JP7654489B2 - Image forming apparatus and method for controlling the image forming apparatus - Google Patents

Description

The present invention relates to an image forming device that forms an image on a sheet, such as a copier, printer, facsimile, or multifunction device having multiple functions of these, and a method for controlling the image forming device.

Conventionally, electrophotographic image forming apparatuses equipped with an inspection device that reads the image on a formed sheet and compares it with the original image information to determine whether the image formed on the sheet is good or bad are known. In such image forming apparatuses, sheets on which an image is determined to be abnormal are discharged to an escape tray as defective sheets, and all sheets on which images have already been formed upstream of the sheet determined to be an abnormal image are discharged as discarded sheets. After that, the sheets after the sheet determined to be an abnormal image are automatically reprinted, making it possible to obtain a high-quality product without the user having to perform any special work. However, sheets on which images have already been formed upstream of the sheet determined to be abnormal are not necessarily abnormal, and discharging all of them to the escape tray is not preferable because it would increase the number of discarded sheets.

To solve this problem, an image forming device has been developed that is provided with a second transport path in addition to the first transport path normally used in the inspection device (see Patent Document 1). In this image forming device, sheets on which images have already been formed upstream of the sheet determined to be an abnormal image are made to wait on the second transport path. Then, only the sheets determined to be an abnormal image during this time are discharged to an escape tray and reprinted, and normal sheets that have been made to wait thereafter are discharged to a normal tray. With this image forming device, there is no need to discard sheets on which images have already been formed upstream of the sheet determined to be an abnormal image, so the number of discarded sheets can be reduced.

JP 2017-058564 A

However, in the image forming device described in the above-mentioned Patent Document 1, a dedicated second transport path is provided inside the device body for evacuating sheets on which an image has already been formed upstream of the sheet determined to be an abnormal image. This increases the number of parts compared to a case in which a second transport path is not provided, and there is a risk that this will lead to an increase in the size and complexity of the device.

The present invention aims to provide an image forming device and a control method for the image forming device that has a function of discharging sheets determined to be abnormal images by an inspection device to an escape tray, and that can reduce the number of discarded sheets while preventing the device from becoming larger and more complicated.

The image forming apparatus of the present invention comprises an image forming unit which forms an image on a sheet based on image information, a reading unit which reads the image formed on the sheet by the image forming unit, a transport unit which transports the sheet on which the image has been read by the reading unit, a first discharge unit, a second discharge unit, and a third discharge unit which selectively discharge the sheet transported by the transport unit, and a control unit which compares the image read by the reading unit with image information to determine whether it is a normal image or an abnormal image, and which selects a discharge destination for discharging the sheet from among the first discharge unit, the second discharge unit, and the third discharge unit, and the control unit is configured such that one unit is composed of a plurality of sheets, and When executing an image forming job in which multiple copies are continuously image-formed, if the image read by the reading unit is a normal image, the sheet on which the normal image is formed is discharged to the first discharge unit, and if the image read by the reading unit is an abnormal image, the abnormal sheet on which the abnormal image is formed is discharged to the second discharge unit, and among the multiple remaining sheets on which image formation was started after the abnormal sheet at the time the abnormal image was read, the sheets constituting the first copy that included the abnormal sheet are discharged to the second discharge unit, and among the remaining sheets, sheets that do not constitute the first copy are discharged to the third discharge unit.

The image forming apparatus of the present invention includes an image forming unit that forms an image on a sheet based on image information, a reading unit that reads the image formed on the sheet by the image forming unit, a transport unit that transports the sheet on which the image has been read by the reading unit, a first discharge unit, a second discharge unit, and a third discharge unit to which the sheet transported by the transport unit is selectively discharged, and a control unit that compares the image read by the reading unit with image information to determine whether the image is a normal image or an abnormal image, and selects a discharge destination for discharging the sheet from among the first discharge unit, the second discharge unit, and the third discharge unit, and the control unit selectively selects the first discharge unit and the third discharge unit as a discharge unit for discharging the sheet on which the normal image has been formed when the image read by the reading unit is a normal image. The apparatus selectively executes a first mode in which the reading unit uses the first discharge unit and a second mode in which the third discharge unit is not used and the first discharge unit is used, and in the first mode, if the image read by the reading unit is an abnormal image, the abnormal sheet on which the abnormal image is formed is discharged to the second discharge unit, and among the multiple remaining sheets on which image formation began after the abnormal sheet at the time the abnormal image was read, sheets constituting a first section that included the abnormal sheet are discharged to the second discharge unit, and among the remaining sheets, sheets that do not constitute the first section are discharged to the third discharge unit, and in the second mode, if the image read by the reading unit is an abnormal image, the abnormal sheet on which the abnormal image is formed and the remaining sheets are discharged to the second discharge unit.

The control method of the image forming apparatus of the present invention includes an image forming unit that forms an image on a sheet based on image information, a reading unit that reads the image formed on the sheet by the image forming unit, a transport unit that transports the sheet on which the image has been read by the reading unit, a first discharge unit, a second discharge unit, and a third discharge unit to which the sheet transported by the transport unit is selectively discharged, and a control unit that compares the image read by the reading unit with image information to determine whether the image is normal or abnormal, and selects a discharge destination for discharging the sheet from among the first discharge unit, the second discharge unit, and the third discharge unit. In the control method of the image forming apparatus, when an image forming job is executed in which one unit is made up of multiple sheets and multiple units are continuously image-formed, the image read by the reading unit is compared with image information to determine whether the image is normal or abnormal. The image forming apparatus is characterized by comprising a determination step for determining whether the image is a normal image or an abnormal image, a first normal discharge step for discharging the sheet on which the normal image is formed to the first discharge section when it is determined in the determination step that the image read by the reading section is a normal image, a first abnormal discharge step for discharging the abnormal sheet on which the abnormal image is formed to the second discharge section when it is determined in the determination step that the image read by the reading section is an abnormal image, a second abnormal discharge step for discharging to the second discharge section sheets constituting a first section that included the abnormal sheet among a plurality of remaining sheets on which image formation was started after the abnormal sheet at the time the abnormal image was read, and a second normal discharge step for discharging to the third discharge section sheets of the remaining sheets that do not constitute the first section.

The control method for the image forming apparatus of the present invention includes an image forming unit that forms an image on a sheet based on image information, a reading unit that reads the image formed on the sheet by the image forming unit, a transport unit that transports the sheet on which the image has been read by the reading unit, and a first discharge unit, a second discharge unit, and a third discharge unit to which the sheet transported by the transport unit is selectively discharged, and a control unit that compares the image read by the reading unit with image information to determine whether the image is normal or abnormal, and determines the discharge destination for the sheet to be discharged from the first discharge unit, the second discharge unit, and the third discharge unit. and a control unit for selecting from among a first mode and a second mode, the control unit selectively executes a first mode in which the first discharge unit and the third discharge unit are selectively used and a second mode in which the first discharge unit is used without using the third discharge unit, for a discharge unit that discharges a sheet on which a normal image is formed when an image read by the reading unit is a normal image, and the control unit selectively executes a second mode in which the first discharge unit and the third discharge unit are selectively used and a second mode in which the first discharge unit is used without using the third discharge unit, for a discharge unit that discharges a sheet on which a normal image is formed, when an image read by the reading unit is a normal image, and The image forming apparatus performs a determination process for comparing the image read by the reading unit with the information to determine whether the image is normal or abnormal; a first normal discharge process for discharging the sheet on which the normal image is formed to the first discharge unit when the determination process determines that the image read by the reading unit is a normal image; a first abnormal discharge process for discharging the abnormal sheet on which the abnormal image is formed to the second discharge unit when the determination process determines that the image read by the reading unit is an abnormal image; a second abnormal discharge process for discharging the sheets constituting the first part including the abnormal sheet among the multiple remaining sheets on which image formation was started after the abnormal sheet at the time the abnormal image was read to the second discharge unit; and a second normal discharge process for discharging the sheets of the remaining sheets that do not constitute the first part to the third discharge unit, and in the second mode, the determination process, the first normal discharge process, the first abnormal discharge process, and a third abnormal discharge process for discharging the remaining sheets to the second discharge unit when the determination process determines that the image read by the reading unit is an abnormal image are performed.

The present invention has a function of discharging sheets that are determined to be abnormal images by the inspection device to an escape tray, which reduces the number of discarded sheets while preventing the device from becoming larger and more complicated.

1 is a front view showing a schematic configuration of an image forming system according to a first embodiment. FIG. 2 is a block diagram showing a control system of the image forming system according to the first embodiment. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus according to a first embodiment. FIG. 11 is an explanatory diagram showing a state when a discharge destination is set on the display of the external controller according to the first embodiment. 6 is a flowchart showing a processing procedure in an external controller according to the first embodiment. 5 is a flowchart showing the first half of a processing procedure in the printing device according to the first embodiment. 10 is a flowchart showing a second half of the processing procedure in the printing device according to the first embodiment. 5 is a flowchart showing the first half of a processing procedure in the inspection device according to the first embodiment. 10 is a flowchart showing a second half of the processing procedure in the inspection device according to the first embodiment. 5 is a flowchart showing a processing procedure in the stacker according to the first embodiment. 5A and 5B are explanatory diagrams showing changes in the ejection destination in the image forming apparatus according to the first embodiment; FIG. 11 is an explanatory diagram showing a state when a discharge destination is changed on the display of an external controller according to the second embodiment. 10 is a flowchart showing a processing procedure in an external controller according to the second embodiment. 10 is a flowchart showing the first half of a processing procedure in a printing device according to a second embodiment. 10 is a flowchart showing a second half of the processing procedure in the printing device according to the second embodiment. FIG. 13 is an explanatory diagram showing a state when a discharge destination is set on the display of an external controller according to the third embodiment. 13 is a flowchart showing a processing procedure in an external controller according to the third embodiment. 13 is a flowchart showing the first half of a processing procedure in a printing device according to a third embodiment. 13 is a flowchart showing the second half of the processing procedure in the printing device according to the third embodiment. 13 is a flowchart showing the first half of a processing procedure in an inspection device according to a third embodiment. 13 is a flowchart showing a second half of the processing procedure in the inspection device according to the third embodiment.

First Embodiment
A first embodiment of the present invention will be described in detail below with reference to Figures 1 to 11. In this embodiment, a case in which an image forming apparatus 101 is applied to an image forming system 1 will be described.

[General Configuration of Image Forming System]
1 is an overall diagram of the hardware configuration of an image forming system 1 according to this embodiment. The image forming system 1 includes an image forming apparatus 101 and an external controller 102. The image forming apparatus 101 and the external controller 102 are communicatively connected via an internal LAN 105 and a video cable 106. The external controller 102 is communicatively connected to a client PC 103 via an external LAN 104, and a print instruction is sent from the client PC 103 to the external controller 102.

A printer driver that has the function of converting print data into a print description language that can be processed by the external controller 102 is installed in the client PC 103. A user who performs printing can send a print instruction from various applications via the printer driver. The printer driver installed in the client PC 103 sends print data to the external controller 102 based on the print instruction from the user. When the external controller 102 receives a print instruction from the client PC 103, it performs data analysis and rasterization processing, and sends print data including image information to the image forming device 101 to issue a print instruction.

The image forming device 101 is connected to devices with multiple different functions, and is configured to be capable of complex printing processes such as bookbinding. In this embodiment, the image forming device 101 has a printing device 107, an inspection device 108, and a first stacker 111 and a second stacker 112 that are large-capacity stackers. The image forming device 101 is also called a multifunction device, multifunction peripheral, or MFP. In this embodiment, the sheets that are recording materials are those on which a toner image is formed, and specific examples include plain paper, synthetic resin sheets that are substitutes for plain paper, cardboard, and sheets for overhead projectors.

The printing device 107 forms an image using toner on a sheet transported from the feed cassettes 301 and 302 located at the bottom of the printing device 107. That is, the printing device 107 is an example of an image forming unit that forms an image on a sheet based on image information. The inspection device 108 is a device that reads the image of the sheet transported from the printing device 107 and compares it with a correct image registered in advance to determine whether the printed image is normal. That is, the inspection device 108 is an example of a reading unit that reads the image formed on the sheet by the printing device 107. The first stacker 111 and the second stacker 112 are large-capacity stackers that can stack a large amount of sheets. Note that the image forming system 1 described in FIG. 1 is configured such that the external controller 102 is connected to the image forming device 101, but the present invention is not limited to a configuration in which the external controller 102 is connected. That is, the image forming apparatus 101 may be connected to an external LAN 104, and print data that can be processed by the image forming apparatus 101 may be sent from the client PC 103. In this case, data analysis and rasterization processing are performed in the image forming apparatus 101, and printing processing is executed.

[Control system of image forming system]
FIG. 2 is a block diagram showing a system configuration of the image forming apparatus 101, the external controller 102, and the client PC 103. As shown in FIG.

First, the configuration of the printing device 107 will be described. The printing device 107 has a communication I/F 217, a LAN I/F 218, a video I/F 220, a HDD 221, a CPU 222, a memory 223, an operation unit 224, a display 225, a laser exposure unit 227, an image creation unit 228, a fixing unit 229, and a feed unit 230. Each component is connected via a system bus 231. In this embodiment, a tandem type full-color printer is described as an example of the printing device 107. However, the present invention is not limited to the tandem type printing device 107, and may be other types of image forming devices, and is not limited to full color, but may be monochrome or mono color.

The communication I/F (interface) 217 is connected to the inspection device 108, the first stacker 111, and the second stacker 112 via a communication cable 249, and communication for controlling each device is performed. The LAN I/F 218 is connected to the external controller 102 via the internal LAN 105, and communication of print data and the like is performed. The video I/F 220 is connected to the external controller 102 via a video cable 106, and communication of image data and the like is performed. The HDD 221 is a storage device in which programs and data are stored. The CPU 222 comprehensively controls image processing and printing based on the programs and the like stored in the HDD 221. The memory 223 stores programs and image data required when the CPU 222 performs various processes, and operates as a work area. The operation unit 224 accepts various setting inputs and operation instructions from the user. The display 225 displays setting information of the image forming device 101, the processing status of a print job, and the like.

The laser exposure unit 227 is a device that performs primary charging and laser exposure to irradiate the photosensitive drum with laser light to transfer a toner image. In the laser exposure unit 227, first, primary charging is performed to charge the surface of the photosensitive drum to a uniform negative potential. Next, the laser driver irradiates the photosensitive drum with laser light while adjusting the reflection angle with a polygon mirror. This neutralizes the negative charge of the irradiated area and forms an electrostatic latent image. The image creation unit 228 is a device for transferring toner to a sheet, and is composed of a development unit, a transfer unit, a toner supply unit, etc., and transfers the toner on the photosensitive drum to the sheet. In the development unit, negatively charged toner from the development cylinder is attached to the electrostatic latent image on the photosensitive drum surface to make it visible. In the transfer unit, primary transfer is performed by applying a positive potential to the primary transfer roller to transfer the toner on the photosensitive drum surface to the transfer belt, and secondary transfer is performed by applying a positive potential to the secondary transfer outer roller to transfer the toner on the transfer belt to the sheet. The fixing unit 229 is a device for melting and fixing the toner on the sheet to the sheet using heat and pressure, and is composed of a heater, a fixing belt, a pressure belt, etc. The feeding unit 230 is a device for feeding the sheet, and the sheet feeding and transporting operations are controlled by rollers and various sensors.

Next, the configuration of the inspection device 108 will be described. The inspection device 108 has a communication I/F 232, a CPU 233 which is an example of a control unit, a memory 234, an image reading unit 235, a display unit 236, an operation unit 237, and an image processing unit 238, and each component is connected via a system bus 250. The communication I/F 232 is connected to the printing device 107 via a communication cable 249, and communication necessary for control is performed. The memory 234 is a storage device in which a control program is stored. The image reading unit 235 reads an image on the conveyed sheet based on an instruction from the CPU 233. The CPU 233 performs various controls necessary for inspection according to the control program stored in the memory 234. The CPU 233 compares the image read by the image reading unit 235 with the correct image stored in the memory 234 and judges whether the printed image is normal. The display unit 236 displays the inspection result, a setting screen, and the like. The operation unit 237 is operated by the user and accepts instructions such as changing the settings of the inspection device 108 and registering a correct image. The image processing unit 238 performs operations such as setting gain adjustment values for image reading by the image reading unit 235, and reflects the settings in the image reading results.

Next, the configuration of the first stacker 111 will be described. The first stacker 111 has a communication I/F 239, a CPU 240, a memory 241, and a discharge control unit 242, and each of the components is connected via a system bus 243. The communication I/F 239 is connected to the printing device 107 via a communication cable 249, and communication necessary for control is performed. The CPU 240 performs various controls necessary for discharge according to the control program stored in the memory 241. The memory 241 is a storage device in which the control program is saved. The discharge control unit 242 controls the conveying of the conveyed sheet to the first stack tray 331 (see FIG. 3) or the escape tray 334 (see FIG. 3) based on an instruction from the CPU 240. Next, the configuration of the second stacker 112 will be described. The second stacker 112 has a communication I/F 244, a CPU 245, a memory 246, and a discharge control unit 247, and each of the components is connected via a system bus 248. The configuration of each part is the same as that of the first stacker 111, so detailed explanations will be omitted.

Next, the configuration of the external controller 102 will be described. The external controller 102 may also be called an image processing controller, a digital front end, a print server, a DFE, etc. The external controller 102 has a CPU 208, a memory 209, a HDD 210, a keyboard 211, a display 212, a LAN I/F 213, a LAN I/F 214, and a video I/F 215, which are connected through a system bus 216. The CPU 208 comprehensively executes processes such as receiving print data from the client PC 103, RIP processing, and sending print data to the image forming device 101 based on the programs and data stored in the HDD 210. The memory 209 stores programs and data required for the CPU 208 to perform various processes, and operates as a work area. The HDD 210 stores programs and data required for operations such as printing processing. The keyboard 211 is a device for inputting operation instructions for the external controller 102. The display 212 can display information such as the application executed by the external controller 102 using video signals for still images and moving images. The LAN I/F 213 is connected to the client PC 103 via the external LAN 104, and performs communication such as print instructions. The LAN I/F 214 is connected to the image forming apparatus 101 via the internal LAN 105, and performs communication such as print instructions. The video I/F 215 is connected to the image forming apparatus 101 via the video cable 106, and performs communication such as print data.

Next, the configuration of the client PC 103 will be described. The client PC 103 has a CPU 201, a memory 202, a HDD 203, a keyboard 204, a display 205, and a LAN I/F 206, which are connected via a system bus 207. The CPU 201 creates print data and issues print instructions based on a document processing program or the like stored in the HDD 203, and comprehensively controls each device connected to the system bus. The memory 202 stores programs and data required for the CPU 201 to perform various processes, and operates as a work area. The HDD 203 stores programs and data required for operations such as printing. The keyboard 204 is a device for inputting operation instructions for the client PC 103. The display 205 displays information such as the application executed by the client PC 103 using video signals of still images and moving images. The LAN I/F 206 is connected to the external LAN 104, and communication such as print instructions is performed.

In the above description, the external controller 102 and the image forming device 101 are connected by the internal LAN 105 and the video cable 106, but any other configuration is acceptable as long as it allows transmission and reception of data necessary for printing, and for example, a connection configuration using only a video cable is also acceptable. Also, each of the memories 202, 209, 223, 234, 241, and 246 may be a storage device for holding data and programs. For example, they may be replaced by volatile RAM, non-volatile ROM, an internal HDD, an external HDD, a USB memory, etc.

[Image forming apparatus]
3 is a cross-sectional view of the image forming apparatus 101. The configuration and operation principle of the printing apparatus 107 are as follows. In the printing apparatus 107, various sheets can be stored in the feeding cassettes 301 and 302. In each feeding cassette 301 and 302, only the topmost sheet of the stored sheets can be separated and conveyed to a sheet conveying path 303. In the developing stations 304 to 307, toner images are formed using color toners of Y, M, C, and K, respectively, to form color images. In each of the developing stations 304 to 307, a light beam such as a laser beam modulated according to image data is reflected by a rotating polygon mirror such as a polygon mirror and irradiated onto a photosensitive drum as a scanning light. An electrostatic latent image formed on the photosensitive drum by this laser beam is developed with toner, and the toner image is primarily transferred to an intermediate transfer belt 308. This series of image forming processes is performed sequentially for yellow (Y), magenta (M), cyan (C), and black (K) toners, forming a full-color image on intermediate transfer belt 308. Intermediate transfer belt 308 rotates clockwise in FIG. 3, and the toner image is secondarily transferred to a sheet conveyed from sheet conveying path 303 at secondary transfer position 309, and the sheet is conveyed to first fixing unit 311. First fixing unit 311 includes a pressure roller and a heating roller, and fixes the toner image to the sheet by melting and pressing the toner as the sheet passes between the rollers. The sheet that has passed through first fixing unit 311 is conveyed to sheet conveying path 315 through sheet conveying path 312.

If further melting and pressing are required for fixing depending on the type of sheet, after passing through the first fixing unit 311, the sheet is transported to the second fixing unit 313 via the upper sheet transport path. After additional melting and pressing are performed in the second fixing unit 313, the sheet is transported to the sheet transport path 315 via the sheet transport path 314. If the image formation mode is the duplex mode, the sheet is transported to the sheet inversion path 316, inverted in the sheet inversion path 316, and then transported to the duplex transport path 317, where the image is transferred to the back side at the secondary transfer position 309. The display 225 displays the printing status and setting information of the image forming apparatus 101.

The sheet that has passed through the printing device 107 is transported to the inspection device 108. In the inspection device 108, a first CIS unit 321 and a second CIS unit 322 are arranged opposite each other. The first CIS unit 321 is a CIS unit for reading the upper surface of the sheet, and the second CIS unit 322 is a CIS unit for reading the lower surface of the sheet. When the sheet transported to the sheet transport path 323 reaches a predetermined position, the inspection device 108 reads the image of the sheet using the first CIS unit 321 and the second CIS unit 322, and determines whether the image is normal or not based on the reading result. The display unit 236 displays the inspection result performed by the inspection device 108. Note that the first CIS unit 321 and the second CIS unit 322 are not limited to being configured as CIS units as sensors, and may be configured as other optical sensors such as CCD and CMOS. The sheet transport path 323 is an example of a transport unit that transports a sheet whose image has been read by the inspection device 108.

[First stacker]
The first stacker 111 has a first stack tray 331, which is an example of a first discharge section serving as a tray for stacking sheets, and an escape tray 334, which is an example of a second discharge section serving as a discharge tray. A sheet that has passed through the inspection device 108 is transported to the first stacker 111. The sheet is stacked on the first stack tray 331 via a sheet transport path 332 and a sheet transport path 333. The escape tray 334 is a discharge tray used to discharge a sheet whose image has been determined to be abnormal by the inspection device 108. When outputting to the escape tray 334, the sheet is transported from the sheet transport path 332 to the escape tray 334 via a sheet transport path 335. When transporting the sheet to a post-processing device downstream of the first stacker 111, the sheet is transported via a sheet transport path 336.

The inversion unit 337 is provided to invert the sheets, and is used when the sheets are loaded onto the first stack tray 331. That is, when the sheets are loaded onto the first stack tray 331 so that the input sheet orientation is the same as the sheet orientation at the time of output, the inversion unit 337 inverts the sheets. When the sheets are to be transported to the escape tray 334 or a subsequent post-processing device, the sheets are discharged as is, and therefore the inversion operation is not performed by the inversion unit 337.

[Second stacker]
The second stacker 112 has a second stack tray 341, which is an example of a third discharge unit serving as a tray for stacking sheets, and a tray 344. The sheets that have passed through the first stacker 111 are transported to the second stacker 112. The sheets are stacked on the second stack tray 341 via a sheet transport path 342 and a sheet transport path 343. When outputting to the tray 344, the sheets are transported from the sheet transport path 342 to the tray 344 via a sheet transport path 345. The reversing unit 347 is provided to reverse the sheets, and is used when stacking the sheets on the second stack tray 341. That is, when stacking the sheets on the second stack tray 341 so that the orientation of the input sheet is the same as the orientation of the sheet at the time of output, the sheets are reversed by the reversing unit 347. When transporting to the tray 344, the sheets are discharged as is, so that the reversing operation is not performed by the reversing unit 347.

In this embodiment, the sheet transported by the sheet transport path 332 of the inspection device 108 is selectively discharged from the first stack tray 331, the second stack tray 341, or the escape tray 334. The CPU 233 of the inspection device 108 compares the image read by the inspection device 108 with the image information to determine whether the image is normal or abnormal, and selects the discharge destination for the sheet from among the trays 331, 341, and 334.

[Destination setting]
4 is an example of a screen displayed on the display 212 of the external controller 102. The button 401 for setting the discharge destination allows the selection of "Automatic", "First stack tray", or "Second stack tray". When "Automatic" is selected, the external controller 102 sets the discharge destination designation as automatic. When "First stack tray" is selected, the external controller 102 sets the first stack tray 331 as the discharge destination. When "Second stack tray" is selected, the external controller 102 sets the second stack tray 341 as the discharge destination. The button 402 for setting the priority discharge destination allows the selection of "First stack tray" or "Second stack tray". When "First stack tray" is selected, the external controller 102 sets the first stack tray 331 as the discharge destination when the discharge destination designation is automatic. When "Second stack tray" is selected, the external controller 102 sets the second stack tray 341 as the discharge destination when the discharge destination designation is automatic.

[Inspection System]
A sheet whose image is determined to be abnormal by the inspection device 108 is discharged to the escape tray 334 and recovery printing is required. At the time when the image is determined to be abnormal, image formation has already started on several sheets (referred to as "residual sheets") upstream of the inspection device 108 in the printing device 107. That is, the "residual sheets" refer to a plurality of sheets on which image formation has started after the abnormal sheet at the time when the abnormal image is read. Here, when the first stack tray 331 is designated by the button 401 in FIG. 4, only the first stack tray 331 is used as the discharge destination of normal sheets. Therefore, in order to guarantee the stacking order of the sheets, all the residual sheets are discharged to the escape tray 334, and then recovery printing is performed on the sheet determined to be abnormal. This reduces productivity, and all the residual sheets become discarded sheets.

In contrast, in this embodiment, in order to reduce discarded sheets without reducing productivity, if the user sets the discharge destination to automatic, if the discharge destination of the first sheet of a set is waiting for recovery, the discharge destination is switched to another discharge destination that is not waiting for recovery. By switching the discharge destination for the first sheet of a set, a discharge destination different from the discharge destination waiting for recovery is specified for subsequent copies of a sheet determined to be abnormal. Therefore, subsequent copies of a sheet determined to be abnormal can be discharged as deliverables without being discarded.

The processing procedures for the inspection process in each part of the image forming system 1 will be explained in detail below with reference to the flowcharts in Figures 5 to 10.

[Processing on external controller]
Fig. 5 is a flowchart showing a process flow when various settings are made to the external controller 102. Each process shown in Fig. 5 is executed by the CPU 208 of the external controller 102. When the external controller 102 is started, the CPU 208 judges whether or not a stop instruction has been received from the user (step S1). When the CPU 208 judges that a stop instruction has been received from the user (YES in step S1), the process of the external controller 102 is terminated.

When the CPU 208 determines that it has not received a stop instruction from the user (NO in step S1), it receives a print instruction from the user (step S2). When the CPU 208 receives a print instruction from the user, it acquires the settings of the number of copies of the job, the discharge destination designation, and the priority discharge destination designation. Here, a case will be described in which the number of copies of the job is set to X, the discharge destination designation to Y, and the priority discharge destination designation to Z. The discharge destination designation Y and the priority discharge destination designation Z are settings that are specified on the screen of the display 212 shown in FIG. 4.

The CPU 208 assigns an initial value of 0 to I (step S3). The CPU 208 assigns I+1 to I and counts up (step S4). The CPU 208 determines whether the discharge destination designation Y is automatic (step S5). If the CPU 208 determines that the discharge destination designation Y is automatic (YES in step S5), it assigns the priority discharge destination designation Z to the external controller designated discharge destination J (step S6). If the CPU 208 determines that the discharge destination designation Y is not automatic (NO in step S5), it assigns the discharge destination designation Y to the external controller designated discharge destination J (step S7).

The CPU 208 instructs the printing device 107 to print the Ith copy (step S8). At this time, the CPU 208 sets the designated discharge destination to Y and the designated discharge destination of the external controller to J. The CPU 208 judges whether I is equal to X (step S9). If the CPU 208 judges that I is not equal to X (NO in step S9), printing of all copies has not been completed, so it again assigns I+1 to I and counts up (step S4). If the CPU 208 judges that I is equal to X (YES in step S9), printing of all copies has been completed, so it again judges whether a stop instruction has been received from the user (step S1).

[Printing process]
6 and 7 are flow charts showing the flow of the process performed by the printing device 107 before the inspection process. The process in FIG. 6 and FIG. 7 is executed by the CPU 222 of the printing device 107. When the printing device 107 is started, the CPU 222 assigns an initial value of 0 to the discharge destination buffer A (step S11). The CPU 222 judges whether the printing device 107 has received a stop instruction (step S12). If the CPU 222 judges that the printing device 107 has received a stop instruction (YES in step S12), the processing of the printing device 107 is terminated. If the CPU 222 judges that the printing device 107 has not received a stop instruction (NO in step S12), the CPU 222 receives a print instruction from the external controller 102 (step S13). This corresponds to the case where the external controller 102 instructs the printing device 107 to print in step S8 shown in FIG. 5.

The CPU 222 determines whether the destination Y is automatic (step S14). If the CPU 222 determines that the destination Y is automatic (YES in step S14), it determines whether the destination buffer A is the initial value 0 (step S15). If the CPU 222 determines that the destination buffer A is the initial value 0 (YES in step S15), it assigns the external controller designated destination J to the destination buffer A (step S16) and assigns the destination buffer A to the destination K (step S17). If the CPU 222 determines that the destination buffer A is not the initial value 0 (NO in step S15), it assigns the destination buffer A to the destination K (step S17). If the CPU 222 determines that the destination Y is not automatic (NO in step S14), it assigns the destination Y to the destination K (step S18).

The CPU 222 prints the image formation job received from the external controller 102, designates K as the discharge destination, and conveys the sheet to the inspection device 108 (step S19). The CPU 222 controls the inspection device 108, the first stacker 111, and the second stacker 112 via the communication cable 249 according to the contents of the image formation job received from the external controller 102. The CPU 222 receives a discharge completion notification from the first stacker 111 or the second stacker 112 (step S20). Note that the image formation job is the image formation instruction content received from the user, and is the following series of operations performed based on a print command signal (image formation instruction signal). That is, it refers to the period from the pre-rotation (preparatory operation before image formation) after receiving the print command signal (input of the image formation job) to the post-rotation (operation after image formation), including the image formation period and the paper interval (when not forming an image). However, in this embodiment, in addition to the above definition, the image formation job may also mean that the printing device 107 forms an image on one sheet.

The CPU 222 judges whether the sheet was discharged normally (step S21). If the CPU 222 judges that the sheet was discharged normally (YES in step S21), it judges whether the discharge destination Y is automatic (step S22). If the CPU 222 judges that the discharge destination Y is automatic (YES in step S22), it designates the discharge destination from which the discharge completion notification received in step S20 was sent to the discharge destination buffer A (step S23), and judges whether a stop instruction has been received again (step S12). If the CPU 222 judges that the discharge destination Y is not automatic (NO in step S22), it does not change the discharge destination buffer A, and judges whether a stop instruction has been received again (step S12). If the CPU 222 judges that the sheet was not discharged normally (NO in step S21), it reprints the print data to recover the sheet that was not discharged normally (step S24), and judges whether a stop instruction has been received again (step S12).

[Inspection device processing]
8 and 9 are flowcharts showing the flow of the process performed by the inspection device 108 when performing the inspection process. The process in FIG. 8 and FIG. 9 is executed by the CPU 233 of the inspection device 108. The CPU 233 judges whether or not a sheet has been conveyed to the inspection device 108 (step S31). When the CPU 233 judges that a sheet has not been conveyed to the inspection device 108 (NO in step S31), the process of the inspection device 108 is terminated. When the CPU 233 judges that a sheet has been conveyed to the inspection device 108 (YES in step S31), the CPU 233 reads the image of the sheet using the first CIS unit 321 and the second CIS unit 322, and stores it in the memory 234 of the inspection device 108 (step S32). The CPU 233 compares the read image with the correct image (step S33).

The CPU 233 judges whether the read image is a normal image or not based on the result of comparing the read image with the correct image (step S34, judgment process). That is, the CPU 233 compares the image read by the inspection device 108 with the image information to judge whether the image is a normal image or an abnormal image. If the CPU 233 judges that the read image is not a normal image (NO in step S34), it changes the original discharge destination L to the discharge destination K (step S38). Since the sheet with the abnormal image needs to be discharged to the discharge destination K by recovery printing, the CPU 233 sets the discharge destination K to waiting for recovery (step S39). The CPU 233 notifies the first stacker 111 of inspection NG discharge (step S40, first abnormal discharge process) and ends the processing of the inspection device 108. That is, if it is judged that the image read by the inspection device 108 is an abnormal image in the judgment process, the abnormal sheet on which the abnormal image is formed is discharged to the escape tray 334.

If the CPU 233 determines that the scanned image is a normal image (YES in step S34), it determines whether the printed sheet is a recovery print (step S35). If the CPU 233 determines that the printed sheet is not a recovery print (NO in step S35), it determines whether the printed sheet is the first sheet of a set and whether the discharge destination Y is automatic (step S36). In this embodiment, the timing for setting recovery printing is after printing of the set that includes the final sheet of remaining sheets has ended, at which point a stop instruction is issued to start recovery printing.

If the CPU 233 determines that the printed sheet is the first sheet of a set and that the designated discharge destination Y is automatic (YES in step S36), it determines whether the designated discharge destination K is waiting for recovery (step S44). If the CPU 233 determines that the designated discharge destination K is not waiting for recovery (NO in step S44), it notifies the discharge destination K determined by the inspection device processing up to this point of the inspection device of inspection OK discharge (step S48, first normal discharge process), and ends the processing of the inspection device 108. That is, if the CPU 233 determines that the image read by the inspection device 108 in the judgment process is a normal image, it discharges the sheet on which the normal image is formed to the first stack tray 331.

In this manner, in this embodiment, when a sheet reaches the inspection device 108, the image formation job is considered to have already started image formation output of the next copy of sheets. In such an image formation job, when the CPU 233 determines the destination for the first sheet of a copy, if the intended destination is not available, it determines the available destination between the first stack tray 331 and the second stack tray 341 as the destination for the copy.

When the CPU 233 determines that the specified discharge destination K is waiting for recovery (YES in step S44), it determines whether the specified discharge destination K is the first stacker 111 (step S45). When the CPU 233 determines that the specified discharge destination K is the first stacker 111 (YES in step S45), it changes the discharge destination K to the second stacker 112 (step S46). The CPU 233 notifies the confirmed discharge destination K of inspection OK discharge (step S48, second normal discharge process), and ends the processing of the inspection device 108. That is, among the remaining sheets, sheets that do not constitute the first part including the abnormal sheet are discharged to the second stack tray 341.

If the CPU 233 determines that the specified discharge destination K is not the first stacker 111 (NO in step S45), the specified discharge destination K is the second stacker 112, and so the CPU 233 changes the discharge destination K to the first stacker 111 (step S47). The CPU 233 notifies the confirmed discharge destination K that the paper has been discharged after inspection (step S48), and ends the processing of the inspection device 108.

If the CPU 233 determines that the printed sheet is the first sheet of the set and the discharge destination Y is not automatic (NO in step S36), it determines whether the specified discharge destination K is waiting for recovery (step S37). Here, when it is determined that the printed sheet is the first sheet of the set and the discharge destination Y is not automatic, it means at least one of the following: the printed sheet is not the first sheet of the set, or the discharge destination Y is not automatic. If the CPU 233 determines that the specified discharge destination K is not waiting for recovery (NO in step S37), it notifies the confirmed discharge destination K of inspection OK discharge (step S48, supplementary process), and ends the processing of the inspection device 108. That is, in the second set including the last sheet of the remaining sheets, for the sheets on which image formation by the printing device 107 has not been performed at the time when the abnormal image was read, image formation by the printing device 107 is performed. Then, after the execution, the image-formed sheet is discharged to the second stack tray 341. If the CPU 233 determines that the specified discharge destination K is waiting for recovery (YES in step S37), it notifies the first stacker 111 of an inspection NG discharge (step S40, second abnormal discharge process) and ends the processing of the inspection device 108. That is, among the multiple remaining sheets, the sheets constituting the first set, which included the abnormal sheet, are discharged to the escape tray 334.

When the CPU 233 determines that the printed sheet is recovery printing (YES in step S35), it determines whether the original discharge destination L is waiting for recovery (step S41). When the CPU 233 determines that the original discharge destination L is waiting for recovery (YES in step S41), it cancels the recovery waiting state of the original discharge destination L (step S42) and changes the discharge destination K to the original discharge destination L (step S43). This allows the sheet printed by recovery printing to be discharged to the original discharge destination. The CPU 233 notifies the confirmed discharge destination K that the inspection is OK (step S48) and ends the processing of the inspection device 108. That is, for the sheets on which images have been formed by the printing device 107 from the abnormal sheet constituting the first part to the final sheet of the first part, the image formation is performed again by the printing device 107, and then the image-formed sheets are discharged to the first stack tray 331.

When the CPU 233 determines that the original discharge destination L is not waiting for recovery (NO in step S41), since this is the second or subsequent page of recovery printing, it leaves the discharge destination as it is and notifies the confirmed discharge destination K of inspection OK discharge (step S48). Then, the processing of the inspection device 108 ends. In this embodiment, the CPU 233 determines that recovery is waiting in steps S44 and S37, but this is not limited to the above, and this determination may be made by the external controller 102 or the printing device 107.

[Stacker Processing]
Fig. 10 is a flowchart showing the flow of processing performed by the first stacker 111 and the second stacker 112. The processing in Fig. 10 is executed by the CPU 240 of the first stacker 111 or the CPU 245 of the second stacker 112. The CPUs 240, 245 receive a discharge notification from the inspection device 108 (step S51). This corresponds to the case where the inspection device 108 issues a discharge notification to the first stacker 111 or the second stacker 112 in step S40 or step S48 shown in Fig. 7.

The CPU 240, 245 determines whether the ejection notification is inspection OK (step S52). If the CPU 240, 245 determines that the ejection notification is inspection OK (YES in step S52), the first stacker 111 ejects to the first stack tray 331, and the second stacker 112 ejects to the second stack tray 341 (step S53). This step S53 corresponds to a part of the first normal ejection process, the second normal ejection process, the supplementary process, and the first recovery process. If the CPU 240, 245 determines that the ejection notification is not inspection OK (NO in step S52), the first stacker 111 ejects to the escape tray 334, and the second stacker 112 ejects to the tray 344 (step S54, first abnormal ejection process, second abnormal ejection process).

After step S53 or step S54 is completed, the CPU 240, 245 notifies the printing device 107 of completion of ejection (step S55), and ends the processing of the first stacker 111 and the second stacker 112. The ejection completion notification corresponds to the case where the printing device 107 receives the ejection completion notification in step S20 of FIG. 7.

(Example)
A specific embodiment using the image forming apparatus 101 described above will be described with reference to FIG. 11. Here, it is assumed that one copy is composed of a plurality of sheets (e.g., three sheets), and an image forming job is executed in which a plurality of copies (e.g., four copies) are continuously image-formed. First, the CPU 233 compares the image read by the inspection device 108 with image information to determine whether the image is normal or abnormal (determination step). If the image read by the inspection device 108 is a normal image, the sheet (1-1) on which the normal image is formed is discharged to the first stack tray 331 (first normal discharge step). If the image read by the inspection device 108 is an abnormal image, the abnormal sheet (1-2) on which the abnormal image is formed is discharged to the escape tray 334 (first abnormal discharge step).

When the abnormal image (1-2) is read, the multiple sheets on which image formation has begun after the abnormal sheet (1-2) are called the remaining sheets (1-3 to 3-1). Of these remaining sheets (1-3 to 3-1), the sheet (1-3) that constitutes the first part (1-1 to 1-3) that included the abnormal sheet (1-2) is discharged to the escape tray 334 (second abnormal discharge process). Of the remaining sheets (1-3 to 3-1), the sheets (2-1 to 3-1) that do not constitute the first part (1-1 to 1-3) are discharged to the second stack tray 341 (second normal discharge process).

There is an image formation job that forms an image on the second set (3-1 to 3-3) that includes the final sheet (3-1) of the remaining sheets (1-3 to 3-1). Among these image formation jobs, the following is done for unexecuted image formation jobs that occur after the image formation job that formed an image on the final sheet (3-1). That is, after the unexecuted image formation job is executed (complementary printing), the sheets (3-2 to 3-3) on which the image was formed are discharged to the second stack tray 341 (complementary process). At this point, the printing state is switched from normal printing to recovery printing.

Then, there is an image formation job in which images are formed on the abnormal sheet (1-2) that constitutes the first copy (1-1 to 1-3) through the final sheet (1-3) of the first copy. For this image formation job, the image formation job is executed again (recovery printing), and then the sheets on which the images are formed (1-2 to 1-3) are discharged to the first stack tray 331 (first recovery process). After the recovery printing is completed, the printing state is switched to normal printing, and an image formation job is executed for the final fourth copy, and then the sheets on which the images are formed (4-1 to 4-3) are discharged to the first stack tray 331.

As such, the control method for the image forming device 101 according to this embodiment includes a determination process, a first normal discharge process, a first abnormal discharge process, a second abnormal discharge process, a second normal discharge process, a complementation process, and a first recovery process.

In this embodiment, the image formation job for the sheets (3-2 to 3-3) is executed before the image formation job for the sheets (1-2 to 1-3). That is, the first recovery step is executed after the completion step is executed. However, this order is not limited, and the image formation job for the sheets (3-2 to 3-3) may be executed after the image formation job for the sheets (1-2 to 1-3). That is, the completion step may be executed after the first recovery step is executed. In this case, when the sheets (2-1 to 3-1) that do not constitute the first copy (1-1 to 1-3) among the remaining sheets (1-3 to 3-1) are discharged to the second stack tray 341, the printing state is switched from normal printing to recovery printing. Alternatively, after the completion step, the last fourth copy may be printed, and then the first recovery step may be executed. In this case, when the printing of the last fourth copy is completed, the printing state is switched from normal printing to recovery printing.

When an inspection failure occurs by the inspection device 108, if another inspection failure occurs before the first stack tray 331 is released from recovery standby by recovery printing, the first stack tray 331 and the second stack tray 341 will be in recovery standby. Therefore, all remaining sheets at that point are discharged to the escape tray 344, and recovery printing is performed on the first stack tray 331 and the second stack tray 341.

As described above, according to the image forming apparatus 101 of the present embodiment, the sheets constituting the first part including the abnormal sheet among the remaining sheets are discharged to the escape tray 334, and the sheets not constituting the first part are discharged to the second stack tray 341. That is, when the inspection device 108 judges an abnormality in the print image, all the parts of the sheets judged to be abnormal upstream of the sheet judged to be abnormal are discharged to the escape tray 334. Then, for the part next to the part judged to be abnormal and thereafter, when the leading sheet of the part reaches the inspection device 108, it is discharged to a discharge destination where it can be discharged. Therefore, compared to the case where all the remaining sheets are discharged to the escape tray 334, it is possible to reduce the number of discarded sheets. Moreover, since a dedicated conveying path for temporarily evacuating a part of the remaining sheets is not required, it is possible to avoid an increase in the number of parts. As a result, in the image forming apparatus 101 having the function of discharging the sheet judged to be an abnormal image by the inspection device 108 to the escape tray 334, it is possible to suppress the size and complexity of the device while reducing the number of discarded sheets.

Furthermore, according to the image forming apparatus 101 of this embodiment, if the image is normal (inspection OK), the discharge destination specified in step S13 is not changed, and the image is discharged to the same discharge destination J until an inspection NG occurs. After the copy after the inspection NG occurs, the copy is discharged to a different discharge destination than the copy after the inspection NG occurred. Therefore, sheets from the same copy as the one with the inspection NG are discharged to the escape tray 334 and become discarded sheets, but after the copy with the inspection NG, sheets can be discharged without being discarded. Furthermore, since printing is not stopped, productivity does not decrease.

In addition, according to the image forming apparatus 101 of this embodiment, as shown in the example, the image forming job for sheets (3-2 to 3-3) is executed before the image forming job for sheets (1-2 to 1-3). In other words, the first recovery process is executed after the complement process is executed. Therefore, the number of times the discharge destination is switched after all the remaining sheets are discharged can be set to a minimum of once, making control simpler.

In the above-described example of the image forming apparatus 101 of this embodiment, the image forming job for the sheets (3-2 to 3-3) is executed before the image forming job for the sheets (1-2 to 1-3), but this is not limited to the above. For example, the image forming job for the sheets (3-2 to 3-3) may be executed after the image forming job for the sheets (1-2 to 1-3). In this case, the sheets are quickly discharged to the first stack tray 331 where they should be discharged, improving the user experience.

The control method for the image forming apparatus 101 of the present embodiment described above has been described as including a determination process, a first normal discharge process, a first abnormal discharge process, a second abnormal discharge process, a second normal discharge process, a supplementary process, and a first recovery process. However, this is not limited to this, and as long as the method includes at least a determination process, a first normal discharge process, a first abnormal discharge process, a second abnormal discharge process, and a second normal discharge process, the number of discarded sheets can be reduced compared to the case where all remaining sheets are discharged to the escape tray 334.

Second Embodiment
Next, a second embodiment of the present invention will be described in detail with reference to Figures 12 to 15. This embodiment differs from the first embodiment in that a notification is given when the discharge destination is changed. However, other configurations are the same as those of the first embodiment, so the same reference numerals are used and detailed description is omitted.

In this embodiment, as shown in FIG. 12, when an inspection is not successful, a message is displayed on the display 212, which is an example of a display unit of the external controller 102 (see FIG. 2), informing the user that the discharge destination is to be changed to the second stack tray 341 due to the inspection being not successful. In other words, when the discharge destination for discharging the sheet is changed from among the first stack tray 331, the second stack tray 341, and the escape tray 334, the display 212 displays a message indicating that the change has been made.

Figure 13 is a flowchart showing the flow of processing performed by the external controller 102 when displaying a message. Each process shown in Figure 13 is executed by the CPU 208 of the external controller 102. Note that the flowchart shown in Figure 13 is partially common to the flowchart shown in Figure 5, so the common parts are displayed with the same step numbers and detailed explanations are omitted. As shown in Figure 13, the CPU 208 instructs the printing device 107 to print the Ith copy (step S8) and determines whether or not a discharge destination change notification has been received from the printing device 107 (step S61). If the CPU 208 determines that a discharge destination change notification has been received from the printing device 107 (YES in step S61), it displays the discharge destination change on the display 212 of the external controller 102 (step S62, change display process). The screen displayed at this time is the display 212 shown in Figure 12. After displaying, the CPU 208 determines whether I is equal to X (step S9). Furthermore, if the CPU 208 determines that it has not received a discharge destination change notification from the printing device 107 (NO in step S61), it determines whether I is equal to X without displaying it (step S9).

Figures 14 and 15 are flowcharts showing the flow of processing performed by the printing device 107 when displaying a message. The processing in Figures 14 and 15 is executed by the CPU 222 of the printing device 107. Note that the flowcharts shown in Figures 14 and 15 share some parts in common with the flowcharts shown in Figures 6 and 7, so the common parts are indicated by the same step numbers and detailed explanations are omitted.

As shown in FIG. 15, when the CPU 222 determines that the discharge destination designation Y is automatic (YES in step S22), it determines whether or not the discharge destination buffer A is the same as the notification source discharge destination of the discharge completion notification received in step S20 (step S63). When the CPU 222 determines that the discharge destination buffer A is the same as the notification source discharge destination of the discharge completion notification received in step S20 (YES in step S63), it determines again whether or not a stop instruction has been received without changing the discharge destination buffer A (step S12).

If the CPU 222 determines that the discharge destination buffer A is not equal to the notification source discharge destination of the discharge completion notification received in step S20 (NO in step S63), it designates the notification source discharge destination of the discharge completion notification received in step S20 as the discharge destination buffer A (step S23). The CPU 222 notifies the external controller 102 of the change of discharge destination. This corresponds to step S61 in FIG. 13.

As described above, according to the image forming apparatus 101 of this embodiment, when the destination to which the sheets are discharged is changed among the first stack tray 331, the second stack tray 341, and the escape tray 334, the display 212 displays a message indicating that the destination has been changed. This allows the user to know in real time that the destination to which the sheets are discharged has been changed, thereby improving operability.

Third Embodiment
Next, a third embodiment of the present invention will be described in detail with reference to Figures 16 to 21. This embodiment is different from the first embodiment in that the user can set the discharge destination to be switched to when an abnormal image is detected. However, other configurations are the same as those of the first embodiment, so the same reference numerals are used and detailed description is omitted.

16 shows an example of a display screen when setting the destination to be changed. The screen shown in FIG. 16 is displayed on the display 212 of the external controller 102 (see FIG. 2). The button 403 is used to set the destination output tray, and "Do not change" or "Second stack tray" can be selected. If "Do not change" is selected, the output tray will not be changed even if an inspection NG occurs and the output tray is waiting for recovery. If "Second stack tray" is selected, the output tray will be switched to the second stack tray 341 when the output tray is waiting for recovery. That is, in this embodiment, the display 212 has the button 403 for setting the output tray to be changed, and if the expected output tray is not available at the time of determining the output destination of the first sheet of the set, the output destination set by the button 403 is determined as the output destination.

In the image forming apparatus 101 of this embodiment, the CPU 208 can selectively execute a first mode or a second mode for the discharge section that discharges a sheet on which a normal image is formed when the image read by the inspection device 108 is a normal image. The first mode here is a mode in which the first stack tray 331 and the second stack tray 341 are selectively used, and is the case when "Second stack tray" is selected with the button 403. The second mode is a mode in which the first stack tray 331 is used without using the second stack tray 341, and is the case when "Do not change" is selected with the button 403.

Figure 17 is a flowchart showing the flow of processing performed by the external controller 102 when setting a new discharge destination. The processing shown in Figure 17 is executed by the CPU 208 of the external controller 102. Note that the flowchart shown in Figure 17 shares some parts with the flowchart shown in Figure 5, so the common parts are indicated with the same step numbers and detailed explanations are omitted.

If the CPU 208 determines that it has not received a stop instruction from the user (NO in step S1), it receives a print instruction from the user (step S71). When the CPU 208 receives a print instruction from the user, it acquires the settings of the number of copies of the job, the discharge destination designation, the priority discharge destination designation, and the change destination designation. Here, a case will be described in which the number of copies of the job is set to X, the discharge destination designation is Y, the priority discharge destination designation is Z, and the change destination designation is P. The CPU 208 also assigns the priority discharge destination designation Z to the external controller designated discharge destination J (step S6) or assigns the discharge destination designation Y to the external controller designated discharge destination J (step S7), and instructs the printing device 107 to print the Ith copy (step S72). At this time, the CPU 208 sets the discharge destination designation to Y, the external controller designated discharge destination to J, and the change destination designation to P.

18 and 19 are flowcharts showing the flow of the process performed by the printing device when setting a new discharge destination. The process shown in FIG. 18 and FIG. 19 is executed by the CPU 222 of the printing device 107. When the CPU 222 determines that the printing device 107 has not received a stop instruction (NO in step S12), it receives a print instruction from the external controller 102 (step S73). This corresponds to the case where the external controller 102 instructs the printing device 107 to print in step S72 shown in FIG. 17. The CPU 222 assigns the discharge destination buffer A to the discharge destination K (step S17), or assigns the discharge destination designation Y to the discharge destination K (step S18), and prints the image formation job received from the external controller 102 (step S74). At this time, the CPU 222 designates the discharge destination designation as Y, the changed destination designation as P, and the discharge destination as K, and conveys the image to the inspection device 108.

20 and 21 are flowcharts showing the flow of the process performed by the inspection device 108 when setting the discharge destination to be changed. The process shown in FIG. 20 and FIG. 21 is executed by the CPU 233 of the inspection device 108. When the CPU 233 determines that the specified discharge destination K is waiting for recovery (YES in step S44), it determines whether the specified discharge destination K is not equal to the changed destination designation P and whether the changed destination designation P is not "changed" (step S75). When the CPU 233 determines that the specified discharge destination K is not equal to the changed destination designation P and whether the changed destination designation P is not "changed" (YES in step S75), it changes the discharge destination K to the changed destination designation P specified in FIG. 16 (step S76). When the CPU 233 determines that the specified discharge destination K is equal to the changed destination designation P and/or the changed destination designation P is "changed" (NO in step S75), it notifies the first stacker 111 of inspection NG discharge (step S40).

In this way, when "Second stack tray" is selected by button 403 on the screen shown in FIG. 16 (first mode), the following steps are executed. That is, the judgment step, the first normal discharge step, the first abnormal discharge step, the second abnormal discharge step, the second normal discharge step, the supplement step, and the first recovery step are executed. On the other hand, when "Do not change" is selected by button 403 on the screen shown in FIG. 16 (second mode), the judgment step, the first normal discharge step, the first abnormal discharge step, the third abnormal discharge step, and the second recovery step are executed. Here, the third abnormal discharge step is a step of discharging the remaining sheets to the escape tray 334 when it is determined that the image read by the inspection device 108 in the judgment step is an abnormal image. In addition, in the second recovery step, for the sheets on which images have been formed by the printing device 107 from the abnormal sheet to the final sheet of the first part, the image formation by the printing device 107 is executed again, and then the image-formed sheets are discharged to the first stack tray 331. Furthermore, in the second recovery process, for sheets on which images are formed by the printing device 107 in the copies following the first copy, after image formation is performed by the printing device 107, the sheets on which images are formed are discharged to the first stack tray 331.

As described above, the image forming apparatus 101 of this embodiment allows the user to select between the first mode and the second mode. For example, when productivity is not a priority, only the first stack tray 331 may be used, allowing for greater freedom in usage.

In the above-described control method for the image forming apparatus 101 of this embodiment, the second mode is described as executing a determination process, a first normal discharge process, a first abnormal discharge process, a third abnormal discharge process, and a second recovery process, but this is not limited to the above. For example, it is sufficient to have at least a determination process, a first normal discharge process, a first abnormal discharge process, and a third abnormal discharge process.

In the above-described embodiments, the first stack tray 331 and the second stack tray 341 are used as the discharge destinations for normal sheets. However, this is not limited to this, and three or more discharge destinations may be provided. In this case, even if two of the three discharge destinations are waiting for recovery, the sheets can be discharged to the remaining one, thereby further improving productivity.

101: image forming apparatus, 107: printing apparatus (image forming section), 108: inspection device (reading section), 212: display (display section), 233: CPU (control section), 323: sheet transport path (transport section), 331: first stack tray (first discharge section), 334: escape tray (second discharge section), 341: second stack tray (third discharge section)

Claims (14)

an image forming unit that forms an image on a sheet based on image information;
a reading unit that reads an image formed on a sheet by the image forming unit;
a conveying unit that conveys the sheet on which the image has been read by the reading unit;
a first discharge section, a second discharge section, and a third discharge section to which the sheet conveyed by the conveying section is selectively discharged;
a control unit that compares the image read by the reading unit with image information to determine whether the image is normal or abnormal, and selects a discharge destination for discharging the sheet from among the first discharge unit, the second discharge unit, and the third discharge unit;
The control unit is
When an image forming job is executed in which one copy is made up of a plurality of sheets and the plurality of copies are continuously image-formed,
When the image read by the reading section is a normal image, the sheet on which the normal image is formed is discharged to the first discharge section;
If the image read by the reading section is an abnormal image, the abnormal sheet on which the abnormal image is formed is discharged to the second discharge section;
Among the remaining sheets on which image formation has started after the abnormal sheet at the time when the abnormal image is read, sheets constituting a first set including the abnormal sheet are discharged to the second discharge section;
Among the remaining sheets, sheets that do not constitute the first portion are discharged to the third discharge section.
1. An image forming apparatus comprising: The control unit is
In a second section including the last sheet among the remaining sheets, for a sheet on which image formation by the image forming section has not been performed at the time when the abnormal image is read, after performing image formation by the image forming section, the sheet on which the image has been formed is discharged to the third discharge section;
and performing image formation again on the sheets constituting the first section from the abnormal sheet to the final sheet of the first section by the image forming section, and then discharging the sheets on which the images have been formed to the first discharge section.
2. The image forming apparatus according to claim 1, The control unit is
image formation for sheets on which image formation by the image forming unit has not been performed at the time when the abnormal image in the second part is read is performed prior to re-execution of image formation for sheets constituting the first part from the abnormal sheet to the final sheet of the first part.
3. The image forming apparatus according to claim 2, The control unit is
image formation for sheets on which image formation by the image forming unit has not been performed at the time when the abnormal image in the second part is read is performed after re-execution of image formation for sheets constituting the first part from the abnormal sheet to the final sheet of the first part.
3. The image forming apparatus according to claim 2, an image forming unit that forms an image on a sheet based on image information;
a reading unit that reads an image formed on a sheet by the image forming unit;
a conveying unit that conveys the sheet on which the image has been read by the reading unit;
a first discharge section, a second discharge section, and a third discharge section to which the sheet conveyed by the conveying section is selectively discharged;
a control unit that compares the image read by the reading unit with image information to determine whether the image is normal or abnormal, and selects a discharge destination for discharging the sheet from among the first discharge unit, the second discharge unit, and the third discharge unit;
the control unit selectively executes, with respect to a discharge unit that discharges a sheet on which a normal image is formed when the image read by the reading unit is a normal image, a first mode in which the first discharge unit and the third discharge unit are selectively used, and a second mode in which the first discharge unit is used without using the third discharge unit;
In the first mode,
If the image read by the reading section is an abnormal image, the abnormal sheet on which the abnormal image is formed is discharged to the second discharge section;
Among the remaining sheets on which image formation has started after the abnormal sheet at the time when the abnormal image is read, sheets constituting a first set including the abnormal sheet are discharged to the second discharge section;
Among the remaining sheets, sheets that do not constitute the first portion are discharged to the third discharge section;
In the second mode,
If the image read by the reading unit is an abnormal image, the abnormal sheet on which the abnormal image is formed and the remaining sheet are discharged to the second discharge unit.
1. An image forming apparatus comprising: The control unit is
In the first mode,
In a second section including the last sheet among the remaining sheets, for a sheet on which image formation by the image forming section has not been performed at the time when the abnormal image is read, after performing image formation by the image forming section, the sheet on which the image has been formed is discharged to the third discharge section;
With respect to the sheets constituting the first section from the abnormal sheet to the final sheet of the first section, image formation is performed again by the image forming section, and then the sheets on which the images have been formed are discharged to the first discharge section;
In the second mode,
With respect to the sheets constituting the first section from the abnormal sheet to the final sheet of the first section, image formation is performed again by the image forming section, and then the sheets on which the images have been formed are discharged to the first discharge section;
for sheets of the next set after the first set, image formation is performed by the image forming unit, and then the sheets on which the images are formed are discharged to the first discharge unit.
6. The image forming apparatus according to claim 5, A display unit capable of displaying information is provided,
When a destination to which the sheet is discharged is changed among the first discharge unit, the second discharge unit, and the third discharge unit, the display unit displays a message indicating that the destination has been changed.
7. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction. an image forming unit that forms an image on a sheet based on image information;
a reading unit that reads an image formed on a sheet by the image forming unit;
a conveying unit that conveys the sheet on which the image has been read by the reading unit;
a first discharge section, a second discharge section, and a third discharge section to which the sheet conveyed by the conveying section is selectively discharged;
a control unit that compares an image read by the reading unit with image information to determine whether the image is normal or abnormal, and selects a discharge destination for discharging a sheet from among the first discharge unit, the second discharge unit, and the third discharge unit,
When an image forming job is executed in which one copy is made up of a plurality of sheets and the plurality of copies are continuously image-formed,
a determination step of comparing the image read by the reading unit with image information to determine whether the image is normal or abnormal;
a first normal discharge step of discharging the sheet on which the normal image is formed to the first discharge section when the image read by the reading section is determined to be a normal image in the determination step;
a first abnormality discharge step of discharging the abnormal sheet on which the abnormal image is formed to the second discharge step when the image read by the reading unit is determined to be an abnormal image in the determination step;
a second abnormality discharge step of discharging sheets constituting a first set including the abnormal sheet among a plurality of remaining sheets on which image formation has started after the abnormal sheet at the time when the abnormal image is read, to the second discharge section;
and a second normal discharge step of discharging sheets that do not constitute the first portion, among the remaining sheets, to the third discharge section.
23. A method for controlling an image forming apparatus comprising: a complementing step of, for a sheet on which image formation has not been performed by the image forming unit at the time when the abnormal image is read in a second section including the final sheet of the remaining sheets, performing image formation by the image forming unit and then discharging the image-formed sheet to the third discharge section;
a first recovery step of performing image formation again by the image forming unit on the sheets from the abnormal sheet constituting the first part to the final sheet of the first part, and then discharging the image-formed sheets to the first discharge unit;
9. The method for controlling an image forming apparatus according to claim 8. After executing the complementation step, execute the first recovery step.
10. The method for controlling an image forming apparatus according to claim 9. After performing the first recovery step, perform the complement step.
10. The method for controlling an image forming apparatus according to claim 9. an image forming unit that forms an image on a sheet based on image information;
a reading unit that reads an image formed on a sheet by the image forming unit;
a conveying unit that conveys the sheet on which the image has been read by the reading unit;
a first discharge section, a second discharge section, and a third discharge section to which the sheet conveyed by the conveying section is selectively discharged;
a control unit that compares an image read by the reading unit with image information to determine whether the image is normal or abnormal, and selects a discharge destination for discharging a sheet from among the first discharge unit, the second discharge unit, and the third discharge unit,
When an image forming job is executed in which one copy is made up of a plurality of sheets and the plurality of copies are continuously image-formed,
a discharge section for discharging a sheet on which a normal image is formed when the image read by the reading section is a normal image, selectively executing a first mode in which the first discharge section and the third discharge section are selectively used, and a second mode in which the first discharge section is used without using the third discharge section;
In the first mode,
a determination step of comparing the image read by the reading unit with image information to determine whether the image is normal or abnormal;
a first normal discharge step of discharging the sheet on which the normal image is formed to the first discharge section when the image read by the reading section is determined to be a normal image in the determination step;
a first abnormality discharge step of discharging the abnormal sheet on which the abnormal image is formed to the second discharge step when the image read by the reading unit is determined to be an abnormal image in the determination step;
a second abnormality discharge step of discharging sheets constituting a first set including the abnormal sheet among a plurality of remaining sheets on which image formation has started after the abnormal sheet at the time when the abnormal image is read, to the second discharge section;
a second normal discharge step of discharging sheets that do not constitute the first portion among the remaining sheets to the third discharge section;
In the second mode,
The determination step;
The first normal discharge step;
The first abnormality discharge step;
a third abnormality discharge step of discharging the remaining sheet to the second discharge section when it is determined in the determination step that the image read by the reading section is an abnormal image.
23. A method for controlling an image forming apparatus comprising: In the first mode,
a complementing step of, for a sheet on which image formation has not been performed by the image forming unit at the time when the abnormal image is read in a second section including the final sheet of the remaining sheets, performing image formation by the image forming unit and then discharging the image-formed sheet to the third discharge section;
a first recovery step of performing image formation again by the image forming unit for the sheets from the abnormal sheet constituting the first part to the final sheet of the first part, and then discharging the image-formed sheets to the first discharge unit;
In the second mode,
a second recovery step is performed in which, for sheets constituting the first part from the abnormal sheet to the final sheet of the first part, image formation is performed again by the image forming unit, and the image-formed sheets are discharged to the first discharge part; and, for sheets of the next part and subsequent parts of the first part, image formation is performed by the image forming unit, and the image-formed sheets are discharged to the first discharge part.
13. The method for controlling an image forming apparatus according to claim 12. the image forming apparatus includes a display unit capable of displaying information;
a change display step of displaying a change to the destination of the sheet discharged from among the first discharge unit, the second discharge unit, and the third discharge unit,
14. The method for controlling an image forming apparatus according to claim 8.

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