JP2017009847A - Image forming apparatus, recovery method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that suppresses an increase in unrecovered residual material when receiving a print job during a recovery operation.SOLUTION: A printer 100 includes a cleaner 55, and causes the cleaner 55 to suck a residual material during execution of a print job and causes the cleaner 55 to discharge the residual material after completion of the print job. When receiving a new print job during the discharge, the printer 100 suspends the discharge and executes the new print job. In executing the new print job, the printer 100 changes at least one of an initial value and threshold of the number of continuous printing to reduce the difference between the initial value and threshold of the number of continuous printing. When the number of continuous printing from the initial value exceeds the threshold, the printer 100 suspends the printing and causes the cleaner 55 to discharge a residual material.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus that forms an image by an electrophotographic method, a residue collection method, and a program. More specifically, the present invention relates to a technique for recovering a residue left on an image carrier such as a photoconductor.

  2. Description of the Related Art Conventionally, in an image forming apparatus that forms an image by an electrophotographic method, an operation for collecting a residue associated with image formation such as waste toner left on a photoreceptor without being transferred is known. For the operation of collecting the residue, for example, a cleaning operation for removing the residue on the image carrier such as a photoconductor from the image carrier by a cleaning device, and a recovery for moving the removed residue to a collection container and collecting it. Behavior.

  As a document disclosing the operation of collecting the residue, there is, for example, Patent Document 1. Patent Document 1 discloses an image forming apparatus that executes a recycled toner discharge mode in which waste toner removed from a photoreceptor by toner recycling means is moved to a developing device and collected. Discloses a configuration for determining whether or not to execute the recycled toner discharge mode according to the average coverage of the image.

JP 2011-128525 A

  However, the conventional technique described above has the following problems. That is, the operation when a print job is received during the collecting operation is not considered. For example, if the collection operation is interrupted and a print job is executed, the collection operation is not completed, so that unrecovered residues increase until the next collection operation, and the possibility of print smearing increases.

  The present invention has been made to solve the above-described problems of the prior art. That is, the problem is to provide a technique for suppressing an increase in unrecovered residues when a print job is received during the recovery operation.

  An image forming apparatus for solving this problem includes a photoconductor, a developing unit that develops an electrostatic latent image formed on the photoconductor using toner, and a toner image on the photoconductor. A sheet on the belt or a transfer portion to be transferred to the belt; and an electrical residue for at least one of toner and paper dust remaining on the photoreceptor after passing through the transfer portion. A suction unit that sucks the toner, a collection unit that collects the residue on the belt, a reception unit that receives a print job for forming an image using the photoconductor, and a control unit, and the control unit includes: An image forming process for forming an image in the image forming unit in accordance with a print job received in the receiving unit; and a first voltage is applied to the suction unit while an image is formed in the image forming unit; Residue in the suction part A suction process for automatically sucking, applying a second voltage having a polarity opposite to the first voltage to the suction part, electrically discharging the residue to the suction part, and passing through the belt , A discharge process for collecting the residue in the collection unit, and when the reception unit receives a new print job during the discharge process, the discharge process is interrupted, and the image forming unit according to the new print job A post-interrupt formation process for forming an image on the image, an initial amount of a continuous print amount that is an amount related to image formation of the image forming unit in the post-interrupt formation process, and a comparison target of a continuous print amount in the post-interrupt formation process The difference between the initial amount of the continuous printing amount in the post-interruption forming process and the continuous printing threshold is the difference between the initial amount of the continuous printing amount in the image forming process and the continuous printing threshold. During the execution of the change process to be changed and the post-interruption forming process based on the initial amount of the continuous print quantity after the change process so that the change is smaller than the difference between When the continuous printing threshold after processing is exceeded, the formation processing after the interruption is interrupted, a third voltage having a polarity opposite to that of the first voltage is applied to the suction portion, and the residual voltage remains in the suction portion. And a post-interrupt discharge process for electrically discharging an object.

  The image forming apparatus disclosed in this specification executes a suction process in which a residue is sucked by a suction unit during execution of a print job. In addition, the image forming apparatus executes a discharge process in which a voltage different from that in the suction process is applied to the suction unit to discharge and collect the residue. When the image forming apparatus receives a new print job during the discharge process, the image forming apparatus interrupts the discharge and executes the new print job. When executing a new print job, the image forming apparatus changes at least one of the initial continuous printing amount and the continuous printing threshold value to reduce the difference between the initial continuous printing amount and the continuous printing threshold value.

  That is, according to the image forming apparatus disclosed in the present specification, when the discharge is interrupted and the execution of the print job is started, the initial amount of the continuous printing amount and the continuous printing threshold value are compared with those during normal continuous printing. Reduce the difference between That is, when the ejection is interrupted, the continuous printing amount that is possible from the start of the print job until the continuous printing amount reaches the continuous printing threshold is smaller than when the ejection is not interrupted. As a result, in continuous printing after the ejection is interrupted, the opportunity for ejection by the suction portion is increased, and an increase in the residue can be expected.

  Further, in the present specification, as another image forming apparatus, an image forming unit for forming an image, which includes a photosensitive member, a first transfer unit that transfers a toner image on the photosensitive member to an intermediate transfer belt, A conveyance surface that is a surface that conveys a sheet and a toner image of the intermediate transfer belt, or a second transfer unit that contacts the sheet and transfers the toner image on the conveyance surface of the intermediate transfer belt to the sheet. An image is formed using the image forming unit, a collecting unit that collects at least one of toner and paper dust remaining on the intermediate transfer belt after passing through the second transfer unit, and the photoconductor. An image forming process for causing the image forming unit to form an image according to the print job received by the receiving unit; and the image forming unit. Shape the image During the transfer, a first voltage is applied to the second transfer unit to transfer the toner image on the conveyance surface of the intermediate transfer belt onto a sheet, and the first voltage is applied to the second transfer unit. And applying a second voltage having a polarity opposite to that of the toner to electrically discharge a residue, which is at least one of toner and paper powder, to the second transfer unit, and via the intermediate transfer belt, the recovery unit When the accepting unit accepts a new print job during the ejection process, the ejection process is interrupted, and an image is formed on the image forming unit according to the new print job. At least one of an initial amount of continuous printing amount and a continuous printing threshold value in the post-interruption forming processing, and a difference between the initial amount of continuous printing amount in the post-interruption forming processing and the continuous printing threshold value. , The image Execution of the post-interruption forming process based on the change process to be changed so as to be smaller than the difference between the initial amount of the continuous print amount by the composition process and the continuous print threshold, and the initial amount of the continuous print amount after the change process If the continuous print amount after the change process exceeds the continuous print threshold after the change process, the post-interrupt formation process is interrupted, and the second transfer portion has a polarity opposite to that of the first voltage. An image forming apparatus is disclosed that performs a post-interrupt discharge process in which a third voltage, which is a voltage, is applied and a residue is electrically discharged to the second transfer unit.

  The other image forming apparatus disclosed in the specification executes a discharge process in which a voltage having a polarity opposite to that during execution of the print job is applied to the second transfer unit, and the residue is discharged and collected. When the image forming apparatus receives a new print job during the discharge process, the image forming apparatus interrupts the discharge and executes the new print job. When executing a new print job, the image forming apparatus changes at least one of the initial continuous printing amount and the continuous printing threshold value to reduce the difference between the initial continuous printing amount and the continuous printing threshold value.

  Even in the above-described other image forming apparatuses disclosed in this specification, when the discharge is interrupted and the execution of the print job is started, the initial amount of the continuous printing amount and the continuous printing threshold value are compared with those during normal continuous printing. Reduce the difference between As a result, even in the above-described other image forming apparatuses, in the continuous printing after the ejection is interrupted, the chance of performing the ejection by the suction unit increases, and an increase in the residue can be expected.

  A collection method for realizing the functions of the image forming apparatus, a computer program, and a computer-readable storage medium for storing the computer program are also novel and useful.

  According to the present invention, when a print job is received during a collecting operation, a technique for suppressing an increase in unrecovered residues is realized.

It is sectional drawing which shows schematic structure of the printer concerning a 1st form. FIG. 2 is a block diagram illustrating an electrical configuration of a printer. 4 is a flowchart illustrating a printing process procedure of the printer according to the first embodiment. 6 is a flowchart illustrating a printing process procedure of a printer according to a second embodiment. It is sectional drawing which shows schematic structure of the printer concerning a 3rd form.

  Hereinafter, a first embodiment in which an image forming apparatus according to the present invention is embodied will be described in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to a printer having an electrophotographic image forming function.

  As shown in FIG. 1, a printer 100 according to the first embodiment is an apparatus that forms an image on a sheet by a laser exposure type electrophotographic technique, and has a color image forming function by a so-called tandem direct transfer system. Yes. The printer 100 includes a process unit 5, an exposure unit 6, a conveyance belt 7, a fixing unit 8, and a belt cleaner 9. The conveyor belt 7 is an endless belt member that rotates and moves as shown by an arrow in FIG. 1 and has a function of conveying a sheet. The process unit 5 is an example of an image forming unit, and the conveyance belt 7 is an example of a belt.

  The process unit 5 includes four process units 50K, 50C, 50M, and 50Y having the same configuration except for the toner color. The process units of the respective colors are arranged along the transport belt 7 in the order of the process units 50K, 50C, 50M, and 50Y in the moving direction of the transport belt 7. Note that the arrangement order of the process parts for each color is not limited to the example in FIG.

  Further, each of the process units 50K, 50C, 50M, and 50Y includes a photoconductor 51, a charging unit 52, a developing unit 53, a transfer unit 54, and a cleaner 55, as shown in the process unit 50K of FIG. , Provided. The photoconductor 51 is in the form of a drum, and is rotated along with the conveyor belt 7 as indicated by an arrow in FIG. The charging unit 52, the developing unit 53, the transfer unit 54, and the cleaner 55 are arranged around the photoconductor 51 in this order with respect to the rotation direction of the photoconductor 51. The transfer unit 54 is disposed on the opposite side of the photoconductor 51 with the conveyance belt 7 interposed therebetween.

  The charging unit 52 has a function of charging the surface of the photoconductor 51 to which a charging bias is applied. The charging unit 52 is, for example, a scorotron charger, and is disposed in a non-contact manner with respect to the surface of the photoreceptor 51.

  The developing unit 53 includes a developing roller 531 to which a developing bias is applied, and has a function of supplying toner to the surface of the photoreceptor 51. Further, the developing unit 53 has a mechanism for bringing the developing roller 531 into contact with and separating from the surface of the photoreceptor 51. Strictly speaking, the contact includes a state in which the developing roller 531 and the photosensitive member 51 are close to each other at a developable distance without being in contact with the surface of the photosensitive member 51. That is, the axial position of the developing roller 531 is arranged at either a developing position where the developing unit 53 can develop the surface of the photoconductor 51 or a non-developing position where development is not possible. FIG. 1 shows the developing unit 53 at the development position. The developing roller 531 may be fixed at the developing position.

  The transfer unit 54 is applied with a transfer bias and electrically sucks the toner on the photoconductor 51 toward the transport belt 7. At the time of image formation, the printer 100 causes the conveyance belt 7 to convey the sheet so that the toner image on the photoconductor 51 and the sheet on the conveyance belt 7 reach the position of the transfer unit 54 in synchronization. The transfer unit 54 has a function of transferring the toner image on the photoreceptor 51 to a sheet.

  The cleaner 55 is applied with a suction bias, and functions as a suction member that electrically sucks residues such as transfer residual toner from the surface of the photoreceptor 51. Further, the cleaner 55 is applied with a discharge bias having a reverse polarity to the suction bias, and functions as a discharge member that electrically discharges the sucked residue to the surface of the photoreceptor 51. The cleaner 55 is a roller member or a brush member, and is disposed in contact with the surface of the photoreceptor 51. The cleaner 55 is an example of a suction unit. The residue discharged from the cleaner 55 onto the photosensitive member 51 is transferred onto the conveyor belt 7 by the transfer unit 54. The residue includes, for example, waste toner such as transfer residual toner and reverse polarity toner, external additives such as silica, and paper powder.

  The exposure unit 6 has a function of exposing the photoreceptor 51 to form an electrostatic latent image. As shown in FIG. 1, the exposure unit 6 is disposed above the process unit 5 and includes a polygon mirror 61 and a polygon motor 62. The polygon motor 62 rotates the polygon mirror 61 at a predetermined constant speed. The polygon mirror 61 reflects the laser light emitted from the laser diode and irradiates the surface of the photoconductor 51 with the laser light. During printing, laser light is scanned in the axial direction of the photosensitive member 51 by the polygon mirror 61 rotated by the polygon motor 62.

  The fixing unit 8 includes a heating roller 81 incorporating a heater, a pressure roller 82, and a thermistor 83, and has a function of thermally fixing an unfixed toner image on the sheet to the sheet. As shown in FIG. 1, the fixing unit 8 is disposed on the downstream side of the process unit 5 in the moving direction of the conveyor belt 7. The fixing unit 8 is controlled based on a signal from the thermistor 83 so that the surface temperature of the heating roller 81 is within a predetermined temperature range.

  The belt cleaner 9 includes a collection roller 91 and a collection container 92 and has a function of collecting the residue on the conveyor belt 7. The belt cleaner 9 is an example of a collection unit. The belt cleaner 9 is arranged on the semicircular side of the conveyor belt 7 different from the semicircular side where the process unit 5 is arranged. Since the electrical polarity of the residue varies, the printer 100 collects various residues by changing the polarity of the bias applied to the collection roller 91 of the belt cleaner 9. The residue collected by the collection roller 91 is stored in the collection container 92. The belt cleaner 9 may be a mechanical device such as a blade that collects the residue.

  As shown in FIG. 1, the printer 100 includes a paper feed tray 11, a paper discharge tray 12, and a plurality of conveying members 13 for conveying sheets. The conveying member 13 also includes a conveying belt 7. The paper feed tray 11 accommodates sheets before printing. The paper discharge tray 12 accommodates printed sheets. A sheet conveyance path 14 extending from the paper feed tray 11 to the paper discharge tray 12 is formed inside the printer 100. Further, a part of the housing of the printer 100 is an openable / closable cover 15 that is opened and closed by the user during maintenance or the like.

  The printer 100 of this embodiment uses positively charged toner. When printing is performed, the printer 100 controls the power supply circuit to apply a printing bias to each of the charging unit 52, the developing unit 53, the transfer unit 54, and the cleaner 55.

  Specifically, the printer 100 applies a positive charging bias to the charging unit 52 to charge the surface of the photoconductor 51 to the positive polarity. The charged portion of the photoconductor 51 is exposed by being irradiated with laser light from the exposure unit 6, and the absolute value of the potential is partially reduced. As a result, an electrostatic latent image based on the print data is formed on the surface of the photoreceptor 51.

  In addition, the printer 100 applies a positive developing bias to the developing roller 531 and sets the developing unit 53 to the developing position. In the printer 100, toner is supplied from the developing roller 531 when the electrostatic latent image on the photoconductor 51 passes through the developing area by the developing unit 53, and a toner image is formed on the photoconductor 51.

  On the other hand, the printer 100 carries a printing sheet from the paper feed tray 11 to the conveyance path 14 and conveys the sheet by the conveyance member 13 and the conveyance belt 7. Then, the printer 100 applies a negative transfer bias to the transfer unit 54 to transfer the toner image on the photoconductor 51 to the sheet being conveyed. When forming a color image, the printer 100 superimposes the toner images on the photoreceptors 51 of the respective colors on the sheet. Further, the printer 100 causes the fixing unit 8 to fix the toner image placed on the sheet to the sheet. The printer 100 discharges the printed sheet to the paper discharge tray 12.

  In addition, the printer 100 applies a negative suction bias to the cleaner 55 during execution of printing, and electrically attracts residual matter such as transfer residual toner remaining on the photosensitive member 51 after the transfer to the cleaner 55. Let The suction bias is an example of a first voltage. That is, during printing, the cleaner 55 functions as a suction member.

  Note that the suction residue during the printing is accumulated in the cleaner 55 by repeating the suction during the printing. Therefore, the printer 100 executes a collecting operation in which the residue accumulated in the cleaner 55 is discharged and collected by the belt cleaner 9 at a timing other than during printing. The collection operation will be described later.

  Next, the electrical configuration of the printer 100 will be described. As shown in FIG. 2, the printer 100 includes a controller 30 including a CPU 31, a ROM 32, a RAM 33, an NVRAM (nonvolatile RAM) 34, and an ASIC 35. The printer 100 includes a process unit 5, an exposure unit 6, a fixing unit 8, a belt cleaner 9, a cover sensor 16, a network interface 37, a USB interface 38, and an operation panel 40. Are electrically connected to the controller 30.

  The cover sensor 16 is used to detect whether the cover 15 is open or closed. The cover sensor 16 is, for example, a sensor that outputs different signals depending on whether the cover 15 is open or closed. The cover sensor 16 is an example of a sensor. The printer 100 only needs to be able to detect that the cover 15 is opened and closed, and may be configured to be mechanically displaced by opening and closing the cover 15 instead of being detected by the cover sensor 16.

  The ROM 32 stores various control programs for controlling the printer 100, various settings, initial values, and the like. The RAM 33 or NVRAM 34 is used as a work area from which various control programs are read or as a storage area for temporarily storing data.

  The CPU 31 controls each component of the printer 100 while storing the processing result in the RAM 33 or the NVRAM 34 according to the control program read from the ROM 32. The CPU 31 is an example of a control unit. The controller 30 may be a control unit, and the ASIC 35 may be a control unit. Note that the controller 30 in FIG. 2 is a collective term for hardware used for controlling the printer 100, such as the CPU 31, and does not necessarily represent a single piece of hardware that actually exists in the printer 100.

  The network interface 37 is hardware for communicating with devices connected via a network. The USB interface 38 is hardware for communicating with a device connected via a USB cable or the like. The operation panel 40 is hardware for displaying various messages and receiving instruction inputs from the user. Each of the network interface 37, the USB interface 38, and the operation panel 40 is an example of a reception unit.

  Next, the collection operation will be described. As described above, the collection operation is an operation in which the residue accumulated in the cleaner 55 is discharged from the cleaner 55 onto the photosensitive member 51 and collected by the belt cleaner 9. In the collecting operation, the printer 100 moves the residue from the cleaner 55 to the belt cleaner 9 through the photosensitive member 51 and the conveying belt 7.

  Therefore, the printer 100 applies a bias different from that at the time of printing to the cleaner 55, the charging unit 52, and the transfer unit 54 during the collecting operation, and rotates the photoconductor 51 and the transport belt 7 in the same manner as at the time of printing. Further, the printer 100 stops the functions of the developing unit 53, the exposure unit 6, and the fixing unit 8 during the collecting operation. That is, during the collecting operation, the developing roller 531 is in the non-developing position, the polygon motor 62 is not driven to rotate, and the fixing unit 8 is not heated.

  Specifically, the printer 100 applies a positive discharge bias to the cleaner 55 in the recovery operation, and electrically discharges the positive residue accumulated in the cleaner 55 to the photoconductor 51. That is, in the collecting operation, the cleaner 55 functions as a discharge member. The ejection bias is an example of a second voltage, a third voltage, and a fourth voltage. The residue discharged on the photoconductor 51 moves as the photoconductor 51 rotates.

  Further, the printer 100 causes the charging unit 52 to apply a positive weak charging bias having an absolute value smaller than the charging bias for printing in the collecting operation. The absolute value of the weak charging bias is smaller than the absolute value of the discharge bias of the cleaner 55. Accordingly, the residue on the photoconductor 51 passes through the charging region of the charging unit 52 as the photoconductor 51 rotates without being attracted to the charging unit 52.

  Further, the printer 100 applies a negative weak transfer bias having a smaller absolute value than the transfer bias for printing to the transfer unit 54 in the collecting operation. The absolute value of the weak transfer bias may be equal to the absolute value of the transfer bias for printing. In the collecting operation, the residue is directly transferred to the conveyance belt 7 without passing through the sheet. Therefore, the residue on the photosensitive member 51 is transferred to the conveyance belt 7 even with a weak transfer bias having an absolute value smaller than that for printing. be able to. The residue transferred from the photosensitive member 51 to the transport belt 7 reaches the collection position of the belt cleaner 9 as the transport belt 7 moves.

  Then, the printer 100 applies a negative cleaner bias to the collecting roller 91 of the belt cleaner 9 in the collecting operation. The absolute value of the cleaner bias is about the same as the absolute value of the cleaner bias at the time of printing. As a result, the residue on the conveyor belt 7 is sucked by the collection roller 91 and collected in the collection container 92.

  During execution of the print job, the printer 100 counts the number of continuous prints that have been printed after the previous collection operation, and when the number of continuous prints exceeds a predetermined threshold number, interrupts printing and collects the print job. Start operation. The continuous printing number is an example of a continuous printing amount, and the threshold number is an example of a continuous printing threshold value. The printer 100 stores the threshold number in the ROM 32 or the NVRAM 34. Instead of the continuous print number, a continuous print amount based on the rotation amount of the photosensitive member 51, the rotation amount of the developing roller 531, the execution time of printing, the toner usage amount, etc. may be used. In this case, the threshold number is also set to a corresponding value.

  When a predetermined discharge time has elapsed since the start of discharge by the cleaner 55 in the collecting operation, the printer 100 considers that discharge has been completed and stops applying the discharge bias. In the printer 100, the ejection time is stored in advance in the ROM 32 or the NVRAM 34. In the collecting operation, the printer 100 continues the movement of the discharged residue and the collection by the belt cleaner 9 for a predetermined time after the discharge time has elapsed. Then, after the collection operation is completed, the printer 100 initializes the number of continuous prints to 0, and resumes the execution of the interrupted print job and the count of the continuous prints.

  In addition, the printer 100 starts the collecting operation when a predetermined condition is satisfied in a state where printing is not being executed even if the continuous printing number does not exceed the threshold number. As the predetermined condition, for example, printing of a print job is completed and the next print job is not received, opening / closing of the cover 15 is detected, and power is turned on. In addition, even when the collecting operation is started in a state where the continuous printing number does not exceed the threshold number, the printer 100 sets the initial value of the continuous printing number to 0 when executing the print job after the collecting operation is completed. .

  Furthermore, the printer 100 according to the present embodiment performs a new printing operation during the collecting operation that has started without the threshold number of sheets exceeding the threshold number, that is, before the discharge time has elapsed after the discharge by the cleaner 55 has started. When a job is received, the ejection is interrupted and a new print job is executed. When the discharge is interrupted before the discharge time elapses, there is a high possibility that a part of the residue sucked by the cleaner 55 is not discharged and is accumulated in the cleaner 55. For this reason, the printer 100 changes the initial value of the continuous print number and the threshold number for a print job that has started to be executed after discontinuing ejection, and continuously prints until the next collection operation. Less than when the collection operation is completed.

  Next, a printing process procedure for realizing the printing operation including the collection operation described above in the printer 100 will be described with reference to the flowchart of FIG. This print processing is started by the CPU 31 when a print job is received in the standby state.

  In the printing process, the printer 100 first reads out the threshold number from the ROM 32 or the NVRAM 34, sets the read threshold number as a threshold used for determination of ejection execution, and sets the continuous print number to an initial value of zero ( S101). The threshold value is an example of a continuous printing threshold value, and the initial value of the continuous printing number is an example of an initial amount of continuous printing amount.

  Next, the printer 100 starts executing the received print job. Specifically, the printer 100 first executes printing of one sheet and counts up the number of continuous prints (S102). S102 is an example of an image forming process. As described above, the printer 100 also performs suction by the cleaner 55 when printing is performed, and S102 is an example of suction processing.

  Then, the printer 100 determines whether or not the continuous printing number is larger than the threshold (S103). In response to determining that the number of continuous prints is not greater than the threshold (S103: NO), the printer 100 determines whether the print job is completed and there is no next print job that has been received (S104). ). In response to determining that the print job has not ended or that the next print job has been received (S104: NO), the printer 100 returns to S102, executes printing, and counts the number of continuous prints. Up. Even if the print job is finished, if the next print job has been received, the next print job is executed continuously, and the cumulative number of prints at the end of the previous print job is counted up. To do.

  On the other hand, in response to determining that the number of continuously printed sheets is larger than the threshold (S103: YES), the printer 100 interrupts printing and starts a collecting operation (S106). Specifically, the printer 100 changes the bias applied to the cleaner 55 from the suction bias to the discharge bias, and starts discharge by the cleaner 55. In addition, the printer 100 also changes the bias applied to the members other than the cleaner 55 to the bias during the collecting operation.

  Then, the printer 100 determines whether or not the above-described discharge time has elapsed from the start of discharge (S107). In response to determining that the ejection time has not elapsed (S107: NO), the printer 100 continues ejection. On the other hand, when it is determined that the ejection time has elapsed (S107: YES), the printer 100 stops the ejection by the cleaner 55 (S108), and sets the number of continuous prints to 0 (S109).

  Further, the printer 100 returns to S102 and resumes the interrupted print job. Note that after the discharge time has elapsed, the printer 100 appropriately collects the discharged residue on the belt cleaner 9 and then restarts the print job. When the print job is resumed, the printer 100 changes the bias of each part to the bias for printing again, and causes the cleaner 55 to perform suction.

  On the other hand, in response to determining that the number of continuous prints is equal to or less than the threshold value, the print job being executed is completed, and there is no next print job that has been received (S104: YES), the printer 100 performs the collection operation. The discharge is started by the cleaner 55 (S110). S110 is an example of a discharge process.

  After starting the ejection, the printer 100 determines whether or not the above-described ejection time has elapsed (S111). In response to determining that the ejection time has not elapsed (S111: NO), the printer 100 determines whether a print job has been received (S112). The print job is accepted via the network interface 37, the USB interface 38, or the operation panel 40. In response to determining that the print job has not been received (S112: NO), the printer 100 returns to S111 and continues the discharge until either the discharge time has elapsed or the print job has been received.

  In response to determining that a print job has been received before the ejection time has elapsed (S112: YES), the printer 100 interrupts ejection by the cleaner 55 (S114). Specifically, the printer 100 stops applying the ejection bias to the cleaner 55. The operation for recovering the discharged residue to the belt cleaner 9 may be continuously performed even after the discharge is interrupted.

  Then, the printer 100 determines an initial value of the number of continuous prints when printing of the received print job is started (S115). Due to the interruption of the discharge, the cleaner 55 is in a different state depending on whether it is continuously printed without discharging or when the discharging is completed. Therefore, in S115, the printer 100 determines the initial value of the continuous print number of a new print job to a value larger than 0, thereby reducing the difference between the initial value of the continuous print number and the threshold value. S115 is an example of a change process.

In S115, the printer 100 sets the initial value of the continuous print number as, for example, the continuous print number before the start of the interrupted ejection, that is, the continuous print number at the time when the print job executed immediately before is completed. That is, the printer 100 maintains the continuous print number as it is when the YES determination is made in S104, and the continuous print job executed immediately before is performed as in the case where the interrupted ejection is not performed. Counts up continuously with the number of prints. Specifically, the printer 100 determines the initial value of the continuous print number by the following (Formula 1).
Initial value of the number of continuous prints = The number of continuous prints when the previous print job is completed (Formula 1)

Further, the printer 100 may determine the initial value of the continuous print number based on, for example, the execution time Δt that is the time from the start of discharge to the stop of discharge. The longer the execution time Δt, the higher the possibility that there will be less residue remaining in the cleaner 55 after the interruption. Therefore, the printer 100 decreases the initial value of the continuous printing number as the execution time Δt is longer. Specifically, the printer 100 uses the ratio of the execution time Δt to the discharge time T described above to determine the initial value of the continuous print number by the following (Formula 2).
Initial value of the number of continuous prints = the number of continuous prints at the completion of the previous print job × (1− (Δt / T)) (Formula 2)

  In the configuration including the execution time Δt, ejection is executed during execution of the print job and the completion of the print job is delayed, compared to the case where the initial value of the continuous print number is set to the continuous print number at the time when the previous print job is completed. The possibility can be reduced. For example, in the case of the printer 100 in which the residue that has been ejected and remains on the photoreceptor 51 is appropriately transported after the ejection is interrupted and is collected by the belt cleaner 9, it is preferable to consider the execution time Δt. On the other hand, the control is simple in the configuration in which the continuous printing number at the completion of the immediately preceding print job is maintained without taking the execution time Δt into consideration. For example, in the printer 100 that causes the cleaner 55 to suck the residue that has been ejected and remains on the photosensitive member 51, it is desirable that the continuous print number at the time of completion of the immediately preceding print job be the initial value of the continuous print number.

  Then, the printer 100 returns to S102 after S115, executes printing, and counts up from the initial value of the continuous print number determined in S115. S102 after S115 is an example of a post-interruption forming process. In step S103, the number of continuously printed sheets is compared with a threshold value. That is, since the printer 100 counts up the number of continuous prints as an initial value after the interruption of ejection, the number of continuous prints is smaller than in the case of a print job started from a standby state. It is determined YES in S103. S106, which is executed when YES is determined in S103 after S115, is an example of the post-interrupt discharge process.

  On the other hand, in response to determining that the discharge time of the started discharge has elapsed (S111: YES), the printer 100 stops the discharge by the cleaner 55 (S117), shifts to a standby state (S118), and prints. End the process. In S <b> 118, the printer 100 stops applying each bias and stops the rotation of the photosensitive member 51 and the conveyance belt 7. In the standby state, the printer 100 does not cause the cleaner 55 to perform suction or discharge.

  As described above in detail, according to the printer 100 of the first embodiment, the cleaner 55 performs suction when printing is performed. Further, the printer 100 causes the cleaner 55 to discharge when the print job is completed without the number of continuous prints exceeding the threshold number. When a new print job is received during ejection that has started without the continuous printing number exceeding the threshold number, the printer 100 interrupts ejection and starts a new print job. Further, in the printing operation after the interruption of ejection, the printer 100 uses the continuous print number at the completion of the immediately preceding print job so as to reduce the difference between the initial value of the continuous print number and the threshold number. Determine the initial value. Therefore, when a print job is accepted during ejection, even if the ejection is interrupted and the printing operation is executed, the number of pages that can be printed continuously decreases in the printing operation after the ejection is suspended. Increase in residue is suppressed.

  Next, a second embodiment in which the image forming apparatus according to the present invention is embodied will be described with reference to the accompanying drawings. This embodiment is a printer 100 having the same configuration as that of the first embodiment, and a part of the contents of the printing process of this embodiment is different from the printing process of the first embodiment. The same configurations and the same processes as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The procedure of the printing process of the second embodiment will be described with reference to the flowchart of FIG. In the printing process of the second mode, a step for changing the threshold value is provided instead of S115 of the printing process of the first mode.

  Specifically, the printer 100 according to the second embodiment changes the threshold value when a print job is received during ejection (S201). S201 is also an example of a change process. Further, the printer 100 sets the continuous printing number to 0 (S202). That is, the printer 100 sets the initial value of the number of continuous prints counted when executing a print job received during ejection to zero.

In step S <b> 201, the printer 100 changes the threshold value to a value obtained by subtracting the continuous print number at the completion of the immediately preceding print job from the threshold number read from the ROM 32 or the NVRAM 34. Even if the threshold value is changed in this way, the difference between the initial value of the continuous print number of zero and the threshold value is smaller than before the change. That is, similarly to the case where the interrupted ejection is not performed, the printer 100 performs ejection when the total value of the subsequent continuous printing number and the continuous printing number at the completion of the immediately preceding print job becomes the threshold number. Specifically, the printer 100 changes the threshold value by the following (Equation 3).
Threshold = threshold number of sheets − number of continuous prints when the previous print job is completed (Formula 3)

Further, the printer 100 may change the threshold based on the execution time Δt described above. The printer 100 increases the threshold value as the execution time Δt is longer. Specifically, the printer 100 uses the ratio of the execution time Δt to the discharge time T described above to change the threshold value according to the following (formula 4).
Threshold = threshold number of sheets−continuous number of prints at completion of previous print job × (1- (Δt / T)) (Equation 4)

  As in the first embodiment, in the configuration in which the execution time Δt is taken into account, the discharge is performed during the execution of the print job, compared to the case where the threshold value is a value obtained by subtracting the continuous print number at the completion of the immediately preceding print job from the threshold number. It is possible to reduce the possibility that execution of the print job is delayed. On the other hand, in a configuration in which the execution time Δt is not taken into account and the threshold value is a value obtained by subtracting the continuous print number at the time of completion of the immediately preceding print job from the threshold number, the control is simple.

  As described above in detail, similarly to the first embodiment, when the printer 100 of the second embodiment receives a new print job during discharge, the discharge is interrupted and execution of the print job is started. . Further, in the printer 100 according to the second embodiment, in the printing operation after the interruption of ejection, the continuous printing number at the completion of the immediately preceding print job is used so that the difference between the initial value of the continuous printing number and the threshold value becomes small. Change the threshold. Further, in the printing operation after the interruption of the discharge, the printer 100 starts the discharge when the continuous print number exceeds the changed threshold value. As a result, when a print job is received during ejection, even if the ejection is interrupted and the printing operation is executed, printing can be continuously performed in the printing operation after the ejection is suspended, as in the first embodiment. Since the number of sheets decreases, an increase in unrecovered residues is suppressed.

  Next, a third embodiment in which the image forming apparatus according to the present invention is embodied will be described with reference to the accompanying drawings. The printer 102 of the third embodiment is a secondary transfer type printer. As shown in FIG. 5, the printer 102 includes a secondary transfer belt 71 and a secondary transfer roller 72 instead of the transport belt 7 of the printer 100 of the first embodiment. In the printer 102, the transfer unit 54 is an example of a first transfer unit, and the secondary transfer roller 72 is an example of a second transfer unit. The secondary transfer belt 71 is an example of an intermediate transfer belt.

  The printer 102 transfers the toner images of each color formed on the photoconductor 51 of each process unit onto the secondary transfer belt 71 and superimposes them. Further, the printer 102 applies the superimposed toner images to the secondary image. The image is transferred from the secondary transfer belt 71 to the sheet by the transfer roller 72. That is, the printer 102 also executes a transfer process when printing is performed. Therefore, the sheet conveyance path 14 of the printer 102 passes between the secondary transfer belt 71 and the secondary transfer roller 72.

  At the time of printing, since the secondary transfer roller 72 is in contact with the secondary transfer belt 71, residues such as toner and paper dust are attracted to the secondary transfer roller 72. Then, the printer 102 performs a discharge operation of the residue from the secondary transfer roller 72 at a timing other than when printing is performed. That is, the printer 102 applies a discharge bias having a polarity opposite to that at the time of executing the secondary transfer operation to the secondary transfer roller 72, and discharges the residue from the secondary transfer roller 72 onto the secondary transfer belt 71. The printer 102 applies a recovery bias to the belt cleaner 9 to recover the residue on the secondary transfer belt 71.

  When the printer 102 receives a print job during the execution of the discharge operation, the printer 102 stops the discharge operation and starts executing the print job. Further, the printer 102 changes at least one of the initial value and the threshold value of the continuous printing number so that the difference between the initial value and the threshold value of the continuous printing number becomes small in the printing operation after the interruption of ejection. The changing method is the same as in the first embodiment or the second embodiment.

  As described above in detail, also by the printer 102 of the third embodiment, when a print job is received during the execution of the collecting operation, the ejection is interrupted and the printing operation is executed. Furthermore, in the printing operation after the interruption of ejection, the number of sheets that can be printed continuously is reduced, so that an increase in unrecovered residues is suppressed.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the present invention is not limited to a printer, and can be applied to any apparatus having an image forming function, such as a copying machine, a multifunction machine, and a FAX apparatus. Further, the present invention is applicable not only to a color printer but also to a monochrome printer.

  Further, for example, both the first form and the second form may be executed. That is, when the ejection is interrupted and printing of a new print job is performed, the printer 100 sets the initial value of the continuous print number and the threshold value so that the difference between the initial value of the continuous print number and the threshold value becomes small. Both may be changed.

  For example, when the printer 100 detects a change from the open state of the cover to the closed state based on the output signal of the cover sensor 16, the printer 100 performs a recovery operation and causes the cleaner 55 to discharge the residue. This discharge is an example of a discharge process after the cover is closed. Furthermore, even when a new print job is received during discharge after the cover is closed, the printer 100 interrupts the discharge and executes printing of the new print job, and also sets the initial value and threshold value of the continuous print number. It is good to change at least one of these. In this case, for example, the printer 100 sets the “continuous print number at the time of completion of the immediately preceding print job” in each of the above-described expressions (Expression 1) to (Expression 4) as the continuous print sheet immediately before opening and closing the cover.

  Further, for example, the printer 100 performs a collecting operation as an initial operation when the power is turned on, and causes the cleaner 55 to discharge the residue. This discharge is an example of a discharge process after power-on. Further, when the printer 100 receives a new print job during the discharge after the power is turned on, the printer 100 interrupts the discharge and executes the printing of the new print job. It is good to change at least one of these. In this case, for example, the printer 100 sets “the number of continuous prints when the immediately preceding print job is completed” in each of the above-described formulas (1) to (4) to zero.

  Further, for example, the absolute value of the ejection bias used for ejection of the printer 100 may be different depending on the situation. For example, the absolute value of the discharge bias may be different between the discharge in S106 and the discharge in S110. In S106 after the ejection is interrupted, a different value may be used.

  In each of the above embodiments, the cleaner 55 is exemplified as a member that sucks and discharges the residue, but is not limited thereto. For example, in a printer including a contact-type charging member, the charging member electrically sucks a residue having a polarity opposite to the charging polarity during a charging operation. Therefore, the printer can also apply a bias having a polarity opposite to the charging polarity to the charging member to discharge the sucked residue. Even when discharging from the charging member, if a new print job is received during discharge, the printer may interrupt the discharge and print a new print job. Further, the printer may change at least one of the initial value and the threshold value of the continuous print number when printing a new print job.

  The processing disclosed in each embodiment may be executed by a single CPU, a plurality of CPUs, hardware such as an ASIC, or a combination thereof. Further, the processing disclosed in each embodiment can be realized in various modes such as a recording medium or a method recording a program for executing the processing.

7 Conveyor belt 9 Belt cleaner 15 Cover 16 Cover sensor 31 CPU
37 Network interface 38 USB interface 40 Operation panel 51 Photoconductor 53 Developing section 54 Transfer section 55 Cleaner 71 Secondary transfer belt 72 Secondary transfer roller 100, 102 Printer

Claims (14)

An image forming unit for forming an image,
A photoreceptor,
A developing unit that develops the electrostatic latent image formed on the photoreceptor using toner;
A transfer unit for transferring the toner image on the photosensitive member to a sheet on the belt or the belt;
The image forming unit having:
A suction part that electrically sucks at least one of toner and paper dust remaining on the photoreceptor after passing through the transfer part; and
A collection unit for collecting residues on the belt;
A reception unit for receiving a print job for forming an image using the photosensitive member;
A control unit;
With
The controller is
Image forming processing for causing the image forming unit to form an image in accordance with a print job received by the receiving unit;
A suction process in which a first voltage is applied to the suction unit while the image is formed in the image forming unit, and a residue is electrically sucked into the suction unit;
A second voltage having a polarity opposite to that of the first voltage is applied to the suction part, the residue is electrically discharged to the suction part, and the residue is discharged to the recovery part via the belt. A discharge process to be collected;
During the ejection process, when the accepting unit accepts a new print job, the ejection process is interrupted, and the post-interruption forming process for forming an image on the image forming unit according to the new print job;
At least one of an initial amount of a continuous print amount that is an amount related to image formation of the image forming unit in the post-interrupt formation process and a continuous print threshold that is a comparison target of the continuous print amount in the post-interrupt formation process, The difference between the initial amount of the continuous printing amount in the post-interruption forming process and the continuous printing threshold value is changed so as to be smaller than the difference between the initial amount of the continuous printing amount by the image forming process and the continuous printing threshold value. Change processing,
During the execution of the post-interrupt formation process based on the initial amount of the continuous print amount after the change process, the post-interrupt formation is performed when the continuous print amount after the change process exceeds the continuous print threshold after the change process Discontinuing processing, causing the suction portion to apply a third voltage having a polarity opposite to that of the first voltage, and discharging the residue to the suction portion electrically after discharge;
An image forming apparatus characterized in that The image forming apparatus according to claim 1,
The controller is
In the changing process, the initial amount of the continuous printing amount in the post-interruption forming process is changed to the continuous printing amount at the completion of the image forming process immediately before the post-interrupt forming process is executed.
An image forming apparatus. The image forming apparatus according to claim 1,
The controller is
In the changing process, the continuous printing threshold value is changed from the continuous printing threshold value at the completion of the image forming process immediately before the post-interrupt forming process is executed to the image forming process immediately before the post-interrupt forming process is executed. Change the value to the value obtained by subtracting the continuous print amount at completion.
An image forming apparatus. The image forming apparatus according to any one of claims 1 to 3,
The controller is
In the change process, the longer the execution time, which is the time from the start of discharge by the discharge process to the stop of the discharge, the difference between the initial amount of the continuous print amount in the post-interrupt forming process and the continuous print threshold value. Change it to be bigger,
An image forming apparatus. In the image forming apparatus according to any one of claims 1 to 4,
The controller is
In the changing process, the smaller the continuous printing amount at the completion of the image forming process immediately before the post-interrupt forming process is performed, the difference between the initial amount of the continuous printing amount in the post-interrupt forming process and the continuous printing threshold value. Change to be larger,
An image forming apparatus. The image forming apparatus according to any one of claims 1 to 5,
A cover covering the image forming unit;
A sensor used to detect whether the cover is open or closed;
With
The controller is
When a change from the open state to the closed state of the cover is detected by the sensor, a discharge process after closing the cover that electrically discharges the residue to the suction unit is performed,
In the post-interrupt forming process, even when the receiving unit receives a new print job during the discharge process after the cover is closed, the post-cover close discharge process is interrupted and the image formation is performed according to the new print job. Forming an image on the part,
An image forming apparatus. The image forming apparatus according to any one of claims 1 to 6,
The controller is
When the power is turned on, a discharge process is performed after the power is turned on to electrically discharge the residue to the suction part.
In the post-interruption forming process, even when the receiving unit receives a new print job during the post-power-on discharge process, the post-power-on discharge process is interrupted and the image formation is performed according to the new print job. Forming an image on the part,
An image forming apparatus. In the image forming apparatus according to any one of claims 1 to 7,
The controller is
When the continuous printing amount by the image forming process exceeds the continuous printing threshold, the image forming process is interrupted, and a fourth voltage having a polarity opposite to the first voltage is applied to the suction unit. , Electrically discharging the residue to the suction part,
An image forming apparatus. In the image forming apparatus according to any one of claims 1 to 8,
The image forming unit has a charging unit that charges the surface of the photoconductor,
The suction unit is positioned upstream of the charging unit in the rotation direction of the photoconductor, and is positioned downstream of the transfer unit in the rotation direction of the photoconductor to electrically remove the residue on the photoconductor. Suction,
An image forming apparatus. An image forming unit for forming an image,
A photoreceptor,
A developing unit that develops the electrostatic latent image formed on the photoreceptor using toner;
A transfer unit for transferring the toner image on the photosensitive member to a sheet on the belt or the belt;
The image forming unit having:
A suction part that electrically sucks at least one of toner and paper dust remaining on the photoreceptor after passing through the transfer part; and
A collection unit for collecting residues on the belt;
A reception unit for receiving a print job for forming an image using the photosensitive member;
A method for collecting residues in an image forming apparatus comprising:
An image forming step of causing the image forming unit to form an image in accordance with a print job received by the receiving unit;
A suction step in which a first voltage is applied to the suction portion while the image forming portion is forming an image, and a residue is electrically sucked into the suction portion;
A second voltage having a polarity opposite to that of the first voltage is applied to the suction part, the residue is electrically discharged to the suction part, and the residue is discharged to the recovery part via the belt. A discharge step to be collected;
A post-interruption forming step of interrupting execution of the ejection step and forming an image on the image forming unit according to the new print job when the accepting unit accepts a new print job during the ejection step; ,
At least one of an initial amount of a continuous print amount that is an amount related to image formation in the image forming unit in the post-interruption forming step and a continuous print threshold that is a comparison target of the continuous print amount in the post-interrupt formation step, The difference between the initial amount of the continuous printing amount in the post-interruption forming step and the continuous printing threshold value is changed to be smaller than the difference between the initial amount of the continuous printing amount in the image forming step and the continuous printing threshold value. Change step,
If the continuous print amount after the change step exceeds the continuous print threshold after the change step during the execution of the post-interrupt formation step based on the initial amount of the continuous print amount after the change step, the post-interrupt formation is performed. A post-interrupt discharge step of interrupting execution of the step, causing the suction portion to apply a third voltage having a polarity opposite to the first voltage, and electrically discharging the residue to the suction portion;
The collection method characterized by including. An image forming unit for forming an image,
A photoreceptor,
A developing unit that develops the electrostatic latent image formed on the photoreceptor using toner;
A transfer unit for transferring the toner image on the photosensitive member to a sheet on the belt or the belt;
The image forming unit having:
A suction part that electrically sucks at least one of toner and paper dust remaining on the photoreceptor after passing through the transfer part; and
A collection unit for collecting residues on the belt;
A reception unit for receiving a print job for forming an image using the photosensitive member;
In an image forming apparatus comprising
Image forming processing for causing the image forming unit to form an image in accordance with a print job received by the receiving unit;
A suction process in which a first voltage is applied to the suction unit while the image is formed in the image forming unit, and a residue is electrically sucked into the suction unit;
A second voltage having a polarity opposite to that of the first voltage is applied to the suction part, the residue is electrically discharged to the suction part, and the residue is discharged to the recovery part via the belt. A discharge process to be collected;
During the ejection process, when the accepting unit accepts a new print job, the ejection process is interrupted, and the post-interruption forming process for forming an image on the image forming unit according to the new print job;
At least one of an initial amount of a continuous print amount that is an amount related to image formation of the image forming unit in the post-interrupt formation process and a continuous print threshold that is a comparison target of the continuous print amount in the post-interrupt formation process, The difference between the initial amount of the continuous printing amount in the post-interruption forming process and the continuous printing threshold value is changed so as to be smaller than the difference between the initial amount of the continuous printing amount by the image forming process and the continuous printing threshold value. Change processing,
During the execution of the post-interrupt formation process based on the initial amount of the continuous print amount after the change process, the post-interrupt formation is performed when the continuous print amount after the change process exceeds the continuous print threshold after the change process Discontinuing processing, causing the suction portion to apply a third voltage having a polarity opposite to that of the first voltage, and discharging the residue to the suction portion electrically after discharge;
A program characterized by having executed. An image forming unit for forming an image,
A photoreceptor,
A first transfer portion for transferring a toner image on the photosensitive member to an intermediate transfer belt;
A transfer surface that is a surface for transferring a sheet and a toner image of the intermediate transfer belt, or a second transfer unit that contacts the sheet and transfers the toner image on the transfer surface of the intermediate transfer belt to the sheet;
The image forming unit having:
A collection unit for collecting a residue that is at least one of toner and paper powder remaining on the intermediate transfer belt after passing through the second transfer unit;
A reception unit for receiving a print job for forming an image using the photosensitive member;
A control unit;
With
The controller is
Image forming processing for causing the image forming unit to form an image in accordance with a print job received by the receiving unit;
A transfer process in which a first voltage is applied to the second transfer unit while an image is being formed in the image forming unit, and a toner image on the conveyance surface of the intermediate transfer belt is transferred to a sheet;
Applying a second voltage having a polarity opposite to that of the first voltage to the second transfer unit, and causing the second transfer unit to electrically discharge a residue that is at least one of toner and paper dust, A discharge process for collecting the residue in the collection unit via the intermediate transfer belt;
During the ejection process, when the accepting unit accepts a new print job, the ejection process is interrupted, and the post-interruption forming process for forming an image on the image forming unit according to the new print job;
The difference between the initial amount of the continuous printing amount in the post-interruption forming process and the continuous printing threshold value is the difference between the initial amount of the continuous printing amount in the post-interruption forming process and the continuous printing threshold value. A change process for changing the print amount to be smaller than the difference between the initial print amount and the continuous print threshold;
During the execution of the post-interrupt formation process based on the initial amount of the continuous print amount after the change process, the post-interrupt formation is performed when the continuous print amount after the change process exceeds the continuous print threshold after the change process A post-interrupt discharge process in which the process is interrupted, a third voltage having a polarity opposite to the first voltage is applied to the second transfer unit, and a residue is electrically discharged to the second transfer unit; ,
An image forming apparatus characterized in that An image forming unit for forming an image,
A photoreceptor,
A first transfer portion for transferring a toner image on the photosensitive member to an intermediate transfer belt;
A transfer surface that is a surface for transferring a sheet and a toner image of the intermediate transfer belt, or a second transfer unit that contacts the sheet and transfers the toner image on the transfer surface of the intermediate transfer belt to the sheet;
The image forming unit having:
A collection unit for collecting a residue that is at least one of toner and paper powder remaining on the intermediate transfer belt after passing through the second transfer unit;
A reception unit for receiving a print job for forming an image using the photosensitive member;
A method for collecting residues in an image forming apparatus comprising:
An image forming step of causing the image forming unit to form an image in accordance with a print job received by the receiving unit;
A transfer step in which a first voltage is applied to the second transfer unit while an image is formed on the image forming unit, and a toner image on a conveyance surface of the intermediate transfer belt is transferred to a sheet;
Applying a second voltage having a polarity opposite to that of the first voltage to the second transfer unit, and causing the second transfer unit to electrically discharge a residue that is at least one of toner and paper dust, A discharge step for collecting the residue in the collecting unit via the intermediate transfer belt;
A post-interruption forming step for interrupting the ejection step when the accepting unit accepts a new print job during execution of the ejection step, and forming an image on the image forming unit according to the new print job;
At least one of the initial amount of the continuous printing amount and the continuous printing threshold value in the post-interruption forming step is the difference between the initial amount of the continuous printing amount in the post-interruption forming step and the continuous printing threshold value. A change step for changing so as to be smaller than the difference between the initial amount of printing and the continuous printing threshold;
If the continuous print amount after the change step exceeds the continuous print threshold after the change step during the execution of the post-interrupt formation step based on the initial amount of the continuous print amount after the change step, the post-interrupt formation is performed. A post-interrupt discharge step of interrupting the step, applying a third voltage having a polarity opposite to the first voltage to the second transfer portion, and electrically discharging a residue to the second transfer portion; ,
The collection method characterized by including. An image forming unit for forming an image,
A photoreceptor,
A first transfer portion for transferring a toner image on the photosensitive member to an intermediate transfer belt;
A transfer surface that is a surface for transferring a sheet and a toner image of the intermediate transfer belt, or a second transfer unit that contacts the sheet and transfers the toner image on the transfer surface of the intermediate transfer belt to the sheet;
The image forming unit having:
A collection unit for collecting a residue that is at least one of toner and paper powder remaining on the intermediate transfer belt after passing through the second transfer unit;
A reception unit for receiving a print job for forming an image using the photosensitive member;
In an image forming apparatus comprising
Image forming processing for causing the image forming unit to form an image in accordance with a print job received by the receiving unit;
A transfer process in which a first voltage is applied to the second transfer unit while an image is being formed in the image forming unit, and a toner image on the conveyance surface of the intermediate transfer belt is transferred to a sheet;
Applying a second voltage having a polarity opposite to that of the first voltage to the second transfer unit, and causing the second transfer unit to electrically discharge a residue that is at least one of toner and paper dust, A discharge process for collecting the residue in the collection unit via the intermediate transfer belt;
During the ejection process, when the accepting unit accepts a new print job, the ejection process is interrupted, and the post-interruption forming process for forming an image on the image forming unit according to the new print job;
The difference between the initial amount of the continuous printing amount in the post-interruption forming process and the continuous printing threshold value is the difference between the initial amount of the continuous printing amount in the post-interruption forming process and the continuous printing threshold value. A change process for changing the print amount to be smaller than the difference between the initial print amount and the continuous print threshold;
During the execution of the post-interrupt formation process based on the initial amount of the continuous print amount after the change process, the post-interrupt formation is performed when the continuous print amount after the change process exceeds the continuous print threshold after the change process A post-interrupt discharge process in which the process is interrupted, a third voltage having a polarity opposite to the first voltage is applied to the second transfer unit, and a residue is electrically discharged to the second transfer unit; ,
A program characterized by having executed.

Images