JP2009279785A - Stencil printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stencil printing apparatus capable of obtaining a superior printed matter by preventing occurrence of rolling-up even in the presence of a high density image on one side in a paper transporting direction. <P>SOLUTION: The stencil printing apparatus 1 include a plate cylinder 9, a platemaking section 3, a pressurizing means 10, a paper feeding section 4 having a plurality of paper feeding trays 22, 23, 24 for feeding paper between the plate cylinder 9 and the pressurizing means 10. The apparatus also has a density detecting means 51 for detecting density distribution of a platemaking image and has a function of arbitrarily changing the direction of the platemaking image. The paper feeding section 4 is provided with the paper feeding trays 22, 23, 24 capable of feeding paper at least in one direction of the vertical and horizontal directions of at least one size paper. On the basis of the detection result of the density detecting means 51, the direction of the platemaking image is changed in a conditionally better direction against the roll-up. In the presence of the paper feeding tray corresponding to the platemaking image, it is automatically selected in the structure of the apparatus. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for preventing roll-up of a stencil printing apparatus.

  Conventionally, digital thermal stencil printing is known as a simple printing method. This is because a thermal head having a plurality of fine heating elements is brought into contact with a master obtained by bonding a thermoplastic resin film and a porous support, and the master is placed on a platen roller or the like while energizing the heating elements in a pulsed manner. After the punched image based on the image information is hot-melt perforated and engraved on the thermoplastic resin film of the master by conveying with a conveying means, the perforated master is wound around a porous cylindrical plate cylinder and pressed. By pressing the paper against the outer peripheral surface of the plate cylinder by pressing means such as a roller, the ink supplied to the inner peripheral surface of the plate cylinder is oozed out from the plate cylinder opening portion and the master punching portion, and this ink is transferred to the paper A printed image is obtained on a sheet.

  In the stencil printing apparatus that performs the stencil printing described above, ink is oozed from the inside of the plate cylinder through the plate making image punched in the master wound on the outer peripheral surface of the plate cylinder and transferred to the paper. If a high-density image such as a solid image is present at the leading end in the conveyance direction, a problem of so-called rolling up occurs in which the sheet is not discharged while adhering to the master due to the adhesive force of the ink and rotates with the plate cylinder as it is. When the roll-up occurs, the sheet remains stuck on the master, and printing on the next sheet is not performed, resulting in a printing failure.

  In order to prevent the above-described roll-up, if the amount of image information on the front side in the paper conveyance direction is larger than the amount of image information on the rear side in the paper conveyance direction, the image information output is reversed by 180 degrees, and the front side in the paper conveyance direction A stencil printing apparatus that performs plate making so that a small amount of image information is located is disclosed in, for example, “Patent Document 1”.

JP 2001-341400 A

  In the above-described technique, since the front end side and the rear end side in the paper transport direction are compared, it is impossible to cope with a case where a portion having a large amount of image information continues on at least one side portion in the paper transport direction. This portion may adhere to the master on the outer peripheral surface of the plate cylinder and may be rolled up. The present invention solves the above-mentioned problems, and can prevent a roll-up from occurring even when a high-density image exists on at least one side in the paper conveyance direction, and can obtain a good printed material. An object is to provide a printing apparatus.

  The invention according to claim 1 is a plate cylinder around which a master is wound, a plate making unit for making a plate from the master, a pressing unit that presses a sheet against the plate cylinder to transfer ink to the sheet, and a sheet that is transferred to the plate. In a stencil printing apparatus comprising a paper feed section having a plurality of paper feed trays fed toward a cylinder and the pressing means, density detecting means for detecting a density distribution of a plate-making image made by the master And a function capable of arbitrarily changing the orientation of the plate-making image, and the paper feed unit can feed at least one size of paper in at least one of portrait orientation and landscape orientation. When a sheet feeding tray is provided, the direction of the plate-making image is changed in a favorable direction with respect to winding based on the detection result of the density detection means, and the sheet feeding tray corresponding to the plate-making image exists. Does this automatically Characterized in that it-option.

  According to a second aspect of the present invention, in the stencil printing apparatus according to the first aspect of the invention, the direction of the plate-making image is changed to a favorable direction with respect to the roll-up and the plate-making image based on the detection result of the density detection means. When there is no paper feed tray corresponding to the above, a warning is given to the user that the paper direction will be changed.

  The invention described in claim 3 includes a plate cylinder around which the master is wound, a plate making unit for making the master, a pressing means for pressing the paper against the plate cylinder and transferring the ink to the paper, and a paper as the plate. In a stencil printing apparatus comprising a paper feed unit having a paper feed tray for storing paper fed toward the cylinder and the pressing means, a density for detecting a density distribution of a plate-making image made by the master The image forming apparatus has a detecting unit and a function capable of arbitrarily changing the direction of the plate-making image. Based on the detection result of the density detecting unit, the direction of the plate-making image is changed in a favorable direction with respect to winding. If the paper stored in the paper feed tray does not correspond to the plate-making image, the user is warned that the paper orientation is to be changed.

  According to the present invention, it is possible to perform the plate making operation and the printing operation under the condition that the paper is stuck to the circumferential surface of the plate cylinder and is difficult to be rolled up, and the printing is prevented by preventing the winding from occurring. Can be continued.

FIG. 1 shows a stencil printing apparatus that employs a first embodiment of the present invention. In FIG. 1, a stencil printing apparatus 1 includes a printing unit 2, a plate making unit 3, a paper feeding unit 4, a plate discharging unit 5, an image reading unit 6, a paper discharge unit 7, and the like.
The printing unit 2 disposed almost at the center of the apparatus main body 8 has a plate cylinder 9 and a press roller 10 as pressing means. A plate cylinder 9 having a porous support plate having an aperture portion in which a large number of apertures are formed and a non-aperture portion on its outer peripheral surface has a rotational peripheral speed corresponding to a printing speed set by a plate cylinder drive motor (not shown). Is driven to rotate. A plurality of mesh screens made of resin or metal nets are wound on the apertures of the porous support plate, and the clamper 11 sandwiches the tip of the master on the non-apertures of the porous support plate. Can be opened and closed. Inside the plate cylinder 9, known ink supply means 14 including an ink roller 12 and a doctor roller 13 for supplying ink to the inner peripheral surface of the plate cylinder 9 is disposed.

  Below the plate cylinder 9 is disposed a press roller 10 in which both ends of the support shaft are rotatably supported by a pair of arm members 15. The press roller 10 is configured such that each arm member 15 is swung by a swinging means (not shown) so that the outer peripheral surface thereof can be brought into contact with and separated from the outer peripheral surface of the plate cylinder 9.

  A plate making unit 3 is disposed on the upper right side of the printing unit 2. The plate making unit 3 includes a thermal head 17 and a platen roller 18 that perform perforating plate making on the master 16, master cutting means 19 that cuts the master 16 to a predetermined length, and a master conveying roller pair that conveys the master 16 toward the printing unit 2. 20, 21 and so on. The master that has been made by the plate making unit 3 is sent toward the plate cylinder 9 and then wound around the outer peripheral surface of the plate cylinder 9.

  A sheet feeding unit 4 is disposed below the plate making unit 3. The paper feed unit 4 has a first paper feed tray 22 that is moved up and down with paper P loaded thereon, a second paper feed tray 23 and a third paper feed tray 24 that are arranged in series below the printing unit 2. , Paper feed rollers 25, 26, 27, separation roller pair 28, paper transport roller pair 29, registration roller pair 30 and the like. Each paper feed tray 22, 23, 24 is provided with a paper size detection sensor (not shown) that detects the size of the stacked paper P. Each paper feed tray 22, 23, 24 has a postcard size to A3 size. Paper up to is loaded. In the present embodiment, the sheets stacked on each of the paper feed trays 22, 23, and 24 are vertically oriented (the paper conveying direction is the longitudinal direction of the paper) and horizontally (the paper conveying direction is the paper conveying direction) in the postcard size, B5 size, and A4 size. Each of the B4 size and the A3 size is limited to the vertical direction.

  A plate discharging unit 5 is disposed on the upper left side of the printing unit 2. The plate removal unit 5 includes an upper plate release member 31 and a lower plate release member 32 that peel and transport a used master from the outer peripheral surface, a plate release box 33 that contains a used master and is detachable from the apparatus main body 8, and a plate discharge This is a known configuration having a compression plate 34 or the like for pushing a used master into the box.

  An image reading unit 6 is disposed on the upper part of the apparatus main body 8. The image reading unit 6 includes a contact glass 35 on which a document to be printed is placed, a scanning unit 36 that scans and reads a document image, an imaging lens 37 that focuses the scanned image, and an image sensor that recognizes the focused image. 38 is a known configuration having an A / D converter (not shown) for A / D converting an image output from the image sensor, an ADF unit 39 for continuously processing a plurality of originals, and the like.

  A paper discharge unit 7 is disposed on the lower left side of the printing unit 2. The paper discharge unit 7 includes a peeling claw 40, a paper discharge transport means 41, a paper discharge tray 42, and the like. The peeling claw 40 is swingably attached to the apparatus main body 8 and selectively occupies a position where its tip end is close to the outer peripheral surface of the plate cylinder 9 and a position where it is separated by the operation of a claw swinging means (not shown). . The paper discharge conveying means 41 disposed below the peeling claw 40 includes a driving roller, a driven roller, an endless belt, a suction fan, and the like. The paper discharge tray 42 has a pair of side fences 43 and one end fence 44 on the upper surface thereof.

  FIG. 2 shows a control unit of the stencil printing apparatus 1 described above. In the figure, a system control unit 45 that performs overall control of the stencil printing apparatus 1 is provided inside the apparatus main body 8. The system control unit 45 has a known configuration including a CPU that performs all data processing, a memory for storing data, a peripheral LSI that supplements the functions of the CPU, an interface circuit with external function blocks, and the like.

  The system control unit 45 is connected to an operation panel (not shown) provided on the upper front of the apparatus main body 8. On the operation panel, a key operation unit 46 for performing various operations and a display unit 47 for performing various displays are provided. Is provided. Further, a paper feed control unit 48 for controlling the paper feed unit 4 is connected to the system control unit 45, and the paper feed control unit 48 controls the size of the paper stored in each of the paper feed trays 22, 23, and 24. Orientation information is entered. The display unit 47 displays not only the paper size and orientation information input from the paper feed control unit 48 but also all the information of the stencil printing apparatus 1 and warnings.

Based on the configuration described above, the operation of the stencil printing apparatus 1 in the present embodiment will be described based on the block diagram shown in FIG. 2 and the flowchart shown in FIG.
When a plate making start key (not shown) provided in the key operation unit 46 is pressed (S1), image input from the image data input unit 49 such as the image reading unit 6 or an external input device such as a personal computer is started (S2). ). The input multi-value data is sent to a binarization processing unit 50 for generating print data to a plurality of resistance heating elements provided in the thermal head 17 and an image density distribution analysis unit 51 as density detection means. (S3, S4), each processing is executed.

  The image density distribution analysis unit 51 calculates the rotation condition of the binary print data with respect to the paper discharge direction based on the density distribution of the input image (S5). The calculated result is sent to the print data rotation control unit 52, and processing corresponding to the analysis result is executed. The processed print data is sent to the resistance heating element 54 of the thermal head 17 via the punching data generation unit 53. The condition where it is not necessary to rotate the image is that the paper is stuck to the peripheral surface of the plate cylinder 9 and is not easily rolled up, that is, the portion where the image density is high is on the downstream side of the paper transport direction or the paper If it does not exist on at least one side, the print data rotation control unit 52 starts the transfer to the resistance heating element 54 without rotating the print data (S6), and the transfer of all the print data is completed. (S7) When the plate making operation is started, the printing operation is performed when the plate making operation is completed (S8). When the set number of printed sheets is digested (S9), all the operations are completed and the stencil printing apparatus is completed. The operation of 1 stops.

  In step S5, if the image is required to be rotated and the roll-up is likely to occur, as shown in FIG. 4, if a portion with a high image density exists on the downstream side in the paper conveyance direction, printing is performed. The data rotation control unit 52 rotates the print data by 180 degrees (S10) and starts transfer to the resistance heating element 54 (S6). In this case, the rotation of the print data changes the image orientation with respect to the paper transport direction, but the image positional relationship with respect to the paper does not change, so that a printed matter desired by the user can be obtained.

  In step S5, if the image is necessary to be rolled up, and the portion where the image density is high is present on one side of the paper as shown in FIG. The data rotation control unit 52 rotates the print data by 90 degrees (S10). However, in the case shown in FIG. 5, for example, when normal printing uses paper fed from the first paper feed tray 22 and vertical paper is stacked on the first paper feed tray 22. Since the paper passing direction (horizontal orientation) and the paper setting direction (vertical orientation) do not match, the system control unit 45 detects a paper feed tray in which the same size paper is set horizontally (S11). For example, when paper of the same size is set horizontally in the second paper feed tray 23, the second paper feed tray 23 is automatically selected (S12), and the operations from steps S6 to S9 are performed and stopped. To do. If there is no paper feed tray that matches the rotated print data in step S11, the system control unit 45 displays that there is no paper feed tray that matches the display unit 47 and stores the paper in the paper feed tray. The user is warned to change the direction.

  According to the above-described configuration, the plate-making operation and the printing operation can be performed under the condition that the paper is stuck to the peripheral surface of the plate cylinder 9 and is not easily rolled up, and the occurrence of winding is prevented. Good printing can be continued.

  In the above embodiment, an example in which the paper feed unit 4 has a plurality of paper feed trays 22, 23, and 24 has been described. However, the present invention also applies to a stencil printing apparatus in which the paper feed unit has a single paper feed tray. Applicable. In this case, when the print data is rotated under conditions where winding is unlikely to occur, if there is no suitable paper feed tray, the user is warned to change the orientation of the paper stored in the paper feed tray. Do.

1 is a schematic front view of a stencil printing apparatus to which an embodiment of the present invention can be applied. It is a block diagram of the system control part used for one Embodiment of this invention. It is a flowchart explaining operation | movement of the stencil printing apparatus in one Embodiment of this invention. It is the schematic explaining the rotation of the printing data in one Embodiment of this invention. It is the schematic explaining the rotation of the printing data in one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stencil printing apparatus 3 Plate making part 4 Paper feed part 9 Plate cylinder 10 Pressing means (press roller)
16 Master 22, 23, 24 Paper feed tray 51 Density detection means (image density distribution analysis unit)

Claims (3)

A plate cylinder around which the master is wound, a plate making unit for making the master, a pressing means for pressing the paper against the plate cylinder and transferring ink onto the paper, and a paper between the plate cylinder and the pressing means A stencil printing machine comprising a paper feed unit having a plurality of paper feed trays that feed toward
It has density detecting means for detecting the density distribution of the plate-making image made by the master and has a function capable of arbitrarily changing the direction of the plate-making image, and the paper feed unit is configured to place at least one size of paper vertically. Each of the paper feed trays capable of feeding in at least one of a horizontal orientation and a horizontal orientation, and based on the detection result of the density detection means, the orientation of the plate-making image is oriented in a favorable condition with respect to winding. A stencil printing apparatus, wherein the sheet feeding tray corresponding to the plate-making image is automatically selected when it is changed. In the stencil printing apparatus according to claim 1,
Based on the detection result of the density detection means, the direction of the plate-making image is changed in a favorable direction with respect to the roll-up, and when the paper feed tray corresponding to the plate-making image does not exist, the paper direction is indicated to the user. A stencil printing apparatus which warns of a change. A plate cylinder around which the master is wound, a plate making unit for making the master, a pressing means for pressing the paper against the plate cylinder and transferring ink onto the paper, and a paper between the plate cylinder and the pressing means In a stencil printing apparatus comprising a paper feed unit having a paper feed tray for storing paper to be fed toward
It has density detection means for detecting the density distribution of the plate-making image to be made by the master and has a function capable of arbitrarily changing the orientation of the plate-making image. Based on the detection result of the density detection means, The stencil is characterized in that the direction of the plate-making image is changed to a favorable direction and the user is warned to change the paper direction when the paper stored in the paper feed tray does not correspond to the plate-making image. Printing device.

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