JP6048664B2 - Image forming apparatus, image forming system, and image forming method - Google Patents

Description

  The present invention relates to an image forming apparatus that forms an image on a sheet, an image forming system including the image forming apparatus, and an image forming method.

In an image forming apparatus such as a copying machine, a printer, or a multifunction machine, a toner image is formed on a photoconductor provided in an image forming unit based on image data obtained by reading from a document reading device, and the toner Printing is performed by transferring an image onto a sheet fed from a sheet feeding tray and further fixing the image. Further, the sheet on which the image is formed on the front side can be reversed and conveyed by a reversing conveyance unit if desired, and can be recirculated to the sheet conveyance unit, whereby image formation and fixing can be performed on the back side.
The fixing device passes the paper through a fixing roller, a pressure belt, etc., and fixes the toner image on the paper by heating, pressing, etc., but the paper as it is formed is conveyed to the fixing device. Therefore, over time, the fixing member such as the fixing roller and the pressure belt may be soiled with toner, or the toner may adhere to the fixing member due to a paper jam. When a new sheet is passed through the fixing device, the toner on the fixing member adheres to the sheet and becomes dirty.
In addition, image formation position shift may occur in front and back printing, and the image density may change over time. Depending on the degree, these stains, misregistration, image density changes, and the like may cause the image quality to be deteriorated. For this reason, it is necessary to visually inspect the output.

However, when printing a large number of pages or printing a large number of copies, enormous man-hours and costs are required to visually check the printed results. In addition, the accuracy also varies. Therefore, there is a mechanism for detecting whether there is an abnormality in the image data after the image data is transferred to the paper.
When it is determined by such a mechanism that the page is defective, it is usually necessary to perform stop processing, remove the defective page, and start reprint processing. However, there are problems such as “downtime occurs” and “it is necessary to keep monitoring”.

For example, in Japanese Patent Application Laid-Open No. 2003-228620, for example, in Japanese Patent Application Laid-Open No. 2003-228620, a paper sheet determined to be defective is discharged to a paper discharge destination that is different from a normal paper discharge destination. An image forming apparatus that discharges paper has been proposed. Japanese Patent Application Laid-Open No. 2004-228867 proposes a method that enables inspection of page missing of printed paper and places colored paper at a position where the page is missing. According to these, printing can be continued without causing downtime.
Patent Document 3 proposes a printing apparatus that prevents the insertion of out-of-order order sheets by skipping blank order sheets in printing for which only some pages are to be output.

JP 2010-2463 A JP-A-4-156365 JP 2010-187079 A

However, in recent years, the printing speed has been increased, and even if it is determined to be defective, the next page is often already printed. That is, at the time of detection, pages that are not defective and that have been fed and not ejected remain in the machine. There are cases where it is not desirable or possible to stop printing immediately in terms of machine configuration or control even if the printing is still in progress. Therefore, if it is temporarily stopped, a defective page is removed, and reprinting is performed, there arises a problem that downtime occurs and monitoring must be performed.
In addition, when a large amount of paper is stacked at the paper discharge destination, the stacking amount increases as the subsequent paper discharge continues. As a result, as shown in FIG. 13, not only a defective page but also a good page is discharged. That is, if the paper discharge is continued even after it is determined to be defective, the defective paper YP1 is stacked on the normal paper P0, and the normal paper P2 is further stacked thereon. After that, when the defective paper is removed from the stacked paper and the paper determined to be defective is reprinted, the paper is stacked in the order of P0, P2, and P1, as shown in FIG. In order to arrange the page order, it is necessary to correctly replace the sheets while removing the stacked sheets, and there is a problem that the work load is large.
In the preceding example, the splinter paper is discharged to a separate paper discharge port. However, even if only the defective page is changed, there is no consideration of the pages in the machine that follow, and it is necessary to change the page order after printing is complete. become.

  The present invention has been made against the background of the above circumstances, and an image forming apparatus that can easily adjust the page order by discharging a reprinted sheet to a discharge destination different from the discharge destination immediately before the defect determination, An object is to provide an image forming system and an image forming method.

That is, among the image forming apparatuses of the present invention, the first aspect of the present invention is:
A paper feed tray for storing paper and feeding the paper;
A paper transport unit for transporting the fed paper;
An image forming unit for forming an image on the paper;
A defect detection unit for detecting a defect state in the sheet on which the image is formed;
A plurality of paper discharge destinations for discharging the paper;
A control unit that controls switching of the paper feed, the conveyance, the image formation, and the paper discharge destination, and acquires a detection result of the defect detection unit,
The control unit determines whether the sheet is defective based on the detection result. If it is determined that the sheet is defective , the page is determined to be defective before reprinting, and at least in-machine transported on subsequent pages. A part or all of the remaining paper is discharged as a scraped paper to the paper discharge destination immediately before the defective determination, and the page including the page determined after the defective is reprinted, and the same page as the defective paper is defective. Paper discharged to a different paper discharge destination than the paper discharge destination immediately before the determination, and the paper printed for the subsequent pages are the paper discharge destination immediately before the failure determination and the paper discharge destination from which the same page as the paper is discharged. Is characterized in that it is discharged to another discharge destination .

According to the present invention, reprinting can be performed so as to be discharged to another discharge destination in accordance with the timing at which the discharge destination can be switched. Furthermore, according to the present invention, it is possible to easily check the splinter paper and the page to be replaced with it, and it is possible to easily perform the replacement.
The image forming apparatus of the second aspect of the present invention is
A paper feed tray for storing paper and feeding the paper;
A paper transport unit for transporting the fed paper;
An image forming unit for forming an image on the paper;
A defect detection unit for detecting a defect state in the sheet on which the image is formed;
A plurality of paper discharge destinations for discharging the paper;
A control unit that controls switching of the paper feed, the conveyance, the image formation, and the paper discharge destination, and acquires a detection result of the defect detection unit,
The control unit determines whether the sheet is defective based on the detection result. If the sheet is determined to be defective, the control unit reprints a page including the page determined to be defective and then discharges immediately before the defect determination. Control to discharge to a different output destination,
When the second paper discharge destination becomes full during the reprinting or the subsequent page printing, the second paper discharge destination immediately before the defect determination and another paper discharge destination different from the second paper discharge destination are reprinted. The printed sheet is discharged.
According to the present invention, reprinting can be performed so as to be discharged to another discharge destination in accordance with the timing at which the discharge destination can be switched. Furthermore, according to the present invention, when it is detected that another paper discharge destination is full, the paper discharge can be continued by switching to the third paper discharge destination.

The image forming apparatus according to a third aspect of the present invention is the image forming apparatus according to the second aspect of the present invention, in which, when the control unit determines that there is a defect in the determination, a page determined to be defective before the reprinting, and a subsequent page The reprinting is performed after discharging at least a part or all of the sheet remaining in a state of conveyance on the page as a scraped sheet to a discharge destination immediately before the defect determination.

  According to the present invention, prior to reprinting, not only a paper determined to be defective but also a succeeding paper that may become a waste paper can be discharged as a waste paper. Subsequent sheets may be all of the sheets that have been fed and are being transported, and if paper discharge switching is in time, some of the remaining sheets in the machine will be scraped The paper may be discharged, and the remaining paper may be discharged and switched. At this time, the remaining sheets can be reprinted. Further, the succeeding paper as the paper is not limited to the paper remaining in the machine, and may be discharged to paper such as a section.

In the image forming apparatus according to a fourth aspect of the present invention, in the first or third aspect of the present invention, the control unit includes information on the scraped paper before the reprinting when the determination is defective. The paper is discharged.

  According to the present invention, it is possible to immediately confirm that the paper is scraped based on the information.

An image forming apparatus according to a fifth aspect of the present invention is the image forming apparatus according to the fourth aspect , wherein the control section discharges the sheet including the information to a discharge destination immediately before the defect determination.

  According to the present invention, the paper including the information on the paper is discharged together with the paper, and the information on the paper can be easily grasped.

In the image forming apparatus according to a sixth aspect of the present invention, in the fourth or fifth aspect of the present invention, the control unit refers to a paper feed tray on which the paper on which the image is formed is fed from the paper including the information. It is characterized in that paper is fed from different paper feed trays.

  According to the present invention, it is possible to feed sheets of different sizes, different sheet types, and the like from other sheet feeding trays as sheets including information about the gap sheet.

The image forming apparatus according to a seventh aspect of the present invention is the image forming apparatus according to any one of the fourth to sixth aspects of the present invention, wherein the sheet including the information is a sheet type and size relative to a sheet on which the information is printed and a sheet just before the defect determination. Is either a different sheet or a sheet discharged by a different discharge function.

  According to the present invention, it is possible to easily grasp the fact that the print contents of information, the paper type, the size difference, and the paper discharge function are indicated by the paper discharge function. The different sizes include those in which one or both of the size of the paper and the sub-scanning direction and the main scanning direction are different, and examples of the different paper discharge functions include a shift function and a paper discharge direction.

An image forming apparatus according to an eighth aspect of the present invention is the image forming apparatus according to any one of the first to seventh aspects of the present invention, wherein the controller is determined to be defective before the reprinting when it is determined to be defective in the determination. In this case, after the paper is discharged to the paper discharge destination immediately before the defect determination as a scrap sheet, the reprint is performed from the first page of the separator including the paper determined to be defective.

  According to the present invention, it is possible to organize in units of divisions, and it is possible to easily organize output products. Examples of the delimiter unit include a group of parts and tabs, and the delimiter page includes a delimiter of the last page of the section and a tab.

The image forming apparatus according to a ninth aspect of the present invention is the image forming apparatus according to any one of the first to eighth aspects of the present invention, wherein the control unit does not immediately perform the reprinting when a failure is determined in the determination. The reprinting of pages including pages other than those determined to be defective is performed.

  According to the present invention, it is possible to perform reprinting at an appropriate timing in time for paper discharge switching and discharge the reprinted paper to another paper discharge destination. For example, it is possible to use an operator's request or a timing when a predetermined time has elapsed.

An image forming apparatus according to a tenth aspect of the present invention is the image forming apparatus according to any one of the first to ninth aspects, wherein the control unit performs the determination on a page basis.

An image forming apparatus according to an eleventh aspect of the present invention is characterized in that, in any of the first to tenth aspects of the present invention, the control unit performs the determination in units of copies.

An image forming apparatus according to a twelfth aspect of the present invention is the image forming apparatus according to any one of the first to eleventh aspects of the present invention, wherein the control unit displays or / and records information related to the determination when the determination is defective. It is characterized by doing.

  According to the present invention, the displayed information and stored information, for example, the determination of a defect, the paper discharge destination where the waste paper is present, the image data of the sheet determined to be defective, the control, and various operations used for the operation Information can be used.

In the image forming apparatus according to a thirteenth aspect of the present invention, in any one of the first to twelfth aspects of the present invention, the control unit temporarily stops feeding the paper when it is determined to be defective in the determination. Features.

  According to the present invention described above, it is possible to prevent the amount of waste paper from increasing due to the stop of paper feeding.

In an image forming apparatus according to a fourteenth aspect of the present invention, in any one of the first to thirteenth aspects, the control unit notifies the operator that the scraped paper has been removed after the paper feeding is temporarily stopped. If there is, reprinting is performed, and the reprinted paper is discharged to a paper discharge destination immediately before the defect determination.

An image forming apparatus according to a fifteenth aspect of the present invention is the image forming apparatus according to any one of the first to fourteenth aspects, wherein the defect detection unit is an image detection unit that detects an image formed on a sheet. To do.

According to the present invention, it is possible to determine whether the image is defective according to the state of the image on the paper.
In the present invention, the defect detection unit is not limited to the image detection unit, and page disturbance is determined by comparing the image data read by the image reading unit with the image data used for image formation. It may also be one that detects a deviation of the conveyed paper and infers an image displacement.

An image forming system according to a sixteenth aspect of the present invention includes an image forming apparatus having the paper feed tray, the paper transport unit, the image forming unit, and the control unit according to any one of the first to fifteenth aspects of the present invention,
A defect detection unit for detecting a defect state in a sheet conveyed downstream of the image forming apparatus;
A plurality of paper discharge destinations located downstream of the defect detection unit,
The control unit determines whether the sheet is defective based on the detection result. If the sheet is determined to be defective, the control unit reprints a page including the page determined to be defective and discharges paper immediately before the defect determination. Control is performed to discharge the paper to a different paper discharge destination.

In an image forming method according to a seventeenth aspect of the present invention, a defect state is detected in a sheet that has been conveyed and undergoes image formation, and the detection result is obtained. Based on the detection result, it is determined whether the sheet is defective. If it is determined that the paper is defective, before reprinting, the page determined to be defective, and at least a part or all of the remaining paper in the machine in the subsequent pages are used as scrap paper immediately before the defect determination. The paper including the pages after the page judged as defective is reprinted, and the same page as the paper is discharged to a different paper discharge destination from the paper discharge destination immediately before the defective judgment. Then, the sheet printed on the subsequent pages is discharged to a discharge destination different from the discharge destination immediately before the defect determination and the discharge destination from which the same page as the waste paper is discharged .
According to an eighteenth aspect of the present invention, there is provided an image forming method for detecting a defective state in a sheet conveyed and subjected to image formation, obtaining the detection result, determining whether the sheet is defective based on the detection result, If it is determined that the paper is defective, the pages including the pages determined as defective are reprinted and discharged to a different paper discharge destination from the paper discharge destination immediately before the bad determination,
When the second paper discharge destination becomes full during the reprinting or the subsequent page printing, the second paper discharge destination immediately before the defect determination and another paper discharge destination different from the second paper discharge destination are reprinted. The printed sheet is discharged.

In the image forming method according to the nineteenth aspect of the present invention, in the eighteenth aspect of the present invention, when it is determined to be defective in the determination, at least the page determined to be defective before the reprinting and the following pages at least in-machine. The reprinting is performed after a part or all of the remaining sheet in the transported state is discharged as a scraped sheet to a discharge destination immediately before the defect determination.

According to the present invention, reprinting can be performed without causing downtime, and it is not always necessary to monitor, and a page to be removed at any time (either after discharging all pages or during resumption) (for example, a defective page) Pages that have been ejected from the start to the stop) can be removed.
Further, the page to be removed is not sandwiched between pages that are not so, and is present at the end portion, so that it is easy to remove.

1 is a diagram schematically illustrating an image forming apparatus according to an embodiment of the present invention. Similarly, it is a figure which shows a control block. Similarly, it is a figure which shows the outline of the image forming apparatus in another form. Similarly, it is a figure which shows an example of the defect detection method. Similarly, it is a figure which shows the example of a failure event. Similarly, it is a figure which shows the example of a defect detection by a unit. Similarly, it is a flowchart showing a procedure of paper discharge destination switching and reprinting when a defect is detected. Similarly, it is a diagram for explaining discharge destination switching. Similarly, it is a flowchart showing a procedure of paper discharge destination switching and reprinting in units of separation when a defect is detected. Similarly, it is a flowchart illustrating a procedure of paper discharge destination switching, paper discharge information paper discharge and reprinting when a defect is detected. Similarly, it is a diagram for explaining sheet discharge destination switching including sheet paper information sheet discharge. Similarly, it is a diagram for explaining discharge destination switching at the time of defect detection and reprinting and discharge destination switching at the time of printing after reprinting. It is a figure explaining the paper discharge state at the time of the conventional defect detection.

Hereinafter, an image forming system 1 according to an embodiment of the present invention will be described with reference to the accompanying drawings.
In the image forming system 1, as shown in FIG. 1, an image forming apparatus 10 that forms an image, a relay apparatus 20, a paper stack apparatus 30, and a post-processing apparatus 40 are connected in series.
In the present invention, the connection configuration of the image forming system is not limited to this, and may be configured only by the image forming apparatus.

The image forming apparatus 10 is provided with an automatic document feeder (ADF) 14 on the upper side, and a document fed by the automatic document feeder (ADF) 14 is imaged by a scanner unit 130 shown in FIG. Reading is possible. The document can be read on a platen glass (not shown).
Further, the LCD 141 of the operation display unit 140 is installed at a position where the platen glass is not positioned on the upper side of the image forming apparatus 10 or the relay apparatus 20. The LCD 141 is configured by a touch panel, and can be operated by an operator and information can be displayed. The LCD 141 serves as both an operation unit and a display unit. The operation unit may be configured with a mouse, a tablet, or the like, and may be configured separately from the display unit. The LCD 141 may be movable.

A plurality of paper feed trays 12 (two stages in the figure) are arranged on the lower side of the image forming apparatus 10.
In the image forming apparatus 10, a transport path 13 for transporting paper fed from one of the paper feed trays 12 is provided, and the image forming unit 11 is provided in the middle of the transport path in the image forming apparatus 10. It has been. The image forming unit 11 includes a photoconductor 11a, a charger, an LD, a developing device, and a transfer unit (not shown) arranged around the photoconductor 11a. Further, the image forming unit 11 has a conveyance path 13 on the downstream side of the photoconductor 11a. A fixing device 15 is disposed. The conveyance path 13 constitutes a paper conveyance unit of the present invention together with a conveyance roller, a drive motor, and the like (not shown).
On the downstream side of the fixing device 15, the conveyance path 13 extends and is connected to the conveyance path 23 of the relay device 20.

  In the image forming unit 11, the surface of the photoconductor 11a is uniformly charged by the charger before the image is written, and the photoconductor 11a having the surface uniformly charged by the LD is irradiated with a semiconductor laser to thereby apply the photoconductor 11a to the photoconductor 11a. An electrostatic latent image is formed. The developing device develops the electrostatic latent image formed on the photoconductor 11a by the LD with the toner member. By this development processing, a toner image is formed on the photoreceptor 11a. The transfer unit transfers the toner image on the photoconductor 11 a onto the paper conveyed from the paper feed tray 12. The sheet onto which the toner image has been transferred is separated from the photoreceptor 11a and conveyed to the fixing device 15. The toner member remaining on the photoconductor 11a is removed by a cleaning unit (not shown). The fixing device 15 fixes the toner image transferred to the front side of the sheet as an output image by heating the conveyed sheet.

The relay apparatus 20 has a transport path 23 connected to the transport path 13 and connected to the post-processing apparatus 30 at the subsequent stage. An inline sensor 25 that detects an output image on the surface of the paper P that is transported through the transport path 23 is disposed in the transport path 23. The inline sensor 25 can detect an output image with a length corresponding to the maximum width of the paper P, and uses an array of CCDs, CMOSs, and the like arranged in a direction (for example, an orthogonal direction) intersecting the paper transport direction. Can do. The inline sensor 25 corresponds to an image detection unit and a defect detection unit of the present invention.
Note that inline sensors may be arranged on the upper and lower surfaces of the paper so that images on the front and back surfaces of the paper can be detected simultaneously or selected.

  The paper stacking device 30 is a device for stacking paper on which images have been formed, and has a plurality of stacking units 31 and 32 and the like. The stack units 31 and 32 correspond to a plurality of paper discharge destinations of the present invention. Further, the paper stacking device 30 may include a post-processing unit that performs predetermined post-processing.

The post-processing device 40 includes a post-processing unit (not shown) that performs predetermined post-processing on the paper that bypasses the paper stacking device 30 and the paper that is stacked on the paper stacking device 30, and the paper according to the post-processing setting. Predetermined post-processing such as folding and saddle stitching is performed on the paper conveyed from the stacking device 30. The post-processing device 40 includes paper discharge trays 41 and 42. The paper discharge trays 41 and 42 also correspond to the paper discharge destination of the present invention.
In this embodiment, the stack units 30 and 31 provided in the paper stacking device 30 and the paper discharge trays 41 and 42 provided in the post-processing device 40 have been described as paper discharge destinations. A plurality of paper discharge destinations may be configured by the stack unit and the paper discharge tray.

Next, the functional configuration of the image forming apparatus 10 will be described with reference to FIG.
The image forming apparatus 10 includes a control block unit 110, a scanner unit 130, an operation display unit 140, and a printer unit 150, and further processes image data input from an external device 40 such as a terminal PC through the LAN 3, or An image processing unit (print & scanner controller) 160 that enables image data obtained by the scanner unit 130 to be transferred to the external device 40 through the LAN 3 is provided.

  The control block unit 110 has a PCI bus 112 connected to an image processing unit (print & scanner controller) 160, and a DRAM control IC 111 is connected to the PCI bus 112. An image memory (DRAM) 120 is connected to the DRAM control IC 111. The image memory (DRAM) 120 has a compression memory 121 for storing compressed image data and a page memory 122 for temporarily storing uncompressed image data to be printed before image formation. .

In addition, an HDD 119 (hard disk) is connected to the PCI bus 112 via a controller IC 118, and the HDD 119 is connected to image data acquired by the scanner unit 130 and an image processing unit (print & scanner controller) 160. The image data generated by the external device 40 is stored.
The image data acquired by the image processing unit (print & scanner controller) 160 and the image data stored in the HDD 119 are transmitted to the DRAM control IC 111 through the PCI bus 112 along with the printing operation.

The control block unit 110 includes a control CPU 113, and a DRAM control IC 111 is connected to the control CPU 113.
A RAM 114 is connected to the control CPU 113, and is used as a work area or a temporary storage of data when the control CPU 113 operates.
Further, the control CPU 113 is connected to a non-volatile memory 115 constituted by a flash memory or the like. In the nonvolatile memory 115, initial print setting information of the image forming apparatus 10, machine setting information such as process control parameters, initial data of output setting, designation for reading the output image, and factors when the read image is determined to be defective And a standard for each factor when determining that it is defective, a program for operating the control CPU 113, and the like are stored.
The RAM 114, the nonvolatile memory 115, the HDD 119, and the like can function as a storage unit.

The control CPU 113 can read nonvolatile data in the nonvolatile memory 115 and can write desired data in the nonvolatile memory 115.
The control CPU 113 controls the operations of the image forming apparatus 10, the relay apparatus 20, the paper stack apparatus 30, and the post-processing apparatus 40 according to the machine setting information, print setting information, output settings, and the like.
The control CPU 113 constitutes a control unit of the present invention and controls the entire image forming system 1.
The control CPU 113 can perform job output settings and operation instructions through the operation display unit 140.

The scanner unit 130 includes a CCD 131 that performs optical reading and a scanner control unit 132 that controls the entire scanner unit 130. The scanner control unit 132 is connected to the control CPU 113 so that serial communication is possible. The CCD 131 is connected to a reading processing unit 116 that processes image data read by the CCD 131, and the reading processing unit 116 is connected to the DRAM control IC 111 in a controllable manner. The scanner unit 130 corresponds to a reading unit.
The reading processing unit 116 performs various processing such as analog signal processing, A / D (Analog to Digital) conversion processing, shading processing, and the like on the analog image signal input from the CCD 131 to generate digital image data, and compress / Output to the decompression IC 117.
The scanner unit 130 reads an image of a document placed on the upper platen glass of the image forming apparatus 10 or a document automatically conveyed by an automatic document feeder (ADF) 14.

The operation display unit 140 includes an LCD 141 configured as a touch panel that serves as both a display unit and an operation unit, and an operation display unit control unit 142 that controls the entire operation display unit. The operation display unit control unit 142 is a control unit. It is connected to the CPU 113 so that serial communication is possible.
In the operation display unit 140, under the control of the control CPU 113, input of machine settings such as output condition setting and operation control condition in the image forming apparatus 10 and setting of paper information (size, paper type) of each paper feed tray are performed by the LCD 141. Input, display of setting contents, display of desired information such as a message, image display of an output image read by the inline sensor 25, operation instruction and setting input for image display, display, and the like are possible.

The DRAM control IC 111 is connected to a compression / decompression IC 117 capable of compressing or decompressing image data. The DRAM control IC 111 controls image data compression processing and compression image data decompression processing by the compression / decompression IC 117 in accordance with an instruction from the control CPU 113, and performs input / output control of image data to the image memory (DRAM) 120. .
The write processing unit 123 is connected to the image forming unit 11 including the LD 152 of the printer unit 150 and the like, and generates write data used for the operation of the LD 152 based on the image data.

The printer unit 150 includes the image forming unit 11, a paper feed tray 12, a conveyance path 13, a reverse conveyance path 16, a fixing device 15, and the like.
In addition, the printer unit 150 includes a printer control unit 151 that controls the entire printer unit 150 (paper feeding, image formation, paper discharge, post-processing, and the like). The printer control unit 151 performs serial communication with the control CPU 113 described above. Connected as possible. The printer control unit 151 operates according to a control command from the control CPU 113 to control the printer unit 150 to perform paper conveyance, image formation, and the like.

  Further, the DRAM control IC 161 of the image processing unit (print & scanner controller) 160 is connected to the PCI bus 112 to which the DRAM control IC 111 is connected as described above. The image processing unit (print & scanner controller) 160 receives image data or the like from the external device 40 connected to the LAN 3 when the image forming apparatus 10 is used as a network printer or a network scanner. The image data acquired by the scanner unit 130 is transmitted to the external device 40 connected to the LAN 3 or the like.

  In the image processing unit (print & scanner controller) 160, an image memory 162 composed of a DRAM or the like is connected to the DRAM control IC 161. Further, in the image processing unit (print & scanner controller) 160, a DRAM control IC 161 and a controller control unit 163 for controlling the entire image processing unit (print & scanner controller) 160, a LAN control unit 164, and a LAN interface 165 are provided on a common bus. Is connected. The LAN interface 165 is connected to the LAN 3.

  Further, the control CPU 113 is connected to the inline sensor control unit 250 of the inline sensor 25 disposed in the relay device 20 in a controllable manner, and the control CPU 113 controls the operation of the inline sensor 25 via the inline sensor control unit 250. Can be controlled. Further, the reading result of the inline sensor 25 can be received by the control CPU 113.

Next, basic operations of the image forming apparatus 10 and the image forming system 1 will be described.
First, a procedure for accumulating image data in the image forming apparatus 10 will be described.
A case where the image forming apparatus 10 reads an image with the scanner unit 130 and generates image data will be described. The scanner unit 130 optically reads an image from a document by the CCD 131. At this time, the operation of the CCD 131 is controlled by the scanner control unit 132 that receives a command from the control CPU 113. The document reading may be performed while automatically feeding the document by the automatic document feeder (ADF) 14 or may be performed by placing the document on the platen glass.

  The control CPU 113 operates according to a program and issues a command to the scanner unit 130 based on an operation (reading instruction or copying instruction) by the operation display unit 140. The image read by the CCD 131 is subjected to data processing by the reading processing unit 116, and the image data subjected to the data processing is sent to the compression / expansion IC 117 via the DRAM control IC 111 and compressed by a predetermined method. The compressed data is stored in the image memory (DRAM) 120 via the DRAM control IC 111. When data is stored in the HDD 119, the data once stored in the compression memory 121 is sent to the HDD 119 via the DRAM control IC 111 and the controller IC 118.

In addition, the image data may be input to the image forming apparatus 10 via the LAN 3. Examples of the image data include data generated by an application program such as the external device 40. The method for generating image data is not particularly limited.
The image data is received by the image processing unit (print & scanner controller) 160 via the LAN 3 and the LAN interface 165, and is temporarily stored in the image memory 162 by the DRAM control IC 161. Data stored in the image memory 162 is transferred to the DRAM control IC 111 via the PCI bus 112 and temporarily stored in the page memory 122. Data stored in the page memory 122 is sent to the compression / decompression IC 117 via the DRAM control IC 111, subjected to compression processing, and stored in the compression memory 121 via the DRAM control IC 111. When data is stored in the HDD 119, the data once stored in the compression memory 121 is sent to the HDD 119 via the DRAM control IC 111 and the controller IC 118.

  When the image data is stored, output settings are made before or after storing the image data. The output setting can be performed by an operation input by an operator by displaying a setting screen on which operation input is possible on the operation display unit 140. Further, when the output setting item is selected in the initial setting and the setting input by the operator is not made, the output setting is made by the initial setting.

  When the image forming apparatus 10 outputs an image, that is, when used as a copying machine or a printer, the image data stored in the compression memory 121 is sent to the compression / decompression IC 117 via the DRAM control IC 111 to decompress the data. The decompressed data is sent to the writing processing unit 123, and writing is performed by the LD 152 on the photosensitive member 11a charged by the charging unit. When image data stored in the HDD 119 is used, the image data stored in the HDD 119 is temporarily stored in the compression memory 121 via the DRAM control IC 111, and the image data stored in the compression memory 121 is DRAM-controlled. The data is decompressed by sending to the compression / decompression IC 117 via the IC 111, and the decompressed data is sent to the write processing unit 123 in the same manner as described above.

In the printer unit 150, each unit is controlled by the printer control unit 151 that receives a command from the control CPU 113. In the image forming unit 11, the latent image written on the photoconductor 11 a is developed as a toner image by a developing unit (not shown), and the toner image is transferred to a sheet supplied by a conveyance path 13 by a transfer unit (not shown). Is fixed. In the photoreceptor 11a, after the toner image is transferred onto the paper, the residual toner is removed by a cleaning unit (not shown).
In this embodiment, the description has been made on the assumption of monochrome image formation. However, an image forming apparatus provided with a photoconductor for each color (for example, cyan, magenta, yellow, and black) may be used.

The sheet on which the image has been formed is conveyed to the relay device 20 via the conveyance path 13. In the relay device 20, all or a part of the output image on the sheet conveyed through the conveyance path 23 is read by the inline sensor 25 controlled by the inline sensor control unit 250, and the read image data is transmitted to the control CPU 113. Is done. Reading of the output image is performed according to the set instruction content. The setting contents are stored in the nonvolatile memory 115 or the like. The instruction content may be set initially or set by the user. The paper is transported along the transport path 23 according to the setting and transported to the paper stacking device 30. In the sheet stacking device 30, predetermined post-processing and stacking to predetermined stack units 31 and 32 are performed according to the setting.
Further, the sheet is conveyed from the sheet stacking device 30 to the post-processing device 40 according to the setting, is subjected to predetermined post-processing, and is discharged to predetermined discharge trays 41 and 42.

In the above description, the image detection unit is provided in the subsequent device of the image forming apparatus 10. However, the image detection unit may be provided in the image forming apparatus.
FIG. 3 shows an image forming apparatus 10a provided with an inline sensor 25a corresponding to an image detection unit. The inline sensor 25a can have the same configuration as the inline sensor 25.
The image forming apparatus 10a may be further connected to another apparatus in the subsequent stage, or may be configured only by the image forming apparatus 10a. In addition, the same code | symbol is attached | subjected about the structure same as above-described embodiment, and the description is abbreviate | omitted or simplified.
In this embodiment, an inline sensor 25a is arranged on the conveyance path 13 downstream of the fixing device 15 and upstream of the point where the reverse conveyance path 16 branches from the conveyance path 13, and images are printed on the front and back sides of the sheet. When forming, the front and back output images can be read by the inline sensor 25a.
That is, the paper that has passed through the fixing device 15 is introduced into the paper reversing path 16, the front and the back are reversed by the reversing unit 17, and then returned to the transport path 13, whereby an image is formed on the back side of the paper. The in-line sensor 25a can read the image on the downstream side of the fixing device 15. Then, the reading result of the inline sensor 25a is transmitted to the control CPU 113.
In this embodiment, since reading can be performed after passing through the fixing device 15 and before reaching the reversal conveyance path 16, it is not necessary to reverse the sheet only for the purpose of reading both sides with an inline sensor.

In the image forming system 1, an image is detected by the inline sensor 25 or the inline sensor 25 a, and information on the image is transmitted to the control CPU 113.
For example, as shown in FIG. 4, the control CPU 113 that has acquired the image information grasps the image data acquired by the image reading unit and compares the image data with the image information detected by the inline sensor 25. Thus, it can be determined whether the image output on the paper in units of pages is normal or defective.
FIG. 5 shows an example of an event determined to be defective, and examples include toner spillage, color position deviation (for each color of Y / M / C / K), transfer deviation, and the like. A standard is set for each of these defective events, and if any of the items is out of the standard, it can be determined as defective. The criterion for determining the defect can be stored in, for example, the nonvolatile memory 115 or the HDD 119.
In a job that outputs a plurality of copies, for example, as shown in FIG. 6, the first copy data read by the inline sensor 25 is recorded and compared with the output N copy data read by the inline sensor 25. It can be determined whether there is a defect in units of copies.

Next, the procedure for switching the paper discharge destination when a defect is determined will be described with reference to the flowchart of FIG. The following procedure is controlled by the control CPU 113.
When printing is started, a normal printing process is executed (step s1), and an image of a sheet (output paper) on which an image has been formed is read by an inline sensor (step s2). Next, it is determined whether the paper is a defective page based on the read image data (step s3). When it is determined that the page is not a defective page (step s3, No), the sheet is discharged to a predetermined discharge destination, and it is determined whether printing is completed (step s8). If printing is not completed (step s8, No). Returning to step s1, the procedure is repeated, and if printing is completed (step s8, Yes), the process is terminated.

If it is determined in step s3 that the page is a bad page (step s3, Yes), the paper feed process from the paper feed tray is stopped (step s4), and the paper that has become a bad page and other paper in the machine. Is discharged to the same paper discharge destination as that immediately before the defect determination (step s5).
Next, the reprint start page is set to a page determined to be defective (step s6), the paper discharge destination is changed to a paper discharge destination different from that immediately before the defect determination (step s7), and the process returns to step s1 to cope with the paper. Execute the printing process for the page to be printed and the subsequent pages.

According to the above procedure, the reprinted paper and the subsequent printing paper can be delivered to a paper discharge destination different from the previous paper discharge destination. A schematic diagram thereof is shown in FIG. The original paper output destination 300 is loaded with normal output paper P0 and the paper YP2 including the paper YP1 determined to be defective, and the paper corresponding to the page determined to be defective in the other paper output destination 301. P1 and the paper P2 of the page corresponding to the subsequent paper are reprinted and stacked, and the paper P3 of the subsequent pages is further printed and stacked on the paper discharge destination 301. The spear sheets YP1 and YP2 are located at the uppermost part of the paper discharge destination and can be easily removed at an arbitrary timing. If the paper discharge destination 300 can be operated even during paper discharge to the paper discharge destination 301, the waste paper can be removed.
Note that, when reprinting with the changed discharge destination is performed, if it is detected that the switched discharge destination is full, the reprint can be continued by switching to another discharge destination.

In the above description, reprinting is performed automatically. However, reprinting may be performed at a predetermined timing without immediately performing reprinting. For example, reprinting can be started by an operator's instruction operation or elapse of a predetermined time.
In addition, before reprinting, the operator notifies the machine that the defective page has been removed by pressing a button on the operation unit, etc., so that the reprinted paper is discharged to the paper discharge destination before the defective determination. Also good.
Furthermore, defective page detection, paper discharge destination information where a defective page exists, image data of a read defective page, and the like may be displayed on the operation unit or stored in an HDD or the like.

Next, a procedure for discharging up to a separator page as a waste paper after detection of a defective page will be described based on the flowchart of FIG. The following procedure is controlled by the control CPU 113.
When printing is started, normal printing processing is executed (step s10), and the image of the paper (output paper) on which the image has been formed is read by an inline sensor (step s11). Next, it is determined whether the paper is a defective page based on the read image data (step s12). When it is determined that the page is not a defective page (step s12, No), the sheet is discharged to a predetermined discharge destination, and it is determined whether printing is completed (step s16). If printing is not completed (step s16, No) Returning to step s10, the procedure is repeated, and if printing is complete (step s16, Yes), the process is terminated.

If it is determined in step s12 that the page is a defective page (step s12, Yes), paper feeding is continued and printing is performed up to a separation page, and the paper is discharged as a waste paper to a discharge destination immediately before the defective page determination (step s13). . Paper feed is stopped after printing to the end of the set is completed.
Next, the reprint start page is set to the first page of the separator including the page determined to be defective (step s14), the paper discharge destination is changed to a paper discharge destination different from that immediately before the defect determination (step s15), and step s10. Returning to FIG. 4, the printing process is executed so as to continue the reprinting of the page corresponding to the paper and the subsequent printing of the page.
According to the above procedure, the last page of the splinter paper can be easily confirmed by printing the splinter paper to the end. Examples of the separator include the last page of the section, tab separator, and the like.

  In each of the above procedures, after the paper is discharged to the paper discharge destination immediately before the defect determination, the reprinted paper is discharged to another paper discharge destination. You may make it discharge the sheet | seat containing the information regarding spear paper.

Next, a procedure for discharging a sheet including information on a slip sheet will be described with reference to the flowchart of FIG. The following procedure is controlled by the control CPU 113.
When printing is started, normal printing processing is executed (step s20), and the image of the paper (output paper) on which the image has been formed is read by an inline sensor (step s21). Next, it is determined whether the paper is a defective page based on the read image data (step s22). When it is determined that the page is not a defective page (step s22, No), the sheet is discharged to a predetermined discharge destination, and it is determined whether printing is completed (step s28). If printing is not completed (step s28, No) Returning to step s20, the procedure is repeated, and if printing is completed (step s28, Yes), the process is terminated.

If it is determined in step s22 that the page is a bad page (step s22, Yes), the paper feed process from the paper feed tray is stopped (step s23), and the paper that has become a bad page and other paper in the machine. Is discharged to the same paper discharge destination as that immediately before the defect determination (step s24). Next, a page including information related to scraping paper such as a failure occurrence event is discharged to a discharge destination immediately before the failure determination (step s25). In addition, it may be a paper on which information is printed as a page including information on the splinter paper, and the paper may not include text information. When information is not printed, colored paper, tab paper, paper different in size from that used before, and the like may be used. Moreover, colored paper, tab paper, and paper of different sizes may be used together with information printing.
Next, the reprint start page is set to the page determined to be defective (step s26), the paper discharge destination is changed to a paper discharge destination different from that immediately before the defect determination (step s27), and the process returns to step s20 to cope with the paper. The printing process is executed so as to continue the reprinting of the page to be printed and the printing of the subsequent page.

FIG. 11A is a schematic diagram for explaining switching of a paper discharge destination and paper discharge including information. The paper output destination 300 used immediately before the defect determination is a normal output sheet P0, a defective sheet YP1 determined to be defective, and a subsequent sheet of the transfer sheet YP2 are discharged and stacked, and further includes information regarding the offset sheet. The PI is discharged to the top. The reprinted sheets P1 and P2 and the sheet P3 of the subsequent page are discharged to another discharge destination and stacked.
FIG. 11B shows an example of the paper PI on which information about the paper is printed. The paper PI indicates that a defective page has been detected, and further indicates the range of the waste paper and the discharge destination of the reprinted paper. The above information makes it easier to remove the waste paper.

In each of the above procedures, description has been given of switching the paper discharge destination at two places, but it is also possible to discharge paper by switching over three or more paper discharge destinations.
Hereinafter, an example in which the three paper discharge destinations are switched will be described with reference to FIG.
In this example, as in each of the above procedures, the normal paper P0 and the waste paper (YP1, YP2) are discharged to the same paper discharge destination 300, and the paper PI including the information on the paper is optionally further supplied to the same paper discharge destination. The paper can be discharged to 300. After reprinting, the paper (P1 + P2) of the page corresponding to the paper is discharged to a paper discharge destination 301 different from the paper discharge destination 300, and the paper P3 of the page after the paper is further discharged. The paper is discharged to a paper discharge destination 302 different from 300 and the paper discharge destination 301.
Based on the above, it is possible to easily confirm the reprinted paper related to the scraped paper.

  As described above, the present invention has been described based on the above embodiments, but the present invention is not limited to the description of the above embodiments, and can be appropriately changed without departing from the scope of the present invention. It is.

DESCRIPTION OF SYMBOLS 1 Image forming system 10 Image forming apparatus 10a Image forming apparatus 11 Image forming part 20 Relay apparatus 25, 25a Inline sensor 30 Paper stack apparatus 31 Stack part 32 Stack part 40 Post-processing apparatus 41 Paper discharge tray 42 Paper discharge tray 113 Control CPU
115 Non-volatile memory 130 Scanner unit 140 Operation display unit 150 Printer unit

Claims (19)

A paper feed tray for storing paper and feeding the paper;
A paper transport unit for transporting the fed paper;
An image forming unit for forming an image on the paper;
A defect detection unit for detecting a defect state in the sheet on which the image is formed;
A plurality of paper discharge destinations for discharging the paper;
A control unit that controls switching of the paper feed, the conveyance, the image formation, and the paper discharge destination, and acquires a detection result of the defect detection unit,
The control unit determines whether the sheet is defective based on the detection result. If it is determined that the sheet is defective , the page is determined to be defective before reprinting, and at least in-machine transported on subsequent pages. A part or all of the remaining paper is discharged as a scraped paper to the paper discharge destination immediately before the defective determination, and the page including the page determined after the defective is reprinted, and the same page as the defective paper is defective. Paper discharged to a different paper discharge destination than the paper discharge destination immediately before the determination, and the paper printed for the subsequent pages are the paper discharge destination immediately before the failure determination and the paper discharge destination from which the same page as the paper is discharged. Is an image forming apparatus that discharges paper to another paper discharge destination . A paper feed tray for storing paper and feeding the paper;
A paper transport unit for transporting the fed paper;
An image forming unit for forming an image on the paper;
A defect detection unit for detecting a defect state in the sheet on which the image is formed;
A plurality of paper discharge destinations for discharging the paper;
A control unit that controls switching of the paper feed, the conveyance, the image formation, and the paper discharge destination, and acquires a detection result of the defect detection unit,
  The control unit determines whether the sheet is defective based on the detection result. If the sheet is determined to be defective, the control unit reprints a page including the page determined to be defective and then discharges immediately before the defect determination. Control to discharge to a different output destination,
  When the second paper discharge destination becomes full during the reprinting or the subsequent page printing, the second paper discharge destination immediately before the defect determination and another paper discharge destination different from the second paper discharge destination are reprinted. An image forming apparatus for discharging printed paper. If the control unit determines that the paper is defective in the determination, the controller determines whether the page is determined to be defective before the reprinting, and at least a part or all of the paper remaining in the machine in the subsequent pages. The image forming apparatus according to claim 2 , wherein the reprinting is performed after the paper is discharged to a paper discharge destination immediately before the defect determination. Wherein, the case where it is defective in the determination, the before reprinting, the image forming apparatus according to claim 1 or 3, characterized in that discharges the sheet that contains the information of the spoiled paper. The image forming apparatus according to claim 4 , wherein the control unit discharges the sheet including the information to a discharge destination immediately before the defect determination. 6. The image according to claim 4 , wherein the control unit feeds a sheet including the information from a sheet feeding tray different from a sheet feeding tray into which the sheet on which the image formation has been performed is fed. Forming equipment. The paper including the information is any one of a paper on which information is printed, a paper having a different paper type and size, and a paper ejected by a different paper ejection function with respect to the paper immediately before the defect determination. Item 7. The image forming apparatus according to any one of Items 4 to 6 . If the control unit determines that there is a failure in the determination, the control unit discharges the page after the page determined to be defective up to a separation page as a scrap paper before the reprinting, the image forming apparatus according to any one of claims 1 to 7, characterized in that to re-print from the first page delimiter that contains the determined paper and. 2. The control unit according to claim 1, wherein if the determination is defective, the reprinting is not performed immediately, but the reprinting of pages including pages other than those determined to be defective at a predetermined timing is performed. The image forming apparatus according to any one of 8 to 8 . Wherein the control unit, the image forming apparatus according to any one of claims 1 to 9, characterized in that the determination in units of pages. Wherein the control unit, the image forming apparatus according to any one of claims 1 to 10, characterized in that the determination Collate. Wherein, the case where it is defective in the determination, the image forming apparatus according to any one of claims 1 to 11, characterized in that display and / or record information relating to the determination. Wherein, the case where it is defective in the determination, the image forming apparatus according to any one of claims 1 to 12, characterized in that pause feeding of the paper. The control unit executes reprinting and discharges the reprinted paper to the paper discharge destination immediately before the defect determination when there is a notice that the paper is removed by the operator after the paper feeding is temporarily stopped. the image forming apparatus according to any one of claims 1 to 13, characterized in that. The failure detection unit, an image forming apparatus according to any one of claims 1 to 14, characterized in that an image detection unit for detecting an image formed on the sheet. Paper feed tray, the paper transport unit according to any one of claims 1 to 15 and an image forming apparatus having an image forming unit and the control unit,
A defect detection unit for detecting a defect state in a sheet conveyed downstream of the image forming apparatus;
A plurality of paper discharge destinations located downstream of the defect detection unit,
The control unit determines whether the sheet is defective based on the detection result. If the sheet is determined to be defective, the control unit reprints a page including the page determined to be defective and discharges paper immediately before the defect determination. An image forming system that performs control to discharge paper to a different paper discharge destination. If it is the sheet conveyed by detecting the fault condition in the sheet that has passed through the image forming obtains the detection result, wherein the sheet based on the detection result to determine whether failures, determines the sheet is defective, re Before printing, the pages judged as defective and at least some or all of the remaining paper in the machine on the subsequent pages are discharged as paper to the paper discharge destination just before the failure is determined. Reprint the page including the determined page and after, discharge the same page as the paper, to a different output destination than the output destination immediately before the defective determination, and print the printed paper for the subsequent pages An image forming method, wherein the paper is discharged to a paper discharge destination different from a paper discharge destination immediately before the defect determination and a paper discharge destination from which the same page as the waste paper is discharged . If a defective state is detected in a sheet that has been transported and subjected to image formation, the detection result is obtained, and it is determined whether the sheet is defective based on the detection result, and it is determined that the sheet is defective. Reprint the page including the page after the page determined to be, and discharge it to a different output destination than the output destination immediately before the defect determination,
When the second paper discharge destination becomes full during the reprinting or the subsequent page printing, the second paper discharge destination immediately before the defect determination and another paper discharge destination different from the second paper discharge destination are reprinted. An image forming method comprising discharging a printed sheet. If it is determined to be defective in the determination, the page determined to be defective before the reprinting, and at least a part or all of the paper remaining in the state of conveyance in the machine immediately after the reprinting is immediately before the defect determination. The image forming method according to claim 18 , wherein the reprinting is performed after the paper is discharged to a paper discharge destination.

Images