Image processing device, image processing method and computer readable medium

Abstract

The present invention provides an image processing device, an image processing method, and a computer-readable medium. The image processing device includes a processor, the processor sets the image position of a reference image in the conveying direction of a recording medium at an arbitrary position of a specific page of the recording medium, the reference image is formed in a first color and serves as a reference for the position of an image of a second color formed after the image of the first color is formed, and uses image information of the reference image formed on the specific page to adjust the position of the image of the second color in an adjacent page adjacent to the upstream side of the conveying direction of the specific page.

Description

Technical Field

[0001] The present disclosure relates to an image processing device, an image processing method, and a computer-readable medium. Background Art

[0002] Japanese Patent Application Laid-Open No. 2007-079296 describes a technique that can not only suppress the occurrence of color shift but also prevent a mark for color detection from remaining on a recording medium such as paper. Summary of the invention

[0003] The purpose of the present disclosure is to reduce the constraints on the configuration position of the reference image compared to the following structure, in which, when adjusting the image position of an image formed on a recording medium, the reference image formed at the beginning of a page is detected and the image position of an image formed on the same page as the reference image is adjusted.

[0004] According to the first scheme of the present disclosure, an image processing device is provided, wherein the image processing device includes a processor, which sets the image position of a reference image in the conveying direction of a recording medium to an arbitrary position of a specific page of the recording medium, the reference image is formed in a first color and serves as a reference for the image position of a second color formed after the image of the first color is formed, and the processor uses the image information of the reference image formed on the specific page to adjust the image position of the second color in an adjacent page adjacent to the upstream side of the conveying direction of the specific page.

[0005] According to a second aspect of the present disclosure, the image processing device includes a display unit that displays an image, and the processor causes the display unit to display an input screen on which the arbitrary position can be set.

[0006] According to the third aspect of the present disclosure, when the position input by the operation on the input screen cannot be set as the arbitrary position, the processor causes the display unit to display a position that can be set as the arbitrary position.

[0007] According to the fourth aspect of the present disclosure, the processor performs image forming processing on the reference image formed on the specific page and the normal image formed in the first color separately from the reference image on the adjacent page as a whole.

[0008] According to a fifth aspect of the present disclosure, the image processing device includes: a first image forming unit that forms an image of the first color; a second image forming unit that is disposed on the downstream side of the conveying direction of the first image forming unit and forms an image of the second color; a first detection unit that is disposed on the upstream side of the conveying direction of the first image forming unit and detects a pre-formed specific image; and a second detection unit that is disposed on the downstream side of the conveying direction of the first image forming unit and on the upstream side of the conveying direction of the second image forming unit and detects the reference image formed by the first image forming unit. When the first detection unit detects the specific image, the processor outputs an image formation instruction of the reference image formed on the specific page and the normal image formed on the adjacent page to the first image forming unit, and when the second detection unit detects the reference image formed on the specific page, the processor adjusts the position of the second color image formed by the second image forming unit on the adjacent page using the image information of the detected reference image.

[0009] According to a sixth aspect of the present disclosure, the image processing device according to any one of the first to fifth aspects includes: a first image forming unit that forms an image of the first color; a second image forming unit that is disposed on the downstream side of the conveying direction of the first image forming unit and forms an image of the second color; a first detection unit that is disposed on the upstream side of the conveying direction of the first image forming unit and detects a pre-formed specific image; and a second detection unit that is disposed on the downstream side of the conveying direction of the first image forming unit and on the upstream side of the conveying direction of the second image forming unit and detects the reference image formed by the first image forming unit. When the first detection unit detects the specific image, the processor outputs an image formation instruction of at least the reference image formed on the specific page to the first image forming unit, and when the second detection unit detects the reference image formed on the specific page, the processor adjusts the position of the second color image formed by the second image forming unit on the adjacent page using the image information of the detected reference image and the reference information of the reference image acquired in advance.

[0010] According to the seventh scheme of the present disclosure, a computer-readable medium is provided, which stores a program that enables a computer to perform processing, wherein in the processing, the image position of a reference image in the conveying direction of a recording medium is set at an arbitrary position of a specific page of the recording medium, the reference image is formed in a first color, and becomes a reference for the image position of a second color formed after the image of the first color is formed, and the image information of the reference image formed on the specific page is used to adjust the image position of the second color in an adjacent page adjacent to the upstream side of the conveying direction of the specific page.

[0011] According to the 8th scheme of the present disclosure, an image processing method is provided, wherein the image position of a reference image in the conveying direction of a recording medium is set at an arbitrary position of a specific page of the recording medium, the reference image is formed in a first color and serves as a reference for the image position of a second color formed after the image of the first color is formed, and the image information of the reference image formed on the specific page is used to adjust the image position of the second color in an adjacent page adjacent to the upstream side of the conveying direction of the specific page.

[0012] Effects of the Invention

[0013] According to the first scheme, the constraints on the configuration position of the reference image are reduced compared to the following structure: when adjusting the image position of an image formed on a recording medium, the reference image formed at the beginning of a page is detected and the image position of the image formed on the same page as the reference image is adjusted.

[0014] According to the second aspect, the user sets an arbitrary position.

[0015] According to the third aspect, the time required to set an arbitrary position is reduced compared to a configuration in which, when a position input by operating the input screen cannot be set as an arbitrary position, the operation must be continued until a settable position is input.

[0016] According to the fourth aspect, compared with a configuration in which a reference image formed on a specific page and a normal image formed on an adjacent page are processed as different data, positional deviation of the first color and second color images in the conveying direction is suppressed.

[0017] According to the fifth scheme, the positional deviation of the image positions of the first color and the second color in the transmission direction is suppressed compared to the following structure, in which, when the first detection unit detects a specific image, the same image formation instruction for forming a reference image and a normal image is output to the first image forming unit.

[0018] According to the sixth aspect, compared with a configuration in which the image position of the second color in the adjacent page is adjusted using either the image information of the reference image or the reference information of the reference image, positional deviation between the image positions of the first color and the second color in the conveying direction is suppressed.

[0019] According to the seventh scheme, the constraints on the configuration position of the reference image are reduced compared to the following structure: when adjusting the image position of an image formed on a recording medium, the reference image formed at the beginning of a page is detected and the image position of the image formed on the same page as the reference image is adjusted.

[0020] According to the eighth scheme, the constraints on the configuration position of the reference image are reduced compared to the following structure: when adjusting the image position of an image formed on a recording medium, the reference image formed at the beginning of a page is detected and the image position of the image formed on the same page as the reference image is adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram showing an example of the configuration of the image forming apparatus in the first embodiment.

[0022] Figure 2 Detailed description of the invention is a block diagram showing the hardware configuration of the image forming apparatus according to the present embodiment.

[0023] Figure 3 This is a conceptual diagram showing a specific page and adjacent pages of continuous paper in the first embodiment.

[0024] Figure 4 This is a display example of the display unit in the first embodiment.

[0025] Figure 5 This is a display example of the display unit in the first embodiment.

[0026] Figure 6 This is a diagram showing an example of the configuration of the image forming apparatus in the second embodiment and the third embodiment.

[0027] Figure 7 This is a conceptual diagram showing a specific page and adjacent pages of continuous paper in the second embodiment.

[0028] Figure 8 This is an example of the detection result of the detection unit in the third embodiment. DETAILED DESCRIPTION

[0029] Hereinafter, an inkjet image forming apparatus 10 according to the present embodiment will be described with reference to the drawings.

[0030] (First embodiment)

[0031] like Figure 1 As shown, an image forming apparatus 10 as an example of an image processing apparatus includes a head unit 12 , conveying rollers 14 and 16 , and a detection unit 18 .

[0032] The head unit 12 ejects ink droplets onto a continuous paper (= roll paper) P as a recording medium to form an image on the continuous paper P. The head unit 12 includes a head 12K for forming an image of K (= black), a head 12C for forming an image of C (= cyan), a head 12M for forming an image of M (= magenta), and a head 12Y for forming an image of Y (= yellow). In the first embodiment, the head 12K forms an image using K color, and forms K marks of C color, M color, and Y color, which serve as a reference for the image position, on the continuous paper P. This will be described in detail later. In addition, K color is an example of a first color, C color, M color, and Y color are examples of a second color, and the K mark is an example of a reference image.

[0033] The heads of the head unit 12 are arranged in the order of K→C→M→Y along the conveying direction S of the continuous paper P. In addition, the arrangement order of the heads of the head unit 12 is not particularly limited. In addition, in the following description, when C, M, Y, and K are not distinguished, C, M, Y, and K are omitted in the reference numerals. In addition, the head 12K is an example of a first image forming unit, and the head 12C, the head 12M, and the head 12Y are examples of a second image forming unit.

[0034] Here, in the first embodiment, in order to identify each nozzle of each head of the head unit 12, nozzle numbers are assigned to each nozzle in the order of 1, 2, ... starting from 1. Furthermore, in the first embodiment, the nozzles of each head of the head unit 12 are arranged along the width direction of the continuous paper P (hereinafter referred to as "paper width direction").

[0035] The conveying rollers 14 and 16 are rotatably supported by a frame member (not shown). The continuous paper P is wound around the conveying rollers 14 and 16. The winding roller (not shown) receives a rotational force from a motor (not shown) and rotates to wind up the continuous paper P, thereby conveying the continuous paper P in the conveying direction S.

[0036] The detection unit 18 includes: a first detection unit 18A disposed on the upstream side of the head 12K in the conveying direction S; a second detection unit 18B disposed between the head 12K and the head 12C; a third detection unit 18C disposed between the head 12C and the head 12M; and a fourth detection unit 18D disposed between the head 12M and the head 12Y. The detection unit 18 detects the K mark formed on the continuous paper P. For example, the detection unit 18 irradiates light to the K mark formed on the continuous paper P, and the light receiving element receives the reflected light from the K mark, thereby detecting the image position of the K mark. Then, the detection unit 18 sends the detected image position of the K mark to the control unit 20 described later.

[0037] Next, the hardware configuration of the image forming apparatus 10 will be described.

[0038] Figure 2 2 is a block diagram showing the hardware configuration of the image forming apparatus 10 .

[0039] like Figure 2 As shown, the image forming apparatus 10 includes a control unit 20 for controlling the operation of the image forming apparatus 10. The CPU 22 (=Central Processing Unit), ROM 24 (=Read Only Memory), RAM 26 (=Random Access Memory), and input / output interface (=I / O 28) of the control unit 20 are connected via a bus so as to be able to communicate with each other.

[0040] The CPU 22 is a central processing unit for executing various programs or controlling various components. That is, the CPU 22 reads the program from the ROM 24 and executes the program using the RAM 26 as a work area. The CPU 22 controls the above-mentioned components and performs various calculations according to the program recorded in the ROM 24.

[0041] The ROM 24 stores various programs and various data. The various programs include at least an image processing program for causing the computer to function as the CPU 22 of the image forming device 10. The image processing program may be pre-installed in the image forming device 10, or may be stored in a non-volatile storage medium or distributed via a network and installed in the image forming device 10 as appropriate. Examples of non-volatile storage media include CD-ROMs, magneto-optical disks, HDDs (=Hard Disk Drives), DVD-ROMs, flash memories, memory cards, and the like.

[0042] The RAM 26 temporarily stores programs and data as a work area.

[0043] The head unit 12 , the detection unit 18 , the storage unit 30 , the display unit 32 , the operation unit 34 , and the communication unit 36 ​​are connected to the I / O 28 .

[0044] As the storage unit 30 , for example, a HDD, an SSD (=Solid State Drive), a flash memory, or the like is used.

[0045] For example, a liquid crystal display (LCD), an organic EL (Electro Luminescence) display, etc. are used for the display unit 32. The display unit 32 has a touch panel integrally therewith.

[0046] The operation unit 34 is provided with an operation key group for accepting various instructions from a user of the image forming apparatus 10 .

[0047] The display unit 32 and the operation unit 34 receive various instructions from the user. The display unit 32 displays various information such as the result of the process executed according to the instruction received from the user and a notification of the process.

[0048] The communication unit 36 ​​communicates with a terminal device such as a personal computer (not shown) via a network. For example, the Internet, LAN (Local Area Network), WAN (Wide Area Network), etc. are used in this network.

[0049] Next, use Figures 3 to 5 The flow of forming an image on the continuous paper P will be described.

[0050] In the first embodiment, the image positions in the conveyance direction S of the heads 12C, 12M, and 12Y in the adjacent pages adjacent to the upstream side in the conveyance direction S of the specific page are adjusted using the image information of the K mark formed on the specific page by the head 12K.

[0051] Figure 3 2 is a conceptual diagram showing a specific page and adjacent pages in the continuous paper P. Figure 3 In the following description of , a specific page may be described as "page N", and an adjacent page may be described as "page N+1". Figures 3 to 5 In FIG. 4 , the K mark as the reference image is shown by a black rectangular graphic mark, and the number “40K” is annotated.

[0052] The CPU 22 receives setting of the image position of the K mark 40K on the continuous paper P (hereinafter referred to as “image position setting”). For example, the CPU 22 receives the image position setting when the user operates an image position setting button (not shown) displayed on the display unit 32 .

[0053] Here, if Figure 3 As shown in the figure, each page of the continuous paper P is divided into a "print image area P1" indicated by a dashed line, which is an area where a print image corresponding to a print job is formed, and an "end area P2" indicated by a dotted line, which is an area at the end of the continuous paper P in the paper width direction. The end area P2 is a portion cut from the continuous paper P before shipment. In addition, the K mark 40K is preset to be formed in the end area P2 but not in the print image area P1.

[0054] When receiving the image position setting, the CPU 22 Figure 4 The input screen of the image position of the K mark 40K shown in FIG. Figure 4 As shown in FIG. 1 , the display unit 32 displays a “preview 32A”, a “coordinate value input screen 32B”, and a “determine button 32C” as image position settings. In this way, by displaying the coordinate value input screen 32B and inputting coordinate values, the image position of the K mark 40K can be set to an arbitrary position in the conveying direction S. In addition, the coordinate value input screen 32B is composed of a numerical value section 32D for inputting numerical values ​​and a variable section 32E for varying the numerical value input to the numerical value section 32D up and down.

[0055] When the user inputs X and Y coordinate values ​​and operates the enter button 32C, the CPU 22 sets the image position corresponding to the input coordinate values ​​as the image position of the K mark 40K if the image position is within the end region P2.

[0056] On the other hand, when the image position corresponding to the coordinate value input by the user is not within the end area P2, that is, when the image position cannot be set to the image position of the K mark 40K, the CPU 22 displays the position that can be set as the image position of the K mark 40K on the display unit 32.

[0057] like Figure 5 As shown in (A) of FIG. 1 , for example, when the image position corresponding to the coordinate value input by the user is within the print image area P1, the CPU 22 displays a warning display 32F indicating that the image position cannot be set to the image position of the K mark 40K on the display unit 32. Figure 5 As shown in (B), the CPU 22 displays the K mark 40K in the end area P2 of the preview 32A, and displays the change display 32G indicating that the image position corresponding to the coordinate value input by the user has been changed on the display unit 32 instead of the notice display 32F. Figure 5The position of the K mark 40K displayed in the end region P2 of the preview 32A in (B) is a candidate position, and the position of the K mark 40K can be moved by the user inputting coordinate values ​​again.

[0058] After the above-described image position setting is completed, when a print job is input to the control unit 20 via the communication unit 36 ​​, an image is formed on the continuous paper P as follows.

[0059] Here, the image forming apparatus 10 includes a rotary encoder (not shown) provided on the rotation shaft of the conveying rollers 14 and 16, which outputs a clock signal every time the conveying rollers 14 and 16 rotate by a predetermined angle. Then, each head of the head unit 12 is driven based on the clock signal output from the rotary encoder.

[0060] First, if Figure 3 As shown, the head 12K forms the K mark 40K at the image position set by the above-mentioned image position setting in the edge region P2 of the Nth page.

[0061] In addition, the head 12K forms a K color image (hereinafter referred to as "K image 45K") in the print image area P1 of the N+1th page. Figure 3 The black square graphic mark shown in FIG. 1 is used as the K image 45K. Furthermore, the head 12K forms the K mark 40K at the image position set by the above-mentioned image position setting in the end area P2 of the N+1th page. The K mark 40K of the N+1th page is used to adjust the image position in the conveying direction S of the head 12C, the head 12M, and the head 12Y in the N+2th page adjacent to the upstream side of the conveying direction S of the N+1th page. In this case, the N+1th page corresponds to the "specific page" and the N+2th page corresponds to the "adjacent page".

[0062] When the K mark 40K of the Nth page reaches the detection range by the conveyance of the continuous paper P, the second detection unit 18B detects the K mark 40K, and sends the detection result of the detected K mark 40K to the control unit 20 as measured information. The "measured information" refers to information that can determine the image position of the K mark 40K by switching the waveform to valid or invalid. The valid and invalid are switched based on the intensity of the reflected light received by the light receiving element of the detection unit 18. In addition, the measured information is an example of image information.

[0063] Next, the CPU 22 compares the measured information sent from the second detection unit 18B with the reference information corresponding to the measured information stored in the ROM 24, and adjusts the image position of the head 12C in the conveying direction S in the N+1th page when the offset in the conveying direction S is greater than the threshold value. At this time, the CPU 22 advances or delays the ejection timing of the ink droplets from the nozzle as "adjustment". That is, when the detection timing of the detection unit 18 is earlier than expected, the CPU 22 advances the ejection timing of the ink droplets accordingly, and when the detection timing of the detection unit 18 is later than expected, the CPU 22 delays the ejection timing of the ink droplets accordingly.

[0064] Here, the reference information is information of the K mark 40K detected by the detection unit 18 at a reference time different from the actual measurement time. This reference information is sent to the control unit 20 after the detection of the K mark 40K by each detection unit 18, and is pre-stored in the ROM 24 as reference information indicating the image position in the continuous paper P that serves as a reference for each head of the head unit 12.

[0065] Then, the head 12C forms an image of color C (hereinafter referred to as "C image 45C") in the print image area P1 of the N+1th page. Figure 3 The square graphic mark with a downward left slash is used as the C image 45C. At this time, the head 12C ejects ink droplets at the ejection timing adjusted by the CPU 22 based on the detection result of the second detection unit 18B. That is, the head 12C shifts the ejection timing of the ejected ink droplets from the reference in order to correspond to the positional deviation of the image position in the conveying direction S. In addition, this "positional deviation of the image position" refers to the relative positional deviation between the images formed by each head of the head unit 12, so-called color shift.

[0066] In addition, the following process is the same as the above, so the description is omitted.

[0067] (Effect)

[0068] Conventionally, when adjusting the image position of an image formed on continuous paper P, there is a structure in which a K mark formed at the beginning of a page is detected and the image position of an image formed on the same page as the K mark is adjusted (hereinafter referred to as "comparison structure A").

[0069] However, in the comparative structure A, in order to facilitate adjustment of the color shift in the same page, the K mark needs to be formed at the beginning of the same page, that is, at the upstream end in the conveying direction S, which results in constraints on the configuration position of the K mark.

[0070] In contrast, in the first embodiment, the CPU 22 sets the image position of the K mark in the conveying direction S to an arbitrary position of a specific page of the continuous paper P, and uses the K mark of the specific page to adjust the image positions of the C color, the M color, and the Y color in the adjacent page adjacent to the upstream side of the conveying direction S of the specific page. Thus, in the first embodiment, it is not necessary to form the K mark at the beginning of the same page in order to cope with the color matching adjustment in the same page. That is, in the first embodiment, the K mark can be formed at an arbitrary position in the conveying direction S of the specific page.

[0071] Therefore, according to the first embodiment, compared with the comparative structure A, the restrictions on the arrangement positions of the K marks are reduced.

[0072] In the first embodiment, the CPU 22 displays an input screen for setting an arbitrary position of a specific page in the conveying direction S on the display unit 32. Therefore, according to the first embodiment, the user operates the display unit 32 to set an arbitrary position.

[0073] Furthermore, in the first embodiment, when the position input by operating the input screen cannot be set as the image position of the K mark, the position that can be set as the image position of the K mark is displayed on the display unit 32 by the CPU 22, wherein the input screen can be used to set an arbitrary position in the conveying direction S of the specific page. Therefore, according to the first embodiment, the time required to set the image position of the K mark is reduced compared with the following structure, in which, when the position input by operating the input screen cannot be set as the image position of the K mark, it is necessary to continue the operation until a position that can be set is input, wherein the input screen can be used to set an arbitrary position in the conveying direction S of the specific page.

[0074] (Second embodiment)

[0075] Next, the second embodiment will be described while omitting or simplifying portions overlapping with other embodiments.

[0076] Figure 6 1 is a diagram showing an example of the structure of the image forming apparatus 10 in the second embodiment. The image forming apparatus 10 has a so-called dual-machine structure, and includes a first image forming apparatus 50 as a first machine, a second image forming apparatus 60 as a second machine, and a reversing device (not shown) disposed between the first image forming apparatus 50 and the second image forming apparatus 60 and reversing the front and back of the continuous paper P.

[0077] here, Figure 6 The structures of the first image forming device 50 and the second image forming device 60 shown in FIG. Figure 1The structure of the image forming apparatus 10 of the first embodiment shown is the same, but the first image forming apparatus 50 and the second image forming apparatus 60 are denoted by reference numerals different from those of the image forming apparatus 10 of the first embodiment.

[0078] The first image forming device 50 includes a head unit 52, conveying rollers 54, 56 and a detection unit 58. The head units 52 include a head 52K, a head 52C, a head 52M and a head 52Y. The detection units 58 include a first detection unit 58A, a second detection unit 58B, a third detection unit 58C and a fourth detection unit 58D.

[0079] The second image forming device 60 includes a head unit 62, conveying rollers 64, 66, and a detection unit 68. The head unit 62 includes a head 62K, a head 62C, a head 62M, and a head 62Y. The detection units 68 include a first detection unit 68A, a second detection unit 68B, a third detection unit 68C, and a fourth detection unit 68D. The first detection unit 68A is used to detect a K mark (hereinafter referred to as a "surface K mark") formed on one side (hereinafter referred to as a "surface") of the continuous paper P. The surface K mark is an example of a specific image formed in advance.

[0080] In addition, the hardware configuration of the image forming apparatus 10 in the second embodiment is similar to that of the image forming apparatus 10 in the second embodiment. Figure 2 The hardware configuration of the image forming apparatus 10 of the first embodiment shown is the same as that of the first embodiment, and therefore the same reference numerals as those of the first embodiment are given.

[0081] Here, the image forming device 10 forms an image on the surface of the continuous paper P through the first image forming device 50, and after turning over the front and back of the continuous paper P through the turning device, forms an image on the other side (hereinafter referred to as the “back side”) of the continuous paper P through the second image forming device 60.

[0082] At this time, in the first image forming device 50, the front K mark is formed on the front surface of the continuous paper P, and in the second image forming device 60, the first detection unit 68A detects the front K mark and sends the detection result as measured information to the control unit 20. Then, the CPU 22 drives the head 62K at the image formation timing based on the measured information of the front K mark, so that the K mark (hereinafter referred to as "back K mark") and the K image are formed on the back surface of the continuous paper P. Then, in the second image forming device 60, the second detection unit 68B, the third detection unit 68C, and the fourth detection unit 68D respectively detect the back K mark, and send the detection results as measured information to the control unit 20. Then, the CPU 22 drives the head 62C, the head 62M, or the head 62Y at the image formation timing based on the measured information of the back K mark, so that the C image, the M image, or the Y image is formed on the back surface of the continuous paper P. In addition, the M image is an image of M color formed by the head 62M, and the Y image is an image of Y color formed by the head 62Y.

[0083] That is, in the second embodiment, as a premise, when the back side of the continuous paper P is formed, unlike the first embodiment driven based on the clock signal output from the rotary encoder, the head 62K forms the back side K mark and K image based on the measured information of the front side K mark, and the head 62C, the head 62M, and the head 62Y form the C image, the M image, or the Y image based on the measured information of the back side K mark. Moreover, while having this premise structure, there is a structure (hereinafter referred to as "comparison structure B") in which the back side K mark formed on a specific page and the K image formed on an adjacent page are processed as different data. In this comparison structure B, the image data of the back side K mark of a specific page and the image data of the K image of an adjacent page are processed as image data of different pages.

[0084] In the comparative configuration B, when the first detection unit 68A detects the front K mark, the same ejection signal for forming the back K mark and the K image is sent to the head 62K. Then, in the comparative configuration B, only the back K mark is formed on the first page of the back side of the continuous paper P, and the back K mark, the K image, the C image, the M image, and the Y image are formed on the second page and thereafter. In this case, the head 62K forms the back K mark on the first page based on the first detection of the front K mark by the first detection unit 68A, and forms the back K mark and the K image on the second page based on the second detection of the front K mark by the first detection unit 68A. In addition, the head 62C, the head 62M, and the head 62Y form the C image, the M image, and the Y image on the second page based on the detection of the back K mark of the first page by the second detection unit 68B, the third detection unit 68C, or the fourth detection unit 68D. In addition, the "front page of the back side of the continuous paper P" refers to a portion on the surface of the corresponding continuous paper P where the print image corresponding to the print job does not exist.

[0085] In the comparison structure B constructed as described above, for example, based on the reading accuracy of the surface K mark read by the first detection unit 68A, color shift may occur between the K image and the C image, M image, and Y image. For example, in the comparison structure B, when the first page on the back side of the continuous paper P is regarded as the "specific page" and the second page is regarded as the "adjacent page", if the actual measurement information of the surface K mark for the second time fluctuates with respect to the actual measurement information of the surface K mark for the first time, in the adjacent pages, color shift in the conveying direction S between the K image and the C image, M image, and Y image occurs according to the difference.

[0086] In contrast, in the second embodiment, in order to solve the above problem, the CPU 22 performs image forming processing on the back side K mark formed on a specific page on the back side of the continuous paper P and the K image formed on the adjacent page on the back side of the continuous paper P as a whole. Here, the back side K mark is an example of a reference image, and the K image is an example of a normal image.

[0087] Below, use Figure 7 , the image forming process performed in the second embodiment is described.

[0088] Figure 7 2 is a conceptual diagram showing a specific page and adjacent pages on the back side of the continuous paper P. Figure 7 In the following description, a specific page may be described as "page N", and an adjacent page may be described as "page N+1". Figure 7 The specific page shown, that is, the Nth page, becomes the leading page on the back side of the continuous paper P. Figure 7In the figure, the “back K mark” is labeled with “70K” and the “K image” is labeled with “80K”. Figure 7 The K image and the C image shown are simplified examples for use in the description of the second embodiment, and images different from this example may be used as the K image and the C image.

[0089] As the above-mentioned image formation processing, the CPU 22 processes the back K mark 70K of the Nth page and the K image 80K of the N+1th page as one data. In the second embodiment, the image area in each page is divided into a printing image area P1 and an end area P2, and the image data of the printing image area P1 and the end area P2 in each page are divided. Thus, in the second embodiment, the CPU 22 can process the end area P2 of a specific page and the printing image area P1 of an adjacent page as the same page across two consecutive pages of K color image data. For example, in Figure 7 In the case shown, the CPU 22 processes the end area P2 of the Nth page and the print image area P1 of the N+1th page as the same page, and processes the image data of the K mark 70K of the Nth page and the image data of the K image 80K of the N+1th page as one data. In this case, it can also be said that the image data of the K mark 70K of the Nth page and the image data of the K image 80K of the N+1th page have the same coordinates for determining the image position of the image data.

[0090] Here, when the surface K mark reaches the detection range due to the conveyance of the continuous paper P, the first detection unit 68A detects the surface K mark and transmits the detection result of the detected surface K mark to the control unit 20 as measured information.

[0091] Next, the CPU 22 sends a discharge signal as an image formation instruction for forming the back K mark 70K on the Nth page and the K image 80K on the N+1th page to the head 62K at the image formation timing obtained based on the actual measurement information of the obtained front K mark. Specifically, the CPU 22 sends a discharge signal divided into a first K color discharge signal for forming the back K mark 70K in the end area P2 of the Nth page and a second K color discharge signal for forming the K image 80K in the print image area P1 of the N+1th page to the head 62K.

[0092] The head 62K having received the first K color ejection signal forms a back K mark 70K in the edge region P2 of page N. The head 62K having received the second K color ejection signal forms a K image 80K in the print image region P1 of page N+1.

[0093] In addition, each time the first detection unit 68A detects the surface K mark, it sends the measured information of the detected surface K mark to the control unit 20. Each time the CPU 22 obtains the measured information of the surface K mark, it sends a discharge signal to the head 62K at the image formation timing obtained based on the obtained measured information of the surface K mark, and the discharge signal is used to form the back K mark 70K on the specific page and form the K image 80K on the adjacent page. Each time the head 62K obtains the first K color discharge signal, it forms the back K mark 70K in the end area P2 of the specific page based on the obtained first K color discharge signal. In addition, each time the head 62K obtains the second K color discharge signal, it forms the K image 80K in the print image area P1 of the adjacent page based on the obtained second K color discharge signal.

[0094] Therefore, although in Figure 7 Although not shown in the figure, when the first detection unit 68A detects the second front K mark after the first detection described above, the head 62K performs the following image formation. In this case, the head 62K forms the back K mark in the end area P2 of the N+1th page, which is a specific page, and forms the K image in the print image area P1 of the N+2th page, which is an adjacent page.

[0095] Thus, in the second embodiment, only the back side K mark 70K is formed on the Nth page, ie, the first page, of the back side of the continuous paper P, and the back side K mark 70K and the K image 80K are formed on the N+1th page and thereafter.

[0096] Next, when the back side K mark 70K of the Nth page reaches the detection range due to the conveyance of the continuous paper P, the second detection unit 68B detects the back side K mark 70K and sends the detection result of the detected back side K mark 70K to the control unit 20 as measured information.

[0097] Next, when the second detection unit 68B detects the back K mark 70K of the Nth page, the CPU 22 uses the measured information of the detected back K mark 70K to adjust the image position of the C image formed by the head 62C in the N+1th page. Specifically, the CPU 22 sends a C color ejection signal for forming a C image in the print image area P1 of the N+1th page to the head 62C at the image formation timing obtained based on the measured information of the back K mark 70K.

[0098] The head 62C that has received the C color ejection signal forms a C image 80C in the print image area P1 of the N+1th page. Figure 7 In the figure, the “C image” is labeled “80C”.

[0099] In addition, the subsequent process is the same as above, so the description is omitted.

[0100] In the second embodiment configured as described above, the color shift in the conveying direction S is suppressed as compared with the comparative configuration B.

[0101] Specifically, in the second embodiment, the measured information of the first front K mark is used to form a back K mark on a specific page by the head 62K, and a K image is formed on an adjacent page. In addition, in the second embodiment, the measured information of the back K mark on a specific page is used to form a C image, an M image, and a Y image on adjacent pages by the head 62C, the head 62M, and the head 62Y.

[0102] That is, in the second embodiment, the image formation timing of the K image, C image, M image, and Y image in the adjacent pages is realized based on the actual measurement information of the surface K mark for the first time. Therefore, according to the second embodiment, even if the detection timing of the surface K mark for the first time is advanced or delayed, the image positions of the K image, C image, M image, and Y image in the adjacent pages are shifted by the same amount along the conveying direction S, thereby suppressing the color shift.

[0103] (Third embodiment)

[0104] Next, the third embodiment will be described while omitting or simplifying portions overlapping with other embodiments.

[0105] The premise structure of the third embodiment is the same as that of the second embodiment, but the third embodiment replaces the main part structure of the second embodiment and is a method for solving the problem shown in the second embodiment. Figure 8 , the structure of the third embodiment is described.

[0106] When the front surface K mark reaches the detection range due to the conveyance of the continuous paper P, the first detection unit 68A detects the front surface K mark and transmits the detection result of the detected front surface K mark to the control unit 20 as measurement information.

[0107] The CPU 22 transmits a discharge signal for forming a back K mark on a specific page and a K image on an adjacent page to the head 62K at the image formation timing obtained based on the acquired measured information of the front K mark.

[0108] The head 62K which has received the ejection signal forms a back-side K mark in an edge region of a specific page, and forms a K image in a print image region of an adjacent page.

[0109] Next, when the back K mark of a specific page reaches the detection range due to the conveyance of the continuous paper P, the second detection unit 68B detects the back K mark and sends the detection result of the back K mark to the control unit 20 as measured information. Figure 8 In (A), the actual measurement information of the back surface K mark detected by the second detection unit 68B, the third detection unit 68C, and the fourth detection unit 68D is shown by the dotted waveform.

[0110] Next, the CPU 22 compares the measured information sent from the second detection unit 68B with the reference information corresponding to the measured information stored in the ROM 24, and adjusts the image position of the head 62C in the adjacent page in the conveying direction S when the offset in the conveying direction S is greater than the threshold value. The reference information is sent to the control unit 20 after the detection of the back K mark by each detection unit 68 at the time of reference, and is pre-stored in the ROM 24 as reference information, which indicates the image position in the continuous paper P that serves as the reference for each head of the head unit 62. Figure 8 In (B), the solid line waveform shows the reference information of the back K mark detected by the second detection unit 68B, the third detection unit 68C, and the fourth detection unit 68D stored in the ROM 24. In addition, the measured information is an example of image information of the reference image, and the reference information is an example of reference information of the reference image.

[0111] After obtaining the measured information from the second detection unit 68B, the CPU 22 compares the measured information with the reference information corresponding to the measured information. For example, the CPU 22 takes the difference α1 between the start point of the effective time of the measured information of the second detection unit 68B and the start point of the effective time of the reference information corresponding to the measured information, and calculates the amount of deviation in the transmission direction S from the image position that serves as the reference and the direction of deviation. Figure 8 Therefore, the CPU 22 adjusts the image position of the head 62C in the conveying direction S in the adjacent page to advance or delay the ejection timing of ink droplets ejected from the nozzles in accordance with the offset amount.

[0112] The head 62C forms the C image in the print image area of ​​the adjacent page. At this time, since the head 62C is adjusted as described above, the ejection timing of ink droplets ejected from the nozzles is advanced or delayed relative to the reference time.

[0113] In addition, the subsequent process is the same as above, so the description is omitted.

[0114] In the third embodiment, when a back side K mark formed on a specific page is detected, the CPU 22 uses the measured information of the detected back side K mark and the reference information of the back side K mark to adjust the image positions of the C image, the M image, and the Y image in the adjacent pages.

[0115] That is, in the third embodiment, the difference between the measured information and the reference information is used to calculate the offset amount and offset direction of the transmission direction S, and the ejection timing of ink droplets in adjacent pages is advanced or delayed before the heads 62C, 62M, and 62Y respectively form images, thereby adjusting the image positions of the C image, the M image, and the Y image.

[0116] Therefore, according to the third embodiment, compared with the configuration in which the image positions of the C image, the M image, and the Y image in the adjacent pages are adjusted using either the actual measurement information of the back K mark or the reference information, the color shift in the conveying direction S is suppressed.

[0117] (other)

[0118] In the above embodiment, as the "adjustment of the image position in the conveying direction S", the ejection timing of the ink droplets ejected from the nozzle is advanced or delayed. However, this is not limiting, and as the above adjustment, the head unit to be adjusted may be moved in the conveying direction S. In this case, the CPU 22 calculates the movement amount in the conveying direction S of the head unit to be adjusted using the detection results of each detection unit. Then, the moving unit such as the actuator is driven to move the head unit to be corrected in the conveying direction S by the movement amount calculated by the CPU 22.

[0119] In the above-described embodiment, the image forming apparatus 10 adopts the inkjet method, but the image forming apparatus 10 is not limited to the inkjet method.

[0120] In the above embodiment, an example of the image processing device is the image forming device 10, but the present invention is not limited thereto, and other terminal devices such as personal computers may also be used as an example of the image processing device. That is, the processor of the above terminal device may also perform the processing of the CPU 22 of the image forming device 10 of the above embodiment.

[0121] In the above-described embodiment, in the image forming apparatus 10 of the first embodiment, the X coordinate value and the Y coordinate value can be input in the coordinate value input screen 32B, but the present invention is not limited thereto. It is also possible that the X coordinate value for setting the image position of the K mark in the paper width direction cannot be input, and only the Y coordinate value for setting the image position of the K mark in the conveying direction S can be input.

[0122] In the above-described embodiment, in the image forming apparatus 10 of the first embodiment, the image positions of the heads 12C, 12M, and 12Y in the conveying direction S of the adjacent pages are adjusted by comparing the measured information with the reference information corresponding to the measured information. However, the present invention is not limited thereto, and in the image forming apparatus 10 of the first embodiment that forms an image only on the surface of the continuous paper P, the above-described adjustment may be performed using only the measured information without using the reference information.

[0123] In the above-mentioned embodiment, the image forming apparatus 10 of the first embodiment and the first image forming apparatus 50 of the second embodiment and the third embodiment do not perform the image forming process of the CPU 22 described in the second embodiment or the third embodiment, but the present invention is not limited thereto, and the image forming process may be performed. By performing the image forming process, when continuous paper P pre-printed with a specific mark is used, even if the image formation by the head K is performed based on the detection of the specific mark, the occurrence of color shift can be suppressed.

[0124] In the above-mentioned embodiment, the third embodiment adopts a structure obtained by replacing the structure of the second embodiment. However, the third embodiment is not limited to this, and the image forming process of the CPU 22 in the second embodiment may also be performed. That is, the image forming process of both the CPU 22 in the second embodiment and the third embodiment shown in the above-mentioned embodiment may also be performed.

[0125] In the above-mentioned embodiments, in the third embodiment, when a back side K mark formed on a specific page is detected, the image positions of the C image, the M image, and the Y image in the adjacent pages are adjusted by the CPU 22 using the measured information of the detected back side K mark and the reference information of the back side K mark.

[0126] However, the present invention is not limited thereto, and the CPU 22 may also adjust the image positions of the C image, the M image, and the Y image in the adjacent pages by using the actual measurement information of the detected surface K mark and the reference information of the surface K mark acquired in advance when the first detection unit 68A detects the surface K mark. In this case, based on the detection of the surface K mark by the first detection unit 68A at the reference time, the reference information of the surface K mark is sent to the control unit 20 and stored in the ROM 24 in advance.

[0127] In the above-mentioned embodiment, the CPU 22 provided in the image forming apparatus 10 is an example of a processor. Moreover, the processor refers to a processor in a broad sense, including a general-purpose processor (e.g., CPU: = Central Processing Unit, etc.), a dedicated processor (e.g., GPU: = Graphics Processing Unit (Graphics Processing Unit), ASIC: = Application Specific Integrated Circuit (Application Specific Integrated Circuit), FPGA: = Field Programmable Gate Array (Field Programmable Gate Array), a programmable logic device, etc.).

[0128] In addition, the actions of the above-mentioned processors are not only constituted by one processor, but can also be constituted by multiple processors in physically separated positions in cooperation. Furthermore, the order of each action of the above-mentioned processors is not limited to the order described in the above-mentioned embodiment, but can also be appropriately changed.

[0129] In the above embodiment, K color is set as an example of the first color, and C color, M color and Y color are set as an example of the second color. That is, in the above embodiment, the image forming device 10 that performs full-color printing with the first color and the second color being different colors is described as an example. However, as long as the image formation based on the second color is performed after the image formation of the first color, it is not limited to that the first color and the second color are different colors, and they can also be the same color. That is, in the image forming device 10 that performs monochrome printing with K color, the structure described in the above embodiment can also be applied. In this case, K color, which is the same color, becomes an example of the first color and the second color.

Claims

1. An image processing device, wherein: The image processing device includes a processor. The processor sets an image position of a reference image in a conveying direction of the recording medium at an arbitrary position of a specific page of the recording medium, the reference image being formed in a first color and serving as a reference for a position of an image of a second color formed after forming the image of the first color, the processor adjusts the position of the image of the second color in an adjacent page adjacent to the upstream side of the specific page in the conveying direction using the image information of the reference image formed on the specific page, When a preformed specific image is detected, the processor sends an ejection signal for forming the reference image formed in the specific page and a normal image formed in the first color separately from the reference image in the adjacent page.

2. The image processing device according to claim 1, wherein: The image processing device includes a display unit for displaying an image. The processor causes the display unit to display an input screen capable of setting the arbitrary position.

3. The image processing device according to claim 2, wherein: The processor causes the display unit to display a position that can be set as the arbitrary position when the position input by the operation on the input screen cannot be set as the arbitrary position.

4. The image processing device according to claim 1, wherein: The image processing device comprises: a first image forming unit that forms an image of the first color; a second image forming section disposed on a downstream side of the first image forming section in the conveying direction and forming an image of the second color; a first detection section disposed on an upstream side of the first image forming section in the conveying direction and detecting a specific image formed in advance; and a second detection section disposed on the downstream side of the first image forming section in the conveying direction and on the upstream side of the second image forming section in the conveying direction, and detecting the reference image formed by the first image forming section, the processor outputting, to the first image forming unit, an image forming instruction for forming the reference image on the specific page and the normal image on the adjacent page when the first detection unit detects the specific image, When the second detection unit detects the reference image formed on the specific page, the position of the second color image formed by the second image forming unit on the adjacent page is adjusted using the image information of the detected reference image.

5. The image processing device according to any one of claims 1 to 4, wherein: The image processing device comprises: a first image forming unit that forms an image of the first color; a second image forming section disposed on a downstream side of the first image forming section in the conveying direction and forming an image of the second color; a first detection section disposed on an upstream side of the first image forming section in the conveying direction and detecting a specific image formed in advance; and a second detection section disposed on the downstream side of the first image forming section in the conveying direction and on the upstream side of the second image forming section in the conveying direction, and detecting the reference image formed by the first image forming section, the processor outputting, to the first image forming unit, an image forming instruction for at least forming the reference image on the specific page when the first detection unit detects the specific image, When the second detection unit detects the reference image formed on the specific page, the position of the second color image formed by the second image forming unit in the adjacent page is adjusted using the image information of the detected reference image and the reference information of the reference image acquired in advance.

6. A computer-readable medium storing a program for causing a computer to execute a process, wherein: In the process described, The image position of a reference image in a conveying direction of a recording medium is set at an arbitrary position on a specific page of the recording medium, the reference image being formed in a first color and serving as a reference for the position of an image of a second color formed after forming the image of the first color. adjusting the position of the image of the second color in an adjacent page adjacent to the upstream side of the specific page in the conveying direction using the image information of the reference image formed on the specific page, When a previously formed specific image is detected, an ejection signal is transmitted for forming the reference image formed in the specific page and a normal image formed in the first color separately from the reference image in the adjacent page.

7. An image processing method, wherein: The image position of a reference image in a conveying direction of a recording medium is set at an arbitrary position on a specific page of the recording medium, the reference image being formed in a first color and serving as a reference for the position of an image of a second color formed after forming the image of the first color. adjusting the position of the image of the second color in an adjacent page adjacent to the upstream side of the specific page in the conveying direction using the image information of the reference image formed on the specific page, When a previously formed specific image is detected, an ejection signal is transmitted for forming the reference image formed in the specific page and a normal image formed in the first color separately from the reference image in the adjacent page.

Images