JP2010208703A - Postprocessing system, image forming system and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain a reduction in productivity in an image forming system, even if time is required for processing in a processing object unit of a postprocessing means. <P>SOLUTION: This image forming system 10 includes an image forming device 12 for ejecting by forming an image on a recording medium, a first folding-up processing part 56 and a second folding-up processing part 62 for performing predetermined postprocessing, for example, folding-up processing, with every processing object unit to the carried recording medium, when the recording medium ejected from the image forming device 12 is carried. When the time required for the processing in the processing object unit of the first folding-up processing part 56 and the second folding-up processing part 62, is longer than an ejecting interval of the recording medium ejected from the image forming device 12, a carrying destination of the recording medium is switched to a processible postprocessing part with every processing object unit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a post-processing system, an image forming system, and a program.

  Japanese Patent Application Laid-Open No. 2004-151561 discloses a technique for performing parallel processing of an image forming operation and a post-processing operation by dividing a final set group by a number of copies in an image forming system that performs post-processing by transferring a plurality of sets from an image forming device to a post-processing device Is described.

  Japanese Patent Application Laid-Open No. 2003-228561 discloses an image forming apparatus that performs start / stop control of an image forming apparatus in consideration of initialization time of the post-processing apparatus. An image forming apparatus that controls the timing of paper discharge from the apparatus is described.

Japanese Patent Laid-Open No. 11-18431 JP 2004-249638 A

  The present invention relates to a post-processing system, an image forming system, and a program capable of performing post-processing without increasing the recording medium discharge interval from the image forming unit even if processing of the post-processing unit in units of processing targets takes time. The purpose is to provide.

  According to the first aspect of the present invention, when the recording medium ejected from the image forming means for forming and ejecting the image on the recording medium is transported, the processing medium is predetermined for the transported recording medium. A plurality of post-processing means for performing post-processing, a transport means for switching the transport destination of the recording medium ejected from the image forming means to one of the plurality of post-processing means, and processing of the post-processing means When the time required for processing in the target unit is longer than the discharge interval of the recording medium discharged from the image forming unit, the transport destination is switched to a post-processing unit capable of processing for each processing target unit. And a control means for controlling the conveying means.

  According to a second aspect of the present invention, in the post-processing system according to the first aspect, the control unit is configured to transport the recording medium discharged from the image forming unit among the post-processing units that can be processed by the transport destination. The conveying means is controlled so as to switch to the post-processing means with the shortest or the post-processing means with the fastest processing speed.

  The invention according to claim 3 is designated in the post-processing system according to claim 1 or claim 2 by the designation means for designating whether or not to permit switching of the transport destination, and by the designation means to be non-switchable. In this case, a prohibiting unit for prohibiting the control by the control unit is further provided.

  According to a fourth aspect of the present invention, there is provided an image forming system comprising: an image forming unit that forms and discharges an image on a recording medium; and the post-processing system according to any one of the first to third aspects.

  According to the fifth aspect of the present invention, a plurality of post-processing means for forming and discharging an image on a recording medium and performing predetermined post-processing for each unit to be processed, and conveying the recording medium discharged from the image forming means A time required for processing in units of processing targets of the post-processing means for a computer mounted in a system including a transport means that switches the destination to one of the plurality of post-processing means and transports the image formation A program for functioning as a control unit for controlling the transport unit so that the transport destination is switched to a post-processing unit capable of processing for each unit to be processed when the recording medium discharge interval is longer than the unit. It is.

  According to the first aspect of the present invention, the post-processing can be performed without increasing the interval of discharging the recording medium from the image forming unit even if the post-processing unit takes a long time to process the processing target unit.

  According to the invention of claim 2, the end of the post-processing can be accelerated.

  According to the invention of claim 3, it is possible to designate whether or not the post-processing means can be switched.

  According to the fourth aspect of the present invention, the post-processing can be performed without increasing the interval of discharging the recording medium from the image forming unit even if the post-processing unit takes a long time to process the processing target unit.

  According to the fifth aspect of the present invention, the post-processing can be performed without increasing the discharge interval of the recording medium from the image forming unit even if the post-processing unit takes a long time to process the processing target unit.

1 is a schematic configuration diagram of an image forming system according to an embodiment. 1 is a schematic configuration diagram of a control system of an image forming system according to an embodiment. 3 is a flowchart illustrating a flow of post-processing control performed by a CPU of the image forming system. (A) is a diagram for explaining image formation (paper discharge state) and post-processing state when binding processing is performed for every two sheets only by the first binding processing unit, and (B) to (D) are It is a figure explaining the switching control in the case of performing a binding process every 2 sheets, switching a 1st binding process part and a 2nd binding process part.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an image forming system 10 according to the present embodiment. The image forming system 10 of the present embodiment includes an image forming apparatus 12 and post-processing apparatuses 14, 16, 18, and 20 connected to the image forming apparatus 12. The image forming system 10 receives an image formation request including image data and attribute information (described later) via a communication interface (not shown) from the outside, and operates based on the received image data and attribute information.

  The image forming apparatus 12 forms an image represented by the image data on a sheet as a recording medium according to the attribute information. The image forming apparatus 12 includes Y (yellow), M (magenta), C (cyan), and K (black) developing units 32Y, 32M, 32C, and 32K, and an endless intermediate transfer member 34. Yes.

  The intermediate transfer member 34 is wound around rollers 36A and 36B and a transfer roller 38 on the paper conveyance path side, and is driven to rotate in the direction of arrow A at a predetermined speed. The intermediate transfer member 34 is in contact with the photoreceptors 40Y, 40M, 40C, and 40K provided in the developing units 32Y, 32M, 32C, and 32K.

  The surfaces of the photoreceptors 40Y, 40M, 40C, and 40K are charged to a predetermined charging potential by a charger provided in the developing units 32Y, 32M, 32C, and 32K, and are converted into image data by an image processing apparatus (not shown). By irradiating light based on image signals (raster data) of each color Y, M, C, and K generated based on the electrostatic latent image, an electrostatic latent image is formed on the surface. Further, a developer (toner) is applied to the electrostatic latent images formed on the surfaces of the photoreceptors 40Y, 40M, 40C, and 40K by the developing devices provided in the developing units 32Y, 32M, 32C, and 32K, and development is performed. As a result, a toner image is formed.

  The toner images of the respective colors Y, M, C, and K formed on the photoreceptors 40Y, 40M, 40C, and 40K are transferred (primary transfer) while being superimposed on the intermediate transfer body 34. The toner image transferred to the intermediate transfer member 34 moves toward the transfer roller 38 by the rotation of the intermediate transfer member 34.

  On the other hand, the image forming apparatus 12 includes a storage unit 22 that stores paper. In the present embodiment, as the storage unit 22, storage units 22A and 22B that store a relatively large size sheet and storage units 22C and 22D that store a relatively small size sheet are provided, and the storage unit 22A22D. A large number of sheets are stacked and accommodated in each.

  Each of the storage units 22 </ b> A to 22 </ b> D is provided with a paper feed roller 26 that takes out the paper from the uppermost layer. The paper feed roller 26 takes out the paper from the storage units 22 </ b> A to 22 </ b> D and is conveyed toward the transfer roller 38. . In FIG. 1, the path indicated by the alternate long and short dash line is the transport path for transporting the paper.

  At the secondary transfer position, a roller (bias transfer roller) 38A is provided opposite to the transfer roller 38, and the sheet taken out from the storage unit 22 is sent between the transfer roller 38 and the roller 38A, and is intermediate. It is sandwiched between the transfer body 34 and the transfer roller 38 and the roller 38A.

  As a result, the sheet is sent out while the toner image on the intermediate transfer member 34 is transferred. Note that the intermediate transfer member 34 does not substantially affect the image (toner image) onto which the seam is transferred.

  Further, a fixing unit 42 is provided downstream of the secondary transfer position in the sheet conveyance direction. The fixing unit 42 includes a pair of fixing rollers 44. The sheet on which the toner image is transferred is sent between the fixing rollers 44. The fixing unit 42 heats the sheet fed between the fixing rollers 44 while pressing the sheet sandwiched between the fixing rollers 44 to fix the toner image on the sheet and send it out. As a result, an image corresponding to the image data is formed on the paper. Note that the development units 32Y, 32M, 32C, and 32K are used when forming a color image on a sheet, and the development unit 32K is used when forming a monochrome image.

  The paper on which the image is formed is discharged to the post-processing devices 14, 16, 18, and 20 by the discharge roller 46.

  A circulation conveyance path R that conveys the sheet that has passed through the fixing unit 42 toward the secondary transfer position of the transfer roller 38 is provided on the front side in the sheet conveyance direction with respect to the discharge roller 46 of the image forming apparatus 12. Is formed. When the sheet that has passed through the fixing unit 42 is sent to the circulation conveyance path R, the sheet is reversed and sent to the secondary transfer position. That is, images are formed on both sides of the sheet by the circulation conveyance path R.

  In addition, a display unit 24 and an operation unit 28 are connected to the image forming apparatus 12. The display unit 24 is a display for displaying various messages and information to the user. The operation unit 28 includes a plurality of keys, and various instruction information is designated by the user operating the keys. In the above description, the attribute information is described as being received from the outside together with the image data via a communication interface (not shown). However, the content of the attribute information may be designated by operating the operation unit 28. .

  The post-processing devices 14, 16, 18, and 20 connected to the image forming apparatus 12 perform predetermined post-processing on a sheet on which an image is formed by the image forming apparatus 12 according to the attribute information.

  The post-processing device 14 includes a curl correction unit 54. The curl correction unit 54 corrects curl (curved lines) of the paper discharged from the image forming apparatus 12 and conveyed. The curl correction is performed on any sheet on which an image is formed regardless of the attribute information. In FIG. 1, there is a conveyance path that takes in the sheets stacked in the storage unit 50 and joins the sheets discharged from the image forming apparatus 12, but the description is omitted in the present embodiment.

  The post-processing device 16 includes a first folding processing unit 56, a first switching unit 58, and a discharge unit 60. The first folding processing unit 56 folds the conveyed paper so as to be in a folded state (such as bi-fold or tri-fold) according to the attribute information for each number of sheets corresponding to the attribute information, and discharges it to the discharge unit 60. And accumulate. The first switching unit 58 switches the paper conveyance path to either a conveyance path toward the first folding processing unit 56 or a conveyance path toward the post-processing device 18.

  The post-processing device 18 includes a second folding processing unit 62, a second switching unit 64, and a discharge unit 66. The second folding processing unit 62 folds the conveyed paper so as to be in a folded state (such as bi-fold or tri-fold) according to the attribute information for each number of sheets according to the attribute information, and discharges the paper to the discharge unit 66. And accumulate. The second switching unit 64 switches the paper conveyance path to either a conveyance path toward the second folding processing unit 62 or a conveyance path toward the post-processing device 20.

  The post-processing device 20 includes a punching unit 68, a first binding processing unit 70, a second binding processing unit 72, a booklet creation unit 74, a third switching unit 76, a fourth switching unit 78, a fifth switching unit 80, and a discharging unit 82. , A discharge portion 84, a discharge portion 86, and a discharge portion 88.

  The punching unit 68 makes a hole in the conveyed paper according to the attribute information.

  The first binding processing unit 70 performs the binding process according to the attribute information for each number of sheets according to the attribute information, and discharges the conveyed paper to the discharge unit 84. Note that the binding process specifically refers to a process of binding the end portions of a plurality of sheets as a single sheet bundle using an alignment binding tool. The details of the binding process, such as where to bind or how many places to bind, are specified by the attribute information.

  The second binding processing unit 72 performs a binding process corresponding to the attribute information for each number of sheets corresponding to the attribute information, and discharges the conveyed paper to the discharge unit 86. The details of the binding process, such as where to bind or how many places to bind, are specified by the attribute information.

  The booklet creation unit 74 stacks the number of sheets according to the attribute information and performs saddle stitching, then folds the sheet in two, and discharges the conveyed sheet to the discharge unit 88 as a booklet.

  The third switching unit 76 is provided on the downstream side in the sheet conveyance direction with respect to the punching unit 68, and the sheet conveyance path is either a conveyance path toward the fourth switching unit 78 or a conveyance path toward the fifth switching unit 80. Switch to.

  The fourth switching unit 78 switches the conveyance path of the sheet conveyed from the third switching unit 76 to either the conveyance path toward the discharge unit 82 or the conveyance path toward the first binding processing unit 70.

  The fifth switching unit 80 switches the conveyance path of the sheet conveyed from the third switching unit 76 to either the conveyance path toward the second binding processing unit 72 or the conveyance path toward the booklet creation unit 74.

  The curl correction processing performed by the curl correction unit 54, the folding processing performed by the first folding processing unit 56 and the second folding processing unit 62, the punching processing performed by the punching unit 68, the first binding processing unit 70, and the second binding processing unit 70. Since the binding process performed by the binding processing unit 72 and the booklet creation process performed by the booklet creation unit 74 are performed after an image is formed on a sheet, in the present embodiment, these processes are collectively referred to as “post-processing”. It is called.

  In the following description, the curl correction unit 54, the first folding processing unit 56, the second folding processing unit 62, the punching unit 68, the first binding processing unit 70, the second binding processing unit 72, and the second binding are performed. When the processing unit 72 and the booklet creation unit 74 are described without being distinguished from each other, they are referred to as “post-processing units”.

  FIG. 2 is a schematic configuration diagram of a control system of the image forming system 10. The image forming system 10 includes a central processing unit (CPU) 100, a read only memory (ROM) 102, a random access memory (RAM) 104, a non-volatile memory (NVM) 106, a display unit 24, an operation unit 28, The image forming apparatus 12, the post-processing apparatus 14, the post-processing apparatus 16, the post-processing apparatus 18, the post-processing apparatus 20, and a bus 108 that connects them are provided. The image forming system 10 also includes a communication interface for communicating with the outside, but the illustration is omitted here.

  The CPU 100 governs the overall operation of the image forming system 10. The ROM 102 stores in advance a control program for controlling the operation of the image forming system 10, a post-processing switching control program described later, various parameters, and the like. The RAM 104 is used as a memory for temporarily storing various setting information set by the operation unit 28, image data / attribute information received from the outside, a work area for executing various programs, and the like. . The NVM 106 stores various data and the like.

  The display unit 24 and the operation unit 28 are as described above. The display unit 24 displays an image based on the display information transmitted from the CPU 100. In addition, an operation result on the operation unit 28 is transmitted to the CPU 100, and the CPU 100 performs control according to the instruction content indicated by the operation result.

  The image forming apparatus 12 includes an image forming unit 30 and a paper transport unit 48. The image forming unit 30 includes developing units 32Y, 32M, 32C, and 32K described with reference to FIG. 1, an intermediate transfer member 34, a transfer roller 38, a fixing unit 42, and a drive motor (not shown) that rotationally drives them. And is configured. The paper transport unit 48 includes a plurality of transport rollers (including the paper feed roller 26 and the discharge roller 46) provided on the paper transport path indicated by the alternate long and short dash line in the image forming apparatus 12 described with reference to FIG. And a drive motor (not shown) that rotationally drives the transport roller. The operations of the image forming unit 30 and the paper transport unit 48 are controlled by the control of the CPU 100.

  The post-processing device 14 includes the curl correction unit 54 as described above. Further, the post-processing device 14 uses a transport route (see also the transport route indicated by the one-dot chain line in FIG. 1) that transports the paper discharged from the image forming device 12 to the curl correction unit 54 and sends it to the post-processing device 16 side. A sheet conveying unit 90 including a plurality of conveying rollers and a driving motor (not shown) that rotationally drives these conveying rollers is provided. The operations of the curl correction unit 54 and the paper transport unit 90 are controlled by the CPU 100.

  The post-processing device 16 includes the first folding processing unit 56 as described above. Further, the post-processing device 16 includes the first switching unit 58 described above, a transport path for transporting the paper transported from the post-processing device 14 to the first switching unit 58, and the first folding processing from the first switching unit 58 to the paper. A transport path for transporting toward the section 56 and a transport path for transporting paper from the first switching section 58 toward the post-processing apparatus 18 (each transport path in the post-processing apparatus 16 indicated by a one-dot chain line in FIG. 1). A paper transport unit 92 having a large number of transport rollers and a drive motor (not shown) that rotationally drives these transport rollers is provided. The operations of the first folding processing unit 56 and the sheet conveying unit 92 are controlled by the control of the CPU 100.

  The post-processing device 18 includes the second folding processing unit 62 as described above. Further, the post-processing device 18 includes the second switching unit 64 described above, a transport path for transporting the paper transported from the post-processing device 16 to the second switching unit 64, and a second folding process from the second switching unit 64 to the paper. A transport path for transporting toward the section 62 and a transport path for transporting paper from the second switching section 64 toward the post-processing apparatus 20 (each transport path in the post-processing apparatus 18 indicated by a one-dot chain line in FIG. 1). A paper transport unit 94 having a large number of transport rollers and a drive motor (not shown) that rotationally drives the transport rollers is provided. The operations of the second folding processing unit 62 and the sheet conveying unit 94 are controlled by the control of the CPU 100.

  As described above, the post-processing device 20 includes the punching unit 68, the first binding processing unit 70, the second binding processing unit 72, and the booklet creation unit 74. Further, the post-processing device 18 includes a paper transport unit 96 having the third switching unit 76, the fourth switching unit 78, and the fifth switching unit 80 described above.

  Further, the post-processing device 20 includes a transport path for transporting the paper transported from the post-processing device 18 to the third switching unit 76, and the paper from the third switching unit 76 to the third switching unit 76, as indicated by a dashed line in FIG. A conveyance path for conveying the sheet toward the fourth switching unit 78, a conveyance path for conveying the sheet from the third switching unit 76 to the fifth switching unit 80, and a conveyance for conveying the sheet from the fourth switching unit 78 toward the discharge unit 82. A path, a conveyance path for conveying the sheet from the fourth switching unit 78 toward the first binding processing unit 70, a conveyance path for conveying the sheet from the fifth switching unit 80 toward the second binding processing unit 72, and a sheet of the fifth A transport path for transporting from the switching unit 80 toward the booklet creation unit 74 is provided. The paper transport unit 96 includes a plurality of transport rollers provided in the transport path, and a drive motor that rotationally drives the transport rollers. The operations of the punching unit 68, the first binding processing unit 70, the second binding processing unit 72, the booklet creation unit 74, and the paper transport unit 96 are controlled by the control of the CPU 100.

  In the present embodiment, except for the curl correction processing by the curl correction unit 54, different types of post-processing are not continuously performed (for example, binding processing is performed after the folding processing). Shall.

  In the present embodiment, the post-processing paper discharge destination corresponds to the type of post-processing to be executed and the post-processing unit to execute the post-processing. For example, when the folding process is performed, the paper discharge destination is either the discharge unit 60 or the discharge unit 66. When the folding process is executed by the first folding processing unit 56, the paper discharge destination is the discharge unit 60. Similarly, when the folding process is executed by the second folding processing unit 62, the paper discharge destination is the discharge unit 66.

  When the binding process is performed, the paper discharge destination is either the discharge unit 84 or the discharge unit 86. Further, when the binding process is executed by the first binding processing unit 70, the paper discharge destination is the discharge unit 84. Further, when the binding process is executed by the second binding processing unit 72, the paper discharge destination is the discharge unit 86.

  When the punching process is performed by the punching unit 68, the paper discharge destination is the discharge unit 82. When the booklet creation process is performed by the booklet creation unit 74, the paper discharge destination is the discharge unit 88. It becomes.

  Note that the curl correction processing by the curl correction unit 54 is performed on any sheet discharged from the image forming apparatus 12. When post-processing other than the curl correction processing by the curl correction unit 54 is not performed, the paper discharge destination is the discharge unit 82. In this case, the drilling unit 68 is controlled not to perform the drilling operation.

  Hereinafter, the operation of the image forming system 10 according to the present exemplary embodiment will be described. Note that the image forming apparatus 12 according to the present embodiment is configured to generate a reference signal, convey a sheet in accordance with the reference signal, and perform an image forming operation. Specifically, when images are continuously formed on a plurality of sheets, the CPU 100 first sends a reference signal for starting conveyance of the preceding sheet and image formation to the image forming unit 30 and the sheet conveying unit 48. In response to the reference signal, an image forming operation and a sheet conveying operation are controlled. When the reference signal is generated, the image forming unit 30 starts an image forming operation at a timing according to the reference signal, and the paper transport unit 48 takes out the paper from the storage unit 22 at a timing according to the reference signal. Start the paper transport operation.

  Then, from the reference signal generation, a reference signal for forming an image on a sheet following the preceding sheet is generated at intervals necessary for image formation of the image forming unit 30 and sheet conveyance of the sheet conveying unit 48, Control is performed so that the image formation for the next sheet starts. Accordingly, in the present embodiment, the sheet conveyance and the image forming process are performed at the reference signal generation interval (see also FIG. 4). Thereby, the discharge interval of the paper discharged from the image forming apparatus 12 depends on the generation interval of the reference signal.

  Further, the image forming operation performed by the image forming apparatus 12 including the generation of the reference signal and the post-processing operation of each post-processing unit of the post-processing devices 14 to 20 are performed according to the attribute information received together with the image data.

  The attribute information is transmitted to the image forming system 10 along with image data to be image formed. The attribute information may be input to the image forming system 10 by operating the operation unit 28.

  The attribute information is information indicating attributes that define image formation contents. For example, the paper attributes such as paper size, paper orientation (whether the long side of the paper is aligned with the transport direction or the short side is aligned with the transport direction), paper quality, paper type (tab paper, perforated paper, etc.) It includes attribute information, attribute information indicating whether the image is a color image or a monochrome image, whether to perform double-sided printing, and the specification of the storage unit 22 from which the paper is to be taken out.

  The attribute information also includes attribute information related to post-processing such as the type of post-processing to be executed (booklet creation processing, binding processing, punching processing, folding processing). Furthermore, when any post-processing is designated, attribute information indicating a post-processing target unit (for example, “2 sheets” for a binding process in which sheets are bound every two sheets) or post-processing Attribute information indicating the detailed contents of (for example, binding the upper left of the paper, folding in three, etc.) is also included.

  The attribute information includes attribute information for specifying a discharge destination for discharging the paper after the post-processing (for example, when performing the binding process as the post-processing, the discharge unit 84 or the discharge unit 86 is specified), Attribute information that specifies an offset (paper conveyance interval required for each post-processing target unit), attribute information that specifies whether or not switching control of a post-processing unit (to be described later) is permitted (hereinafter referred to as other attribute information) It is also called switching permission information.

  Based on the attribute information, the CPU 100 selects / switches a post-processing unit to be applied to paper conveyance, image formation, and post-processing. The attribute information is held in the area of the RAM 104 that can be referred to by the CPU 100 until the operation according to the image formation request is completed.

  Here, a reference signal generation interval (which may be referred to as a discharge interval of paper discharged from the image forming apparatus 12 or an image formation interval of the image forming apparatus 12) will be described. In this embodiment, this interval is an interval for enabling the finishing of each of the preceding sheet and the succeeding sheet to be guaranteed. In other words, this interval is controlled so that each of the constituent elements constituting the image forming unit 30 and the sheet conveying unit 48 forms a high-quality image on the sheet and can be processed smoothly.

  The generation interval of the reference signal is basically set according to the attribute information and each component constituting the image forming apparatus 12.

  For example, “paper quality” is an attribute relating to paper included in the attribute information. Specifically, when a sheet of slippery material is transported, misalignment or rotational misalignment (skew) occurs in the transport direction during transport. Accordingly, when the attribute “paper quality” of the attribute information indicates a paper having a paper quality that is more slippery than the average paper quality, a wider conveyance interval than usual is required.

  In addition, the components constituting the image forming unit 30 such as the fixing unit 42 may be reduced in heat capacity if the paper is thick paper thicker than plain paper or has a large image forming area. Accordingly, since it takes time to recover the proper temperature until the next sheet is fixed, it is necessary to widen the sheet conveyance interval.

  Further, when the sheet on which the image is formed is a specially shaped sheet such as a tab sheet or a holed sheet, untransferred toner is applied to the intermediate transfer member 34 facing the tab horizontal part or the holed part at the rear end of the sheet. In order to remove this, it is necessary to secure a cleaning time. In other words, when the paper type attribute indicates a specially shaped paper, the required interval is longer than that of the normal shaped paper.

  In addition to attributes relating to paper, there is an attribute indicating whether color image formation or monochrome (single color) image formation is an attribute that affects the generation interval of the reference signal.

  For example, in the developing units 32Y, 32M, 32C, and 32K, the fixing unit 42, etc., the processing speed is different and the response is different between color image formation and monochrome image formation. Usually, the required interval is wider in the case of color image formation than in the case of monochrome image formation.

  Therefore, the CPU 100 obtains the minimum necessary interval of each component of the image forming apparatus 12 based on the attribute information, generates a reference signal at an interval that compensates for the longest interval among the intervals, and the image forming unit 30. In addition, the sheet conveyance unit 48 is operated so as to continuously form images on a plurality of sheets. Hereinafter, the generation interval of the reference signal obtained as described above is referred to as a reference interval.

  It should be noted that a table in which attribute information is associated with information on the necessary time interval of each component may be stored in advance in the NVM 106 or the like, and the reference signal generation interval may be obtained from the attribute information and the table.

  By the way, as described above, of the plurality of post-processing units provided in the image forming system 10 according to the present embodiment, both the first folding processing unit 56 and the second folding processing unit 62 use the transported paper. This is a post-processing unit that performs a folding process. Both the first binding processing unit 70 and the second binding processing unit 72 are post-processing units that perform processing for binding the conveyed paper with a binding tool. In the present embodiment, when post-processing is performed after an image is formed on a sheet by the image forming apparatus 12, a plurality of post-processing units performing the same post-processing, the post-processing unit to be post-processed is set for each processing target unit. There are cases where post-processing section switching control for switching to is performed. Hereinafter, this control will be described in detail with reference to FIGS.

  FIG. 3 is a flowchart showing a flow of post-processing control performed by the CPU 100 of the image forming system 10. This control is started when the first reference signal is generated for the received image forming request and the image forming operation is started.

  In step 200, the CPU 100 selects a post-processing unit corresponding to the paper discharge destination indicated by the attribute information. The CPU 100 basically controls the conveyance of the sheet so that the post-processing unit selected here performs the post-processing unless the post-processing unit is switched in the following steps. Note that, as described above, the discharge destination of the post-processed paper corresponds to the type of post-processing to be executed and the post-processing unit that executes the post-processing. Accordingly, the post-processing unit to be operated is uniquely determined according to the type of post-processing to be executed and the paper discharge destination. Further, in this embodiment, when performing any one of a plurality of post-processings excluding the curl correction processing, the operation is performed by looking at the discharge destination without looking at the type of post-processing indicated by the attribute information. The post-processing unit to be executed is uniquely determined.

  In step 202, the CPU 100 determines whether or not to perform post-processing on the paper discharged from the image forming apparatus 12. Here, if a negative determination is made, the process proceeds to step 218, and the CPU 100 generates the next reference signal with the above-described reference interval from the timing at which the previous reference signal was generated. On the other hand, when an affirmative determination is made at step 202, the routine proceeds to step 204.

  In step 204, the CPU 100 determines whether or not the time required for processing in the processing target unit of the post-processing unit that executes post-processing is longer than the reference interval (here, corresponding to the paper discharge interval of the image forming apparatus 12). Determine whether.

  The time required for processing in the processing target unit of the post-processing unit is determined according to the attribute information and the post-processing unit that performs post-processing.

  The attribute information includes offset-designated attribute information as described above. When an offset other than 0 is specified by the attribute information, when the corresponding sheet is the last of the processing target unit in the post-processing that is performed with a plurality of sheets as the processing target unit, this offset is more than normal. Control is performed to widen the conveyance interval. Therefore, the time required for the processing becomes longer accordingly.

  Further, apart from this offset, each post-processing unit performs post-processing in the processing target unit indicated by the attribute information, but the minimum time required for processing for each processing target unit is determined for each post-processing unit. . Therefore, the CPU 100 adds the minimum required time for each processing target unit and the time corresponding to the offset specified by the attribute information to obtain the time required for processing in the processing target unit of the post-processing unit, This is compared with the reference interval.

  In the present embodiment, the post-processing time in the curl correction unit 54 is not considered. This is because it is not a post-processing that affects paper conveyance, and does not become a bottleneck. In addition, the method for obtaining the time required for processing for each processing target unit of the post-processing unit is not limited to the above. For example, when there is no offset attribute information, the minimum time required for each processing target unit is not calculated and the time required for processing in the processing target unit of the post-processing unit is calculated as it is. May be.

  If a negative determination is made in step 204, the process moves to step 218, and the CPU 100 generates the next reference signal with the above-described reference interval from the timing at which the previous reference signal was generated. On the other hand, when an affirmative determination is made at step 204, the routine proceeds to step 206.

  In step 206, the CPU 100 refers to the switching permission information included in the attribute information and determines whether switching of the post-processing unit (discharge destination) is permitted. If a negative determination is made here, the routine proceeds to step 208. In step 208, the CPU 100 waits to generate the reference signal after the time required for processing in the processing target unit of the post-processing unit, rather than generating the reference signal at a reference interval from the previous generation of the reference signal. Then, after the time required for processing in the processing target unit of the post-processing unit from the previous generation of the reference signal, the process proceeds to step 218 to generate the reference signal. On the other hand, if an affirmative determination is made in step 206, the process proceeds to step 210.

  In step 210, the CPU 100 determines whether there is another post-processing unit that can be post-processed instead of the currently selected post-processing unit. For example, when the currently selected post-processing unit is the first folding processing unit 56, in the present embodiment, the second folding processing unit 62 exists as another post-processing unit capable of executing the folding processing. . Therefore, in this case, a positive determination is made here. On the other hand, when the post-processing to be executed is a punching process, in this embodiment, since there is only one punching unit 68 that performs the punching process, a negative determination is made.

  If an affirmative determination is made in step 210, the process proceeds to step 212.

  In step 212, the CPU 100 determines whether or not the currently selected post-processing unit is a post-processing unit corresponding to the discharge destination indicated by the attribute information. If an affirmative determination is made here, the process proceeds to step 214.

  In step 214, the CPU 100 selects the post-processing unit with the shortest processing time from the post-processing units that can be processed. For example, in the present embodiment, the post-processing unit (for example, the post-processing whose position is closest to the image forming apparatus 12 is the shortest conveyance time of the paper discharged from the image forming apparatus 12 among the post-processing means that can be processed). Part). In addition, when the processing speeds of the plurality of post-processing units performing the same post-processing are different, the post-processing unit having the fastest processing speed may be selected. Then, the CPU 100 conveys the sheet to the selected post-processing unit, and discharges the sheet processed by the post-processing unit to a discharge destination corresponding to the post-processing unit 16. 92, the paper transport unit 94 of the post-processing device 18 and the paper transport unit 96 of the post-processing device 20 are controlled.

  On the other hand, if a negative determination is made in step 212, the process proceeds to step 216.

  In step 216, as in step 200, the CPU 100 selects a post-processing unit corresponding to the paper discharge destination indicated by the attribute information. That is, the state is switched from the state switched to another post-processing unit (discharge destination) in step 214 to the original post-processing unit (discharge destination). The CPU 100 conveys the sheet to the selected post-processing unit, and discharges the sheet processed by the post-processing unit to the discharge destination. The conveyance unit 94 and the sheet conveyance unit 96 of the post-processing apparatus 20 are controlled.

  Note that switching of the post-processing unit in steps 214 and 216 is performed for each processing target unit of post-processing. After step 214 and step 216, the process proceeds to step 218, and the CPU 100 generates a reference signal at a reference interval.

  If a negative determination is made in step 210, it means that there is no switchable post-processing unit, so that the reference signal of the reference signal is set so as to increase the interval between sheets discharged from the image forming apparatus 12 by waiting in step 208. Delay generation. When the time required for processing in the processing target unit of the post-processing unit elapses due to the standby in step 208, the process proceeds to step 218 to generate a reference signal.

  After step 218, in step 220, the CPU 100 determines whether an image formation request remains. Specifically, when the image forming operation (including post-processing) for the image forming request is completed, a negative determination is made at step 218, and when the image forming operation for the image forming request is not yet completed, step 218 is performed. Affirmative determination is made at 218. If an affirmative determination is made in step 218, the process returns to step 202, and control for the next sheet is performed. If a negative determination is made in step 218, the image forming operation ends.

  Here, further specific examples will be described.

  FIG. 4A is a diagram for explaining the image formation (paper discharge state) and the post-processing state when the binding processing is performed for every two sheets only by the first binding processing unit 70. In this figure, the reference interval of the reference signal is indicated by x. However, in this case, since the time required for the binding process in the processing target unit of the post-processing unit is longer than the reference interval x, the reference is performed at an interval longer than the reference interval x (indicated by x + α or x + β in the drawing). A signal is generated and controlled so that the paper discharge interval is widened.

  FIGS. 4B to 4D are diagrams illustrating switching control in the case where the binding process is performed for every two sheets while switching the first binding processing unit 70 and the second binding processing unit 72. More specifically, (B) is a diagram showing an image formation (paper discharge) state from the image forming apparatus 12, and (C) is a diagram for explaining a binding processing operation performed in the first binding processing unit 70. (D) is a figure explaining the binding process operation | movement performed by the 2nd binding process part 72. FIG.

  As shown in FIG. 4B, the sheet is discharged from the image forming apparatus 12 at the reference interval x. Then, as shown in FIG. 4C, first, the first binding processing unit 70 performs binding processing, the next two sheets are subjected to binding processing by the second binding processing unit 72, and the next two sheets are processed. The post-processing unit for performing the binding process is switched for each processing target unit such that the original first binding processing unit 70 performs the binding process. That is, while the binding process in the first binding processing unit 70 is being executed, the second binding processing unit 72 starts the binding process for the next two sheets.

  Therefore, even if the time required for the post-processing in the processing target unit is longer than the paper discharge interval (reference interval) x of the image forming apparatus 12, the post-processing is continuously performed without increasing the paper discharge interval of the image forming apparatus 12. Will be performed. (See also steps 204, 206, 210, 212, 214, 216 above.)

  In the above embodiment, the switching permission information is included in the attribute information, and if the switching permission information does not indicate permission, the switching control is prohibited (see step 206, NO, and step 208). However, the present invention is not limited to this, and if there is another post-processing unit that can be processed without preparing switching permission information, the post-processing unit may be controlled to be switched.

  In the above-described embodiment, an example of switching control of two post-processing units has been described. However, switching control of three or more post-processing units may be performed. For example, when the time required for post-processing in units of processing is very long, a post-processing section that can be processed is added to cope with it. In this case, an upper limit number may be provided in the post-processing unit to be switched (upper limit number = 0, switching is prohibited), and switching control may be performed as described above until the upper limit number is reached.

  In the above embodiment, the recording medium is described by taking paper as an example. However, the recording medium is not limited to this, and may be, for example, an OHP sheet.

DESCRIPTION OF SYMBOLS 10 Image forming system 12 Image forming apparatus 14 Post-processing apparatus 16 Post-processing apparatus 18 Recording paper 18 Post-processing apparatus 20 Post-processing apparatus 22 Storage part 24 Display part 26 Paper feed roller 28 Operation part 30 Image formation part 32Y, 32M, 32C, 32K development unit 34 intermediate transfer member 38 transfer roller 38A rollers 40Y, 40M, 40C, 40K photoconductor 42 fixing unit 44 fixing roller 46 discharge roller 48 paper transport unit 54 curl correction unit 56 first folding processing unit 58 first switching unit 60 Discharge unit 62 second folding processing unit 64 second switching unit 66 discharge unit 68 punching unit 70 first binding processing unit 72 second binding processing unit 74 booklet creation unit 76 third switching unit 78 fourth switching unit 80 switching unit 82, 84, 86, 88 Discharge unit 90, 92, 94, 96 Paper transport unit 100 CPU

Claims (5)

When a recording medium discharged from an image forming unit that forms and discharges an image on a recording medium is transported, a plurality of post-processings that are predetermined for each processing target unit are performed on the transported recording medium. Post-processing means;
A transport unit that switches the transport destination of the recording medium discharged from the image forming unit to one of the plurality of post-processing units, and transports the recording medium;
Post-processing that can be processed by the transport destination for each processing target unit when the time required for processing in the processing target unit of the post-processing unit is longer than the discharge interval of the recording medium discharged from the image forming unit Control means for controlling the conveying means to switch to means;
With an aftertreatment system. The control unit switches the transport destination to a post-processing unit in which the transport time of the recording medium discharged from the image forming unit is the shortest or a post-processing unit having the fastest processing speed among the post-processing units that can be processed. The post-processing system according to claim 1, wherein the conveying unit is controlled as follows. A designation means for designating whether to permit switching of the transport destination;
A prohibiting means for prohibiting control by the control means when the designation means designates that switching is impossible;
The post-processing system according to claim 1 or 2, further comprising: Image forming means for forming and discharging an image on a recording medium;
The post-processing system according to any one of claims 1 to 3,
An image forming system. When a recording medium discharged from an image forming unit that forms and discharges an image on a recording medium is transported, a plurality of post-processings that are predetermined for each processing target unit are performed on the transported recording medium. A computer mounted in a system comprising: post-processing means; and transport means for switching and transporting a transport destination of the recording medium discharged from the image forming means to any of the plurality of post-processing means,
Post-processing that can be processed by the transport destination for each processing target unit when the time required for processing in the processing target unit of the post-processing unit is longer than the discharge interval of the recording medium discharged from the image forming unit The program for functioning as a control means which controls the said conveyance means so that it may switch to a means.

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