Image formation system and cutting position adjustment method in image formation system

Abstract

To provide an image formation system that enables more easy and correct adjustment of a cutting position.SOLUTION: An image formation system 1 includes: an image formation unit 14; a cutting unit 22 that cuts a sheet with an image formed thereon by the image formation unit 14; and an adjustment unit 16 that performs adjustment processing on the cutting unit 22. The adjustment unit 16 calculates an amount of positional shift from a planned cutting position of a cutting execution position at which cutting was actually performed on the sheet on the basis of a first read image T1 of the sheet before cutting and a second read image T2 of the sheet after cutting.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to an image forming system and a cutting position adjusting method in an image forming system. [Background technology]

[0002] Conventionally, there has been known an image forming system that includes an image forming device that forms an image on paper and a cutting device that performs a cutting process on the paper on which the image has been formed by the image forming device. Such an image forming system cuts the paper inline, thereby reducing the user's workload and contributing to reducing the production costs of printed materials. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-118316 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the cutting device used in this type of image forming system cuts the paper while transporting it using roller transport or the like, which poses a problem that the actual cutting position may deviate from the cutting position set in the cutting unit.

[0005] This is because the transport amount and transport speed of paper by roller transport etc. vary slightly depending on the paper size, paper type, basis weight (thickness), etc. In particular, the change in the transport amount and transport speed of paper is greatly affected by changes in paper size, and when the paper becomes smaller during cutting, this becomes more noticeable because the number of rollers in contact with the paper changes.

[0006] For this reason, in this type of image forming system, after setting the cutting position in the cutting unit, a process is performed in which fine adjustments are made to the cutting position according to the paper size of the printing target before the actual production of printed matter is carried out. Such fine adjustments, for example, involve adding shift correction and / or tilt correction to each cutting position calculated from the cutting profile that sets the cutting position. Note that such fine adjustments are set as "cutting adjustment values," and fine adjustments are made to the cutting profile during the actual production based on these "cutting adjustment values."

[0007] In light of this, a conventional technique has been developed in which an adjustment chart is printed on a test sheet according to a cutting profile before production begins, and the test sheet is then subjected to actual cutting processing and output. The adjustment chart refers to various images that are pre-printed on the test sheet in order to set cutting adjustment values. For example, an image showing the planned cutting position is printed as an adjustment chart. See, for example, Patent Document 1.

[0008] However, the adjustment method described in Patent Document 1 requires the user to visually check the amount of misalignment of the cutting position from the printed material after cutting, which is difficult and cumbersome in practice. In particular, quantitatively and accurately detecting the amount of misalignment of the cutting position is essential for properly cutting paper, but methods that rely on the user's visual inspection require skill and can lack accuracy. In addition, because the misalignment conditions vary depending on the paper used and job content of the job to be executed, each cutting position must be adjusted in advance for each job, which places a heavy burden on the user's workload.

[0009] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide an image forming system that enables easier and more accurate adjustment of the cutting position, and a method for adjusting the cutting position in an image forming system. [Means for solving the problem]

[0010] The present disclosure mainly solves the above-mentioned problems by: an image forming unit, a cutting unit that cuts paper on which an image has been formed by the image forming unit, and an adjustment unit that performs adjustment processing on the cutting unit; The adjustment unit calculates a positional deviation amount of a cutting execution position actually performed on the paper from a planned cutting position based on a first read image of the paper before cutting and a second read image of the paper after cutting. An image forming system.

[0011] In other respects, 1. A cutting position adjustment method for an image forming system including an image forming unit and a cutting unit that cuts paper on which an image is formed by the image forming unit, A process of acquiring a first scanned image of the paper before cutting; A process of acquiring a second scanned image of the paper after cutting; A process of calculating a positional deviation amount of a cutting execution position actually performed on the paper from a planned cutting position based on the first read image and the second read image; This is a cutting position adjustment method that executes the above. [Effects of the Invention]

[0012] According to the image forming system according to the present disclosure, it is possible to adjust the cutting position more easily and accurately. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram illustrating an example of the overall configuration of an image forming system. [Figure 2] FIG. 1 is a diagram illustrating an example of the overall configuration of an image forming system. [Figure 3] FIG. 10 is a diagram showing an example of a cutting setting screen. [Figure 4] A diagram showing an example of the cutting mode for "10 sheets (business card size)" [Figure 5] An example of a cutting profile for "10 sheets (business card size)" [Figure 6] A diagram showing an example of the planned cutting position for "10 sheets cut (business card size)" [Figure 7]An example of the trimming adjustment value for "10 sheets trimmed (business card size)" [Figure 8] 10 is a flowchart showing an example of the operation of the control unit. [Figure 9] FIG. 10 is a diagram showing an example of a first scanned image (a scanned image of the test paper before cutting); [Figure 10] FIG. 10 is a diagram showing an example of a second read image (a read image of the test paper after cutting); [Figure 11] FIG. 10 is a diagram illustrating an example of an adjustment chart image formed on a test sheet. [Figure 12] FIG. 10 is a diagram illustrating a process for specifying a planned cutting position. [Figure 13] FIG. 10 is a diagram illustrating a process for specifying a cutting execution position. [Figure 14] FIG. 10 is a diagram illustrating a process for specifying a cutting execution position. [Figure 15] FIG. 10 is a diagram illustrating a calculation process for the amount of misalignment of the cutting position. [Figure 16A] FIG. 10 is a diagram illustrating a calculation process for the amount of misalignment of the cutting position. [Figure 16B] FIG. 10 is a diagram illustrating a calculation process for the amount of misalignment of the cutting position. [Figure 17] FIG. 10 is a diagram showing an example of the configuration of an image forming system according to Modification 1. [Figure 18] FIG. 10 is a diagram showing an example of the configuration of an image forming system according to Modification 2. [Figure 19] FIG. 10 is a diagram showing a process for specifying a planned cutting position in an image forming system according to a third modification; [Figure 20] FIG. 10 is a diagram showing a cutting execution position specifying process in an image forming system according to a fourth modification; DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0015] <Configuration of Image Forming System 1> An image forming system according to one embodiment of the present invention (hereinafter referred to as "image forming system 1") will be described below.

[0016] 1 and 2 are diagrams showing an example of the overall configuration of an image forming system 1. FIG.

[0017] The image forming system 1 is configured to include an image forming apparatus 10 and a cutting apparatus 20 as a post-processing apparatus.

[0018] The image forming apparatus 10 forms a color image by electrophotography based on image data obtained by reading an image from a document or image data received from an external device.

[0019] The image forming device 10 is configured to include an operation unit 11, a display unit 12, a document reading unit 13, an image forming unit 14, a paper feeding unit 15, a control unit 16, a memory unit 17, an interface unit 18, and an image processing unit 19.

[0020] The operation unit 11 includes, for example, a touch panel and various operation buttons, and outputs an operation signal to the control unit 16 based on an operation by a user.

[0021] The display unit 12 is configured by, for example, an LCD, and displays various screens in accordance with instructions of a display signal input from the control unit 16.

[0022] The document reading unit 13 includes, for example, an ADF (automatic document feeder), a scanner, and the like, and outputs image data obtained by reading an image of a document to the control unit 16.

[0023] Image forming unit 14 forms an image on paper supplied from paper feed unit 15 based on image data that has been image processed by image processing unit 19. Image forming unit 14 is configured to include photosensitive drums 141Y, 141M, 141C, and 141K corresponding to the colors yellow (Y), magenta (M), cyan (C), and black (K), an intermediate transfer belt 142, a secondary transfer roller 143, a fixing unit 144, and the like.

[0024] After being uniformly charged, the photoconductor drum 141Y is scanned and exposed by a laser beam based on yellow image data, forming an electrostatic latent image. Yellow toner is then attached to the electrostatic latent image on the photoconductor drum 141Y, and development is performed. Photoconductor drums 141M, 141C, and 141K are similar to photoconductor drum 141Y except for the colors they handle, and therefore will not be described here.

[0025] The toner images of each color formed on the photosensitive drums 141Y, 141M, 141C, and 141K are transferred one after another (primary transfer) onto the rotating intermediate transfer belt 142. That is, a color toner image in which the toner images of four colors are superimposed is formed on the intermediate transfer belt 142. The color toner images on the intermediate transfer belt 142 are transferred all at once onto a sheet of paper by the secondary transfer roller 143 (secondary transfer).

[0026] The fixing unit 144 includes a heating roller that heats the paper onto which the color toner image has been transferred, and a pressure roller that pressurizes the paper, and fixes the color toner image to the paper by applying heat and pressure.

[0027] The paper feed unit 15 includes paper feed trays TT1 to TT3, and supplies paper to the image forming unit 14. Each of the paper feed trays TT1 to TT3 stores various types of paper with different paper types and sizes.

[0028] The control unit 16 is configured with, for example, a CPU, a ROM, and a RAM. The CPU reads various processing programs stored in the ROM and performs centralized control of the operations of each unit of the image forming apparatus 10 in accordance with the programs. The ROM is configured with non-volatile semiconductor memory or the like and stores various processing programs, parameters and files required to execute the programs, etc. The RAM temporarily stores various data such as programs and image data related to various image processing.

[0029] The control unit 16 also controls the cutting operation of the cutting device 20, and adjusts the cutting unit 22 based on the results of reading the paper by the first and second reading units 24a and 24b (details will be described later). The control unit 16 functions as the "adjustment unit" of the present invention.

[0030] The storage unit 17 is a non-volatile storage device such as a hard disk drive (HDD) or semiconductor memory that stores various data such as programs and image data. The storage unit 17 stores data such as program data and various setting data in a manner that allows the control unit 16 to read and write data.

[0031] The storage unit 17 also stores various control parameters for controlling the cutting operation of the cutting device 20 (for example, cutting profiles for each cutting type).

[0032] The interface unit 18 receives image data input from an external device.

[0033] The image processing unit 19 performs the necessary image processing on the image data obtained by reading an image from a document using the document reading unit 13 and on image data input from an external device, and sends the processed image data to the image forming unit 14. Image processing includes gradation processing, halftone processing, color conversion processing, etc. Gradation processing is a process of converting the gradation values ​​of each pixel of the image data into corrected gradation values ​​so that the density characteristics of the image formed on the paper match the target density characteristics. Halftone processing includes error diffusion processing and screen processing using an ordered dithering method. Color conversion processing is a process of converting each RGB gradation value into each CMYK gradation value.

[0034] The paper (i.e., the printed matter) on which an image has been formed by the image forming device 10 is transported to a cutting device 20 arranged as a post-processing device (FNS), where the paper is cut and then discharged outside the machine.

[0035] <Configuration of cutting device 20> The cutting device 20 is a device that performs cutting processing as needed on the paper output from the image forming device 10. Note that cutting processing is not essential, and the cutting device 20 performs cutting processing only when instructed to do so by the control unit 16. If cutting processing is not performed, the cutting device 20 simply ejects the paper output from the image forming device 10.

[0036] The cutting device 20 includes a conveying unit 21, a cutting unit 22, a paper discharge unit 23, a first reading unit 24a, and a second reading unit 24b. The operations of these components are controlled under the control of the control unit 16.

[0037] Conveying unit 21 receives, from image forming device 10, paper sheets on which an image has been formed by image forming device 10, and conveys the paper sheets through cutting device 20. Conveying unit 21 has, for example, conveying rollers provided at predetermined intervals, and the paper sheets are conveyed from the upstream side to the downstream side while being pressed from above and below by the conveying rollers. The conveying rollers are arranged, for example, in positions that do not overlap with cutting unit 22 and first and second reading units 24a, 24b in a plan view.

[0038] The conveying section 21 conveys the paper conveyed from the image forming apparatus 10 so that the paper passes through the positions of the first reading section 24a, the cutting section 22, the second reading section 24b, and the paper discharge section 23 in this order from the upstream side.

[0039] The cutting section 22 performs cutting processing on the transported paper using multiple functional units. The cutting section 22 has multiple (four in this case) slots SL1 to SL4 for loading the functional units. In this embodiment, a unit for top and bottom slitting is loaded into the slot SL1, which is the most upstream in the transport direction. Furthermore, units for gutter cutting and slitting are loaded into slots SL2 and SL3. Furthermore, a unit for CD cutting is loaded into the most downstream slot SL4. Multiple cuts are performed by the above combinations.

[0040] In some cases, cutting by the cutting unit 22 involves performing multiple cutting processes on the same sheet of paper along the conveying direction to create multiple small pieces of printed matter (for example, business cards). In this case, the cutting unit 22 executes each cutting process in sequence, for example, using the leading edge of the sheet before cutting as a reference and the amount of movement by the conveying unit 21 as a reference. The multiple cuts are then executed by repeating, for example, "conveying paper," "stopping paper," "cutting," "re-conveying paper," "stopping paper," "cutting," and so on.

[0041] The paper discharge section 23 is disposed at the final stage of the cutting device 20 and discharges the paper conveyed from the conveyance section 21 to the outside of the machine.

[0042] The first reading unit 24a is configured to include, for example, an image sensor, an optical system, a light source, and the like. The first reading unit 24a, for example, photographs the top side of the paper being transported by the transport unit 21. The first reading unit 24a is arranged in a line along the width direction of the paper. For example, the first reading unit 24a photographs the paper at each position while the paper is being transported from the upstream side to the downstream side, thereby photographing the entire paper. Then, the images photographed by the first reading unit 24a at each position are superimposed to generate a read image of the entire paper.

[0043] The first reading unit 24a has a length that exceeds the width of the paper and is capable of detecting the outline of the paper. A black background plate is provided opposite the first reading unit 24a to make it easier to extract the paper area from the scanned image.

[0044] The second reading unit 24b has the same configuration as the first reading unit 24a, except for the position where it is disposed.

[0045] Here, the first reading unit 24a is disposed before the cutting unit 22, reads the paper before it is cut by the cutting unit 22, and outputs the obtained read image to the control unit 16. The second reading unit 24b is disposed after the cutting unit 22, reads the paper after it has been cut by the cutting unit 22, and outputs the obtained read image to the control unit 16.

[0046] Hereinafter, the read image obtained by the first reading unit 24a will also be referred to as a "first read image T1." Also, the read image obtained by the second reading unit 24b will also be referred to as a "second read image T2."

[0047] It is preferable that the first and second reading units 24a and 24b have been subjected to a calibration process in advance. In this calibration process, the control unit 16, for example, prints a calibration image on sample paper using the image forming device 10 and transports the sample paper to the cutting device 20. The control unit 16 then calculates the length of the sample paper from the image read by the first reading unit 24a. The user also measures the length of the output sample paper. The control unit 16 then compares the calculated length of the sample paper with the actually measured length of the output sample paper and adjusts the magnification of the first reading unit 24a. The control unit 16 then performs the same process on the second reading unit 24b.

[0048] In this embodiment, each position in the first scanned image T1 and the second scanned image T2 is represented by a mutually orthogonal XY coordinate system. Here, the direction in which the paper P is transported (upward on the paper surface) is represented as the +X direction, and the right side of the paper surface in the width direction of the paper P is represented as the +Y direction.

[0049] <Basic control of cutting operation> In the cutting control according to this embodiment, in order to eliminate the need for adjustment by the user, adjustment values ​​for the shift direction (width direction or conveyance direction) and tilt angle for each cutting position can be automatically set. Such control is performed under the control of the control unit 16.

[0050] FIG. 3 is a diagram showing an example of the cutting setting screen U10.

[0051] The cutting setting screen U10 is displayed on the display unit 12, for example, when the user sets the job content to execute cutting processing as post-processing.

[0052] The cutting setting screen U10 displays, for example, a "cutting setting input section" U11, an "adjustment value change button" U12, and an "adjustment value automatic setting button" U13.

[0053] The "cutting setting input section" U11 is a user interface (e.g., a select box) that is operated by the user when selecting the type of cutting process. The user can select and input the cutting process to be adjusted by performing a predetermined operation on the "cutting setting input section" U11 using the operation section 11. Here, it is assumed that the cutting profile for each cutting type (e.g., cutting method, cutting position, paper size, etc.) is registered in advance in the storage section 17.

[0054] The "Change Adjustment Value Button" U12 and the "Automatic Adjustment Value Setting Button" U13 are operation buttons for setting a cutting adjustment value for each cutting position calculated from the cutting profile. As described above, the cutting adjustment value is an adjustment value for eliminating positional deviation between the cutting execution position when cutting processing is actually performed by the cutting unit 22 and the planned cutting position set from the cutting profile.

[0055] The "Change Adjustment Value Button" U12 is a user interface for manually setting cutting adjustment values ​​by the user. When the "Change Adjustment Value Button" U12 is pressed, a cutting adjustment value correction screen (not shown) is displayed, allowing the user to manually set cutting adjustment values ​​for each cutting position calculated from the cutting profile.

[0056] The "Automatic Adjustment Value Setting Button" U13 is a user interface for automatically setting the cutting adjustment values. When the "Automatic Adjustment Value Setting Button" U13 is pressed, the control unit 16 causes the image forming device 10 to output a test sheet on which an adjustment chart is drawn. The control unit 16 then causes the cutting device 20 to cut the test sheet under the same conditions (i.e., the same cutting profile) as those used during production. The control unit 16 then calculates the amount of positional deviation from the planned cutting position of the actual cutting performed on the test sheet based on the first scanned image T1 and the second scanned image T2 obtained at this time (details will be described later with reference to FIG. 8, etc.). The control unit 16 then automatically sets the cutting adjustment values ​​based on this amount of positional deviation.

[0057] In this embodiment, as an example, a mode in which "10 sheets cut (business card size)" is selected is shown.

[0058] FIG. 4 is a diagram showing an example of the cutting mode for "10-sheet cutting (business card size)." FIG. 5 is a diagram showing an example of the cutting profile for "10-sheet cutting (business card size)." FIG. 6 is a diagram showing an example of the planned cutting position for "10-sheet cutting (business card size)." FIG. 7 is a diagram showing an example of the cutting adjustment value for "10-sheet cutting (business card size)."

[0059] Figure 4 shows ten "business card" images formed on one sheet of paper L1. Shaded areas L10 represent each "business card" area. White areas L11 represent margin areas and stub areas. Dotted lines L12 represent the planned cutting positions.

[0060] For example, in the "Cut 10 sheets (business card size)" setting, paper measuring 210mm x 297mm (representing transport direction size x width direction size; the same applies below) is used. After printing, this paper is divided into 10 pieces, and 10 business cards measuring 55mm x 91mm each are created. In this case, the paper type is set to a specified business card sheet. This information is set in the cutting profile (see Figure 5).

[0061] In this "10-sheet cutting (business card size)" setting, the left margin is set to 10 mm, the edge trim width is set to 8 mm, and the right margin is set to 10 mm along the width direction. Also, the leading edge margin is set to 11 mm, the edge trim width is set to 0 mm, and the trailing edge margin is set to 11 mm along the conveyance direction.

[0062] Before cutting, the control unit 16 creates planned cutting position data in accordance with this cutting profile. The planned cutting position data in Fig. 6 indicates that the paper will be cut at four locations in the conveyance direction and six locations in the width direction.

[0063] Furthermore, in the cutting control according to this embodiment, adjustment values ​​for the shift direction (width direction or conveyance direction) and tilt angle can be set for each planned cutting position. Fig. 7 shows cutting adjustment value data that is set in association with the planned cutting position data of Fig. 6. As explained in Fig. 3, this cutting adjustment value data can be set manually by the user, or can be set using an automatic setting function. Note that this embodiment will mainly describe an aspect in which cutting adjustment value data is created using the automatic setting function.

[0064] In the following, the paper before cutting will also be referred to as the "original print" or "original paper." Furthermore, the paper after cutting (i.e., each "business card") will also be referred to as the "small piece of print" or "small piece of paper."

[0065] [Operation flow when automatically setting adjustment values ​​of the control unit 16] 8 to 16, an example of the operation flow when the control unit 16 automatically sets the adjustment values ​​will be described. Here, the operation flow of the control unit 16 automatically sets the adjustment values ​​when "10 sheets cutting (business card size)" is selected will be described.

[0066] FIG. 8 is a flowchart showing an example of the operation of the control unit 16.

[0067] 8 is executed, for example, when the "Automatic Adjustment Value Setting Button" U13 is pressed on the cutting setting screen U10. When the "Automatic Adjustment Value Setting Button" U13 is pressed, the control unit 16 first instructs the image forming device 10 to take out a test sheet and form an image of an adjustment chart on the test sheet. That is, the test sheet on which the adjustment chart is printed is transported to the cutting device 20.

[0068] The test paper used in this adjustment value setting flow is typically of the same type, size, and basis weight as the paper used in actual production. The test paper may be taken out of the paper feed trays TT1 to TT3 by the image forming apparatus 10, or may be placed in a manual feed tray (not shown) by the user.

[0069] In step S1, the control unit 16 causes the first reading unit 24a, which is disposed before the cutting device 20, to read the test paper before cutting.

[0070] Fig. 9 is a diagram showing an example of a first scanned image T1 (a scanned image of the test paper before cutting). In Fig. 9, the shaded areas T10 represent individual "business card" areas. The white areas T11 represent blank areas and blemish areas. The black areas T12 represent background areas.

[0071] In step S2, the control unit 16 causes the second reading unit 24b, which is disposed after the cutting device 20, to capture an image of the test paper after cutting.

[0072] FIG. 10 is a diagram showing an example of the second scanned image T2 (scanned image of the test paper after cutting). In FIG. 10, the shaded area T20 represents each "business card" area. Furthermore, the black area T21 represents the margin area, the trimming margin, and the weed trimming area. In FIG. 10, the period during which conveyance is stopped for cutting is represented by the black area T21. The right diagram of FIG. 10 shows the original area corresponding to the black area T21 in the left diagram of FIG. 10. The area T21a shown in the right diagram of FIG. 10 represents the trimming margin. The area T21b shown in the right diagram of FIG. 10 represents the period during which conveyance is stopped for cutting.

[0073] Fig. 11 is a diagram showing an example of an adjustment chart whose image is formed on a test sheet. In this embodiment, as shown in Fig. 11, an identification information image m1 (such as "1", "2", etc.) indicating the image formation position is drawn at the center of each shaded area T20 (image formation area). In addition, marks are drawn at the four corners of each shaded area T20 (image formation area) as index images m2 for alignment.

[0074] In step S3, the control unit 16 extracts the paper region of the test paper from the first scanned image T1. In this step S3, the control unit 16 performs threshold processing based on pixel values ​​on the first scanned image T1, for example, to separate the paper region and the background region from the first scanned image T1.

[0075] In step S4, the control unit 16 identifies a planned cutting position for the test paper in the first scanned image T1 based on a preset cutting profile.

[0076] Fig. 12 is a diagram illustrating the process of identifying the planned cutting position. Note that the left diagram in Fig. 12 shows the planned cutting position d1 identified in accordance with the cutting profile in Fig. 5. The right diagram also shows a method for calculating the inclination θ of the test paper when the test paper is inclined.

[0077] In step S4, the control unit 16 first specifies a reference point in the paper area on the first scanned image T1. Here, the control unit 16 sets the upper left corner of the paper area extracted from the first scanned image T1 as the reference point. Then, the control unit 16 sets this reference point as the origin and aligns it with the planned cutting position calculated from the cutting profile (see FIG. 6), thereby specifying the planned cutting position on the first scanned image T1.

[0078] Here, the control unit 16 determines the planned cutting position based on the distance from the reference point, so even if the paper shrinks due to loss of moisture after passing through the fixing unit, the planned cutting position is prevented from shifting significantly.

[0079] In step S4, the control unit 16 preferably determines the inclination of the test paper based on the paper area of ​​the test paper identified in the first scanned image T1, and corrects the coordinate system of the paper area of ​​the test paper in the first scanned image T1 based on the determined inclination. This is because the paper may become inclined during transportation. The inclination of the paper can be calculated, for example, from the inclination of the direction in which the upper edge of the paper area extends relative to the Y axis. Note that the control unit 16 may use an index image m2 formed on the test paper when determining the inclination of the test paper.

[0080] In step S4, the control unit 16 preferably calculates the magnification of the test paper based on the paper area of ​​the test paper identified in the first scanned image T1 and corrects the coordinate system of the paper area of ​​the test paper in the first scanned image T1 based on the magnification. This is because the paper transport speed may differ from the reference speed used by the cutting profile. In this case, the magnification of the paper image changes along the transport direction. This is because, for example, when the paper is transported at a slow speed, the paper appears elongated in the scanned image compared to when the paper is transported at a high speed. Therefore, the control unit 16 may, for example, compare the length of the paper area along the X axis with a reference length to calculate the magnification, and correct the coordinate system of the paper area of ​​the test paper in the first scanned image T1 based on the magnification.

[0081] In step S5, the control unit 16 extracts, from the second scanned image T2, the paper area of ​​each of the plurality of small paper pieces created by cutting the test paper, and extracts the outline of each of the plurality of small paper pieces.

[0082] In step S5, the control unit 16 extracts the paper regions of the plurality of small paper pieces by, for example, performing threshold processing based on pixel values ​​on the second scanned image T2 to separate the paper region from the background region from the second scanned image T2. Note that at this time, the control unit 16 may assign an identification number to each of the plurality of small paper pieces based on the number and / or position of the small paper pieces after cutting indicated by the cutting profile, and recognize each of the plurality of small paper pieces individually.

[0083] In step S6, the control unit 16 aligns the outlines of the multiple small pieces of paper with the original test paper on the first scanned image T1, and identifies cutting positions for the test paper. Note that the "cutting positions" refer to positions where cutting is actually performed (the same applies below).

[0084] 13 and 14 are diagrams for explaining the process of specifying the cutting execution position.

[0085] In step S6, the control unit 16 aligns the paper areas of the plurality of small paper pieces in order from top to bottom, for example, starting from a reference point on the first scanned image T1. Note that in step S6, from the viewpoint of simplifying the alignment process, it is preferable that the control unit 16 approximate each side of the outline of each of the plurality of small paper pieces with a straight line, as shown in FIG.

[0086] In step S6, if each of the plurality of small paper pieces has an index image m2 for alignment, as in this embodiment, the control unit 16 may perform alignment using the index image m2. In this case, the control unit 16 can align the index images m2 formed on each of the plurality of small paper pieces with the index image m2 formed on the original paper, for example, by using template matching or the like.

[0087] Furthermore, in step S6, the control unit 16 may determine the reference point and inclination of each small piece of paper in the second scanned image T2, and align each small piece of paper with the original paper using the reference point and inclination as reference coordinates. At this time, the control unit 16 may also determine the imaging magnification of each small piece of paper in the second scanned image T2, and correct the coordinate system of the paper area of ​​each small piece of paper using the imaging magnification as a reference. Note that the control unit 16 can determine the reference point, inclination, and imaging magnification of each small piece of paper, for example, using the paper area of ​​each of the multiple small pieces of paper or index image m2 in the second scanned image T2.

[0088] In step S7, the control unit 16 calculates the amount of positional deviation between the planned cutting position and the actual cutting position for the test paper in the first scanned image T1.

[0089] In step S8, the control unit 16 sets cutting adjustment values ​​(shift adjustment value and tilt adjustment value) based on the amount of positional deviation between the planned cutting position and the cutting execution position calculated in step S7.

[0090] 15, 16A, and 16B are diagrams for explaining the calculation process of the amount of misalignment of the cutting position. In FIG. 15, dotted line d1 represents the planned cutting position, and dashed line d2 represents the cutting execution position. Also, Δd represents the amount of misalignment.

[0091] Steps S4 and S6 identify the planned cutting position and the actual cutting position in the first scanned image T1. Therefore, the control unit 16 can calculate the amount of positional deviation by comparing the planned cutting position and the actual cutting position in the first scanned image T1.

[0092] In step S7, the control unit 16 calculates, for example, the amount of misalignment between the planned cutting position and the actual cutting position in the first read image T1 at both ends of each of the plurality of small paper pieces in the Y-axis direction.

[0093] Here, if the amount of misalignment at both ends of the small piece of paper is the same (FIG. 16A), the cutting misalignment is only a shift. Therefore, in this case, the control unit 16 sets the calculated amount of misalignment as the shift adjustment value as is.

[0094] On the other hand, if the misalignment amounts at both ends of the small piece of paper are different (FIG. 16B), this indicates that the paper will be skewed during cutting, and the cutting misalignment is both a shift and a skew. Therefore, in this case, the control unit 16 calculates the skew from the difference in the misalignment amounts at both ends of the small piece of paper and sets this as the skew adjustment value. Then, the control unit 16 sets the misalignment amount excluding the difference in the misalignment amounts at both ends of the small piece of paper as the shift adjustment value.

[0095] Furthermore, since the positional deviation amount calculated in step S7 is calculated in the coordinate system of the first read image T1, the control unit 16 may convert the positional deviation amount calculated in the coordinate system of the first read image T1 into an actual value in the real space coordinate system.

[0096] Through the above-described series of processes, the control unit 16 can automatically set the trimming adjustment values ​​for the shift direction (width direction or conveyance direction) and tilt angle for each trimming position.

[0097] In the above adjustment value setting process, an adjustment chart is formed as an image on the test paper, and then each process is performed. However, in the process of identifying the planned cutting position from the test paper and the process of identifying the cutting execution position, the control unit 16 does not necessarily need to use the adjustment chart (i.e., index images m1 and m2). Therefore, the control unit 16 may perform the adjustment value setting process without the adjustment chart.

[0098] In the above adjustment value setting process, the control unit 16 automatically sets the calculated shift adjustment value and skew adjustment value for each cutting position. However, the control unit 16 may simply calculate the amount of misalignment for each shift direction and skew angle and present it to the user. In other words, the user may set the shift adjustment value and skew adjustment value based on the amount of misalignment for each shift direction and skew angle.

[0099] [effect] As described above, the image forming system 1 according to this embodiment: an image forming unit, a cutting unit that cuts paper on which an image has been formed by the image forming unit, and an adjustment unit that performs adjustment processing on the cutting unit; The adjustment unit calculates the amount of positional deviation of the cutting position actually performed on the paper from the intended cutting position based on a first read image of the paper before cutting and a second read image of the paper after cutting.

[0100] The image forming system 1 according to this embodiment can automatically calculate the amount of deviation of the actual cutting position performed on the paper from the planned cutting position without any effort on the part of the user. This makes it possible to easily and accurately adjust the cutting position before starting the actual production of printed matter.

[0101] In other words, this makes it possible to carry out the cutting process appropriately even when using paper of various different types, sizes or basis weights, or when changing the cutting mode of the printed material in various ways.

[0102] <Variation 1> 17 is a diagram showing an example of the configuration of an image forming system 1 according to Modification 1. The image forming system 1 according to this modification differs from the above embodiment in that a reading unit 24c that photographs paper is provided only after the cutting device 20. The reading unit 24c has the same configuration as the second reading unit 24b described above.

[0103] In some existing image forming systems, the reading unit 24c is provided only after the cutting device 20. The image forming system 1 according to this modified example is able to accommodate such situations.

[0104] In the image forming system 1 according to this modification, the basic flow when the control unit 16 performs the cutting position adjustment process is as shown in FIG.

[0105] However, in the image forming system 1 according to this modification, the control unit 16 outputs the test paper with the setting of not cutting it and reads it with the reading unit 24c in step S1. Thereafter, in step S2, the control unit 16 outputs the same type of test paper with the setting of cutting it and reads it with the reading unit 24c.

[0106] The control unit 16 then treats the scanned image of the test paper output with the setting of not cutting as the scanned image of the test paper before cutting (i.e., the first scanned image T1). The control unit 16 also treats the scanned image of the test paper output with the setting of cutting as the scanned image of the test paper after cutting (i.e., the second scanned image T2). This allows the control unit 16 to perform the cutting position adjustment process, similar to the above embodiment.

[0107] As described above, according to the image forming system 1 of this modified example, even if the reading unit 24c is provided only downstream of the cutting device 20, it is possible to automatically set the cutting adjustment value.

[0108] <Variation 2> 18 is a diagram showing an example of the configuration of an image forming system according to Modification 2. The image forming system according to this modification does not have a reading unit inline with the cutting device 20, and differs from the above embodiment in that the test paper is photographed by a camera of the external terminal DD.

[0109] In some existing image forming systems, the reading unit is not provided in the cutting device 20. The image forming system 1 according to this modified example can accommodate such situations.

[0110] In the image forming system 1 according to this modification, the basic flow when the control unit 16 performs the cutting position adjustment process is as shown in FIG.

[0111] However, in the image forming system 1 according to this modified example, in step S1, the control unit 16 outputs a test paper with a setting that does not require cutting, and after the test paper is ejected from the cutting device 20, the control unit 16 reads the test paper with the camera of the external terminal DD. Thereafter, in step S2, the control unit 16 outputs the same type of test paper with a setting that requires cutting, and after the test paper is ejected from the cutting device 20, the control unit 16 reads the test paper with the camera of the external terminal DD.

[0112] The control unit 16 then treats the scanned image of the test paper output with the setting of not cutting as the scanned image of the test paper before cutting (i.e., the first scanned image T1). The control unit 16 also treats the scanned image of the test paper output with the setting of cutting as the scanned image of the test paper after cutting (i.e., the second scanned image T2). This allows the control unit 16 to perform the cutting position adjustment process, similar to the above embodiment.

[0113] As described above, according to the image forming system 1 of this modified example, even when the reading unit is not provided in the cutting device 20, it is possible to automatically set the cutting adjustment value.

[0114] <Variation 3> The image forming system 1 according to this modification differs from the process for specifying the planned cutting position according to the above embodiment in that an index image m3 printed on the test paper as an adjustment chart is used to specify the planned cutting position for the test paper. The index image m3 is, for example, an image formed on the test paper as a mark indicating the planned cutting position based on the cutting profile.

[0115] 19 is a diagram showing the process of specifying the planned cutting position in the image forming system 1 according to Modification 3. In FIG. 19, the index image m3 is formed as a linear mark in the cutting margin area of ​​the test sheet.

[0116] In the image forming system 1 according to this modified example, the basic flow when the control unit 16 performs the cutting position adjustment process is as shown in FIG.

[0117] However, in step S4 of Fig. 8, the control unit 16 identifies the position of the index image m3 in the first scanned image T1 by, for example, pattern recognition. Then, the control unit 16 obtains data on the planned cutting position along the conveying direction by, for example, connecting the index images m3 formed on both ends of the test paper in the conveying direction as shown in Fig. 19. Also, the control unit 16 obtains data on the planned cutting position along the width direction by, for example, connecting the index images m3 formed on both ends of the test paper in the width direction as shown in Fig. 19.

[0118] The control unit 16 can also specify the planned cutting position by the above-mentioned method.

[0119] The process for specifying the planned cutting position according to this modified example makes it possible to specify the planned cutting position with fewer calculations than the process for specifying the planned cutting position according to the above embodiment. However, paper may shrink due to loss of moisture after passing through the fixing unit 144 of the image forming apparatus 10. In such cases, the printed image also shrinks, and the trimming size changes accordingly. Therefore, the method described in the above embodiment is useful for more accurately specifying the planned cutting position.

[0120] <Variation 4> The image forming system 1 according to this modification differs from the embodiment described above in the method by which the control unit 16 calculates the cutting execution position.

[0121] FIG. 20 is a diagram showing a process for specifying a cutting execution position in the image forming system 1 according to the fourth modification.

[0122] In the image forming system 1 according to this modification, the basic flow when the control unit 16 performs the cutting position adjustment process is as shown in FIG.

[0123] However, in step S6 of Figure 8, the control unit 16 identifies the cutting execution position for the test paper by the following process. For example, the control unit 16 extracts the paper area of ​​each of the multiple small-piece papers from the second scanned image T2, and then determines the coordinates of the four vertices of the small-piece paper from the paper area of ​​the small-piece paper. The control unit 16 then considers the rectangle connecting the coordinates of the four vertices of the small-piece paper to be the outline of the small-piece paper. The control unit 16 then aligns each of the multiple small-piece papers with the original paper based on the outline of the small-piece paper.

[0124] The cutting position determination process according to this modification can determine the cutting position with fewer calculations than the cutting position determination process according to the above embodiment. However, the method described in the above embodiment is useful for determining the cutting position more accurately.

[0125] <Variation 5> In the image forming system 1 according to the above embodiment, the cutting position adjustment process is performed using a test sheet on which an adjustment chart is printed.

[0126] The outer shape of the paper may change depending on the content to be printed (i.e., the printing rate). From this perspective, when performing the cutting position adjustment process in the image forming system 1, the image printed on the test paper may be an actual image printed in production, rather than an adjustment chart.

[0127] However, some actual images have a full-bleed (i.e., borderless) design. In this case, if the background of the reading areas of the first and second reading units 24a and 24b is a black background, it may be difficult to separate the paper from the background in the first read image T1 and the second read image T2. From this perspective, when an actual image is used as the image to be printed on the test paper, it is preferable to provide a mechanism that can switch the background of the reading areas of the first and second reading units 24a and 24b from a black background to a white background.

[0128] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples exemplified above. [Industrial Applicability]

[0129] According to the image forming system according to the present disclosure, it is possible to adjust the cutting position more easily and accurately. [Explanation of symbols]

[0130] 1. Image forming system 10 Image forming device 11 Control section 12 Display section 13 Document reading unit 14 Image forming unit 15 Paper feed section 16 Control unit (adjustment unit) 17 Memory section 18 Interface section 19 Image processing section 20 Cutting device 21 Conveyor 22 Cutting section 23 Paper output section 24a First reading section 24b Second reading unit T1 First scanned image (scanned image of the test paper before cutting) T2 Second scanned image (scanned image of the test paper after cutting)

Claims

1. an image forming unit, a cutting unit that cuts paper on which an image has been formed by the image forming unit, and an adjustment unit that performs adjustment processing on the cutting unit; The adjustment unit calculates a positional deviation amount of a cutting execution position actually performed on the paper from a planned cutting position based on a first read image of the paper before cutting and a second read image of the paper after cutting. Imaging system.

2. The adjustment unit a first process for identifying a paper area of ​​the paper in the first scanned image; a second process of identifying the planned cutting position with respect to the paper in the first read image; a third process of identifying, within the second scanned image, a paper area of ​​each of a plurality of small pieces of paper created from the paper after cutting; a fourth process of aligning each of the plurality of small pieces of paper with respect to the original paper within the first read image and specifying the cutting execution position with respect to the paper; and executing a fifth process of calculating the amount of misalignment for each cutting position where cutting is performed by the cutting unit based on the planned cutting position and the cutting execution position specified in the first read image. The image forming system according to claim 1 .

3. The adjustment unit sets a cutting adjustment value related to shift correction and / or tilt correction for each cutting position where cutting is performed by the cutting unit based on the calculated positional deviation amount. The image forming system according to claim 1 .

4. The adjustment unit specifies the planned cutting position with respect to the paper in the first read image based on a preset cutting profile or position information in the first read image of an index image formed on the paper based on the preset cutting profile. The image forming system according to claim 1 .

5. In the second process, the adjustment unit obtains a reference point and an inclination of the paper in the first read image, and specifies the planned cutting position with respect to the paper using the reference point and the inclination as reference coordinates. The image forming system according to claim 2 .

6. In the fourth process, the adjustment unit determines a reference point and an inclination of each of the plurality of small paper pieces in the second scanned image, and aligns each of the plurality of small paper pieces with respect to the original paper using the reference point and the inclination as reference coordinates. The image forming system according to claim 2 .

7. In the fourth process, the adjustment unit linearly approximates the outline of each of the plurality of small pieces of paper and identifies the cutting execution position for the paper. The image forming system according to claim 2 .

8. In the fourth process, the adjustment unit aligns each of the plurality of small paper pieces with respect to the original paper based on an index image formed on the original paper and the index image formed on each of the plurality of small paper pieces. The image forming system according to claim 2 .

9. The index images are drawn at the four corner positions of each of the plurality of small pieces of paper based on a preset cutting profile. The image forming system according to claim 8 .

10. An image reading unit is provided in each of the upstream and downstream stages of the cutting unit, The adjustment unit acquires the first read image and the second read image from the image reading units in the front and rear stages, respectively. The image forming system according to claim 1 .

11. An image reading unit is provided downstream of the cutting unit, The adjustment unit acquires, from the image reading unit, a read image of the paper output with a setting that does not involve cutting, and also acquires a read image of the paper output with a setting that involves cutting, and treats these read images as the first read image and the second read image. The image forming system according to claim 1 .

12. 1. A cutting position adjustment method for an image forming system including an image forming unit and a cutting unit that cuts paper on which an image is formed by the image forming unit, A process of acquiring a first scanned image of the paper before cutting; A process of acquiring a second read image of the paper after cutting; a process of calculating a positional deviation amount of a cutting execution position actually performed on the paper from a planned cutting position based on the first read image and the second read image; A cutting position adjustment method that performs the above.

Images