JP6747069B2 - Image forming system - Google Patents

Description

The present invention relates to an image forming system for forming an image on continuous paper, and more particularly to a technique for repeatedly forming an image on continuous paper by a plurality of image forming apparatuses connected in series.

An image forming apparatus such as a printer that forms an image on a sheet generally forms an image on a sheet called a cut sheet that is cut into a predetermined standard size such as A4 or B4. On the other hand, in this type of image forming apparatus, it is also possible to form an image on a long paper called roll paper. Such a long paper is often used for the purpose of repeatedly printing a label in a sticker format such as an address, a serial number or a product display. Hereinafter, an image forming apparatus that prints a label will be referred to as a “label printing apparatus”.

Regarding the printed matter output by the label printing apparatus, there are demands such as "printing labels at equal intervals for post-processing (die cutting and pasting processing)" and "desiring to reduce the space between labels as much as possible". Therefore, conventionally, in the original document data for offset, image data in which a plurality of labels are impositioned with a label interval of 0 mm is used. Further, in an inkjet continuous paper printing apparatus or the like, it is possible to perform printing without gaps between pages by processing such as stopping the feeding of pages or rewinding the continuous paper during printing.

For example, as a continuous paper printing device, a tandem continuous printing device that prints on continuous paper by two printing devices has been disclosed (for example, see Patent Document 1). The tandem continuous printing apparatus described in Patent Document 1 uses a part of print data as page identification information in order to synchronize a page printed by the first printing apparatus with a page printed by the second printing apparatus. Both pages are aligned based on the identification information.

JP, 2008-15609, A

By the way, in the electrophotographic continuous paper printer, there is a limitation that the paper cannot be stopped during printing in order to avoid damage to the paper due to heat of the fixing device. In addition, in a general electrophotographic printing apparatus, a gap is provided between the sheets to be conveyed (between pages), so that smoother sheet conveyance can be realized between the pages and adjustment such as color correction can be performed. Processing (for example, color correction and toner removal) was performed. However, in the electrophotographic continuous paper printing apparatus, since it is not possible to perform the adjustment processing and the like conventionally performed between pages, an area that cannot be printed (a non-printable area) is provided as an area between pages. There was a need (limitation). Conventionally, it was not possible to print 0 mm between the labels because of this unprintable area.

The technique described in Patent Document 1 is for aligning the pages printed by the first printing device and the second printing device, and does not mention the limitation of the unprintable area of continuous paper printing.

The present invention has been made in view of the above circumstances, and an object of the present invention is to form an image on continuous paper without limitation.

An image forming system according to an aspect of the present invention is configured such that a first image forming unit that forms an image on continuous paper and a first image forming unit are connected in series. The generation timing of the non-printable area of the second image forming unit, which forms the image on the same surface as the image formed, and the first image forming unit and the second image forming unit is dynamically changed. , And a sharing determination unit that determines sharing of image formation by the first image forming unit and the second image forming unit.

According to at least one aspect of the present invention, the allocation of the first image forming unit and the second image forming unit is dynamically determined so that the adjustment processing of the image forming unit is performed at an arbitrary timing. Thereby, an image can be formed on the continuous paper without limitation.
Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

It is a figure which shows the structural example of the whole system containing the image forming system which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the example of a schematic structure of the image forming system which concerns on the 1st Embodiment of this invention. It is a block diagram showing an example of functional composition of an image forming device concerning a 1st embodiment of the present invention. It is a block diagram which shows the hardware structural example of the printer controller which concerns on the 1st Embodiment of this invention. It is a schematic diagram showing an example of composition of software of a client terminal. FIG. 3 is a schematic diagram showing processing of received print data in the image forming apparatus according to the first embodiment of the present invention. It is a figure which shows the example of the manuscript data used by label printing. FIG. 3 is a diagram showing an example of a print-disabled area in one image forming apparatus. FIG. 3 is a diagram showing a print sharing example of the image forming system according to the first embodiment of the present invention. 6 is a flowchart showing a print sharing determination process according to the first embodiment of the present invention. It is a schematic diagram which shows the schematic structural example of the image forming system which concerns on the 1st example of the 1st Embodiment of this invention. It is a figure which shows the example of initial printing sharing concerning the 1st example of the 1st Embodiment of this invention. It is a figure which shows the example of printing allotment after changing the initial printing allotment concerning each of the 1st example of the 1st Embodiment of this invention, and each definition value. 8 is a flowchart showing a print allocation changing process when a fixed interval abnormality occurs according to the first example of the first embodiment of the present invention. FIG. 6 is a diagram showing an example (1) of a non-printable area due to switching between color and gray printing. FIG. 9 is a diagram showing an example (2) of a non-printable area due to switching between color and gray printing. FIG. 9 is a diagram showing an example of a print assignment change result by a next job according to the second example of the first exemplary embodiment of the present invention. 7 is a flowchart showing a print share changing process by color/gray print switching according to a second example of the first embodiment of the present invention.

Examples of modes for carrying out the present invention will be described below with reference to the accompanying drawings. In addition, in each of the drawings, constituent elements having substantially the same function or configuration are designated by the same reference numerals, and duplicate description will be omitted.

<1. First Embodiment>
[Overall system configuration]
FIG. 1 is a diagram illustrating a configuration example of the entire system including the image forming system according to the first embodiment. An image forming system 10 in FIG. 1 is an application of the present invention to a roll printing apparatus that forms an image on roll paper.

The image forming system 10 is connected to a network N, and a plurality of client terminals 5 and 6 are connected on the network N. The network N is a communication line such as a LAN (Local Area Network). The image forming system 10 includes image forming apparatuses 1 and 2 that form an image on roll paper, a paper feeding device 3 that sends the roll paper to the image forming apparatus 1, and a winding device 4 that winds the roll paper. The image forming system 10 receives a print job sent from the client terminals 5 and 6 and performs an image forming process (hereinafter, also referred to as “printing process”).

[Schematic configuration of image forming system]
FIG. 2 is a schematic diagram showing a schematic configuration example of the image forming system 10.
The image forming system 10 is a tandem type image forming system configured by connecting two image forming apparatuses 1 and 2 in series. The image forming apparatus 2 is arranged downstream of the image forming apparatus 1 in the feed direction of the roll paper R. First, the image forming apparatus 1 forms an image on the surface of the roll paper R, and then the image forming apparatus 2 forms an image on the same surface of the roll paper R on which the image is formed by the image forming apparatus 1. In this specification, the image forming apparatus 1 (first image forming apparatus) that first forms an image on the roll paper R is an upstream machine, and then the image forming apparatus 2 (second image forming apparatus) that forms an image on the roll paper R. Device) as the downstream machine.

The image forming apparatuses 1 and 2 adopt an electrophotographic method for forming an image by using static electricity, and for example, four colors of yellow (Y), magenta (M), cyan (C), and black (K) are used. This is a tandem type color image forming apparatus that superimposes toner images. In this embodiment, the printer engines 12 installed in the image forming apparatuses 1 and 2 are color printer engines having the same specifications.

The printer engine 12 included in the image forming apparatuses 1 and 2 includes, for example, a main controller 12a and an image forming unit 12b as shown in FIG. The image forming apparatuses 1 and 2 are provided with four image forming units 111Y, 111M, 111C, and 111K as the image forming unit 12b in order to form toner images of yellow, magenta, cyan, and black, for example. When the image forming units 111Y, 111M, 111C, and 111K are not distinguished, they may be referred to as the image forming unit 111.

Each image forming unit 111 has a charging unit (not shown), an LED writing unit (laser light source), a developing unit, and a photosensitive drum. Further, in the image forming apparatuses 1 and 2, the intermediate transfer belt 114, the secondary transfer portion 115, and the secondary transfer portion 115 to which the images formed on the photoconductor drums of the image forming units 111Y, 111M, 111C, and 111K are transferred. The fixing unit 116 is provided on the downstream side of the roll paper R in the feeding direction. On the downstream side of the fixing unit 116 in the feeding direction, the conveyance path extends and is connected to the discharge port.

First, in the image forming mode, the image forming apparatus 1 charges the photoconductor drums included in the image forming units 111 of the respective colors and exposes the surface of the photoconductor drums in accordance with the original image to form an electrostatic latent image on the photoconductor drums. Form. Then, toner is attached to the electrostatic latent images of the photoconductor drums corresponding to each of yellow, magenta, cyan, and black by using the developing unit, and toner images of respective colors are formed. Next, the toner images formed on the yellow, magenta, cyan, and black photoconductor drums are sequentially primary-transferred to the surface of the rotationally driven intermediate transfer belt 114.

Next, the secondary transfer unit 115 (secondary transfer roller) secondarily transfers the toner image of each color primarily transferred onto the intermediate transfer belt 114 onto the roll paper R supplied from the paper feeding device 3. A toner image of each color on the intermediate transfer belt 114 is secondarily transferred onto the roll paper R, so that a color image is formed. The image forming apparatus 1 conveys the roll paper R on which the color toner image is formed to the fixing unit 116.

The fixing unit 116 is a device that performs a fixing process on the roll paper R on which the color toner image is formed, which is supplied from the image forming apparatus 1. The fixing unit 116 pressurizes and heats the conveyed roll paper R to fix the transferred toner image on the roll paper R. The fixing unit 116 includes, for example, a fixing upper roller and a fixing lower roller that are fixing members. The upper fixing roller and the lower fixing roller are arranged in pressure contact with each other, and a fixing nip portion is formed as a pressure contact portion between the upper fixing roller and the lower fixing roller. A heating unit is provided inside the upper fixing roller, and the radiant heat from the heating unit heats the roller unit on the outer peripheral portion of the upper fixing roller.

The image forming apparatus 2 forms an image on the roll paper R conveyed from the image forming apparatus 1 by the image forming unit 12b (second image forming unit), and transfers the roll paper R to the winding device 4 via the conveyance path 21. Discharge. The winding device 4 winds the discharged roll paper R by a winding roller.

Although the printer engines of the image forming apparatuses 1 and 2 have the same specifications, they may have different specifications such as a color printer engine that supports or does not support a spot color, and a color printer engine and a monochrome printer engine.

[Functional configuration of image forming apparatus]
FIG. 3 is a block diagram showing a functional configuration example of the image forming apparatuses 1 and 2.
The image forming apparatuses 1 and 2 each include a printer controller 11, a printer engine 12, an operation unit 13, and a storage unit 14. The printer engine 12 includes a main control unit 12a and an image forming unit 12b.

The printer controller 11 receives the print job and generates raster data (image forming data) from the print data of the print job.
The main control unit 12a of the printer engine 12 is connected to each unit in its own device via a system bus and an interface (not shown), and controls the operation of each unit. A CPU (Central Processing Unit), for example, is used for the main controller 12a. Alternatively, an MPU (Micro-Processing Unit) may be used as the main control unit 12a.
The image forming unit 12b of the printer engine 12 forms an image on the roll paper R based on the image forming data under the control of the main control unit 12a.

The operation unit 13 outputs an input signal according to an operation of a user or the like to the main control unit 12a. For example, an input signal for instructing the start of a print job such as an image forming process is output to the main controller 12a. A touch panel or the like is used for the operation unit 13. The operation unit 13 is generally configured as an operation display unit in which a touch panel and a display panel are stacked.
The storage device unit 14 stores a computer program executed by the main control unit 12a, received data, and the like.

[Hardware configuration of printer controller]
FIG. 4 is a block diagram showing a hardware configuration example of the printer controller 11.
The printer controller 11 includes a CPU 121, a RAM (Random Access Memory) 122, a NIC (Network Interface Card) 123, a HDD 124, an engine I/F 125, and a transfer buffer 126, and each unit is connected via a system bus. A transfer buffer 126 is connected to the engine I/F 125.

The CPU 121 (control unit) is connected to each unit in the printer controller 11 via the system bus and controls the operation of each unit. The CPU 121 constitutes a control unit together with the RAM 122. The CPU 121 performs assignment determination processing, RIP (Raster Image Processor) processing, and the like on print data input from the client terminals 5 and 6.
The RAM 122 temporarily stores data necessary for each processing by the CPU 121.
The HDD 124 stores programs and the like for the CPU 121 to perform processing and control.

The NIC 123 is an example of a communication interface, and performs data transmission/reception processing with the client terminals 5 and 6 via the network N.
The engine I/F 25 performs data transmission/reception processing with respect to the printer engine 12.
The transfer buffer 126 is a buffer that temporarily stores the image forming data in order to transfer the image forming data to the printer engine 12.

The CPU 121 will be further described. The CPU 121 includes at least a sharing determination unit 121a and a RIP processing unit 121b. The sharing determining unit 121a may be provided at least in the image forming apparatus 1 which is the upstream machine, but may be provided in both the upstream machine and the downstream machine. The function of each unit of the CPU 121 is realized by the CPU 121 executing a program read from the HDD 124.

The allocation determining unit 121a determines allocation of image formation of print data by the image forming apparatus 1 and the image forming apparatus 2 (print allocation) depending on the content of the print job, the state of the image forming apparatus, and the like. That is, the allocation determining unit 121a determines which of the image forming apparatus 1 and the image forming apparatus 2 should form an image of an object included in the print data according to a standard described later. The allotment determination unit 121a sends the determined allotment contents (hereinafter, may be referred to as “allotment information”) to the RIP processing unit 121b. Due to this sharing, the print area of the print data (or the area where the object is arranged) is substantially the first area in which the image forming apparatus 1 forms an image and the image forming apparatus 2 forms the image. It is divided into two areas.

The RIP processing unit 121b performs rasterizing processing (RIP processing) using the print data of the print job to generate raster data (image forming data) for the image forming apparatuses 1 and 2, and outputs the raster data to the engine I/F 125. To do. The image forming data includes, for example, a tag bit plane, a yellow Y plane, a magenta M plane, a cyan C plane, and a black K plane. These tag bit planes, Y planes, M planes, C planes, and K planes are output to the corresponding image forming units 111Y, 111M, 111C, and 111K together with the output settings included in the print job. Tag bits corresponding to the object type (character object, graphic object, or image object) of each area of print data are attached to the tag bit plane.

In the present embodiment, the printer controller 11 is configured separately from the printer engine 12, but the same function as the printer controller 11 may be configured to be operated by the main control unit 12a of the printer engine 12. The printer controller 11 may be a device separate from the image forming apparatuses 1 and 2.

Further, in the present embodiment, the printer controller 11 is configured to generate raster data for upstream machines and downstream machines on the upstream machine side and send the raster data for downstream machines from the upstream machine to the downstream machine. A method may be used in which the raster data is shared between the downstream side and the downstream side to generate the raster data. For example, when the raster data is shared between the upstream machine and the downstream machine, the downstream machine acquires the print data and the information regarding the sharing from the upstream machine, and the downstream machine generates the raster data for the downstream machine based on these. Alternatively, the downstream machine may obtain the print data after the division from the upstream machine, and subject the print data to the rasterization process as it is.

[Software configuration of client terminal]
FIG. 5 is a schematic diagram showing a configuration example of software of the client terminals 5 and 6.
On the client terminals 5 and 6, an application 131 that edits and browses document data and a printer driver 132 that prints are operating. The printer driver 132 makes settings necessary for printing and generates print data in accordance with a print instruction from the application 131. Then, the printer driver 132 transmits the generated print data to the printer controller 11 via a network I/F (not shown) such as NIC. The print data is PDL (Page Description Language) data described in a language readable by the printer engine 12 (PCL (Printer Control Language), PostScript, or the like).

[Outline of print data processing]
FIG. 6 is a schematic diagram showing processing of received print data in the image forming apparatus 1.
The print data D1 transmitted from the client terminals 5 and 6 to the image forming apparatus 1 is converted into image forming data D2 by the printer controller 11. The image forming data D2 is transmitted to the printer engine 12, and the printer engine 12 (the image forming unit 12b in FIG. 3) uses the image forming data D2 to repeatedly specify the number of images (for example, labels) on the roll paper R. To print. In the case of print data of a plurality of pages, a plurality of pages are continuously printed on the roll paper R. The image forming apparatus 2 also has the same point that an image is printed on the roll paper R based on the image forming data generated from the print data.

[Example of print data]
FIG. 7 is a diagram showing an example of print data used in label printing.
In the label printing, printing is performed based on print data in which a plurality of label images (label objects) are placed on one page. Hereinafter, the label image will be simply referred to as “label”. A mark called an "eye mark" is generally arranged in the print data in addition to the label. The eye mark is a reference position used by a post-processing machine that performs punching after printing to perform alignment, and normally a black square is used. Imposition of the label may be performed by the user using a commercially available application or may be automatically performed by a dedicated application. At that time, the arrangement of the label and the arrangement of the eye mark are performed according to the specifications of the image forming apparatuses 1 and 2 and the post-processing machine owned by the user.

In the example of FIG. 7, eye marks 21a and 21b are arranged at predetermined intervals above the print area of the print data. Then, three elliptical labels 22 are arranged in one line along a direction perpendicular to the sub-scanning direction (corresponding to the feeding direction) with the eye mark 21a as a base point. Similarly, three labels 22 are arranged in one line along the direction perpendicular to the sub-scanning direction, with the eye mark 21b as the base point. The three labels 22 arranged with the eye mark 21a as a base point and the three labels 22 arranged with the eye mark 21b as a base point are in contact with each other in the sub-scanning direction. There is no gap between them.

[Example of non-printable area]
FIG. 8 is a diagram showing an example of the unprintable area in the image forming apparatus 1. The image forming apparatus 2 is also the same in that nonprintable areas are required at regular intervals.

The hatched portions between pages indicate unprintable areas 23 that occur at equal intervals in the sub-scanning direction. In a page printer-based image forming system (roll paper printing apparatus), pages are printed continuously, but hardware (for example, ASIC (Application Due to the limitation of (Specific)), continuous printing may not be possible without gaps between pages.

Hardware limitations include memory, HDD, dedicated IC, and printing process limitations when printing images. For example, conventionally, a count value of the number of images is held in a memory, and the count value is reset when the count value reaches a predetermined count value, but a non-printable area 23 having a predetermined width (for example, 1 mm) is provided between pages for reset processing. ..

Due to these restrictions, there was a situation in which images could not be printed continuously and the distance between labels in printed matter was not 0 mm or even. It should be noted that the non-printable area 23 may be set originally in units of several pages, but in general, it is often set between pages in consideration of the processing by the post-processing machine. Further, in recent variable printing, the content of the page memory is updated page by page, so that the unprintable area 23 is set between pages.

The intervals in the sub-scanning direction between the plurality of unprintable areas 23 differ depending on the data size of the print data. For example, depending on the print data, the interval based on the data size is 400 mm, and when the data size is small, it is 300 mm or 200 mm.

The present embodiment uses an electrophotographic image forming apparatus in which there is a non-printable area and the paper feed cannot be stopped during printing due to the reason that a fixing unit is provided and the like. The printing is performed without any gap between the images in the directions. In the present embodiment, in order to eliminate such a limitation, the sharing of the image forming apparatus 1 and the image forming apparatus 2 is dynamically changed so that the adjustment processing of the image forming unit can be performed at an arbitrary timing. Note that the description of the eye mark is omitted in the following description.

[Example of sharing of printing]
Next, an example of print sharing between the image forming apparatus 1 (upstream machine) and the image forming apparatus 2 (downstream machine) of the image forming system 10 according to the first embodiment will be described with reference to FIGS. 9 and 10.

FIG. 9 is a diagram illustrating a print sharing example of the image forming system 10 according to the first embodiment.
In the image forming system 10, the upstream machine and the downstream machine are arranged in series, and printing is performed on the same surface. In FIG. 9, the objects are printed from left to right (the feed direction of the roll paper R is from right to left), the object printed by the upstream machine is indicated by "1", and the object printed by the downstream machine is indicated by "2". .. Eleven objects 51 to 61 are printed on the roll paper R. In FIG. 9, when three objects are printed by the upstream machine, one object is printed by the downstream machine, and three objects are printed again by the upstream machine.

The unprintable area 71 is an area in which printing cannot be performed by the upstream machine, and the unprintable area 72 is an area in which printing cannot be performed by the downstream machine. In the upstream machine, adjustment processing is required when a certain number of objects (for example, three) are printed, and the adjustment processing is executed and a certain amount of adjustment processing time is required, resulting in a non-printable area 71 (adjustment processing timing).

[Print sharing determination process]
FIG. 10 is a flowchart showing the print share determination processing according to the first embodiment. The CPU 121 on the upstream machine side executes the program read from the HDD 124, thereby realizing the series of processing in FIG. 10.

First, the allocation determining unit 121a (FIG. 4) reads out the size RstLen1 that needs to be adjusted in the upstream machine, which is registered in the HDD 124 or the like in advance (S1). Alternatively, the calculation may be performed based on a hardware limitation, for example, a value when the count value of the number of images held in the memory in the ASIC is reset. Note that RstLen2 in the figure indicates a size that requires adjustment in the downstream machine.

When the upstream machine is the printing start apparatus for the target job, the allocation determining unit 121a uses the object size Obj, the specified object interval size Blank, and the size RstLen1 that needs to be adjusted by the upstream machine to perform the adjustment process on the upstream machine. The number N of printable objects (N is a natural number) is calculated (S2). The calculation formula for the number N of objects is represented by formula (1).

N=RstLen1÷(Obj+Blank)... (1)

Next, the allocation determining unit 121a sets up to the Nth object (three objects in this example) in the printing allocation of the upstream machine (S3). Next, the N+1th object is set to the print sharing of the downstream machine (S4).

Similarly, the allotment determination unit 121a calculates the print allotment of the N+2th object, and thereafter determines the print allotment of all objects. At the same time, the timing at which the printing share is switched is set for each image forming apparatus. Both the upstream machine and the downstream machine perform the adjustment processing when the timing at which the printing allocation is switched (printing prohibited areas 71 and 72) is reached.

In this manner, the allocation determining unit 121a allocates the image formation by the upstream machine and the downstream machine so that the upstream machine and the downstream machine compensate for the area corresponding to the generation timing of the unprintable area in the one machine by the other machine. decide.

[Effects of First Embodiment]
According to the above-described first embodiment, the assignment determination unit 121a causes the upstream machine to preferentially share the printing of the object, and causes the downstream machine to perform the adjustment processing earlier. As a result, for example, when printing cannot be performed by a device to which printing is shared (for example, an upstream machine), when it becomes necessary to change the printing allocation from that device to another device (for example, a downstream machine), It is possible to deal with the equipment of. By performing the adjustment processing of the upstream machine and the downstream machine at such arbitrary timing, it is possible to form an image on continuous paper without limitation.

<2. First Example of First Embodiment>
Next, as a first example of the first embodiment, an example of changing the print sharing when an image abnormality that appears in a constant cycle during printing is found will be described with reference to FIGS. 11 to 14.

[Schematic configuration of image forming system with reading section]
FIG. 11 is a schematic diagram illustrating a schematic configuration example of the image forming system according to the first example of the first embodiment. The image forming system 10A has a configuration in which reading units 7 and 8 for reading an image on the roll paper R are installed in the image forming system 10 of FIG. The reading unit 7 is installed downstream of the image forming apparatus 1 in the feeding direction, and the reading unit 8 is installed downstream of the image forming apparatus 2 in the feeding direction. The reading units 7 and 8 are arranged so as to correspond to the width in the direction (main scanning direction) perpendicular to the feed direction of the roll paper R, read the image according to the feed speed of the roll paper R, and control the read data, for example, by main control. It is output to the unit 12a.

As the reading units 7 and 8, for example, a line sensor in which a plurality of photoelectric conversion elements are linearly arranged along a direction (main scanning direction) perpendicular to the feed direction is used. As the line sensor, for example, a CCD type image sensor or a CMOS type (including MOS type) image sensor can be used.

The main control unit 12a of the image forming apparatus 1 or 2 detects a blank portion between the objects from the read data, for example. Further, the main control unit 12a detects the color correction and the image abnormality by comparing the read data with the color change of the object during printing and the print data. This object can be identified from the print data received from the printer controller 11.

As the abnormality detection processing, the object images acquired by the reading units 7 and 8 are compared with the print data acquired from the printer controller 11, and the difference between the object image and the print data is detected. The main control unit 12a continues printing, and when the same abnormality is detected in the object printed and acquired by the same device, the main control unit 12a determines that the image abnormality occurs at a constant cycle.

[Example of initial print allocation]
In this embodiment, for simplicity, a case where an abnormality is found in the print result of the upstream machine will be described as an example.
FIG. 12 is a diagram illustrating an example of initial print sharing according to the first example of the first embodiment. The initial print sharing example of FIG. 12 is a result of printing sharing according to the print sharing determining process of FIG.

[Print allocation after change and each defined value]
FIG. 13 is a diagram showing an example of print allocation after changing the initial print allocation in FIG. 12 and each definition value.
When the object on the roll paper R in FIG. 13 has an elliptical scratch due to scratches on the photosensitive drum of the upstream machine, the reading unit 7 (FIG. 11) detects the elliptical scratch. When an abnormality is similarly detected in the succeeding object, the main control unit 12a determines that the abnormality occurs at regular intervals. In the example of FIG. 13, elliptical scratches are generated in the areas corresponding to the objects 52, 53, 54, 55, 58, 59, 60, 61 on the roll paper R. In the figure, the description of “1”→“2” means that the printing share is changed from the upstream machine to the downstream machine. The broken line ellipse represents a portion where the image abnormality does not occur due to the change of the printing share. This print sharing change processing is performed according to the flowchart shown in FIG.

[Print sharing change process when a fixed interval error occurs]
FIG. 14 is a flowchart showing the print share changing process when a fixed interval abnormality occurs according to the first example of the first embodiment. The CPU 121 on the upstream machine side executes the program read from the HDD 124, whereby the series of processing in FIG. 14 is realized.

When the sharing determination unit 121a of the upstream machine determines that an image abnormality occurs at a constant abnormality occurrence interval Err based on the read data of the reading units 7 and 8, the object size Obj and the object interval size Blank are used next by the upstream machine. It is determined whether or not an abnormality appears in the object to be printed (S11).

Equation (2) is an equation for determining whether or not an abnormality appears in the object to be printed next. P is a position (current position) for determining whether or not an image abnormality appears in the next object, and Perr indicates a position where the previous error (image abnormality) occurred. Here, the left end of the roll paper R shown in FIG.

Blank+Obj>Err-(P-Perr)... (2)

When the image abnormality does not appear in the next object (NO in S11), that is, when the expression (2) is satisfied, the current print allocation is not changed, and the allocation determining unit 121a prints next in the upstream machine. The decision point is moved to the object to be processed (moving to the end of processing).

On the other hand, when the image abnormality appears in the next object in step S11 (YES in S11), that is, when the expression (2) is not satisfied, the sharing determination unit 121a causes the device in which the image abnormality occurs to print the next object. It is checked whether or not (here, the upstream machine) is in charge (S12). If it is not shared by the upstream machine (NO in S12), the determination point is moved to the object to be printed by the upstream machine next (shift to processing end). When the downstream machine shares the responsibility, no image abnormality occurs.

On the other hand, in step S12, when the upstream device is assigned (YES in S12), the assignment determining unit 121a determines that the printing position of the next object is not printable by a device that does not cause image abnormality (downstream device here). It is determined whether or not it is the area 72 (S13).

Further, the equation for determining whether or not the print position of the next object is the unprintable area of the device in which the image abnormality does not occur is shown in the equation (3). P2 is a print start position of a device that does not cause image abnormality (here, a downstream device). RstLen2 indicates the size that requires adjustment in the downstream machine.

P+Obj+Blank<P2+RstLen2... (3)

Further, when the print position of the next object is not in the unprintable area 72 of the downstream machine (NO in S13), that is, when the expression (3) is not satisfied, the allocation determining unit 121a determines that the printing allocation is performed from the upstream machine to the downstream machine. (S14). If it is the non-printable area 72 of the downstream machine (YES in S13), that is, if the expression (3) is satisfied, printing is carried out with the upstream machine in charge.

The allotment determination unit 121a performs the allotment for all the objects by performing the above-described determination of the objects to be printed by the upstream machine by moving the determination points to all the objects.

As a result of such print sharing change processing, in FIG. 13, the print distribution of the objects 55, 59, 60 is changed from the upstream machine to the downstream machine. As a result, the image abnormality appears on the roll paper R after the fourth object 54 when the eleventh object 61. That is, during that time, the image abnormality is not detected or the image abnormality is not on the object, and the printing is continued.

In FIG. 13, the case where an image abnormality occurs in the upstream machine has been described as an example. However, even when an abnormality occurs in the downstream machine, the same idea is applied to share printing.

[Effects of First Example of First Embodiment]
According to the first example of the first embodiment described above, even if the image forming apparatus 1 or 2 is in a state where an image abnormality occurs (abnormal state), the printing is shared by the image forming apparatuses that are not in the abnormal state. Be seen. As a result, printing can be continued without stopping the print job.

<3. Second example of first embodiment>
Next, a second example of the first embodiment will be described with reference to FIGS.
In a color printing device, when performing monochrome or grayscale printing (hereinafter referred to as "gray printing") after color printing, process adjustment such as cleaning the development system so that color toner does not get on the gray print Processing is required. Printing is not possible during process adjustment processing. Therefore, when a gray print job is performed next to a color print job, an unprintable area is generated by performing the process adjustment processing on the upstream machine and the downstream machine.

Here, FIG. 15 and FIG. 16 show examples of the unprintable area in the case of performing the print sharing according to FIG. 10 and printing the gray print job after the color print job.

[Example of non-printable area by switching between color and gray printing (1)]
FIG. 15 is a diagram showing an example (1) of a non-printable area due to switching between color and gray printing.
In the example shown in FIG. 15, after the last object 55 of the color print job is printed by the upstream machine (job end), after the gray process adjustment processing is completed (gray process adjustment time T1), the gray print job is started by the upstream machine. It is supposed to be.

[Example of non-printable area by switching between color and gray printing (2)]
FIG. 16 is a diagram showing an example (2) of a non-printable area due to switching between color and gray printing.
In the example illustrated in FIG. 16, in the color print job, the print share of the upstream machine (object 55) remains after the last print share of the downstream machine (object 54) is completed. In this case, the adjustment time T2) is started first. As a result, the next gray print job is started early after the color print job is completed. However, in both cases of FIG. 15 and FIG. 16, an unprintable area (for example, the unprintable area A1 of FIG. 15 and the unprintable area A2 of FIG. 16) occurs depending on the timing.

Note that, in FIGS. 15 and 16, objects 81 to 84 represent objects printed in the gray print job. Here, the sizes of the objects 81 to 84 of the gray print job in the sub-scanning direction (feed direction) are larger than the sizes of the objects 51 to 55 of the color print job. In both the upstream machine and the downstream machine, the adjustment process starts when the printing of three objects is completed in the color print job, and the adjustment process starts when the printing of two objects is completed in the gray print job.

[Example of the result of changing the print share by the next job]
FIG. 17 is a diagram illustrating an example of the print sharing change result by the next job according to the second example of the first embodiment. In the example of FIG. 17, before switching from a color print job to a gray print job, printing of a plurality of objects is continuously performed by a device (here, an upstream device) different from the device that starts the gray print job (here, a downstream device). The point is to implement it and gain time.

[Print sharing change processing by switching color/gray printing]
FIG. 18 is a flowchart showing the print sharing change processing by color/gray print switching according to the second example of the first embodiment. The CPU 121 on the upstream machine side executes the program read from the HDD 124, whereby the processing of FIG. 18 is realized. 18 will be described with reference to FIG.

FIG. 18 shows a process when the print allocation is changed at the timing when the next job is determined to be a gray print job. For simplicity, the case where the device currently printing is the upstream machine is described, but the same idea can be applied when the device currently printing is the downstream machine.

When it is determined that the next job is a gray print job while a color print job is being printed by the upstream machine (for example, immediately after the object 52 in FIG. 17), the allocation determining unit 121a of the upstream machine and the downstream machine determines that the job being printed is a gray print job. The number RemObj of the remaining objects that need to be printed is extracted (S21).

In addition, the number of printable objects PrintObj1 is calculated by the upstream machine until the timing of the next unprintable process (unprintable area 71) is reached (S22). The number of objects PrintObj1 is represented by Expression (4).

PrintObj1=RstLen1÷(Obj+Blank)... (4)

Next, the allocation determining unit 121a compares the number of printable objects PrintObj1 of the upstream machine with the number of remaining objects RemObj that need to be printed (S23), and the remaining number of objects RemObj is equal to or less than the number of printable objects PrintObj1. If there is (NO in S23), all the remaining objects are printed by the upstream machine. In this case, the allocation determining unit 121a sets the start device of the next job to the downstream machine (S28), and carries out the process adjustment processing of the downstream machine (S29).

On the other hand, when the remaining object number RemObj is larger than the printable object number PrintObj1 of the upstream machine in step S23, that is, when the downstream machine needs to print (YES in S23), the sharing determination unit 121a determines that the downstream machine The number of printable objects PrintObj2 is calculated (S24). The number of objects PrintObj2 is expressed by Expression (5).

PrintObj2=RstLen2÷(Obj+Blank)... (5)

Next, the allocation determining unit 121a compares the number of continuously printable objects of the downstream machine PrintObj2 with the number of remaining objects RemObj that need to be printed (S25). Here, when the number of objects PrintObj2 is larger than the number of objects RemObj (YES in S25), the assignment determining unit 121a determines that all the remaining objects (objects 53 to 55 here) can be printed by the downstream machine, and the printing assignment is performed. Is set (changed) to the downstream machine (S26). Then, the allocation determining unit 121a starts the process adjustment process 71 of the upstream machine (S27), and sets the starting device of the next job to the upstream machine. By setting the print allocation of the three objects 53 to 55 immediately before switching to the next job to the downstream machine, the adjustment processing of the upstream machine can be started immediately after the object 52 of the upstream machine allocation.

On the other hand, when the number of objects PrintObj2 does not exceed the number of objects RemObj in step S25 (NO in S25), that is, when the remaining objects cannot be printed only by the downstream machine, the allocation determining unit 121a determines that the next object is the upstream. The printing share of the machine remains unchanged (S30). Next, the allocation determining unit 121a sets the object to be checked to the next object (S31), and proceeds to step S21.

Then, in step S21, the allocation determining unit 121a similarly determines the next object, and continues the above processing until the object position becomes printable by any device.

In FIG. 17, the object 83 of the gray print job is assigned to the downstream machine and the object 84 immediately after is assigned to the upstream machine, but the objects 83 and 84 may be shared continuously by the downstream machine. The gray print job of FIG. 17 applies the concept of the print share determination processing of FIG.

[Effects of Second Example of First Embodiment]
According to the second example of the first embodiment described above, at the timing of switching a print job, a useless blank portion (a portion between the object 55 and the unprintable area 72 in FIG. 17) does not occur or is minimized. can do.

<4. Other>
Although the image forming apparatus 1 and the image forming apparatus 2 are separate bodies in the above-described first to third embodiments, the printer engine 12 of the image forming apparatus 1 and the printer engine 12 of the image forming apparatus 2 form one image. It may be provided in the forming device. Further, the printer controller 11 of each of the image forming apparatuses 1 and 2 may be provided outside the image forming apparatuses 1 and 2. Further, the printer controller 11 of each of the image forming apparatuses 1 and 2 may be shared and stored in the image forming apparatus 1.

Furthermore, the present invention is not limited to the above-described embodiments, and it goes without saying that various other application examples and modifications can be taken without departing from the gist of the present invention described in the claims. is there.

For example, the above-described embodiment is a detailed and specific description of the configuration of the device and the system in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to one having all the configurations described. .. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. Further, it is possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

Further, each of the above-described configurations, functions, processing units, processing means, etc. may be realized in hardware by designing a part or all of them with, for example, an integrated circuit. Further, the above-described respective configurations, functions and the like may be realized by software by a processor interpreting and executing a program that realizes each function. Information such as a program, a table, and a file that realizes each function can be stored in a recording device such as a memory, a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

Further, the control lines and information lines are shown to be necessary for explanation, and not all the control lines and information lines are shown in the product. In reality, it may be considered that almost all the configurations are connected to each other.

Further, in the present specification, the processing steps describing the time-series processing are not limited to the processing performed in the time-series according to the described order, but are not necessarily performed in the time-series, and may be performed in parallel or individually. It also includes processing executed by (for example, parallel processing or processing by objects).

DESCRIPTION OF SYMBOLS 1... Image forming apparatus (upstream machine), 2... Image forming apparatus (downstream machine), 7, 8... Reading unit, 10, 10A... Image forming system, 11... Printer controller, 12... Printer engine, 12a... Main control unit , 12b... Image forming unit, 121... CPU, 121a... Allocation determining unit, 121b... RIP processing unit, R... Roll paper

Claims (4)

A first image forming unit for forming an image on continuous paper;
A second image forming unit which is connected in series with the first image forming unit and forms an image on the same surface of the continuous paper as the surface on which the image is formed by the first image forming unit;
Image formation by the first image forming unit and the second image forming unit is performed so as to dynamically change the generation timing of the non-printable area of the first image forming unit and the second image forming unit. A sharing determination unit that determines the sharing ,
The allocation determining unit calculates the number N (N is a natural number) of objects that can be formed by the first image forming unit from the start of printing by the first image forming unit to the timing when adjustment processing is required, and N Up to the number of the objects are shared with the first image forming unit, the (N+1)th object is shared with the second image forming unit, and the (N+2)th object is again shared with the first image forming unit. Of the image forming unit, and in the first image forming unit and the second image forming unit, the other image forming unit supplements the region corresponding to the generation timing of the unprintable region in one image forming unit. As described above, the image forming system that determines the sharing of image formation by the first image forming unit and the second image forming unit . The image forming system according to claim 1 , wherein the allocation determining unit changes the allocation of image formation of the object to the other image forming unit when an abnormality occurs in the one image forming unit. If the adjustment processing of the first image forming unit and the second image forming unit is necessary when executing the next print job from the current print job, the allocation determining unit determines the next print job. the image forming system according to claim 1, the object of satisfying number fraction by calculating back from the timing, to share the different image forming unit and the image forming unit to start the next print job switching to. The first image forming unit and the second image forming unit, an image forming system according to any one of claims 1 to 3 perform the formation of the image by an electrophotographic method.

Images