JP5320205B2 - Image data generation method and apparatus, and printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress dirt of a printed matter such as strike-through, offset and retransfer of ink, due to excess transfer of the ink to a printing paper in order to acquire a successful printed matter without deteriorating the image quality of the printed matter. <P>SOLUTION: Input of image data is accepted, information on a preset specific range on the image data is accepted, the accepted image data are divided into a plurality of areas on the basis of attributes of the image data, a divided area including a range which overlaps the specific range is acquired from the divided areas, and density conversion processing such that density becomes low to the image data in the divided area by unit of the acquired divided area to generate processed image data. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an image data generation method and apparatus that accepts input of image data and performs density conversion processing on the image data, and a printing apparatus.

  Conventionally, a thermal head or the like is driven based on image data obtained by reading a document by a scanner or image data created and edited by a computer, and a stencil sheet is melted and punched to perform a plate making process to create a plate. Various stencil printing apparatuses that perform printing by winding a prepared plate around a printing drum, supplying ink from the inside of the printing drum, and transferring the ink to printing paper by a roller or the like have been proposed.

  Here, in the stencil printing apparatus as described above, for example, when the ink is excessively transferred to the printing paper, a problem of smearing of the printed matter due to so-called back-through, back-off, ink re-transfer, and the like occurs. In particular, in a stencil printing apparatus that performs double-sided printing, since the second plate is printed before the first plate ink is sufficiently dried, for example, the printing drum that performs the first plate printing and the second plate printing are performed. In the case of a stencil printing machine equipped with a printing drum for performing ink re-inking from a conveyance roller or the like on the paper feed path between the printing drum for performing printing of the first plate and the printing drum for printing of the second plate. Prone to metastasis.

  As a method for solving such a problem, for example, the perforation diameter of the stencil sheet is reduced (for example, refer to Patent Document 1), the press pressure against the printing drum is decreased (for example, refer to Patent Document 2), or the entire printing surface. A method has been proposed in which the density of the image data is reduced (for example, see Patent Document 3) to reduce the entire printed image.

Japanese Patent Laid-Open No. 2005-144897 JP 2004-284271 A JP 2004-306422 A

  However, when the density of the entire printed image is reduced as described above, there is a problem that the image quality becomes low and the quality of the printed product is deteriorated.

  Further, as described above, the re-transfer of the ink is caused by the transfer of the ink from the printing surface to the transport roller when the print surface of the printed material on which the first plate is printed contacts the transport roller. A method is also conceivable in which the density is lowered only in the area where the printing paper comes into contact. However, if such a method is adopted, a density difference will occur between the density in the above range and the density in other ranges, and the image quality of the printed image will be reduced. Will deteriorate.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an image data generation method and apparatus, and a printing apparatus that can obtain a good printed material without deteriorating the image quality of the printed material.

  The image data generation method of the present invention accepts input of image data, accepts information of a specific range on preset image data, and accepts the accepted image data into a plurality of regions based on attributes of the image data. Divide and acquire a divided region including a range that overlaps the specific range from the divided regions, and perform density conversion processing that reduces the density of the image data in the divided region in units of the obtained divided regions. And processed image data is generated.

  In the image data generation method of the present invention, the image data is recorded on the one side of the recording medium, the first image is recorded, and the one-side recorded recording medium on which the first image is recorded is conveyed in a predetermined manner. The image data representing the first image used when the second image is recorded on the other surface of the recording medium after being transported by the mechanism, and information on the specific range is a range where the transport mechanism and the recording medium are in contact with each other. Can be information indicating the range on the image data corresponding to.

  The image data generation device of the present invention is received by an image data receiving unit that receives input of image data, a specific range information receiving unit that receives information on a specific range on preset image data, and an image data receiving unit. A region dividing unit that divides image data into a plurality of regions based on the attributes of the image data, and a specific divided region acquisition unit that acquires a divided region including a range that overlaps the specific range from the regions divided by the region dividing unit And a density conversion processing unit that generates processed image data by subjecting the image data in the divided area acquired by the specific divided area acquisition unit to a density conversion process that reduces the density. It is characterized by that.

  In the image data generating device of the present invention, the image data receiving unit records the first image on one side of the recording medium, and the single-side recorded recording medium on which the first image is recorded is a predetermined recording medium. The image data representing the first image used when recording the second image on the other surface of the recording medium is received as image data after being transported by the transport mechanism, and the specific range information receiving unit is transported. Information indicating a range on the image data corresponding to a range where the mechanism and the recording medium come into contact with each other can be received as information on the specific range.

  The image data receiving unit receives image data output from the computer, and the region dividing unit divides the image data into a plurality of regions based on object attribute information added to the image data by the computer. can do.

  The image data receiving unit receives image data output from the image reading unit that reads the original image and outputs image data representing the original image, and the region dividing unit receives the image data received by the image data receiving unit. The attribute of the image data can be recognized based on the data, and the image data can be divided into a plurality of regions based on the recognized attribute.

  A printing apparatus according to the present invention includes the image data generation apparatus, a printing unit that records a first image on one surface of a recording medium based on processed image data generated by the image data generation apparatus, and a printing unit. And a transport mechanism for transporting the one-side recorded recording medium on which the first image is recorded.

  According to the image data generation method and apparatus and the printing apparatus of the present invention, the input of the image data is accepted, the information of the specific range on the preset image data is accepted, and the received image data is set as the attribute of the image data. Is divided into a plurality of regions, and a divided region including a range that overlaps the specific range is acquired from the divided regions, and the density of the image data in the divided region is low for each acquired divided region. Since the processed image data is generated by performing such density conversion processing, for example, information on the specific range is information indicating the range on the image data corresponding to the range where the transport mechanism and the recording medium are in contact with each other. If so, since the transfer of ink to the transport mechanism can be reduced, the retransfer of ink from the transport mechanism to the printing paper can be suppressed. , Since lower concentrations the divided area units can avoid the concentration of the entire print image is lowered, deterioration of image quality can be minimized.

  In addition, since density conversion processing is performed in units of divided areas divided based on the attributes of the image data, density conversion processing can be performed on the entire area such as a photo area and a character area, and natural image quality without density boundaries Can be obtained.

1 is an overall schematic configuration diagram of a stencil printing apparatus using an embodiment of an image data generation apparatus of the present invention. The figure which shows the contact range SR with the single-sided printed printing paper P2, a pick-up roller, and a timing roller The block diagram which shows the structure of the image data generation part of the stencil printing apparatus using one Embodiment of the image data generation apparatus of this invention. The flowchart for demonstrating the effect | action of the stencil printing apparatus using one Embodiment of the image data generation apparatus of this invention. Schematic diagram showing an example of image data G1, specific range TR, and divided regions P1, P2, L1, and L2

  Hereinafter, a stencil printing apparatus using an embodiment of an image data generation apparatus of the present invention will be described in detail with reference to the drawings. The stencil printing apparatus according to the present embodiment is characterized by a method for generating image data. First, the schematic configuration will be described. FIG. 1 is a schematic configuration diagram of the stencil printing apparatus of the present embodiment.

  As shown in FIG. 1, the stencil printing apparatus 1 of the present embodiment reads an image of a document and outputs image data, and the stencil sheet M is printed on the stencil sheet M based on the image data read by the image reading unit 10. The first and second plate making sections 30 and 35 to which the plate making process is performed, and the first and second plate printing sheets P1 are printed using the stencil sheet M made by the first and second plate making sections 30 and 35. The printing units 40 and 50, the paper feeding unit 20 that feeds the printing paper P1 to the first printing unit 40, and the printing paper P2 that has been printed on one side in the first printing unit 40 are temporarily stocked, and then at a predetermined timing. An intermediate stock unit 46 that feeds paper to the second printing unit 50 and a paper discharge unit 70 that discharges the printing paper P3 printed on both sides by the second printing unit 50 are provided.

  The image reading unit 10 includes a line image sensor that photoelectrically reads image information of an original, scans the original with the line image sensor, and outputs image data.

  The first plate making unit 30 has a thermal head 31 in which a plurality of heating elements are arranged in a line, and performs a plate making process on the stencil sheet M fed from a stencil sheet roll using the thermal head 31. Is. The first plate making unit 30 performs plate making processing based on processed image data output from an image data generation unit 60 described later.

  Similarly to the first plate making unit 35, the second plate making unit 35 has a thermal head 36, and performs the plate making process using the thermal head 36 on the stencil sheet M fed from the stencil sheet roll. is there. The second plate making unit 35 performs plate making processing based on image data output from an image data receiving unit 61 of the image data generating unit 60 described later.

  The first printing unit 40 presses the printing paper P1 and the first printing drum 41 with a predetermined press pressure against the first printing drum 41 having a cylindrical shape such as a perforated metal plate or a mesh structure. A first press roller 42 and a first stripping claw 43 for stripping the single-side printed paper P2 from the first printing drum 41 are provided. A pre-made stencil sheet M perforated in the first plate making unit 30 is wound around and attached to the outer periphery of the first printing drum 41. The first press roller 42 extends along the direction in which the central axis of the cylinder of the first printing drum 41 extends (the thickness direction in FIG. 1).

  Similarly to the first printing unit 40, the second printing unit 50 is configured to press the cylindrical second printing drum 51 and the printing paper P2 against the second printing drum 51 with a predetermined press pressure. A press roller 52 and a second peeling claw 53 for peeling the double-side printed paper P3 from the second printing drum 51 are provided. A pre-made stencil sheet M perforated in the second plate making unit 35 is wound around and attached to the outer periphery of the second printing drum 51. The second press roller 52 extends along the direction in which the central axis of the cylinder of the second printing drum 51 extends (the thickness direction in FIG. 1).

  The paper supply unit 20 includes a paper supply base 21 on which the print paper P1 is placed, and a primary paper supply roller 22 that takes out the print paper P1 one by one from the paper supply base 21 and sends it to the secondary paper supply roller 23. The leading end of the printing paper P1 that is disposed downstream of the primary paper feeding roller 22 in the carrying direction is temporarily stopped, and the printing paper P1 is transferred to the first printing drum at a predetermined timing. A secondary paper feed roller 23 is provided between 41 and the first press roller 42.

  The paper discharge unit 70 is a paper discharge feeding belt unit 72 that conveys the double-sided printed printing paper P3 to the paper discharge table 71, and a paper discharge on which the double-sided printed printing paper P3 conveyed by the paper discharge feeding belt unit 72 is stacked. A stand 71 is provided.

  Further, a curved conveyance unit 44 is installed between the first printing unit 40 and the intermediate stock unit 46. As shown in FIG. 1, the curved conveyance unit 44 includes a guide plate having a curved surface along the conveyance path. On the curved surface of the guide plate, a conveyor belt provided with a suction port for sucking the printing paper P1 sent out from the first printing unit 40 is installed. A pulley 45 that circulates and moves the transport belt is provided. The curved conveyance unit 44 sucks the single-side printed paper P2 by the suction port of the conveyance belt, and conveys the single-side printed paper P2 by the conveyance belt along the curved surface of the guide plate by rotating the pulley 45. Is.

  Further, between the intermediate stock unit 46 and the second printing unit 50, a pickup roller 47 that picks up the single-side printed printing paper P <b> 2 carried out from the intermediate stock unit 46, and single-sided printing picked up by the pickup roller 47. There is provided a timing roller 48 that sequentially feeds the finished printing paper P2 between the second printing drum 51 and the second press roller 52 at a predetermined timing.

  Here, a top view of the pickup roller 47 and the timing roller 48 in the present embodiment is shown in FIG. As shown in FIG. 2, the pickup roller 47 includes a pair of rollers 47a and 47b, and the timing roller 48 includes a pair of rollers 48a and 48b. In FIG. 2, a range SR in which the pickup roller 47 and timing roller 48 are in contact with the single-side printed printing paper P2 is indicated by a dotted line. The single-side printed paper P2 is conveyed in the paper feeding direction indicated by the arrow in the drawing while being in contact with the pickup roller 47 and the timing roller 48 in the range SR.

  Further, the stencil printing apparatus 1 of the present embodiment performs a predetermined density conversion process on the image data output from the image reading unit 10 and outputs images to the first and second plate making units 30 and 35, respectively. A data generation unit 60 is provided.

  Specifically, as shown in FIG. 3, the image data generating unit 60 includes an image data receiving unit 61 that receives input of image data output from the image reading unit 10, and an image received by the image data receiving unit 61. On the image data corresponding to the range SR where the area dividing unit 62 that divides the data into a plurality of areas based on the attribute of the image data, the pickup roller 47 and the timing roller 48, and the single-side printed printing paper P2 are in contact with each other. A specific range information receiving unit 63 for receiving information on a specific range indicating a range, a specific divided region acquiring unit 64 for acquiring a divided region including a range overlapping the specific range from the regions divided by the region dividing unit 62, A density conversion process that reduces the density of image data in the divided area in units of divided areas acquired by the specific divided area acquisition unit 64. A density conversion processing unit 65 that generates processed image data by applying a binarization process to the processed image data generated by the density conversion processing unit 65, and outputs the processed image data to the first plate making unit 30. A binarization processing unit 66 that performs binarization processing on the image data output from the data reception unit 61 and outputs the image data to the second plate making unit 35 is provided. The operation of each part will be described later in detail.

  Next, the operation of the stencil printing apparatus 1 of the present embodiment will be described. First, the operation of the image data generation unit 60 will be described with reference to the flowchart shown in FIG.

  First, a front document is placed on a document table of the image reading unit 10 and scanned by a line image sensor while being pressed by a pressing plate to read image data on the surface (S10). Then, multi-value image data representing the surface image is sequentially acquired for each line and received from the image reading unit 10 to the image data receiving unit 61 of the image data generating unit 60.

  The image data receiving unit 61 outputs multi-value image data representing the surface image to the region dividing unit 62. Then, the region dividing unit 62 analyzes the photographic region based on the input multi-value image data by analyzing whether it is multi-value image data that is a photograph attribute or multi-value image data that is a character attribute. And the character area are detected, and the multi-value image data is divided into a plurality of areas such as a photograph area and a character area (S12). Then, the multivalued image data divided into the plurality of regions is output to the specific divided region acquisition unit 64. Note that a photographic region and a character region can be detected by detecting and analyzing an image feature amount such as an edge, for example, and can be detected using various known techniques.

  On the other hand, the specific range information receiving unit 63 receives specific range information indicating the range on the image data corresponding to the range SR in which the pickup roller 47 and the timing roller 48 are in contact with the single-side printed paper P2 (S14). The information on the specific range is obtained by projecting the range SR in which the pickup roller 47 and the timing roller 48 are in contact with the single-side printed printing paper P2 onto the coordinate system of the multivalued image data read by the image reading unit 10. . The information on the specific range may be set in advance in a storage unit (not shown) such as a memory, or may be input and set by an operator. Then, the specific range information received by the specific range information receiving unit 63 is also output to the specific divided region acquisition unit 64.

  Next, as shown in FIG. 5, the specific divided region acquisition unit 64 superimposes the multi-valued image data G1 on the divided surface and the specific range TR. Then, an area including a range overlapping with the specific range TR is acquired from the photograph areas P1 and P2 and the character areas L1 and L2 divided in the multi-value image data G1. That is, in the case of the multi-valued image data G1 shown in FIG. 5, the photo area P1 and the character area L2 are acquired as specific divided areas (S16). Then, the information on the specific divided area and the multi-valued image data G1 obtained by the area division are output from the specific divided area acquisition unit 64 to the density conversion processing unit 65.

  The density conversion processing unit 65 performs density conversion processing that reduces the density on the entire multi-value image data in the specific divided area of the input multi-value image data G1, and generates processed image data. . It should be noted that density conversion processing is not performed on multi-value image data other than the specific divided areas.

  The processed image data generated in the density conversion processing unit 65 is output to the binarization processing unit 66, and after binarization processing is performed in the binarization processing unit 66, the processed image data is sent to the first plate making unit 30. Is output (S20). As the binarization process, a known binarization process such as a simple binarization process, an error diffusion method, and a halftone dot binarization method can be used.

  Then, the first plate making unit 30 performs the plate making process by punching the stencil sheet M using the thermal head 31 based on the input processed image data (S22).

  Then, the plate subjected to the plate making process in the first plate making unit 30 is wound around the first printing drum 41.

  Next, the document on the back side is placed on the document table of the image reading unit 10, and the image data on the back side is scanned by the line image sensor in the same manner as the document on the front side (S24). Then, multi-valued image data G2 representing the back image is acquired and received from the image reading unit 10 by the image data receiving unit 61 of the image data generating unit 60.

  The multi-value image data G2 on the back surface is directly output from the image data receiving unit 61 to the binarization processing unit 66 without being subjected to density conversion processing like the image data on the front surface, and binarization processing is performed. A binarization process is performed in the unit 66 (S26).

  Then, the binary image data of the back surface subjected to the binarization processing in the binarization processing unit 66 is output to the second plate making unit 35, and the second plate making unit 35 receives the input binary data of the back surface. Based on the image data, the stencil sheet M is perforated using the thermal head 36 to perform the plate making process (S28).

  Then, the plate subjected to the plate making process in the second plate making unit 35 is wound around the second printing drum 51.

  After the plates are wound around the first printing drum 41 and the second printing drum 51 as described above, double-sided printing processing is performed (S30).

  Specifically, ink is supplied to the inside of the first and second printing drums 41 and 51 by an ink supply pump (not shown), and the first and second printing drums 41 and 51 are rotationally driven. Then, the printing paper P1 is fed out from the paper feed tray 21 by the primary paper feed roller 22 at a predetermined timing in synchronization with the rotation of the first and second print drums 41 and 51, and once the secondary paper feed roller 23 is reached. 1 is formed by the secondary paper feed roller 23 from the left to the right in FIG. 1 at a predetermined timing, and is supplied between the first printing drum 41 and the first press roller 42. The Then, the printing paper P1 is pressed against the printing paper P1 by the first press roller 42 against the stencil stencil sheet M wound around the outer peripheral surface of the first printing drum 41. Is done.

  Then, when the first printing drum 41 is rotated by a predetermined angle and the single-sided stencil printing on the printing paper P1 is completed, the single-sided printing paper P2 is peeled off from the first printing drum 41 by the peeling claw 43. The single-sided printed printing paper P <b> 2 that has been removed and peeled off is conveyed to the intermediate stock unit 46 by the curved conveyance unit 44.

  The single-side printed paper P2 is once stocked in the intermediate stock section 46, and then discharged from the intermediate stock section 46 with the printing surface facing downward (the unprinted surface is the upper side), and is picked up by a pickup roller 47. And is once abutted against the timing roller 48 to form a slack and then supplied between the second printing drum 51 and the second press roller 52 by the timing roller 48 at a predetermined timing.

  Then, the non-printed surface of the single-sided printed paper P2 is pressed against the stencil stencil sheet M wound around the outer peripheral surface of the second printing drum 51 by the second press roller 52, so that the single-sided printing is completed. The stencil printing on the back surface is performed on the unprinted surface of the printing paper P2.

  When the second printing drum 51 is rotated by a predetermined angle and the stencil printing on the back side of the unprinted surface of the single-sided printed paper P2 is completed, the double-sided printed paper P3 is removed by the peeling claw 53. The double-sided printed printing paper P3 that has been peeled off from the second printing drum 51 is transported to the paper discharge tray 71 by the paper discharge feed belt 72 and stacked on the paper discharge tray 71.

  Then, the printing paper P1 is again fed out from the paper feed tray 21, and double-sided stencil printing is performed on the printing paper P1 in the same manner as described above.

  In the above-described embodiment, double-sided stencil printing is performed based on image data read by the image reading unit 10, but the present invention is not limited to this, and image data created and edited by a predetermined application in a computer is used. It may be received by the image data receiving unit 61 to perform double-sided stencil printing. In this case, object attribute data indicating whether the image data has a photo attribute or a character attribute is added to the image data created by a computer application. Therefore, the area dividing unit 62 may divide the area in units of objects based on the object attribute data. Further, the image data generation unit 60 may be provided in the computer.

  In the above-described embodiment, the image data generation unit is provided in the stencil printing apparatus. However, the apparatus provided with the image data generation unit is not limited to this. For example, a control signal such as a printer job is output to the stencil printing apparatus. It may be provided in the printer controller.

  The stencil printing apparatus of the above embodiment includes two printing drums that perform double-sided printing. However, the present invention is not limited to this, and the image data generation apparatus of the present invention is a stencil that can be mounted with one printing drum. The printing apparatus can also be applied to a stencil printing apparatus that can perform double-sided printing by replacing the printing drum and reloading a single-side printed printing paper into the paper feeding unit.

  The image data generation apparatus of the present invention can be applied not only to a stencil printing apparatus but also to an inkjet printing apparatus capable of duplex printing.

DESCRIPTION OF SYMBOLS 1 Stencil printing apparatus 10 Image reading part 20 Paper feed part 30 1st plate making part 31 Thermal head 35 2nd plate making part 36 Thermal head 40 1st printing part 41 1st printing drum 42 1st press roller 46 Middle Stock unit 47 Pickup roller 48 Timing roller 50 Second printing unit 51 Second printing drum 52 Second press roller 60 Image data generation unit 61 Image data reception unit 62 Area division unit 63 Specific range information reception unit 64 Specific division region Acquisition unit 65 Density conversion processing unit 66 Binary processing unit 70 Paper discharge unit

Claims (7)

While accepting input of image data, accepting information of a specific range on the image data set in advance,
Dividing the received image data into a plurality of regions based on attributes of the image data;
Obtaining a divided region including a range that overlaps the specific range from the divided regions;
A method of generating image data, characterized in that density conversion processing is performed to reduce the density of image data in a divided area in units of the obtained divided areas to generate processed image data. The image data records a first image on one side of a recording medium, and after the one-side recorded recording medium on which the first image is recorded is conveyed by a predetermined conveying mechanism, Image data representing the first image used when recording a second image on a surface;
2. The image data generation method according to claim 1, wherein the information on the specific range is information indicating a range on the image data corresponding to a range where the transport mechanism and the recording medium are in contact with each other. An image data receiving unit for receiving input of image data;
A specific range information receiving unit for receiving information on a specific range on the image data set in advance;
An area dividing unit that divides image data received by the image data receiving unit into a plurality of areas based on attributes of the image data;
A specific divided region acquisition unit that acquires a divided region including a range that overlaps the specific range from the regions divided by the region dividing unit;
A density conversion processing unit is provided that performs density conversion processing on the image data in the divided region obtained by the specific divided region acquisition unit so as to reduce the density and generates processed image data. An image data generation apparatus characterized by the above. The image data receiving unit records a first image on one side of the recording medium, and conveys the one-side recorded recording medium on which the first image is recorded by a predetermined conveying mechanism. Receiving the image data representing the first image used when recording the second image on the other surface as the image data;
The specific range information receiving unit receives information indicating a range on the image data corresponding to a range in which the transport mechanism and the recording medium are in contact as information on the specific range. 3. The image data generation device according to 3. The image data receiving unit receives the image data output from a computer;
5. The image data generation according to claim 3, wherein the area dividing unit divides the image data into a plurality of areas based on object attribute information added to the image data by the computer. apparatus. The image data receiving unit receives the image data output from an image reading unit that reads a document image and outputs image data representing the document image;
The region dividing unit recognizes an attribute of the image data based on the image data received by the image data receiving unit, and divides the image data into a plurality of regions based on the recognized attribute. The image data generation apparatus according to claim 3 or 4, An image data generation device according to claim 4,
A printing unit that records the first image on one surface of the recording medium based on the processed image data generated in the image data generation device;
A printing apparatus comprising: a conveyance mechanism that conveys a single-side recorded recording medium on which the first image is recorded by the printing unit.

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