JP2004122677A - Stencil printing apparatus and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily print a background image which does not deteriorate the visibility of an object image. <P>SOLUTION: The stencil printing apparatus is provided with a mode specifying section for specifying an image processing mode to create a background image to be printed on the background of an object image, a control section having a plate cylinder selecting section to fixedly select any one plate cylinder from a plurality of plate cylinders as the one for the background image, an image processing section to carry out the image processing of a background image data corresponding to the image processing mode specified by the mode specifying section, a plate making section to make a stencil paper on the basis of the image-processed background image data and to process a stencil paper on the basis of an object image data, a printing section to carry out a printing process by winding the stencil paper having the processed background image data around the plate cylinder for the background image, while winding the stencil paper having the processed object image data around the plate cylinder other than the plate cylinder for the background image and pressing the printing paper to each plate cylinder, and a plate discharging section to discharge each used stencil paper from each plate cylinder. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention has a plurality of plate cylinders, and stencil printing processing is performed by winding a stencil sheet subjected to stencil processing based on print data on each of the plate cylinders and pressing a printing sheet against each of the plate cylinders. The present invention relates to a stencil printing apparatus and a method for controlling a stencil printing apparatus that perform a stencil discharging process of discarding used stencil paper from the plate cylinder.
[0002]
[Prior art]
In general, a stencil printing apparatus having a plurality of plate cylinders and capable of performing monochromatic and multicolor printing includes a first plate cylinder, a second plate cylinder, and an impression cylinder which are rotatably arranged in an apparatus main body. Each of the second plate cylinders is arranged close to a position on the outer peripheral surface of the impression cylinder which is approximately 90 degrees apart from the center angle of the paper cylinder. When a printing process is performed by using such a stencil printing apparatus, first, the leading ends of the stencils made based on the image (printing) data for the first and second colors are respectively attached to the first stencil. After being clamped at the base paper clamp portions of the cylinder and the second plate cylinder and attached to the outer peripheral surface of the screen of each plate cylinder, the first plate cylinder, the second plate cylinder, and the impression cylinder are rotated in a synchronized manner, and then the first cylinder is rotated. The printing paper is transported from the paper supply unit between the plate cylinder and the paper cylinder. As a result, the printing paper conveyed from the paper supply unit is clamped by the paper clamp unit of the impression cylinder, and passes between the first plate cylinder and the impression cylinder along the outer peripheral surface of the impression cylinder. The first color ink is transferred onto the printing paper through the perforations in the base paper. When the first color ink is transferred onto the printing paper, the printing paper is subsequently transported between the second plate cylinder and the impression cylinder, and passes between the second plate cylinder and the impression cylinder. Accordingly, the second color ink is transferred onto the printing paper on the same principle as that of the first color ink. Then, the paper discharging unit discharges the printing paper on which the desired image data is printed to a predetermined position, and the multicolor printing process is completed.
[0003]
In a stencil printing apparatus having a plurality of printing cylinders as described above, the present applicant has proposed a stencil printing apparatus that efficiently prints a plurality of print information including common print data (fixed image). (See Patent Document 1).
[0004]
By the way, when a stencil printing apparatus having a plurality of plate cylinders is used to print a background image on one plate cylinder and a target image on another plate cylinder, the background image is printed over the target image. Therefore, printing is often performed at a low density so as not to impair the visibility of the target image.
[0005]
In this specification, the “target image” refers to an image of a portion of the content to be conveyed by the user in the image data printed on the printing paper as illustrated in FIG. I do. Further, the “background image” means an image of a portion other than the content that the user intends to convey, among the image data printed on the printing paper, as exemplified in FIG. 14B. Generally, as shown in FIG. 14C, the background image is printed so as to overlap with the target image so as to be positioned in the background of the target image. A character string such as "copy prohibited" or "sold out" corresponds to the background image.
[0006]
[Patent Document 1]
JP-A-2002-046331
[0007]
[Problems to be solved by the invention]
Since the background image is printed so as to be superimposed on the target image, the density of the background image is reduced so as not to impair the visibility of the target image.
[0008]
However, when a document image of a background image is read using a reading device such as a scanner, a document having a light print density is not suitable as a document due to abrasion of the image. Is often used. For this reason, it is necessary for the user to set the image processing for printing the background image thinly on the stencil printing apparatus, which is a factor that makes it difficult to print the background image.
[0009]
Further, even if the user sets the process of thinning the background image by the density correction process on the stencil printing apparatus as the image process for printing the background image thinly, the user mistakenly performs the simple processing in the binarization process. If the binarization process is selected, the image to be printed will be “pure black” or “pure white” and cannot be used as a background image. In other words, the setting work of the image processing for creating the background image often fails unless the user has detailed knowledge of the image processing contents of the stencil printing machine being used. Consumables such as these may be wasted.
[0010]
The present invention has been made in view of the circumstances described above, and enables a user who does not have detailed knowledge about image processing to easily print a background image that does not impair the visibility of a target image. It is an object of the present invention to provide a stencil printing apparatus and a control method of the stencil printing apparatus.
[0011]
[Means for Solving the Problems]
A stencil printing apparatus according to the present invention includes: (a) a mode designating unit that designates an image processing mode for creating a background image to be printed on the background of a target image; and one of a plurality of plate cylinders for the background image. (B) performing image processing on the background image data in accordance with the image processing mode specified by the mode specifying unit; (C) a stencil making a stencil based on the image-processed background image data, and a stencil making a stencil based on the target image data; and (d) the background image. The stencil sheet for which data printing has been performed is wound around the background image printing cylinder selected by the plate cylinder selection unit, and the stencil printing paper for which the target image data printing has been performed is mounted on the background image printing cylinder. Wrapped around a cylinder other than A printing unit for performing a printing process by pressing a printing sheet against each of the plate cylinders on which paper is wound, and (e) a plate discharging unit for discharging the used stencil sheet from each plate cylinder. And (f) a control unit for controlling each of the operation unit, the image processing unit, the plate making unit, the printing unit, and the plate discharging unit.
[0012]
Further, in the control method of the stencil printing apparatus according to the present invention, (a) an image processing mode for creating a background image to be printed on a background of a target image is designated by a mode designation unit, and any one of a plurality of plate cylinders is designated. Is fixedly selected by the plate cylinder selecting unit as the plate cylinder for the background image, and (b) the image processing unit transmits the background cylinder for the background image in accordance with the image processing mode designated by the mode designating unit. (C) causing a stencil making section to make a stencil sheet based on the image-processed background image data; d) causing the stencil making section to make a stencil sheet based on the target image data; and (e) selecting the stencil sheet having the background image data made by the printing drum selecting section in the printing section. For the background image (F) winding the stencil sheet on which the target image data has been made in the printing unit on a plate cylinder other than the background image plate cylinder; and (g) printing the stencil sheet. (C) causing a printing process to be executed by pressing a printing sheet against each of the plate cylinders on which the respective stencil sheets are wound, and (h) transferring the used stencil sheets to a stencil discharging unit. Discharging the plate from each plate cylinder.
[0013]
According to such a configuration, the user simply designates the processing mode for printing the background image on the operation unit, and the stencil printing apparatus performs the image processing by the density correction processing and the halftone processing on the background image data. The printing process is performed, and one of the plurality of plate cylinders is fixedly selected as a background image plate cylinder, and a printing process is performed. Therefore, even a user who does not have detailed knowledge of image processing can easily print a background image that does not impair the visibility of the target image.
[0014]
More preferably, the control unit does not discharge the stencil sheet after the background image data plate-making to the plate discharge unit while being wound around the background image plate cylinder, by the plate-making unit, The stencil sheet is made on the basis of the other target image data, and the printing unit winds the stencil sheet having the other target image data on the plate cylinder other than the background image plate cylinder. The printing process is executed.
[0015]
Further, of the plurality of plate cylinders, the plate cylinder to which the printing paper is pressed first may be fixedly selected as the background image plate cylinder.
[0016]
The image processing performed by the image processing unit includes a density correction process using a density correction curve and a halftone process using a halftone matrix. The minimum value and the set value of the dot matrix may be specified.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a configuration and a control method of the stencil printing apparatus 1 according to the embodiment of the present invention will be described in detail with reference to FIGS. Note that the same or equivalent parts and components are denoted by the same or equivalent reference symbols throughout the drawings, and the description thereof will be omitted or simplified.
[0018]
As shown in FIG. 1, the stencil printing apparatus 1 includes, as main components, a document reading unit 2, a plate making unit 3, a printing unit 4, a paper feeding unit 5, a paper discharging unit 6, a plate discharging unit 7, and the like. As shown in FIGS. 2 and 3, an operation panel 70 a, a control unit 80, an image processing unit 60 and the like are provided. The operation panel 70a includes an image processing setting button 79 for specifying an image processing mode for creating a background image to be printed on the background of the target image, and one of a plurality of plate cylinders (for example, a first plate cylinder). And 25) a drum fixing button 77 for fixedly selecting 25) as a background image plate cylinder. The image processing unit 60 performs image processing on the background image data according to the image processing mode specified by the image processing setting button 79.
[0019]
The stencil making section 3 makes stencil sheet 11 based on the image-processed background image data, and makes stencil sheet 11 based on the target image data. The printing unit 4 winds the stencil sheet 11 on which the background image data has been prepressed around the first plate cylinder 25, which is the background image plate cylinder selected by the drum fixing button 77, and completes the target image data prepress. The stencil sheet 11 is wound around a second plate cylinder 26 which is a plate cylinder other than the background image plate cylinder, and printed on the first plate cylinder 25 and the second plate cylinder 26 around which each stencil sheet 11 is wound. The printing process is executed by bringing the paper 41 into pressure contact. The plate discharging section 7 discharges each used stencil sheet 11 from the first plate cylinder 25 and the second plate cylinder 26. The control unit 80 includes the original reading unit 2, the plate making unit 3, the printing unit 4, the paper feeding unit 5, the paper discharging unit 6, the plate discharging unit 7, the operation panel 70a, the control unit 80, the image processing unit 60, and the like. The respective parts of the device 1 are controlled.
[0020]
Further, the control unit 80 controls the stencil sheet 3 by the stencil unit 3 without discharging the stencil sheet 11 on which the background image data stencil has been wound around the first plate cylinder 25 as the background image plate cylinder, without discharging the stencil sheet 11 to the plate discharge unit 7. The stencil sheet 11 is made stencil based on the other target image data, and the printing unit 4 converts the stencil sheet 11 with the other target image data into the second plate cylinder 26 which is a plate cylinder other than the background image plate cylinder. Can be controlled so as to execute the printing process.
[0021]
Although any one of the first plate cylinder 25 and the second plate cylinder 26 may be selected as the background image plate cylinder, more preferably, the first plate cylinder is the plate cylinder to which the printing paper 41 is pressed first. The plate cylinder 25 is fixedly selected as the background image plate cylinder.
[0022]
The image processing performed by the image processing unit 60 includes a density correction process using the density correction curve 62 and a halftone process using the halftone matrix 66. The image processing setting button 79 can be configured so that the minimum value of the density correction curve 62 and the set value of the halftone dot matrix 66 can be specified.
[0023]
[Detailed configuration of stencil printing machine]
Next, the configuration of the stencil printing apparatus 1 will be described in more detail with reference to FIG.
[0024]
"Configuration of Document Scanning Unit"
The document reading unit 2 is provided on an upper part of the apparatus main body 8 and reads a document to be printed as an electric signal. The read information is generated as image data for the first printing drum color ink and the second printing drum color ink. The image data can be processed based on commands such as enlargement / reduction from the operation panel 70a.
[0025]
"Configuration of plate making section"
The stencil making section 3 has a stencil making unit 9 provided in the apparatus main body 8 so as to be horizontally movable. And the second stencil sheet supply position for supplying the stencil sheet 11 to the second plate cylinder 26. The plate making unit moving means 10 includes a plate making unit moving motor 12 fixed to the plate making unit 9 side, a worm gear 13 fixed to a rotating shaft of the plate making unit moving motor 12, and a worm wheel (not shown) meshing with the worm gear 13. ), A pinion gear 14 fixed coaxially with the worm wheel, and a rack 15 fixed to the apparatus main body 8 side.
[0026]
The stencil making unit 9 includes a stencil container 16 for accommodating a long stencil 11 wound on a roll, and a plurality of stencils 11 for guiding the leading end side of the stencil 11 accommodated in the stencil accommodation 16 downstream of the conveyance. A transport roll 17, a thermal head 18 disposed downstream of the transport roll 17, a platen roll 19 disposed at a position facing the thermal head 18 and rotated by a driving force of a light pulse motor (not shown), A stencil feed roll 20 disposed downstream of the roll 19 and the thermal head 18 in the transport direction of the stencil sheet 11 and rotated by the driving force of the light pulse motor; a guide plate 21 against which the stencil feed roll 20 is pressed; 20 and a base paper cutter 22 disposed between the guide plate 21 and the platen roll 19 and the thermal head 18.
[0027]
"Composition of printing unit"
The printing unit 4 includes a first plate cylinder 25, a second plate cylinder 26, and an impression cylinder 27 that is a rotating member for printing pressure. Each is arranged at an upper position. More specifically, the first plate cylinder 25 and the second plate cylinder 26 are close to each other at a position on the outer peripheral surface of the impression cylinder 27 which is approximately 90 degrees apart from the center angle of the impression cylinder 27. The first plate cylinder 25, the second plate cylinder 26, and the impression cylinder 27 are provided rotatably, and the plate cylinder rotation mechanism (not shown) is arranged so that the peripheral speed is the same at the proximity and pressure contact point on each outer peripheral surface. ). The plate cylinder rotating mechanism is driven using a main motor (not shown) as a drive source.
[0028]
The first plate cylinder 25 and the second plate cylinder 26 are connected by a plate seat 28 between the left and right annular frame members (especially without reference numerals) designated to be rotatable. The first plate cylinder 25 and a part of the outer peripheral surface of the second plate cylinder 26 are configured. A stencil clamp 29 is provided on the plate seat 28, and the leading end of the stencil 11 is clamped by the stencil clamp 29. The front end side of a screen 30 is fixed to each plate seat 28, and the screen 30 is wound around the outer peripheral surfaces of the first plate cylinder 25 and the second plate cylinder 26.
[0029]
The rear end side of each screen 30 is stretched to each plate seat 28 via a spring 31, and the screen 30 is provided so as to swell against external force against the spring force of the spring 31. Each screen 30 is made of, for example, a mesh structure, and when pressed by the below-described intermediate press roll 33, the ink 38 passes from the inner surface to the outer surface. That is, each screen 30 is configured as an outer peripheral surface of the first plate cylinder 25 and the second plate cylinder 26 to which the ink 38 is supplied.
[0030]
An inner press mechanism 32 is housed inside each screen 30 of the first plate cylinder 25 and the second plate cylinder 26, respectively. Each inner press mechanism 32 has a middle press roll 33 that serves both as a mechanism for applying a printing pressure from the inner peripheral surface side of the screen 30 and a mechanism for supplying the ink 38 to the screen 30.
[0031]
The intermediate press roll 33 is rotatably provided on the roll support members 34 on both sides, and is driven to rotate in synchronization with the rotation of the first plate cylinder 25 and the second plate cylinder 26 by driving means (not shown). The roll support member 34 is rotatably supported about a support shaft 35, the roll support member 34 is rotated in the direction of arrow a, and the middle pressing roll 33 presses the inner peripheral surface of the screen 30. The rotation of the roller 34 in the direction of the arrow b causes the intermediate press roller 33 to move between a standby position where the roller 33 is separated from the inner peripheral surface of the screen 30. The middle press roll 33 is at a pressing position during printing, and is at a standby position except during printing.
[0032]
A first doctor roll 36 and a second doctor roll 37 are attached to the roll support member 34, respectively. The first doctor roll 36 and the second doctor roll 37 have a columnar shape, and are both arranged at positions close to the middle press roll 33. In addition, ink 38 is supplied from an ink supply unit (not shown) to the outer peripheral space of the middle press roll 33 and an upper space surrounded by the first doctor roll 36 and the second doctor roll 37, and the ink is supplied to this position. A pool 39 is formed. A first color ink 38 is supplied to the first plate cylinder 25 side, and a second color ink 38 is supplied to the second plate cylinder 26 side.
[0033]
The gap between the first doctor roll 36 and the middle press roll 33 (distance between the facing rollers) is set so that the ink film thickness adhering to the middle press roll 33 becomes a predetermined size, and the gap between the second doctor roll 37 and the middle press roll 33 is set. The gap is set so as not to cause ink leakage. That is, when the middle press roll 33 rotates, the ink 38 having a predetermined thickness is continuously attached to the outer peripheral surface of the middle press roll 33 by the gap with the first doctor roll 36, and the ink 38 is supplied to the screen 30 by the middle press roll 33. Is done.
[0034]
Further, a paper clamp unit 40 is provided at a predetermined position on the outer peripheral surface of the impression cylinder 27 which is a printing pressure rotating member, and the paper clamp unit 40 can clamp the leading end of the printing paper 41 which is a printing medium.
[0035]
"Configuration of Paper Feeding Unit"
The paper supply unit 5 includes a paper supply unit 42 on which print papers 41 as print media are stacked, a primary paper supply roll 43 pressed from the paper supply unit 42 to the uppermost print paper 41, and a primary paper supply roll It has a pair of secondary paper supply rolls 44 arranged downstream of the transportation of the paper 43, and a guide plate 45 that guides the transportation of the printing paper 41 between the secondary paper supply roll 44 and the impression cylinder 27. Only the uppermost print paper 41 is transported to the pair of secondary paper rolls 44 by the rotation of the primary paper roll 43, and the transported print paper 41 is rotated by the rotation of the pair of secondary paper rolls 44. Are supplied to the printing unit 4 in synchronization with the rotation of the printing unit.
[0036]
"Structure of paper output unit"
The discharge section 6 includes an upper regulation guide section 46 for guiding the leading end of the printing paper 41 on which printing has been completed, a paper stripping claw 47 for stripping the printing paper 41 that is not separated from the impression cylinder 27, and an upper regulation guide section 46. A pair of paper discharge rolls 48 for transporting the print paper 41 guided or stripped by the paper peeling claw 47 and the print papers 41 discharged by the pair of paper discharge rolls 48 are stacked. And a paper discharge table 49 to be used.
[0037]
`` Composition of the plate discharge section ''
The plate discharging section 7 is provided corresponding to the first plate cylinder 25 and the second plate cylinder 26, respectively. Each plate discharging section 7 is placed between a pair of plate discharging rolls 50 and 51 disposed a little apart from the outer peripheral surfaces of the first plate cylinder 25 and the second plate cylinder 26, and is hung between the pair of plate discharging rolls 50 and 51 to form a base paper. A stencil guide belt 52 for guiding the leading end of the stencil sheet 11 released by the clamp unit 29, and the stencil sheet 11 guided from the stencil guide belt 52 cooperate with the stencil roll 51 to form the first plate cylinder 25 and the second plate cylinder. A stencil roll 53 for transporting the stencil sheet 11 conveyed by the stencil rolls 51 and 53; a stencil discharge box 54 for accommodating the stencil sheet 11 conveyed by the stencil rolls 51 and 53; Having.
[0038]
"Control system configuration"
Next, a control system of the stencil printing apparatus 1 will be described with reference to FIGS.
[0039]
The main body of the stencil printing apparatus 1 is provided with an operation panel unit 70a having a form as shown in FIG. 2, the operation panel unit 70a includes a message display unit 71 for displaying various messages, and a print number designated by the user. , An image processing setting display section 73 for displaying the image processing contents set by the user, a print button 74 for designating execution of print processing, a plate making button 75 for designating execution of plate making processing, printing Numerical keys 76 for inputting numerical values such as the number of sheets, a drum fixing button 77 for fixing image processing contents to be executed in the first plate cylinder 25 and / or the second plate cylinder 26, and an execution button for instructing execution of a designated process 78, setting an image processing mode and print density according to the type of the original such as a character print mode, a text / photo mode, a photo mode, a background image mode, and an original density. Image processing setting button 79 is provided for.
[0040]
The control information input by the user via the operation panel unit 70a is input to a control unit 80 provided in the stencil printing apparatus 1 as shown in FIG. 3, and the control unit 80 operates according to the input control information. A document reading unit 2, a plate making unit 3, a first plate cylinder printing processing unit 4a, a second plate cylinder printing processing unit 4b, a paper feeding unit 5, a paper discharging unit 6, and two plate discharging units 7a and 7b. Control to control the stencil printing process.
[0041]
Further, the control unit 80 controls writing and reading of a ROM 83 and a RAM 84 in which various image processing programs such as a density correction processing program 81 and a binarization processing program 82 used in processing described later and a control program are stored. . Further, the control unit 80 is connected to a computer system 85 via an electronic network such as a LAN (Local Area Network) and can read image data to be printed from the computer system 85.
[0042]
[Operation of stencil printing machine]
Next, the operation of the stencil printing apparatus 1 when stencil printing a printed matter including a background image and a target image will be described in detail with reference to a flowchart shown in FIG. In addition,
`` Background image printing process ''
First, in the process of step S01, after setting a document for a background image on the document reading unit 2, in the process of step S02, the user operates the operation panel unit 70 and presses the image processing setting button 79 to set the background image mode. Is selected, the first plate cylinder 25 is selected as the background image plate cylinder by the drum fixing button 77, and thereafter, the first plate cylinder 25 is fixed as the background image plate cylinder until the selection is released by the drum fixing button 77. Is selected.
[0043]
In the process of step S03, the user operates the operation panel unit 70 and instructs the execution of the plate making process using the plate making button 75. In the process of step S03, the print density and the like of the background image can be set as necessary.
[0044]
In the process of step S04, the control unit 80 controls the document reading unit 2 to read background image data from the set document, and stores the read background image data in the RAM 84. Although the background image data is stored in the RAM 84 via the document reading unit 2 here, the background image data may be received via the computer system 85 or an electronic network and stored in the RAM 84. Good.
[0045]
In the process of step S05, the density correction processing circuit 61 of the image processing unit 60 shown in FIG. 5 inputs the background image data (multi-valued image data) stored in the RAM 84 according to the density correction processing program 81, and The density correction of the background image data is performed by converting the density x1 of the background image data into the document density y1 selected by the user using the density correction curve 62 as shown in FIG. The minimum value of the density correction curve 62 may be changed by the user using the image processing setting button 79 of the operation panel 70a. FIG. 8 shows an example in which the minimum value of the density correction curve 62 is changed in order to reduce the density. The output value y1 of the density correction curve 62 of FIG. The density correction curve 62 is set such that the output value y2 in the density correction curve 62 has a lighter density.
[0046]
Further, in the process of step S05, the halftone processing circuit 65 of the image processing unit 60 shown in FIG. 5 binarizes the density-corrected background image data (multi-valued image data) in accordance with the binarization processing program 82. I do. Specifically, the halftone processing circuit 65 performs halftone processing on the background image data using a halftone matrix 66 as shown in FIG. Value. The halftone matrix 66 is used when one pixel of the multi-tone image is expressed using N × N (16 × 16 in the example shown in FIG. 7) pixels. Each numerical value in the halftone matrix 66 indicates a threshold value for the input value. When a value equal to or larger than the threshold value is input, the pixel is turned on. As shown in FIG. 9, the user may be able to set the number of halftone dots by changing the number in the halftone matrix 66 by using the image processing setting button 79 on the operation panel 70a. The dot matrix 66 of FIG. 9 shows an example in which each numerical value is changed so that the dots are coarser than the dot matrix 66 shown in FIG. Although the background image data is binarized by the halftone processing here, the background image data may be binarized by, for example, error diffusion processing.
[0047]
In step S06, the control unit 80 controls the plate making unit 3 to make the stencil sheet 11 the background image data on which the density correction processing and the binarization processing have been performed. Then, when the stencil making process is completed, the control unit 80 controls the first plate stencil printing processing unit 4a to form the stencil sheet 11 on which the background image data has been made on the first plate cylinder 25.
[0048]
In the process of step S07, the control unit 80 controls the first plate cylinder printing processing unit 4a to perform trial printing of the background image data, and prints one print sheet 41 (first sheet) on which the background image data is printed. Print) is discharged to the paper discharge unit 6.
[0049]
Then, in the process of step S08, the user visually checks the background image printed on the discharged printing paper 41 and determines whether or not the printing result is satisfactory. If the print result is not satisfactory, the process returns to step S02, resets the print density, and executes the process again. On the other hand, if the printing result is satisfactory, the series of background image printing processing ends, and the flow shifts to processing after S09.
[0050]
`` Target image printing process ''
In the process of step S09, the user sets a document for the target image on the document reading unit 2. Then, in the process of step S11, the user operates the operation panel unit 70a to change the image processing mode from the background image mode to the target image mode by using the image processing setting button 79, and in the process of step S12, An image processing mode (for example, a character print mode, a character photograph mode, a photograph mode, etc.) and a print density are selected. Further, in the process of step S13, the user operates the operation panel unit 70a and instructs execution of the target plate making process for the target image by using the plate making button 75.
[0051]
In the process of step S14, the control unit 80 controls the document reading unit 2 to read the target image data from the set document, and stores the read target image data in the RAM 84. Although the target image data is stored in the RAM 84 via the document reading unit 2 here, the target image data may be stored in the RAM 84 via the computer system 85 or an electronic network.
[0052]
In the process of step S15, the image processing unit 60 performs image processing corresponding to the image processing mode selected by the user on the target image data according to the image processing program corresponding to the image processing mode selected by the user.
[0053]
In the process of step S16, the control unit 80 controls the stencil making unit 3 to make the stencil sheet 11 the target image data subjected to the image processing. When the stencil making process is completed, the control unit 80 controls the second plate cylinder stencil printing processing unit 4b to form the stencil sheet 11 on which the target image data has been made on the second plate cylinder 25.
[0054]
In the process of step S17, the control unit 80 controls the first plate cylinder stencil printing processing unit 4a and the second plate cylinder stencil printing processing unit 4b to form a plate on the first plate cylinder 25 and the second plate cylinder 26. The stencil printing process is performed using the target image data and the background image data, and one print sheet 41 on which both the target image data and the background image data are printed is discharged to the paper discharge unit 6.
[0055]
Then, in the process of step S18, the user checks the target image printed on the discharged printing paper 41, and confirms that the print result is satisfactory, for example, whether the target image has disappeared due to the background image. Is determined. If the print result is not satisfactory, the process returns to step S11, and the user resets the print density and the image processing mode of the target image and executes the process again.
[0056]
On the other hand, if the print result is satisfactory, the user operates the operation panel unit 70 to specify the number of prints in the process of step S19, and instructs the execution of the print process in the process of step S20. .
[0057]
In the process of step S21, the control unit 80 controls the first plate cylinder stencil printing processing unit 4a and the second plate cylinder stencil printing processing unit 4b to form a plate on the first plate cylinder 25 and the second plate cylinder 26. The target image data and the background image data are used to perform a stencil printing process for the designated number of prints, and the printing paper 41 on which both the target image data and the background image data are printed is discharged to the paper discharge unit 6.
[0058]
FIG. 10A is a diagram illustrating a document for a target image, and FIG. 10B is a diagram illustrating a document for a background image. FIG. 11A illustrates the result of performing only the density correction process and performing the simple binarization process on the image of the background image document illustrated in FIG. FIG. 11B illustrates an example of a result obtained by superimposing and printing the image-processed background image of FIG. 11A on the target image original of FIG. FIG. 12A illustrates the result of executing the density correction processing and the halftone processing according to the present embodiment on the image of the background image original illustrated in FIG. FIG. 12B illustrates an example of a result obtained by superimposing the image-processed background image in FIG. 12A on the target image original in FIG. As shown in the drawing, the printed image shown in FIG. 12B has higher visibility of the target image than the printed image shown in FIG. 11B, and it can be seen that the printed image is beautifully finished.
[0059]
As is apparent from the above description, according to the stencil printing apparatus according to the present embodiment, the user simply designates the processing mode for printing the background image on the operation panel 70a, and the stencil printing apparatus 1 is able to operate the background printing. The image data is subjected to image processing by density correction processing and halftone processing to perform plate making, one of the plurality of plate cylinders 25 and 26 is selected as a background image plate cylinder, and printing processing is performed. Therefore, even a user who does not have detailed knowledge of image processing can easily print a background image that does not impair the visibility of the target image.
[0060]
Although the embodiments of the present invention have been described in detail, the present invention can be embodied in various other forms without departing from the spirit or main features.
[0061]
For example, the first plate cylinder 25 used for printing the background image can be made every time at the same timing as the second plate cylinder 26 used for printing the target image. Is performed only once, and thereafter, the timing of plate making can be set so that only the second plate cylinder 26 performs plate making. In the latter case, the timing of plate making can be set by selecting either the plate making button 91 or the first plate making button 92 on the operation panel unit 70b as shown in FIG. By selecting the process of making a plate only once at the first time by the first plate making button 92, it is necessary to repeatedly execute the plate making process of the background image even when the same background image is used repeatedly like a company logo, for example. Is eliminated, and the printing processing time and the consumption of consumables can be reduced.
[0062]
Either the first plate cylinder 25 or the second plate cylinder 26 may be selected as the background image plate cylinder. In the stencil printing machine 1 having three or more plate cylinders, any one of the plate cylinders may be selected as the background cylinder. It may be selected as an image plate cylinder. However, the first plate cylinder 25, which is the plate cylinder to which the printing paper 41 is pressed first, is fixedly selected as the background image plate cylinder, so that the second plate cylinder 26 (or the second plate cylinder) is fixed. It is possible to prevent the ink 38 transferred to the plate cylinder after the cylinder 26 from being retransferred to the printing paper 41.
[0063]
Further, in the present embodiment, the background image data and the target image data are input to the apparatus using two originals for the background image and the target image. For example, the background image area and the target image By specifying an image area, background image data and target image data may be input. As a method of specifying the area, the user may manually specify the area using a pointer or the like, or may specify the area by inputting an electronic file describing the coordinates of the area and the character type.
[0064]
As described above, the above-described embodiment is merely an example in every aspect, and should not be construed as limiting. The scope of the present invention is defined by the appended claims, and is not limited by the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.
[0065]
【The invention's effect】
According to the present invention, there is provided a stencil printing apparatus and a control method of the stencil printing apparatus that enable even a user without detailed knowledge about image processing to easily print a background image that does not impair the visibility of a target image. it can.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram illustrating the configuration of a stencil printing apparatus according to an embodiment.
FIG. 2 is a schematic diagram showing an example of a configuration of an operation panel in the stencil printing apparatus shown in FIG.
FIG. 3 is a block diagram illustrating a configuration of a control system in the stencil printing apparatus shown in FIG. 1;
FIG. 4 is a flowchart illustrating a processing procedure of stencil making / printing processing in the stencil printing machine shown in FIG. 1;
FIG. 5 is a block diagram illustrating a configuration of an image processing unit in the stencil printing apparatus shown in FIG. 3;
6 is a diagram illustrating an example of a density correction curve used in the image processing unit illustrated in FIG.
FIG. 7 is a diagram illustrating an example of a halftone matrix used in the image processing unit illustrated in FIG. 5;
FIG. 8 is a diagram illustrating another example of a density correction curve used in the image processing unit illustrated in FIG. 5;
FIG. 9 is a diagram illustrating another example of a halftone dot matrix used in the image processing unit illustrated in FIG. 5;
FIG. 10A is a diagram illustrating a target image document according to the embodiment, and FIG. 10B is a diagram illustrating a background image document according to the embodiment.
11A is an image diagram illustrating a result obtained by performing only a density correction process and performing a simple binarization process on the image of the background image document illustrated in FIG. 10B; FIG. FIG. 11B is an image diagram exemplifying a result obtained by superimposing and printing the image-processed background image of FIG. 11A on the target image original of FIG. 10A.
12A is an image diagram illustrating a result of executing a density correction process and a halftone process according to the present embodiment on the image of the background image document illustrated in FIG. 10B; FIG. FIG. 12B is an image diagram exemplifying a result obtained by superimposing and printing the image-processed background image of FIG. 12A on the target image original of FIG. 10A.
13 is a schematic diagram showing another example of the configuration of the operation panel in the stencil printing machine shown in FIG.
FIG. 14 is an image diagram for explaining a target image and a background image.
[Explanation of symbols]
1. Stencil printing machine
2. Document reading section
3. Plate making part
4 ... printing department
4a: First plate cylinder printing processing unit
4b: 2nd stencil printing process
5. Paper feed unit
6 ... paper ejection section
7, 7a, 7b ... plate discharging section
8 ... Main unit
9 ... Plate making unit
10. Plate making unit moving means
11 ... stencil paper
12 ... plate making unit movement motor
13 ... Worm gear
14 ... Pinion gear
15 ... Rack
16 ... Base paper storage unit
17: transport roll
18. Thermal head
19 ... Platen roll
20: Original feed roll
21 ... guide plate
22 ... Base paper cutter
25 ... first plate cylinder
26 ... Second plate cylinder
27 ... impression cylinder
28 ... plate seat
29… Base paper clamp
30 ... Screen
31 ... Spring
32 ... Inner press mechanism
33 ... Medium press roll
34 ... Roll support member
35 ... Support shaft
36 ... First Doctor Roll
37 ... second doctor roll
38 ... Ink
39 ... Ink pool
40 ... paper clamp
41 ... Printing paper
42 ... paper feeding section
43 ... Primary paper feed roll
44 ... Secondary paper feed roll
45 Guide plate
46 ... Upper regulation guide part
47: Paper stripping claw
48: Paper discharge roll
49… Output tray
50 ... Plate discharge roll
51 ... Plate discharge roll
52 ... Plate discharge guide belt
53 ... Plate discharge roll
54… Printing box
55 ... Compression plate
60 ... Image processing unit
61 Density correction processing circuit
62: Density correction curve
65 halftone processing circuit
66 ... Dot matrix
70, 70a, 70b ... operation panel section
71 Message display section
72 print number display section
73 ... Image processing setting display section
74 Print button
75 ... plate making button
76… Numeric key
77… Drum fixing button
78… Execute button
79… Image processing setting button
80 ... Control unit
81: Density correction processing program
82 binarization processing program
83… ROM
84 RAM
85 ... Computer system
91… Every time a prepress button
92: Initial plate making button

Claims (8)

A mode designation unit for designating an image processing mode for creating a background image to be printed on the background of the target image, and a plate cylinder selection for fixedly selecting one of the plurality of plate cylinders as the background image plate cylinder An operation unit having a unit;
An image processing unit that performs image processing on background image data according to the image processing mode specified by the mode specifying unit.
A stencil making section based on the image-processed background image data, and a stencil making section for making a stencil sheet based on the target image data,
The stencil sheet for which the background image data is prepressed is wound around the background image plate cylinder selected by the plate cylinder selecting unit, and the stencil sheet for which the target image data is prepressed is the background image. A printing unit that performs a printing process by pressing a printing sheet against each of the plate cylinders wound around the plate cylinders other than the plate cylinder and the stencil paper, respectively,
A plate discharging section for discharging the used stencil sheets from the plate cylinders,
A stencil printing apparatus comprising: a control unit that controls each of the operation unit, the image processing unit, the stencil making unit, the printing unit, and the stencil discharging unit. The control unit does not discharge the stencil sheet, on which the background image data plate has been made, to the plate discharge unit while being wound around the background image plate cylinder. Making the stencil sheet based on the stencil sheet, and causing the printing unit to wind the stencil sheet after the other target image data plate is formed on the plate cylinder other than the background image plate cylinder to execute the printing process. The stencil printing apparatus according to claim 1, wherein: 3. The printing drum according to claim 1, wherein a printing drum on which the printing paper is pressed first is fixedly selected as the background image printing drum among the printing drums. A stencil printing apparatus according to claim 1. 4. The image processing device according to claim 1, wherein the image processing performed by the image processing unit includes a density correction process using a density correction curve and a halftone dot process using a halftone matrix. 5. Stencil printing machine. The stencil printing apparatus according to claim 4, wherein the mode designating unit designates a minimum value of the density correction curve and a set value of the halftone matrix. An image processing mode for creating a background image to be printed on the background of the target image is designated by the mode designation unit, and one of the plurality of plate cylinders is fixedly set by the plate cylinder selection unit as the background image plate cylinder. Stages to be selected,
Causing the image processing unit to execute image processing by density correction processing and halftone processing on the background image data in accordance with the image processing mode designated by the mode designation unit;
A step of making a stencil sheet based on the background image data after the image processing,
The step of making a stencil sheet based on the target image data,
A printing unit, winding the stencil sheet for which the background image data plate has been made, around the background image plate cylinder selected by the plate cylinder selection unit,
The printing unit, winding the stencil sheet having the target image data plate-making, around a plate cylinder other than the background image plate cylinder,
A step of causing the printing unit to execute a printing process by pressing a printing sheet against each of the plate cylinders on which each of the stencil sheets is wound,
Discharging the used stencil sheet from each of the plate cylinders to a stencil discharging unit. After the step of performing the printing process, the stencil sheet for which the background image data is prepressed is not discharged to the stencil unit while being wound around the background image plate cylinder. The stencil sheet is made based on the target image data, and the printing unit winds the stencil sheet on which the other target image data has been formed on the plate cylinder other than the background image plate cylinder, and performs the printing process. 7. The method of controlling a stencil printing apparatus according to claim 6, wherein In the step of being selected by the plate cylinder selecting unit, a plate cylinder to which the printing paper is pressed first among the plurality of plate cylinders is fixedly selected as the background image plate cylinder. The method for controlling a stencil printing apparatus according to claim 6.

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