Image forming system and program

Abstract

To reduce, in re-printing on continuous paper, the blank space between a last image in normal printing and a re-printed image, and also reduce changes in image quality.SOLUTION: An image formation system 1 includes a sheet conveyance unit T1, 49 that conveys continuous paper P along a sheet conveyance route, an image formation unit 46 that forms an image on the continuous paper P, an image inspection unit 61 that is disposed downstream of the image formation unit 46 in the sheet conveyance route and reads the image formed on the continuous paper to produce image data, and a control unit that determines whether there is an image defect on the basis of the read image data and determines whether to print again the image that has been determined to be defective on the basis of the result of determination. The control unit continues the operation of the image formation unit 46 until the defective image is determined not to be printed again.SELECTED DRAWING: Figure 1

Description

Technical Field

[0005]

[0001] The present invention relates to an image forming system and a program.

Background Art

[0002] Conventionally, an image forming apparatus that forms an image on continuous paper as paper is known. For example, an image forming apparatus that facilitates the correction work of a developed body (output) by inspecting the first print (normal print) and the cut image on continuous paper and reprinting the image included in the defective part of the image or cut at the end of the continuous paper is known (see Patent Document 1).

[0003] On the other hand, for the purpose of preventing deterioration of materials such as a photoreceptor and a developer, it is generally performed to immediately stop the image forming unit as soon as the image forming process of the final image of normal printing is completed. For example, an (color) image forming apparatus that immediately separates and stops a photoreceptor drum as an image forming unit from an intermediate transfer belt as soon as the image forming process of the final image is completed is known (see Patent Documents 2 and 3). <​​​​​​​​​​​​​​​​​​​​​​​​​​​​​However, if the image forming unit is stopped after the image forming process in the image forming apparatus described in Patent Document 1, and if the image near the final image is determined to be defective after the image forming process for the final image by normal printing is completed, the image forming unit will already be stopped or in the process of stopping, and it will be necessary to restart the image forming unit to reprint the defective area. Therefore, not only is there a processing time problem due to the time it takes to restart the image forming unit, but since the continuous paper transport continues during this time, there is a risk that a large blank area will be created between the final image of the normal print and the reprinted image.

[0006] In particular, because the image forming unit is stopped and then restarted, there was a risk that the image quality might change slightly between the final image of a normal print and the image of a reprint due to fluctuations in the high-voltage output, speed, and torque of various control loads.

[0007] The object of this invention is to reduce the blank space between the final image of the normal print and the reprinted image, as well as the change in image quality, when reprinting on continuous paper. [Means for solving the problem]

[0008] To solve the above problems, the image forming system of the invention described in claim 1 is: A paper transport unit that transports continuous paper according to the paper transport path, An image forming unit that forms an image on the continuous paper, An image reading unit is located downstream of the image forming unit in the paper transport path and reads the image formed on the continuous paper to generate image data. The system includes a control unit that determines whether or not there is an image defect based on the image data read, and determines whether or not to reprint the image that was determined to have an image defect based on the result of the determination, The control unit will continue the operation of the image forming unit until it determines that it does not want to reprint the image. death, If the control unit detects an image defect, it places the image to be reprinted after the final image formed by normal printing. If the interval between the image to be reprinted and the image formed before the reprint cannot maintain the predetermined image interval for normal printing, it forms the image to be reprinted by leaving an integer multiple image interval, which is an integer multiple of the predetermined image interval and the smallest possible image interval for reprinting, from the image formed before the reprint. .

[0009] The invention described in claim 2 is an image forming system described in claim 1, The image forming unit comprises an image forming unit body that forms an image on the continuous paper, It includes a fixing unit for fixing the formed image onto the continuous paper.

[0010] The invention described in claim 3 is an image forming system described in claim 1, The control unit causes the paper transport unit to continue transporting the continuous paper under the same transport conditions as during image formation until it determines that reprinting is not to be performed.

[0011] The invention described in claim 4 is an image forming system described in claim 3, The aforementioned transport conditions include at least one of the transport speed and the pressure contact state.

[0012] The invention described in claim 5 is an image forming system described in claim 1, The control unit determines whether or not there is an image defect based on whether or not the read image data contains a defective image.

[0013] The invention described in claim 6 is an image forming system described in claim 5, The control unit determines that the read image data contains defective images and decides to perform the reprint.

[0016] Claim 7 The invention described herein relates to the image forming system described in claim 1, The control unit determines whether or not there is an image defect based on whether or not there is an image formation defect in the read image data.

[0017] Claim 8 The invention described above is as follows: 7 In the image forming system described in any one of the items, The processing unit is located upstream of the image reading unit in the paper transport path. The control unit determines whether there is an image defect based on the presence or absence of a processing defect by the processing unit in the read image data.

[0018] Claim 9 The invention according to claim 8 In the image forming system according to claim The control unit continues the processing of the processing unit until it determines not to perform reprinting.

[0019] Claim 10 The invention according to claim 1 in the image forming system according to claim 1 The control unit does not perform image adjustment processing that may cause image quality changes until it determines not to perform reprinting.

[0020] Claim 11 The invention according to claim 10 In the image forming system according to claim The image adjustment processing includes at least one of image density adjustment, color registration adjustment, and formation of a waste strip.

[0021] Claim 12 The program of the invention according to claim A paper conveyance unit that conveys continuous paper along a paper conveyance path, An image forming unit that forms an image on the continuous paper, An image reading unit that is disposed on the downstream side of the paper conveyance path from the image forming unit and reads the image formed on the continuous paper to generate image data, and causes a computer of an image forming system including the same to Determine whether there is an image defect based on the read image data, and function as a control unit that determines whether to reprint an image determined to be an image defect based on the result of the determination, The control unit continues the operation of the image forming unit until it determines not to reprint the image death, If the control unit detects an image defect, it places the image to be reprinted after the final image formed by normal printing. If the interval between the image to be reprinted and the image formed before the reprint cannot maintain the predetermined image interval for normal printing, it forms the image to be reprinted by leaving an integer multiple image interval, which is an integer multiple of the predetermined image interval and the smallest possible image interval for reprinting, from the image formed before the reprint. .

Advantages of the Invention

[0022] According to the present invention, when reprinting on continuous paper, it is possible to reduce the blank space between the final image of the normal print and the reprinted image, as well as the change in image quality. [Brief explanation of the drawing]

[0023] [Figure 1] This is a schematic diagram of an image forming system according to an embodiment of the present invention. [Figure 2] This is a block diagram showing the functional configuration of an image forming system. [Figure 3] This is a flowchart showing the image formation process. [Figure 4] This is a flowchart showing the image formation process, a continuation of Figure 3. [Figure 5] (a) is a diagram showing an example of image formation on continuous paper when there are no image defects in normal printing. (b) is a diagram showing an example of image formation on continuous paper when there are image defects on multiple pages, which are common in normal printing. [Figure 6] (a) is a diagram showing an example of image formation on continuous paper when there are several pages with few image defects other than near the last page in normal printing. (b) is a diagram showing an example of image formation on continuous paper when there are image defects only on the last page in normal printing. [Figure 7] (a) is a diagram illustrating an example of image formation on continuous paper when there are image defects on a small number of pages, including the last page, during normal printing. (b) is a diagram illustrating an example of image formation on continuous paper when there are image defects on a small number of pages, including the last page, during normal printing, and when the reprint of the last page also has image defects. [Modes for carrying out the invention]

[0024] Embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the illustrated examples.

[0025] First, the apparatus configuration of this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram of the image forming system 1 of this embodiment. Figure 2 is a block diagram showing the functional configuration of the image forming system 1.

[0026] As shown in Figure 1, the image forming system 1 of this embodiment includes a paper feeder 10, a processing device 20, a paper adjustment device 30, an image forming device 40, a processing device 50, an image inspection device 60, and a winding device 70. In the image forming system 1, the paper transport path for continuous paper P is in the following order from upstream to downstream: paper feeder 10, processing device 20, paper adjustment device 30, image forming device 40, processing device 50, image inspection device 60, and winding device 70.

[0027] The paper feeder 10 is a device that feeds continuous paper P to the downstream side of the paper transport path, such as the image forming apparatus 40. Inside the housing of the paper feeder 10, for example, as shown in Figure 1, the roll of continuous paper P is wound around a support shaft 11 and held rotatably. The paper feeder 10 transports the continuous paper P wound around the support shaft 11 to the processing apparatus 20 at a constant speed, passing through a transport path that goes via multiple transport rollers, is exposed on the top surface of the device, and then re-enters the inside of the device. The exposed portion of the continuous paper P in the paper feeder 10 is used as space for cutting the continuous paper P with a cutter or the like and connecting it to a new roll of paper.

[0028] The support shaft 11 of the paper feed device 10, the transport rollers for the continuous paper P inside the housing, and the drive unit such as the motor are referred to as the paper feed section 12 (Figure 2). In the paper feed device 10, the continuous paper P is installed as a roll of paper, but this is not limited to this configuration, and continuous paper in other forms, such as folded paper, may also be used. Furthermore, the continuous paper P is not limited to paper, but may include media such as film. Here, the transport portion of the continuous paper P other than the image forming apparatus 40 in the image forming system 1 is referred to as the paper transport section T1. The paper transport section T1 includes the paper feed section 12, the paper adjustment section 31 of the paper adjustment device 30 (described later), the winding section 72 of the winding device 70 (described later), and the transport drive unit T11 (Figure 2) of the processing apparatus 20, 50 and the image inspection apparatus 60.

[0029] The processing apparatus 20 is a device that applies predetermined processing to continuous paper P transported from the paper feed device 10 and transports it downstream via multiple transport rollers. The predetermined processing is various processing that takes place before image formation in the image forming apparatus 40, such as full-surface varnishing and flexographic printing. Flexographic printing is a processing method in which continuous paper P, which acts as a transparent film, is coated by printing on the entire surface with white or special colored ink or toner. The drive unit that performs the processing in the processing apparatus 20 is designated as the processing processing unit 21, and the transport rollers and motor for the continuous paper P inside the housing of the processing apparatus 20 are included in the transport drive unit T11 (Figure 2).

[0030] The paper adjustment device 30 is a device that adjusts the height of the continuous paper P transported from the processing device 20 via multiple transport rollers and transports it downstream. The paper adjustment device 30 may also be configured to apply tension to the continuous paper P. The drive unit that adjusts the height of the continuous paper P, including the transport rollers and motor inside the housing of the paper adjustment device 30, is called the paper adjustment unit 31 (Figure 2).

[0031] The image forming apparatus 40 is a device that forms an image (toner image formation and fixing) on ​​continuous paper P transported from the paper feeder 10 and transports it downstream. The image forming apparatus 40 comprises an operation display unit 42, a document reading unit 45, an image forming unit 46, and a paper transport unit 49.

[0032] The operation display unit 42 comprises an operation unit 421 and a display unit 422. The operation unit 421 has various keys and a touch panel integrated with the display screen of the display unit 422, and accepts key press input and touch input from the user. The display unit 422 has a display panel such as an LCD (Liquid Crystal Display) or EL (Electro-Luminescence), and displays various display information.

[0033] The document reading unit 45 includes an ADF (Auto Document Feeder) and an image reading unit such as a CCD (Charge Coupled Device). Based on the setting information received by the operation unit 421, it reads the image of the document and generates image data of the read image. More specifically, the document reading unit 45 transports the document placed in the ADF's document tray to the contact glass, which is the reading area, or places the document on the platen glass, and the image reading unit reads images of one or both sides of the document and generates image data.

[0034] The image forming unit 46 comprises an image forming unit body 47 and a fixing unit 48. The image forming unit body 47 forms an image on continuous paper P supplied from the paper adjustment unit 31 to the image forming apparatus 40 and transported via the paper transport unit 49 (transport roller 491, registration roller 492). The image forming unit body 47 includes image forming units 471Y, 471M, 471C, 471K for each color (yellow (Y), magenta (M), cyan (C), and black (K)), an intermediate transfer belt 472, a secondary transfer roller 473, etc. Each image forming unit 471Y, 471M, 471C, 471K includes a photosensitive drum, a charging unit, an exposure unit, a developing unit, a primary transfer roller, and a cleaning unit.

[0035] Here, we will describe the parts of the yellow image forming unit 471Y. The photoreceptor drum is a rotating body on which a yellow toner image is formed. The charging unit uniformly charges the photoreceptor drum. The exposure unit scans and exposes the surface of the photoreceptor drum with a beam such as laser light based on the yellow component of the image data related to image formation, forming an electrostatic latent image. The developing unit stores the yellow toner and deposits the yellow toner onto the electrostatic latent image on the photoreceptor drum, performing development. The primary transfer roller transfers the yellow toner image formed on the photoreceptor drum onto the intermediate transfer belt 472 (primary transfer). The cleaning unit removes any remaining toner from the photoreceptor drum. The parts of the magenta, cyan, and black image forming units 471M, 471C, and 471K are the same as those of the yellow image forming unit 471Y, except that they handle different colors (toners).

[0036] The intermediate transfer belt 472 is an endless belt on which toner images formed on the photoreceptor drums of each color in the image forming units 471Y, 471M, 471C, and 471K are sequentially transferred. The secondary transfer roller 473 transfers the four-color toner images formed on the intermediate transfer belt 472 onto the paper (secondary transfer).

[0037] The fixing unit 48 fixes the toner image transferred onto the continuous paper P by the image forming unit body 47. The fixing unit 48 includes, for example, a pair of rollers consisting of a heating roller 481 and a pressure roller 482 for gripping the continuous paper P. The heating roller 481 is heated to a predetermined temperature by a heater as a heat source. The pressure roller 482 presses against or separates from the heating roller 481. The continuous paper P on which the toner image has been transferred is heated and pressurized as it passes through the nip between the heating roller 481 and the pressure roller 482, and the toner image melts and fixes to the continuous paper P. The continuous paper P on which the toner image has been fixed by the fixing unit 48 is transported via the paper transport unit 49 (transport roller 491) and discharged from the image forming apparatus 40. The fixing unit 48 is configured to allow control of the pressure state on the continuous paper P by the heating roller 481 and the pressure roller 482. Furthermore, the paper transport units T1, 49 are configured to allow control of the pressure state on the continuous paper P by the transport roller pair.

[0038] The processing apparatus 50 is a device that performs predetermined processing on continuous paper P transported from the image forming apparatus 40 and transports it downstream via a plurality of transport rollers. The predetermined processing is various processing performed after image formation by the image forming apparatus 40, such as spot varnishing (varnishing a portion of the entire surface of the continuous paper P) and die-cutting (deleting a portion of the continuous paper P). The drive unit that performs the processing in the processing apparatus 50 is designated as the processing processing unit 51, and the transport rollers and motor for the continuous paper P inside the housing of the processing apparatus 50 are included in the transport drive unit T11 (Figure 2).

[0039] The image inspection device 60 is a device that optically reads continuous paper P transported from the processing device 50 using sensors such as line sensors, generates image data for inspection, and transports it downstream. The drive unit that performs the image reading process of the image inspection device 60 is designated as the image inspection unit 61 as the image reading unit, and the transport rollers and motor for the continuous paper P inside the housing are included in the transport drive unit T11 (Figure 2).

[0040] The winding device 70 is a device that winds up the continuous paper P transported from the image inspection device 60. Specifically, the winding device 70 winds the continuous paper P transported from the image inspection device 60 onto the support shaft 71 at a constant speed, passing through a transport path that goes through multiple transport rollers, is exposed on the top surface of the device, and then re-enters the inside of the device, and holds it in a roll shape. The exposed portion of the continuous paper P on the winding device 70 is used as a space for checking the quality of the continuous paper P after printing.

[0041] Furthermore, the support shaft 71 of the winding device 70, the transport rollers inside the housing, the motor and other drive components are referred to as the winding section 72 (Figure 2).

[0042] The configuration of the image forming system 1 is not limited to the configuration shown in Figure 1. For example, in the image forming system 1, the image forming apparatus 40 may be configured without a document reading unit 45, or at least one of the processing apparatus 20 and the processing apparatus 50 may be configured without a document reading unit 45.

[0043] Next, with reference to Figure 2, the internal functional (circuit) configuration of the image forming system 1 will be explained. As shown in Figure 2, the image forming system 1 comprises a paper transport unit T1, a processing unit 21 of a processing processing device 20, an image forming device 40, a processing unit 51 of a processing processing device 50, and an image inspection unit 61 of an image inspection device 60. The paper transport unit T1 includes a paper feeding unit 12 of a paper feed device 10, a paper adjustment unit 31 of a paper adjustment device 30, a winding unit 72 of a winding device 70, and transport drive units T11 such as transport rollers and motors of processing processing devices 20 and 50.

[0044] The image forming apparatus 40 comprises a control unit 41, an operation and display unit 42 (operation unit 421, display unit 422), a storage unit 43, a communication unit 44, a document reading unit 45, and an image forming unit 46 (image forming unit body 47, fixing unit 48).

[0045] The control unit 41 includes a CPU (Central Processing Unit) 411, RAM (Random Access Memory) 412, and the like. The CPU 411 reads various programs, such as system programs and application programs, stored in the memory unit 43, loads them into the RAM 412, and executes various processes in cooperation with the loaded programs.

[0046] The operation unit 421 receives operation input from the user and outputs the operation information to the control unit 41. The display unit 422 displays various display information on the display panel based on the display information input from the control unit 41.

[0047] The storage unit 43 is composed of, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive), and stores data such as programs executed by the control unit 41 and image data in a read-and-write manner. In particular, the storage unit 43 is assumed to store an image forming program for executing the image forming process described later.

[0048] The communication unit 44 consists of a network card and communicates with external devices such as a PC (Personal Computer). For example, the communication unit 44 receives image data for image formation from an external device and outputs it to the control unit 41, in accordance with the control of the control unit 41.

[0049] The document reading unit 45 reads the image of the set document according to the control unit 41, generates image data of the read image, and outputs it to the control unit 41.

[0050] The image forming unit body 47 forms a YMCK toner image on the continuous paper P based on image data generated by the document reading unit 45 or image data received from an external device via the communication unit 44, in accordance with the control unit 41. The fixing unit 48 heats and pressurizes the toner image formed on the continuous paper P by the image forming unit body 47, in accordance with the control unit 41, to fix it to the continuous paper P.

[0051] The paper feeding unit 12 rotates the support shaft 11 to feed continuous paper P according to the control unit 41 and transports the fed continuous paper P to the downstream processing device 20. The processing device 21, according to the control unit 41, applies processing / does not apply processing to the continuous paper P transported from the paper feeding device 10. The transport drive unit T11, according to the control unit 41, transports the continuous paper P processed / not processed by the processing device 21 to the downstream paper adjustment device 30.

[0052] The paper adjustment unit 31, in accordance with the control unit 41, transports the continuous paper P conveyed from the processing apparatus 20 to the downstream image forming apparatus 40 using transport rollers. The processing processing unit 51, in accordance with the control unit 41, applies or does not apply processing to the image-formed continuous paper P conveyed from the image forming apparatus 40. The transport drive unit T11, in accordance with the control unit 41, transports the continuous paper P that has been processed or not processed by the processing processing unit 51 to the downstream image inspection apparatus 60.

[0053] The image inspection unit 61, following the control of the control unit 41, reads the image of the continuous paper P transported from the processing apparatus 50, generates image data, and outputs it to the control unit 41. The transport drive unit T11, following the control of the control unit 41, transports the continuous paper P whose image has been read by the image inspection unit 61 to the downstream winding device 70. The winding unit 72, following the control of the control unit 41, transports the continuous paper P transported from the image inspection device 60 to the support shaft 71, and winds the transported continuous paper P onto the support shaft 71 for holding.

[0054] Next, the operation of the image forming system 1 will be explained with reference to Figures 3 and 4. Figure 3 is a flowchart of the image forming process. Figure 4 is a flowchart of the image forming process, a continuation of Figure 3.

[0055] In the image forming system 1, the memory unit 43 of the image forming apparatus 40 stores pre-set setting information such as image forming condition information related to image forming to be performed by the image forming unit 46, processing information such as the type and content of processing to be performed by the processing apparatus 20, 50, paper setting information such as the type and basis weight of the continuous paper P during image forming, paper transport condition information that can be selected according to the paper (transport speed of the continuous paper P, pressure contact state by the fixing unit 48 (and paper transport units T1, 49)), and image adjustment information such as the type and content of the image adjustment process to be performed.

[0056] Transport condition information includes the transport speed of the continuous paper P during image formation. Image adjustment information includes image density adjustment information, color resist adjustment information, discard band information, etc. Image density adjustment information This information pertains to the adjustment of the image forming unit body 47 for adjusting the density of the image formed on the continuous paper P. The color resist adjustment information pertains to the adjustment of the image forming positions of the image forming units 471Y, 472M, 472C, and 472K to prevent misalignment of the YMCK colors in the color image on the continuous paper P. The discard band is a solid band formed in an area of ​​the continuous paper P that does not affect the finished product, in order to avoid background staining that occurs in areas that are not to be printed. The discard band information pertains to the presence or absence of a discard band, its contents, etc. The setting information stored in the memory unit 43 of the image forming apparatus 40 can be changed as appropriate in response to input of various printing setting information from the user via the operation unit 421.

[0057] In the image forming system 1, when the user inputs an instruction to execute an image forming process and an instruction to input image data for printing (referred to as print data) via the operation unit 421, the control unit 41 executes the image forming process according to the image forming program stored in the storage unit 43. The input of print data is performed by reading the original document with the original document reading unit 45 and generating print data, or by receiving print data from an external device via the communication unit 44. The input print data shall include at least one image and is stored in the storage unit 43.

[0058] As shown in Figure 3, first, the control unit 41 determines whether the input (and storage) of the print data to be printed has been completed (step S11). If the input of the print data has not been completed (step S11; NO), the process proceeds to step S11.

[0059] When the input of print data is complete (step S11; YES), the control unit 41 assigns image identification information (e.g., an image identification number) to each image of at least one print data to be printed, arranges at least one image identification information in the order of image formation to create a print image list, and stores the created print image list in RAM 412 (step S12). The print image list is a list of image identification information in the order of image formation for normal printing. Then, the control unit 41 selects paper transport condition information based on the paper setting information of the continuous paper P stored in the storage unit 43, and activates the paper transport units T1 and 49 to start transporting the continuous paper P according to the selected paper transport condition information (step S13). From step S13 to step S34, which will be described later, the continuous paper P is transported by the paper transport units T1 and 49 under the same transport conditions as described in the paper transport condition information.

[0060] Then, the control unit 41 starts the processing processing units 21 and 51 (the parts that perform processing) based on the processing processing information of the setting information stored in the storage unit 43 (step S14). From step S14 to step S33, which will be described later, the processing processing units 21 and 51 perform processing on the continuous paper P as appropriate. Then, the control unit 41 starts the image forming unit 46 based on the image forming condition information of the setting information stored in the storage unit 43 (step S15). From step S15 to step S37, which will be described later, the image forming unit 46 continues to perform operations that enable image formation. Then, the control unit 41 refers to the print image list stored in the RAM 412 and determines whether or not there is any remaining (not deleted) image identification information (step S16).

[0061] If there is remaining image identification information in the print image list (step S16; YES), the control unit 41 determines whether the image identification information for the next image formation sequence from the remaining image identification information in step S16 is the second image or later (step S17). If the image identification information for the next image formation sequence is the second image or later (step S17; YES), the control unit 41 determines whether it is possible to start image formation for the image of the next image formation sequence in the print image list, leaving a predetermined image repetition interval (predetermined image interval) from the image that was immediately formed on the continuous paper P (step S18).

[0062] If it is possible to start image formation with a predetermined image interval (step S18; YES), the control unit 41 reads the print data of the image identification information for the next image formation order from the print image list from the storage unit 43, and controls the paper feeding unit 12, processing processing unit 21, paper adjustment unit 31, image formation unit 46, paper transport unit 49, image inspection unit 61 (transport of continuous paper P), winding unit 72, and transport drive unit T11 to start image formation of the read print data on the continuous paper P with a predetermined image interval (step S19). If the remaining image identification information is not the second image or later (step S17; NO), the process proceeds to step S19.

[0063] Then, the control unit 41 removes the image identification information of the image whose image formation was started in step S19 from the print image list (step S20). Then, the control unit 41 adds the image identification information whose image formation was started in step S19 to the inspection list stored in RAM 412 (step S21). When step S21 is executed for the first time, an inspection list including the image identification information whose image formation was started in step S19 is created and stored in RAM 412. The inspection list is a list that stores the image identification information of the images to be inspected in inspection order.

[0064] Then, as shown in Figure 4, the control unit 41 refers to the inspection list stored in the RAM 412 and determines whether there is any remaining (undeleted) image identification information (step S22). If there is remaining image identification information in the inspection list (step S22; YES), the control unit 41 determines whether the inspection start timing is the timing immediately before the portion of the continuous paper P on which the image of the next inspection order of the inspection list has been formed is transported to the image inspection unit 61 (step S23). If it is not the inspection start timing (step S23; NO), the process proceeds to step S16.

[0065] If it is the start of the inspection (step S23; YES), the control unit 41 controls the image inspection unit 61 to read the image of the image identification information for the next inspection sequence in step S23 from the continuous paper P and acquire the read image data (step S24). Then, the control unit 41 deletes the image identification information of the image read in step S19 from the inspection list (step S25).

[0066] Then, the control unit 41 compares the read image data acquired in step S25 with the print data corresponding to the image identification information of the read image data to determine whether or not there are image defects in the read image data as an image inspection process (step S26). The image defects determined in step S26 include image formation defects and processing defects. Image formation defects include misalignment of the image in the read image data relative to the print data, color misalignment of the image, density abnormalities, stains, etc. Processing defects are defects in the processing by the processing units 21 and 51, and include misalignment of the processing position in processing processes such as varnishing and die-cutting, uneven varnish application as a defect in varnishing, and die-cutting defects as a defect in die-cutting.

[0067] If there is no abnormality in the read image data (step S26; NO), the process proceeds to step S16. If there is an abnormality in the read image data (step S26; YES), the control unit 41 adds the image identification information of the image read in step S24 to the reprint list stored in RAM 412 (step S27), and proceeds to step S16. When step S26 is executed for the first time, a reprint list containing the image identification information read in step S24 is created and stored in RAM 412. The reprint list is a list that stores the image identification information of images to be reprinted due to abnormalities in the read image data in the order of image formation (reprint order).

[0068] Returning to Figure 3, if there is no remaining image identification information in the print image list (step S16; NO), the control unit 41 refers to the reprint image list stored in RAM 412 and determines whether there is any remaining (not deleted) image identification information (step S28). If there is no remaining image identification information in the reprint image list (step S28; NO), the process proceeds to step S22. If there is remaining image identification information in the reprint image list (step S28; YES), the control unit 41 determines whether it is possible to start image formation for the image of the next image formation sequence in the reprint image list, leaving an integer multiple of the predetermined image repetition interval in step S18 from the image immediately formed on the continuous paper P, and the smallest integer multiple that allows for immediate reprinting (referred to as the integer multiple image interval) (step S29).

[0069] If it is not possible to start image formation with an integer multiple image interval (step S29; NO), the process proceeds to step S22. If it is possible to start image formation with an integer multiple image interval (step S29; YES), the control unit 41 reads the print data of the image identification information for the next image formation order in the reprint image list from the storage unit 43, and controls the paper feeding unit 12, processing processing unit 21, paper adjustment unit 31, image formation unit 46, paper transport unit 49, image inspection unit 61 (transport of continuous paper P), winding unit 72, and transport drive unit T11 to start image formation (reprinting) of the read print data on the continuous paper P with an integer multiple image interval (step S30).

[0070] Then, the control unit 41 removes the image identification information of the image formed in step S30 from the reprint image list (step S31). Then, the control unit 41 adds the image identification information of the image formed in step S30 to the inspection list stored in RAM 412 (step S32), and proceeds to step S22.

[0071] Returning to Figure 4, if there is no remaining image identification information in the inspection list (step S22; NO), the control unit 41 stops the processing units 21 and 51 (step S33). Step S22; NO is substantially equivalent to deciding not to reprint the image. Then, the control unit 41 stops the paper transport units T1 and 49 (step S34).

[0072] The control unit 41 is set to execute image adjustment processing using the image adjustment information stored in the memory unit 43, and determines whether an image adjustment operation is necessary based on whether the operation of the image forming system 1 satisfies the execution conditions for the image adjustment operation to be performed (step S35). If an image adjustment operation is necessary (step S35; YES), the control unit 41 causes the image forming unit 46 to perform the image adjustment operation based on the image adjustment information (step S36). The execution conditions for the image adjustment operation include the image formation distance (printing distance) of the continuous paper P from the start of image formation to the previous image formation being greater than or equal to a predetermined threshold, and the print coverage (printing rate) from the start of image formation to the previous image formation being less than a predetermined threshold. For example, if the continuous printing distance in the previous image formation was 1000m or more, the image forming unit body 47 creates density adjustment and color resist patches on the intermediate transfer belt 472. Furthermore, if the average coverage during image formation up to that point is less than 3%, the image forming unit body 47 creates a sacrificial strip on the intermediate transfer belt 472 to maintain stability between the driving of the intermediate transfer belt 472 and cleaning.

[0073] Of the image adjustment operations, the discarded band is intended to maintain the stability of the image forming system 1 itself, so the forming operation is performed at the timing of step S36, and the system is configured to accept the next print after the execution is completed. Of the image adjustment operations, the image density adjustment and color resist adjustment need to be performed before the next print, so they can be configured to be performed at the timing of step S36, or they can be configured to be turned on so that they are performed when the next print starts.

[0074] Then, the control unit 41 stops the image forming unit 46 (step S37) and terminates the image forming process. If image adjustment is not required (step S35; NO), the process proceeds to step S37.

[0075] Next, with reference to Figures 5(a) to 7(b), specific examples of image formation using the above image formation process will be explained. Figure 5(a) shows an example of image formation on a continuous sheet of paper P when there are no image defects in normal printing. Figure 5(b) shows an example of image formation on a continuous sheet of paper P when there are image defects on multiple pages, which is common in normal printing. Figure 6(a) shows an example of image formation on a continuous sheet of paper P when there are image defects on a few pages other than near the last page in normal printing. Figure 6(b) shows an example of image formation on a continuous sheet of paper P when there are image defects only on the last page in normal printing. Figure 7(a) shows an example of image formation on a continuous sheet of paper P when there are image defects on a few pages, including the last page, in normal printing. Figure 7(b) shows an example of image formation on a continuous sheet of paper P when there are image defects on a few pages, including the last page, in normal printing, and also when the last page is reprinted.

[0076] First, as shown in Figure 5(a), an example of image formation on continuous paper P when there are no image defects in normal printing will be explained. Here, multiple images from the print data that are formed at predetermined image intervals will be referred to as images on multiple pages. In Figure 5(a), images from normal printing on continuous paper P are indicated by "□", and images from reprinting are indicated by "■". Furthermore, the image inspection completion position (the position where it is determined that there is no reprinting), which is the position of the image forming unit 46 (image forming unit body 47) when image inspection is completed (step S22; NO of the image formation process described above), is indicated by "★", and the image formation stop position, which is the position of the image forming unit 46 (image forming unit body 47) when image formation on continuous paper P is stopped, is indicated by "▲". These symbols are the same in Figures 5(b) to 7(b). This is also an example where no processing is performed.

[0077] If there are no image defects in normal printing, first, steps S16 to S21 are performed to form multiple images on the continuous paper P, and then steps S23 to S27 are performed to perform image inspection, and this process is repeated. After the image is formed on the last page, step S22; NO is performed to terminate the image inspection at the image inspection end position (it is determined that there is no need for reprinting), and the continuous paper P is transported without further image formation. Then, steps S34 and S37 are performed to stop the transport of the continuous paper P and the image formation at the image formation stop position.

[0078] Furthermore, as shown in Figure 5(b), an example of image formation on continuous paper P in the case of multiple page image defects, which are common in normal printing, will be explained. When multiple page image defects are common in normal printing, first, in steps S16 to S21, multiple images of the normal printing are formed on the continuous paper P, and then in steps S23 to S27, image inspection is performed and this process is repeated. After the image of the last page is formed in normal printing, in steps S28 to S32, multiple images of the reprinted images of the images judged to have image defects in normal printing are formed on the continuous paper P, and then in steps S23 to S27, image inspection is performed and this process is repeated. Because there are many pages of images with image defects in normal printing, in steps S29 and S30, images are formed at an image interval that is an integer multiple of 1, the same as the predetermined image interval in normal printing.

[0079] After the image is formed on the last page of the reprint, step S22;NO indicates that the image inspection is terminated at the image inspection end position (it is determined that there is no reprint), and the continuous paper P is transported without image formation. Then, steps S34 and S37 indicate that the transport of the continuous paper P and image formation are stopped at the image formation stop position.

[0080] Furthermore, as shown in Figure 6(a), an example of image formation on continuous paper P when there are several pages with few image defects other than near the last page in normal printing will be explained. When there are several pages with few image defects other than near the last page in normal printing, first, in steps S16 to S21, multiple images of the normal print are formed on the continuous paper P, and then in steps S23 to S27, image inspection is performed and this is repeated. After the image of the last page is formed in normal printing, in steps S28 to S32, multiple images of the reprinted images of the images judged to have image defects in normal printing are formed on the continuous paper P, and then in steps S23 to S27, image inspection is performed and this is repeated.

[0081] Although there are images with image defects near the end of the normal print job, the number of such pages is small. Therefore, in steps S29 and S30, images are formed at image intervals that are integer multiples of 1, the same as the predetermined image interval for normal print. The subsequent processing is the same as the image formation example in Figure 5(b).

[0082] Furthermore, as shown in Figure 6(b), an example of image formation on continuous paper P when there is an image defect only on the last page in normal printing will be explained. When there is an image defect only on the last page in normal printing, first, in steps S16 to S21, multiple images of the image in normal printing are formed on the continuous paper P, and then in steps S23 to S27, image inspection is performed and this process is repeated. After the image of the last page is formed in normal printing, in steps S28 to S32, multiple images of the image that was judged to have an image defect in normal printing are formed on the continuous paper P, and then in steps S23 to S27, image inspection is performed.

[0083] However, since the image with the image defect from normal printing is on the last page, in steps S29 and S30, it is not possible to maintain image formation at an image interval that is an integer multiple of 1, the same as the predetermined image interval for normal printing. Instead, image formation is performed at an image interval that is an integer multiple of 10, which is the shortest distance that allows for reprinting. The subsequent processing is the same as the image formation example in Figure 5(b).

[0084] Furthermore, as shown in Figure 7(a), an example of image formation on continuous paper P when there are image defects on a small number of pages, including the last page, in normal printing will be explained. When there are image defects on a small number of pages, including the last page, in normal printing, first, in steps S16 to S21, multiple images of the normal printing are formed on the continuous paper P, and then in steps S23 to S27, image inspection is performed and this process is repeated. After the image of the last page is formed in normal printing, in steps S28 to S32, multiple images of the reprinted images of the images that were judged to have image defects in normal printing are formed on the continuous paper P, and then in steps S23 to S27, image inspection is performed.

[0085] However, because there are image defects on multiple pages, including the last page, in the normal print, in steps S29 and S30, it is not possible to maintain image formation at the same integer multiple image interval as the predetermined image interval in the normal print between the reprinted images. For example, on the last page of the reprint, image formation is performed at an integer multiple image interval of 8. The subsequent processing is the same as the image formation example in Figure 5(b).

[0086] Furthermore, as shown in Figure 7(b), an example of image formation on continuous paper P in a case where there are image defects on a few pages, including the last page, during normal printing, and the reprint of the last page also has image defects, will be explained. When there are image defects on a few pages, including the last page, during normal printing, first, in steps S16 to S21, multiple images of the normally printed image are formed on the continuous paper P, and then in steps S23 to S27, image inspection is performed, and this process is repeated. After the image of the last page is formed during normal printing, in steps S28 to S32, multiple images of the reprint of the image that was determined to have an image defect during normal printing are formed on the continuous paper P, and then in steps S23 to S27, image inspection is performed.

[0087] However, because there are image defects on multiple pages, including the last page, in the normal print, in steps S29 and S30, it is not possible to maintain image formation at the same integer multiple image interval as the predetermined image interval in the normal print between the reprinted images. For example, on the last page of the first reprint, image formation occurs at an integer multiple image interval of 4. Furthermore, because there are image defects on the last page of the first reprint as well, it is similarly not possible to maintain image formation at an integer multiple image interval of 1, and image formation occurs at an integer multiple image interval of 10. The subsequent processing is the same as the image formation example in Figure 5(b).

[0088] As described above, according to this embodiment, the image forming system 1 includes a paper transport unit T1, 49 that transports continuous paper P according to a paper transport path, an image forming unit 46 that forms an image on the continuous paper P, an image inspection unit 61 located downstream of the image forming unit 46 in the paper transport path that reads the image formed on the continuous paper and generates image data, and a control unit 41 that determines whether or not there is an image defect based on the read image data and decides whether or not to reprint the image that has been determined to have an image defect based on the result of the determination. The control unit 41 continues the operation of the image forming unit 46 until it decides not to reprint the image.

[0089] Therefore, the image forming unit 46 continues to operate (does not stop) until the reprinting is complete, which reduces the gap between the final image of the normal print and the reprinted image, as well as the change in image quality, when reprinting on continuous paper P.

[0090] Furthermore, the image forming unit 46 includes an image forming unit body 47 that forms an image on the continuous paper P, and a fixing unit 48 that fixes the formed image on the continuous paper P. Therefore, since the operation of the fixing unit 48 continues (does not stop), the blank space between the final image of normal printing and the reprinted image, as well as the change in image quality, can be reduced.

[0091] Furthermore, the control unit 41 continues to transport the continuous paper P to the paper transport units T1, 49 and the fuser unit 48 under the same transport conditions as during image formation until it determines that reprinting is not necessary. The transport conditions are the transport speed and the pressure state. As a result, the paper transport units T1, 49 and the fuser unit 48 continue to operate under the same transport conditions until reprinting is complete, which further reduces the change in image quality between the final image of normal printing and the reprinted image when reprinting with continuous paper P.

[0092] Furthermore, the control unit 41 determines whether or not there are image defects based on whether or not the read image data contains defective images. This allows for an accurate determination of whether or not reprinting on continuous paper P is necessary.

[0093] Furthermore, the control unit 41 determines that a defective image is included in the read image data and decides to reprint. This allows for a quick determination of whether or not to reprint on continuous paper P.

[0094] Furthermore, if an image defect is detected, the control unit 41 positions the image to be reprinted after the final image formed by normal printing. This further reduces the blank space between the final image of normal printing and the reprinted image.

[0095] Furthermore, if the interval between the image to be reprinted and the image formed before the reprint cannot maintain the predetermined image interval for normal printing, the control unit 41 forms the image to be reprinted by leaving an integer multiple image interval, which is an integer multiple of the predetermined image interval and the smallest image interval that allows for reprinting, from the image formed before the reprint. This makes it easy to perform post-processing (processing by the processing unit 51) on the reprinted image without misalignment.

[0096] Furthermore, the control unit 41 determines whether or not an image is defective based on the presence or absence of image formation defects in the read image data. Therefore, it is possible to accurately determine whether or not there is an image defect due to image formation defects.

[0097] Furthermore, the image forming system 1 includes processing processing units 21 and 51 upstream of the image inspection unit 61 in the paper transport path. The control unit 41 determines whether or not there is an image defect based on the presence or absence of processing defects by the processing processing units 21 and 51 in the read image data. Therefore, it is possible to accurately determine whether or not there is an image defect due to processing defects.

[0098] Furthermore, the control unit 41 continues the processing of the processing units 21 and 51 until it determines that reprinting is not necessary. As a result, the processing units 21 and 51 continue to operate until reprinting is complete, which further reduces the blank space between the final image of the normal print and the reprinted image, as well as the change in print quality, when reprinting on continuous paper P.

[0099] Furthermore, the control unit 41 does not perform image adjustment processing that may cause changes in image quality until it determines that reprinting is not necessary. Image adjustment processing includes image density adjustment, color resist adjustment, and the formation of a discard band. Therefore, since image adjustment processing is not performed until reprinting is complete, the gap between the final image of the normal print and the reprinted image, as well as changes in image quality, can be further reduced when reprinting on continuous paper P.

[0100] The above description discloses an example in which a storage unit 43 (HDD, SSD) is used as a computer-readable medium for the program according to the present invention, but the invention is not limited to this example. Other computer-readable mediums that can be used include non-volatile memory such as flash memory and portable recording media such as CD-ROMs. Furthermore, a carrier wave can also be used as a medium for providing the program data according to the present invention via a communication line.

[0101] The above description of the embodiment is merely an example of a preferred image forming system and program according to the present invention, and is not limited thereto.

[0102] For example, in the above embodiment, the image inspection device 60 (image inspection unit 61) reads the image formed on the continuous paper P, and the control unit 41 performs the determination process (image inspection process) of whether or not there is an image defect in step S26 of the image forming process, but the configuration is not limited to this. A second control unit, separate from the control unit 41 as the first control unit, may be configured to perform the determination process (processing related to image inspection) of whether or not there is an image defect in step S26 under the control of the control unit 41. The second control unit may be a component of the image forming device 40, or a component of the image inspection device 60, etc.

[0103] Furthermore, the detailed configuration and detailed operation of each part constituting the image forming system 1 in the above embodiments can be appropriately modified without departing from the spirit of the present invention. [Explanation of Symbols]

[0104] 1. Image forming system T1,49 Paper transport section 10 Paper feeder 11 Support shaft 12 Paper feed section 20 Processing Equipment 21 Processing Section 30 Paper adjustment device 31 Paper adjustment section 40 Image forming apparatus 41 Control Unit 411 CPU 412 RAM 42 Operation display section 421 Operation section 422 Display section 43 Storage section 44 Communications Department 45 Manuscript Reading Unit 46 Image forming unit 47 Image forming unit main body 471Y, 471M, 471C, 471K Image Forming Unit 472 Intermediate Transfer Belt 473 Secondary Transfer Roller 48 Fixing section 481 Heating roller 482 Pressure Roller 491 Conveyor Roller 492 Resist Roller 50 Processing equipment 51 Processing Unit 60. Imaging inspection equipment 61 Imaging Inspection Department 70 Winding device 71 Support shaft 72 Winding section T11 Transport drive unit P Continuous Paper

Claims

1. A paper transport unit that transports continuous paper according to the paper transport path, An image forming unit that forms an image on the continuous paper, An image reading unit is located downstream of the image forming unit in the paper transport path and reads the image formed on the continuous paper to generate image data. The system includes a control unit that determines whether or not there is an image defect based on the image data read, and determines whether or not to reprint the image that was determined to have an image defect based on the result of the determination, The control unit continues the operation of the image forming unit until it determines that it does not want to reprint the image. The control unit, when it determines that there is an image defect, places the image to be reprinted at a position after the final image formed by normal printing, and if the interval between the image to be reprinted and the image formed before the reprinting cannot maintain a predetermined image interval for normal printing, the image forming system forms the image to be reprinted by leaving an integer multiple image interval, which is an integer multiple of the predetermined image interval and the smallest image interval that allows for reprinting, from the image formed before the reprinting.

2. The image forming unit comprises an image forming unit body that forms an image on the continuous paper, The image forming system according to claim 1, further comprising a fixing unit for fixing the formed image onto the continuous paper.

3. The image forming system according to claim 1, wherein the control unit causes the paper transport unit to continue transporting the continuous paper under the same transport conditions during image formation until it determines that reprinting is not to be performed.

4. The image forming system according to claim 3, wherein the transport conditions include at least one of transport speed and pressure contact state.

5. The image forming system according to claim 1, wherein the control unit determines whether or not there is an image defect based on whether or not the read image data contains a defective image.

6. The image forming system according to claim 5, wherein the control unit determines that the read image data contains a defective image and decides to perform the reprint.

7. The image forming system according to claim 1, wherein the control unit determines whether or not there is an image defect based on whether or not there is an image formation defect in the read image data.

8. The processing unit is located upstream of the image reading unit in the paper transport path. The image forming system according to any one of claims 1 to 7, wherein the control unit determines whether or not there is an image defect based on whether or not there is a processing defect by the processing unit in the read image data.

9. The image forming system according to claim 8, wherein the control unit continues the processing of the processing unit until it determines that it is not necessary to reprint.

10. The image forming system according to claim 1, wherein the control unit does not perform image adjustment processing that may cause a change in image quality until it determines that reprinting is not to be performed.

11. The image forming system according to claim 10, wherein the image adjustment process includes at least one of image density adjustment, color resist adjustment, and formation of a discard band.

12. A paper transport unit that transports continuous paper according to the paper transport path, An image forming unit that forms an image on the continuous paper, A computer for an image forming system, which includes an image reading unit located downstream of the image forming unit in the paper transport path, and which reads the image formed on the continuous paper and generates image data, Based on the image data read, the control unit determines whether or not there is an image defect, and based on the result of that determination, it decides whether or not to reprint the image that was determined to have an image defect. The control unit continues the operation of the image forming unit until it determines that it does not want to reprint the image. The control unit, when it determines that there is an image defect, places the image to be reprinted after the final image formed by normal printing, and if the interval between the image to be reprinted and the image formed before the reprint cannot maintain a predetermined image interval for normal printing, the program forms the image to be reprinted by leaving an integer multiple image interval, which is an integer multiple of the predetermined image interval and the smallest image interval that allows for reprinting, from the image formed before the reprint.

Images