and the determination of the printing order for the first side and the second side. At the same time as the calculation of the printing rate for the first side, the control unit 13 starts plate-making for the first side in the plate-making unit 4. When the printing rate of the first side is lower than the printing rate of the second side, after the determination of the printing order, the control unit 13 moves the plate-making unit 4 to the first drum 5a, plates the plate-made master for the first side onto the first drum 5a, and then performs plate-making for the second side and plate-making onto the second drum 7a, and controls to perform double-sided printing. When the printing rate of the first side is higher than the printing rate of the second side, after the determination of the printing order, the control unit 13 moves the plate-making unit 4 to the second drum 7a, plates the plate-made master for the second side onto the second drum 7a, and then controls to perform plate-making for the first side and plate-making onto the first drum 5a.

[0052] As a result, since the plate making for the first side is started in the plate making unit 4 at the same time as the printing rate calculation for the first side, the time required for the plate making of the first side (about 20 seconds) can be shortened. Also, since the plate making unit 4 is made to standby at the intermediate position 4C before plate making, it can be moved to either the plate making position 4A or the plate making position 4B in a relatively short time (about 2 seconds). Therefore, compared with the prior art, the total plate making time can be shortened by about 18 seconds (= 20 seconds - 2 seconds), so the time until the first print paper is discharged can be shortened.

[0053] (Appendix) This application discloses the following invention.

[0054] (Appendix 1) In a stencil double-sided printing apparatus that reverses the paper printed on the first side by the first drum and prints the second side by the second drum, a plate making unit that performs plate making for the first side printing and plate making for the second side printing is made to standby at an intermediate position between the two drums, subsequent to the completion of the layout of the print data for the first side, the printing rate calculation for the first side, the layout of the print data for the second side, the printing rate calculation for the second side, and the determination of the printing order for the first side and the second side are sequentially performed. Meanwhile, the plate making for the first side is started in the plate making unit at the same time as the printing rate calculation for the first side, when the printing rate of the first side is lower than the printing rate of the second side, after the determination of the printing order, the plate making unit is moved to the first drum, the stencil master paper for the first side that has been plate made is mounted on the first drum, and then the plate making for the second side and the mounting on the second drum are performed, and control is performed so as to perform double-sided printing, when the printing rate of the first side is higher than the printing rate of the second side, after the determination of the printing order, the plate making unit is moved to the second drum, the stencil master paper for the second side that has been plate made is mounted on the second drum, and then control is performed so as to perform the plate making for the first side and the mounting on the first drum. A stencil double-sided printing apparatus characterized by this.

[0055] As a result, the printing order can be appropriately determined, so that transfer stains on the paper can be reduced. Also, while calculating the printing rate of the first side, plate making for the first side is started in the plate making unit 4, and plate making is performed using the plate making unit that has been made to standby at the intermediate position 4C. Therefore, since the time until plate mounting can be shortened, the time until the first print paper for double-sided printing is discharged can be shortened, and the printing time can be shortened.

Explanation of Signs

[0056] 1 Screen printing apparatus 2 Image reading unit 3 Paper feeding unit 4 Plate making unit (plate making unit) 5 First printing unit 6 Inversion storage unit 7 Second printing unit 8 First typesetting unit 9 Second typesetting unit 10 Paper discharging unit 11 Operation setting unit 13 Control unit

Claims

【Claim 1】 In a stencil double-sided printing apparatus that reverses a sheet printed on the first side by a first drum and prints the second side by a second drum, a plate-making unit that performs plate-making for printing the first side and plate-making for printing the second side is made to standby at an intermediate position between the two drums, subsequent to the completion of the development of the print data for the first side, calculation of the printing rate for the first side, development of the print data for the second side, calculation of the printing rate for the second side, and determination of the printing order for the first side and the second side are sequentially performed. Meanwhile, plate-making for the first side is started by the plate-making unit simultaneously with the calculation of the printing rate for the first side, when the printing rate of the first side is lower than the printing rate of the second side, after determination of the printing order, the plate-making unit is moved to the first drum, the plate-making completed stencil paper for the first side is mounted on the first drum, and then plate-making for the second side and mounting on the second drum are performed, and control is performed to carry out double-sided printing, when the printing rate of the first side is higher than the printing rate of the second side, after determination of the printing order, the plate-making unit is moved to the second drum, the plate-making completed stencil paper for the second side is mounted on the second drum, and then control is performed to carry out plate-making for the first side and mounting on the first drum. A stencil double-sided printing apparatus characterized by this.

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