JP2015086046A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device that is equipped with a plurality of paper feeding trays, enabling reducing degradation of productivity.SOLUTION: A printer 100 includes a plurality of paper feeding trays, and is equipped with a paper feeding roller and a sheet sensor, corresponding to respective paper feeding trays. The printer 100 performs paper feeding operation even with other paper feeding tray when performing a paper feeding operation with one of the plurality of paper feeding trays, and decides an execution tray which supplies paper to an image formation part on the basis of a detection result of a detection part thereof. Then, paper is fed from the paper feeding tray which is decided to be an execution tray, to be transported to an image formation part 10, and rotation of the a paper feeding roller is stopped at a paper feeding tray other than the execution tray.

Description

  The present invention relates to an image forming apparatus. More specifically, the present invention relates to sheet feeding control of an image forming apparatus having a plurality of sheet feeding trays.

  Conventionally, an image forming apparatus including a plurality of paper feed trays has been put into practical use. As a technology related to paper feed control of an image forming apparatus including a plurality of paper feed trays, for example, Patent Document 1 discloses the rotation speed of a paper feed roller when a paper feed tray located at a position away from an image forming unit is used. A technique for forming an image at the same timing no matter which paper feed tray is used is disclosed.

JP-A-10-120216

  However, the conventional technique described above has the following problems. That is, in an image forming apparatus having a plurality of paper feed trays, when a job for which a specific paper feed tray is not specified is executed, a paper feed for supplying paper to the image forming unit from among the paper feed trays having the paper. The execution paper feed tray that is the tray is determined. If the determination of the presence / absence of the paper is sequentially performed for the paper feed trays that are candidates for the execution paper feed tray, there is a concern that productivity deteriorates.

  The present invention has been made to solve the above-described problems of the prior art. That is, an object of the present invention is to provide an image forming apparatus having a plurality of paper feed trays and capable of reducing deterioration in productivity.

  An image forming apparatus for solving this problem includes an image forming unit that forms an image on a sheet, a plurality of storing units that store sheets, and a plurality of sheets that feed sheets from each of the plurality of storing units. A sheet feeding unit, a conveyance unit that conveys a sheet fed by one of the plurality of sheet feeding units to the image forming unit, and a plurality of sheet feeding units, respectively. A plurality of detection units for detecting the detected paper at a position upstream of the transport unit, and a control unit, wherein the control unit performs a paper feeding operation with one of the plurality of paper feeding units. One of the plurality of storage units based on the detection result of the plurality of detection units after the start of the simultaneous sheet feeding processing, A determination process for determining an execution storage unit for supplying paper conveyed to the image forming unit, and the determination process The transport process for transporting the paper fed from the execution storage unit determined in this way to the image forming unit by the transport unit and stopping the paper feed operation of the paper storage unit of the storage unit other than the execution storage unit It is characterized by executing.

The image forming apparatus described in the present specification includes a plurality of storage units and a plurality of corresponding sheet feeding units, and simultaneously performs a sheet feeding operation with the plurality of sheet feeding units in the simultaneous sheet feeding process. Then, the paper fed from each paper feed unit is detected by the corresponding detection unit. Then, in the determination process, an execution storage unit that supplies paper to the image forming unit is determined based on the detection result of each detection unit. Further, in the conveyance process, the sheet is conveyed from the execution storage unit, and the paper feeding operation of the storage units other than the execution storage unit is stopped. In the simultaneous sheet feeding process, the sheet feeding operation may be performed simultaneously by a plurality of sheet feeding units, and the start timing of the sheet feeding operation may be the same or different. In addition, the execution storage unit may be, for example, a storage unit corresponding to the detection unit that first detects the paper, or may be determined according to a predetermined priority order from the storage units in which the detection unit has detected the paper. The priority order may be determined based on, for example, the order in which the paper transport distance is short, the order in which the error occurrence rate is low, and the order in which the usage rate of the paper feed tray is low. In addition, the simultaneous paper feed process (and the determination process and the transport process executed in conjunction with the simultaneous paper feed process) may be performed every time one sheet is fed, or at the first paper feed after the power is turned on. Alternatively, it may be performed only at the time of initial feeding of the job.

  That is, in the image forming apparatus described in this specification, a plurality of paper feeding units simultaneously perform paper feeding operations, and based on the detection result of each detection unit, one storage unit is determined as an execution storage unit, and the paper is loaded. The sheet is conveyed to the image forming unit and the sheet feeding operation of the other sheet feeding unit is stopped. Therefore, it is possible to expect an early determination of the execution storage unit as compared with a procedure for sequentially determining the presence or absence of paper in a plurality of storage units.

  In addition, the control unit determines the execution accommodation unit based on the detection result of each detection unit after a predetermined time has elapsed after starting the paper supply operation by the simultaneous paper supply process in the determination process. It is good to decide. After the specified time has elapsed since the start of the paper feeding operation, the execution storage unit is determined based on the detection result of each detection unit, so that the paper is detected within the specified time in addition to the storage unit that first detected the paper. The execution accommodation section can be determined including the storage section, and a more suitable execution accommodation section can be expected.

  In addition, when there are a plurality of detection units that have detected a sheet before the stipulated time elapses in the determination process, the control unit has a shorter conveying distance to the image forming unit, It is preferable that the priority for the execution accommodation unit is high. By preferentially determining the storage unit having a short transport distance to the image forming unit as the execution storage unit, image formation can be started earlier, and improvement in productivity can be expected.

  Further, the image forming apparatus disclosed in the present specification includes a plurality of open / close detection units that detect that the respective storage units have been opened / closed, and the control unit passes the specified time in the determination process. In the case where there are a plurality of detection units that have detected the paper until the opening / closing detection unit, the opening / closing detection unit has not detected that the opening / closing detection unit has opened / closed the detection unit. It is preferable that the priority of becoming the execution accommodation unit is higher than that of the accommodation unit. There is a high possibility that the storage unit that has been detected to be opened and closed has been supplied with paper. For this reason, the possibility of occurrence of an out-of-paper error is low. Note that the opening and closing of the housing portion means that the housing portion that has been closed with respect to the main body is once opened and then closed again. That is, the open / close detection unit may detect a change from an open state to a closed state, for example. In addition, the opening / closing that is the object of detection here is the first time after the previous paper feeding operation, for a predetermined time before starting the paper feeding operation, or after the power is turned on. It may be detected by the open / close detection unit during any period until the paper feeding operation.

  Further, the specified time may be a time set for each of the housing units. The allowable length of the specified time varies depending on the arrangement of the detection units and the configuration of the paper feed unit. By setting the specified time for each accommodation unit, it is possible to wait for the determination of the execution accommodation unit until an appropriate time for each accommodation unit, and a more suitable execution accommodation unit can be expected. The specified time may be set based on, for example, the time required for conveyance from the paper feeding unit to the detection unit.

  In the determination process, when the detection unit of the storage unit having the highest priority as the execution storage unit among the plurality of storage units detects a sheet, the specified time has elapsed. It is good to determine the said accommodating part as the said execution accommodating part, without waiting. When a sheet is detected by the detection unit of the storage unit having the highest priority, the execution storage unit can be determined as the storage unit without waiting for a specified time. Therefore, it is possible to avoid useless sheet feeding operations for the storage units other than the storage unit by omitting waiting for a specified time and immediately determining the execution storage unit.

  In addition, after the control unit starts the paper feeding operation by the simultaneous paper feeding process in the determination process, the control unit detects the storage unit in which the detection unit first detects the paper among the plurality of storage units. The execution accommodation unit may be determined. If at least one detection unit detects a sheet, the execution storage unit can be determined immediately, so that image formation can be started earlier and an improvement in productivity can be expected.

  Further, the control unit determines the execution storage unit in the determination process, and after the sheet fed from the execution storage unit in the transport process is transported toward the image forming unit, At the time of paper feeding, the simultaneous paper feeding process may be executed again, and the determination process and the conveying process may be executed again as the simultaneous paper feeding process is performed again. At the time of the next sheet feeding after the execution accommodating section is determined, the simultaneous sheet feeding process is performed again, and the execution accommodating section is determined again according to the result. Thereby, even if it is not possible to determine the optimal storage unit by the previous simultaneous paper feed process, the possibility that a better storage unit can be determined as the execution storage unit by the subsequent simultaneous paper feed process is increased.

  Further, the control unit executes the simultaneous paper feeding process every time paper is fed from the start of processing of one job until a predetermined amount of image formation is performed, and the determination is performed each time the simultaneous paper feeding process is performed. The process and the transfer process may be executed. If the simultaneous paper feed process is executed for each paper feed until one job is completed, the number of paper feed operations increases. On the other hand, as the number of simultaneous sheet feeding processes is increased, the possibility that the optimal storage unit is determined as the execution storage unit increases. Therefore, the simultaneous paper feed process is performed until a prescribed amount of image formation is performed, and thereafter the simultaneous paper feed process is not performed, so that it is possible to determine the optimum execution paper feed unit while suppressing the complexity of the paper feed control. I can expect.

  The image forming apparatus disclosed in the present specification further includes a second opening / closing detection unit that detects that at least one of the plurality of storage units is opened / closed, and the control unit includes the second opening / closing detection unit. The simultaneous sheet feeding process may be executed on condition that at least one of the plurality of storage units is detected to be opened and closed by the unit. When any of the storage units is opened and closed, there is a high possibility that the paper has been replenished in the opened and closed storage units. For this reason, it is preferable to execute the simultaneous paper feed process and re-determine the execution accommodation unit accordingly. Note that the second open / close detection unit may or may not be able to specify the opened / closed storage unit. If it can be specified, it may also serve as the open / close detection unit described above.

  In addition, the control unit determines whether or not a sheet is detected by any of the plurality of detection units and detects the sheet before performing the sheet feeding operation in the simultaneous sheet feeding process. It is preferable not to perform the sheet feeding operation of the sheet feeding unit corresponding to the detecting unit. If the paper feeding unit that has already fed paper is fed again, the paper may reach the transport unit. Therefore, it is preferable that such a paper feeding unit is not fed as a paper feed target. In particular, this configuration is suitable when there is no configuration in which the paper once started to be fed by the paper feed unit is returned to the storage unit.

  According to the present invention, an image forming apparatus having a plurality of paper feed trays, which can reduce the deterioration of productivity, is realized.

1 is a cross-sectional view illustrating a schematic configuration of a printer according to an embodiment. FIG. 2 is a block diagram illustrating an electrical configuration of a printer. 6 is a timing chart illustrating an example of retrying paper feeding. 6 is a flowchart illustrating a procedure of paper feed processing. It is a flowchart which shows the procedure of the 1st form of an execution tray determination process. It is a timing chart which shows the example of paper feed operation of the 1st form. It is a timing chart which shows the example of paper feed operation of the 1st form. It is a timing chart which shows the example of paper feed operation of the 1st form. It is a timing chart which shows the example of paper feed operation of the 1st form. It is a timing chart which shows the example of paper feed operation of the 1st form. It is a flowchart which shows the procedure of the 2nd form of execution tray determination processing. 10 is a timing chart illustrating an example of a sheet feeding operation according to a second embodiment. 10 is a timing chart illustrating an example of a sheet feeding operation according to a second embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an image forming apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to an electrophotographic monochrome printer.

[Printer configuration]
As shown in FIG. 1, the printer 100 of this embodiment includes an image forming unit 10 that prints an image on a sheet by an electrophotographic method. The image forming unit 10 includes a process unit 5 that forms a toner image on a sheet, and a fixing unit 8 that fixes an unfixed toner image on the sheet to the sheet. Note that the process unit 5 of the present embodiment has a configuration capable of monochrome printing. In addition, a conveyance path 11 that is a sheet path is formed in the printer 100. In FIG. 1, the conveyance path 11 is indicated by a one-dot chain line.

  The printer 100 includes a first tray 12, a second tray 13, and a third tray 14, which are a plurality of paper feed trays that can store printing sheets. As shown in FIG. 1, all are stacked below the image forming unit 10 in the order of the first tray 12, the second tray 13, and the third tray 14 from the top. That is, since the first tray 12 is closest to the image forming unit 10, the transport distance is short, and the third tray 14 is farthest from the image forming unit 10. The 1st tray 12, the 2nd tray 13, and the 3rd tray 14 are examples of an accommodating part.

  Hereinafter, when it is not necessary to distinguish the first tray 12, the second tray 13, and the third tray 14, they are simply referred to as a paper feed tray. All of these paper feed trays are provided so as to be openable and closable with respect to the printer 100, and the printer 100 can detect the open / closed state of each paper feed tray. For example, it is possible to detect that the paper feed tray has been opened by the position of a rotating piece of a sheet sensor described later.

  As shown in FIG. 1, the printer 100 has a configuration for feeding sheets from each paper feed tray into the apparatus. The printer 100 has a main motor 21, a first paper feed roller 22, and a first electromagnetic clutch 23 for feeding paper from the first tray 12. The rotation shaft of the first paper feed roller 22 is connected to the main motor 21 via the first electromagnetic clutch 23. That is, if the first electromagnetic clutch 23 is connected while the main motor 21 is rotating, the rotational force of the main motor 21 is transmitted to the first paper feed roller 22 and the first paper feed roller 22 rotates. On the other hand, if the first electromagnetic clutch 23 is released, the transmission of the rotational force to the first paper feed roller 22 is cut off regardless of whether the main motor 21 rotates.

  The second tray 13 and the third tray 14 have the same configuration as that of the first tray 12. That is, the second tray 13 is provided with the second paper feed roller 25 and the second electromagnetic clutch 26. The third tray 14 is provided with a third paper feed roller 28 and a third electromagnetic clutch 29. The main motor 21 is shared by all paper feed trays. Each pair of paper feed rollers and electromagnetic clutches is an example of a paper feed unit of a corresponding paper feed tray.

  Further, as shown in FIG. 1, the printer 100 has a plurality of conveyance roller pairs for conveying the sheet along the conveyance path 11. Specifically, in the sheet conveyance direction, the registration roller pair 51, the first conveyance roller pair 52, the second conveyance roller pair 53, and the third conveyance roller pair 54 are provided in order from the process unit 5 to the upstream direction. doing. These roller pairs 51 to 54 are rotationally controlled independently of the states of the electromagnetic clutches 23, 26, and 29. With the cooperation of these roller pairs 51 to 54, the sheet fed into the apparatus from any of the sheet feeding trays is conveyed along the conveying path 11 to the process unit 5. These roller pairs 51 to 54 are an example of a transport unit.

  In the following, in the process of supplying a printing sheet to the image forming unit 10, “feed” from the paper feed tray to the corresponding conveyance roller pair, and “carry” from the corresponding conveyance roller pair to the image forming unit 10. To distinguish. That is, in the printer 100, the sheet feeding operation for printing is controlled by connecting and releasing the electromagnetic clutches. On the other hand, the transport operation is not controlled by each electromagnetic clutch.

  The printer 100 also includes a first sheet sensor 56, a second sheet sensor 57, and a third sheet sensor 58 that are a plurality of sheet sensors that detect the presence or absence of a sheet on the conveyance path 11. The first sheet sensor 56 detects the presence or absence of a sheet at a position downstream of the first paper feed roller 22 and upstream of the first transport roller pair 52. The second sheet sensor 57 detects the presence or absence of a sheet at a position downstream of the second paper feed roller 25 and upstream of the second transport roller pair 53.

  The third sheet sensor 58 detects the presence or absence of a sheet at a position downstream of the third paper feed roller 28 and upstream of the third transport roller pair 54. The printer 100 further includes a registration sensor 59 that detects the presence or absence of a sheet between the registration roller pair 51 and the first conveyance roller pair 52. The first sheet sensor 56, the second sheet sensor 57, and the third sheet sensor 58 are examples of a detection unit.

  The printer 100 has, for example, a light transmission type sensor having a rotating piece as each sheet sensor. Each sheet sensor detects the open state of each sheet feed tray by turning off the turning piece at the center position and turning it on at the turning positions on both sides centering on the off position. In other words, each sheet sensor is off when the sheet feed tray is closed and no sheet is detected, and when the sheet feed tray is closed and a sheet is detected, the sheet tray is opened. Either will be on.

  Therefore, the printer 100 can determine whether the paper feed tray is open or closed by each sheet sensor while the main power is on. Then, the printer 100 can detect that the paper feed tray is opened or closed based on a change from the closed state to the open state of the paper feed tray or a change from the open state to the closed state. Each sheet sensor is an example of an open / close detection unit and an example of a second open / close detection unit. In addition to the sheet sensor, a configuration that can detect a change in the open / close state of each paper feed tray may be provided.

  Note that the printer 100 is not provided with a configuration for detecting the presence or absence of sheets stored in any of the paper feed trays. For this reason, the printer 100 determines that the sheet feeding tray has no sheets when no sheet is detected by the sheet sensor even after the sheet feeding operation. At that time, a retry is made so as not to erroneously determine that a sheet feeding error due to slipping of the electromagnetic clutch or the like is not present. For example, the paper feeding operation is repeated up to three times. The retry is performed by temporarily turning off the power supply to the electromagnetic clutch and turning it on again after a predetermined time.

[Electrical configuration of printer]
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 an image forming unit 10, an operation panel 40, a network interface 37, and a USB interface 38, and these are electrically connected to the controller 30. Furthermore, the main motor 21 described above, three electromagnetic clutches 23, 26, and 29, and three sheet sensors 56, 57, and 58 are provided, and these are electrically connected to the controller 30.

  The ROM 32 stores various control programs for controlling the printer 100, various settings, initial values, and the like. The RAM 33 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 network interface 37 is hardware for performing communication via a network. The USB interface 38 is hardware for communicating with a device connected via a USB cable or the like. In addition, the operation panel 40 includes, for example, a liquid crystal display and a button group, performs various displays for the user, and accepts an instruction input by the user.

  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.

[Feeding from a single paper tray]
Next, a paper feeding operation for supplying sheets to the image forming unit 10 in the printer 100 will be described. When a sheet feed tray for supplying sheets is designated by a print job, the printer 100 drives only a configuration for feeding sheets from the designated sheet feed tray. For example, when paper is fed from the first tray 12, the following operation is performed. The operation when feeding from the second tray 13 or the third tray 14 is substantially the same as the operation when feeding from the first tray 12.

  When paper is fed from the first tray 12, the printer 100 rotates the main motor 21 with the first electromagnetic clutch 23 released. Note that the printer 100 releases any electromagnetic clutch when the paper feeding operation is not performed. Then, with the main motor 21 rotating, the first electromagnetic clutch 23 is connected and the first paper feed roller 22 is rotated. By rotation of the first paper feed roller 22, the uppermost one of the sheets stored in the first tray 12 is pulled out from the first tray 12. When the leading end of the drawn sheet reaches the detection position of the first sheet sensor 56, the detection signal of the first sheet sensor 56 changes from off to on. If the first sheet sensor 56 is not turned on after the predetermined time has elapsed after the first electromagnetic clutch 23 is connected, the printer 100 retries the paper feeding operation.

  Even after the drawn sheet is detected by the first sheet sensor 56, the sheet is fed by the first sheet feeding roller 22, and the leading end of the sheet reaches the first conveying roller pair 52. After the leading end of the sheet is sandwiched between the first conveying roller pair 52, the sheet is conveyed by the first conveying roller pair 52 and the registration roller pair 51 and is supplied to the process unit 5. That is, the printer 100 releases the first electromagnetic clutch 23 and performs the first sheet feeding when a predetermined conveyance time from the detection of the sheet by the first sheet sensor 56 to the first conveyance roller pair 52 has elapsed. The rotation of the roller 22 is stopped.

[Simultaneous paper feeding]
Next, a paper feed operation of the printer 100 when a specific paper feed tray is not designated in the print job will be described. When the printer 100 receives a print job in which a sheet feeding tray for supplying sheets is not specified and satisfies a predetermined condition, the printer 100 executes a simultaneous sheet feeding operation described later to determine an execution tray. The execution tray is a paper feed tray that supplies paper conveyed to the image forming unit 10, and one of the plurality of paper feed trays is determined as the execution tray. The execution tray is an example of an execution accommodation unit.

  The simultaneous sheet feeding operation is a sheet feeding operation that simultaneously performs sheet feeding operations from a plurality of sheet feeding trays. After executing the simultaneous sheet feeding operation, the printer 100 determines an execution tray based on the detection result of each sheet sensor. On the other hand, when the predetermined condition is not satisfied, the paper feed tray used in the previous printing is determined as the execution tray. The predetermined conditions for determining whether or not to execute the simultaneous paper feeding operation include, for example, the first printing after power-on, the first printing of the print job, and the first printing after opening and closing the paper feed tray. Is used.

  For example, in printing the first print job after turning on the power, the printer 100 executes the simultaneous paper feeding operation for each page when printing from the first page to a predetermined first specified page. Alternatively, for example, every time printing of a print job is started, the printer 100 executes the simultaneous paper feeding operation for each page when printing from the first page to a predetermined first specified page. Note that the first specified page may be 1 or 2 or more.

  Further, for example, the printer 100 executes a simultaneous paper feeding operation for each page when printing up to a predetermined opening / closing prescribed page after at least one of the plurality of paper feeding trays is opened and closed by the user. The open / close regulation page may be a common value for each paper feed tray, or may be a different value for each paper feed tray. Since the printer 100 can detect that each paper feed tray has been opened and closed, a value corresponding to the opened and closed paper feed tray can be used as the opening / closing regulation page. Further, the opening / closing regulation page may be 1 or 2 or more.

  Next, the simultaneous paper feeding operation will be described. When the simultaneous sheet feeding operation is started, the printer 100 simultaneously performs sheet feeding operations on a plurality of sheet feeding trays. Furthermore, based on the detection result of the sheet sensor of each paper feed tray, a tray determination process for determining an execution tray from among the paper feed trays whose sheets have been detected by the sheet sensor is executed. Note that if there is a sheet feeding tray whose sheet is already detected by the sheet sensor, the sheet feeding operation of the sheet feeding tray may not be executed and may be the target of the tray determination process. Then, the sheet is fed from the sheet feeding tray determined as the execution tray, the sheet is supplied to the image forming unit 10, and the sheet feeding operation of the other sheet feeding trays is stopped. The tray determination process will be described later.

  On the other hand, after the simultaneous sheet feeding operation is performed, if no sheet is detected by the sheet sensor of any of the sheet feeding trays, as in the case of the sheet feeding operation from the single sheet feeding tray described above. Try again. Specifically, as shown in the time chart of FIG. 3, at the connection time t1, the three electromagnetic clutches 23, 26, and 29 are simultaneously connected. If a sheet is not detected by any of the sheet sensors 56, 57, 58 even after a predetermined specified time ha has elapsed from the connection time t1, the electromagnetic clutches 23, 26, 29 are temporarily released.

  And after releasing each electromagnetic clutch 23,26,29 once, when the predetermined releasing time hb passes, each electromagnetic clutch 23,26,29 will be connected again. If a sheet is not detected even if each electromagnetic clutch is connected three times, it is determined that no sheet is stored in any of the sheet feeding trays. Therefore, an error with no sheet is detected at the error time te which is almost the same timing as in the case of the sheet feeding operation from the single sheet feeding tray described above.

  In an apparatus having a plurality of paper feed trays such as the printer 100, when a paper feed operation is performed in order in each paper feed tray, if there are no sheets in the paper feed tray that started the paper feed operation in that order, that paper feed tray After waiting for the retry of the operation, the sheet feeding operation of the next sheet feeding tray is started. That is, in the configuration in which the presence / absence of sheets in each paper feed tray is sequentially determined, it may take a long time to supply the sheets. On the other hand, since the printer 100 performs the simultaneous sheet feeding operation, it is possible to notify the no sheet error in a shorter time compared to an example in which each sheet feeding tray is sequentially retried one by one.

  The specified time ha is a time equivalent to or slightly longer than the time taken for the sheet sensor to detect the sheet after the electromagnetic clutch is connected when the sheet is normally fed. In FIG. 3, the specified time ha is the same length for each paper feed tray, but it may be different for each paper feed tray. The specified time ha may be determined to be shorter than the time from the start of the sheet feeding operation in each sheet feeding tray until the sheet reaches the corresponding conveyance roller pair. In this way, the occurrence of jam due to the arrival of two or more sheets at the conveying roller pair is suppressed. The printer 100 predetermines and stores a predetermined time ha for each paper feed tray according to, for example, the distance between the position of the paper feed roller and the detection position of the sheet sensor, the paper feed speed of the paper feed roller, and the like. . Also, the release time hb may be different for each paper feed tray.

[Tray determination process]
Next, the tray determination process will be described. The printer 100 executes one of two types of processing as tray determination processing: (A) priority use order tray determination processing and (B) early detection order tray determination processing. The printer 100 may include both of these types or only one of them. When both types are provided, either one is selected and executed by user setting or the like.

  (A) The priority use order tray determination process is executed when a priority order is provided between the paper feed trays. When the priority use order tray determination process is executed, the printer 100 determines the execution tray according to the priority order if sheets are stored in a plurality of paper feed trays. If the execution tray is determined based on the priority order, a more suitable paper feed tray can be determined as the execution tray.

  The priority order is determined to be one order in order from the highest priority based on various priorities. Examples of the order of high priority include the order in which the transport distance to the image forming unit 10 is short, the order in which the paper feed error occurrence rate is low, and the order in which the tray usage rate is low. If the transport distance to the image forming unit 10 is in the short order, the time required for the sheet to reach the image forming unit 10 is short, and image formation can be started earlier, so that improvement in productivity can be expected. Further, if the paper feed error occurrence rate is set in ascending order, the possibility of an error during paper feed is low, so an improvement in productivity can be expected. Further, if the tray usage rate is in ascending order, a plurality of paper feed trays are used as uniformly as possible, and it can be expected that the difference in the degree of wear between the paper feed trays is reduced. Further, priority may be given to a paper feed tray whose opening / closing is detected. In the paper feed tray where opening / closing is detected, there is a high possibility that sheets have been replenished.

  Note that the priority order may be determined based on one predetermined priority, or a plurality of priorities may be combined. For example, the transport distance is applied as the first priority, and when a plurality of paper feed trays correspond to the first priority, the paper feed error occurrence rate is applied as the second priority. Also good. Alternatively, the priority order may be determined based on user settings.

  (B) The early detection order tray determination process is executed when productivity is prioritized. When the early detection order tray determination process is executed, the printer 100 determines the paper feed tray in which the sheet is detected earliest among the paper feed trays as the execution tray. According to this process, since the execution tray can be determined at an early stage, a highly productive process can be expected.

[Paper Feed Processing]
[First embodiment]
Next, the procedure of the first form of the paper feed process for executing the above-described simultaneous paper feed operation and tray determination process will be described with reference to the flowchart of FIG. In the paper feed processing of this embodiment, (A) preferential use order tray determination processing is executed as tray determination processing. This paper feed process is executed by the CPU 31 when a print job for which a paper feed tray is not specified is accepted and a condition for starting paper feed is satisfied.

  When starting the paper feed process, the printer 100 first determines whether or not the current printing is the head part of the print job (S101). For example, it is determined whether or not the printing is within the predetermined first prescribed page from the first page. If it is determined that it is not the head portion of the print job (S101: NO), it is determined whether any of the paper feed trays has been opened or closed (S102). For example, it is determined whether or not printing within the specified opening / closing page corresponds to detection of opening / closing of the paper feed tray.

  If it is determined that the paper feed tray is not opened or closed (S102: NO), the paper feed tray used in the previous printing is determined as the execution tray (S103). Further, the sheet is fed from the execution tray determined in S103, the sheet is conveyed to the image forming unit 10 (S105), and the sheet feeding process is terminated. The printer 100 prints on the sheet supplied by the sheet feeding process by the image forming unit 10.

  On the other hand, when it is determined that the print job is at the head of the print job (S101: YES), or when it is determined that one of the paper feed trays is opened or closed (S102: YES), the execution tray is selected from the paper feed trays. An execution tray determination process is performed to determine (S107).

  Next, the procedure of the execution tray determination process executed in S107 will be described with reference to the flowchart of FIG. When starting the execution tray determination process, the printer 100 first determines the priority order of the paper feed trays (S201). The priority order may be determined by the printer 100 based on, for example, the order in which the conveyance distance to the image forming unit 10 is short, the order in which the error occurrence rate is low, the order in which the usage rate is low, or the like. You may decide based on.

  Then, it is determined whether or not the sheet sensor of the paper feed tray determined as the first priority in S201 is on (S203). In the printer 100, as will be described later, the sheet feeding operation may be stopped after the sheet is fed until the sheet sensor is turned on. Therefore, the sheet sensor may be already turned on before starting the paper feeding operation for printing this page. If the sheet sensor of the first priority paper feed tray is on, that paper feed tray may be used as the execution tray.

  Therefore, when the sheet sensor of the first-priority paper feed tray has been turned on from the beginning (S203: YES), the feeding operation of the first-priority paper feed tray is started (S204), and the priority is given. The first-most feed tray is determined as the execution tray (S205), and the execution tray determination process is terminated.

  On the other hand, if the sheet sensor of the first priority paper feed tray is not turned on (S203: NO), the paper feed operation of the paper feed tray whose sheet sensor is turned off is started (S207). That is, among the plurality of paper feed trays, the respective electromagnetic clutches are connected in the paper feed trays in which the sheet sensor is off, and the rotation of the paper feed rollers is started. That is, if there is a paper feed tray whose sheet sensor is already turned on before the execution of S207, the paper feed operation of that paper feed tray is not performed. This is preferable because the sheet already fed to the position of the sheet sensor is not further advanced.

  Then, it is determined whether or not a sheet has been detected by the sheet sensor of the paper tray having the highest priority (S208). That is, after the sheet feeding operation is started in S207, it is determined whether or not the detection signal of the sheet sensor of the first priority sheet feeding tray has changed from off to on. If it is determined that a sheet has been detected by the sheet sensor of the first-priority paper feed tray (S208: YES), feeding of the paper feed tray that is performing the paper feed operation among the trays other than the first-priority order The paper operation is stopped (S209), the first priority paper feed tray is determined as the execution tray (S205), and the execution tray determination process is terminated.

  If it is determined that no sheet is detected by the sheet sensor of the first-ranked paper feed tray (S208: NO), it is determined whether a time-out has occurred (S210). That is, it is determined whether or not a predetermined specified time ha (see FIG. 3) has elapsed since the sheet feeding operation was started in S207. If it is determined that the time-out has not occurred (S210: NO), the process returns to S208, and it is determined whether or not a sheet is detected by the sheet sensor of the first-priority paper feed tray.

  If it is determined that a time-out has occurred without a sheet being detected by the sheet sensor of the first-priority paper feed tray (S210: YES), sheets are detected by the sheet sensors of other paper-feed trays other than the first priority. Is detected (S211). If it is determined that a sheet is detected by the sheet sensor of another sheet feeding tray (S211: YES), the sheet feeding tray having the highest priority among the sheet feeding trays in which the sheet is detected is selected. The execution tray is determined (S212).

  That is, in S212, if a sheet is detected by the sheet sensor of the second-priority paper feed tray, the second-priority paper feed tray is determined as the execution tray. If no sheet is detected by the sheet sensor of the second-priority paper feed tray, the third-priority paper feed tray is determined as the execution tray. Further, the feeding operation of trays other than the execution tray is stopped (S213), and the execution tray determination process is ended.

  On the other hand, when it is determined that no sheet is detected by any sheet sensor of the sheet feeding tray (S211: NO), the sheet feeding operation of all sheet feeding trays is stopped (S214). Further, 1 is added to the number of retries (S215). Then, it is determined whether or not the number of retries is less than 3 (S216). That is, the sheet feeding operation is executed up to three times. Note that the printer 100 sets the number of retries to 0 at the start of execution of the execution tray determination process.

  If it is determined that the number of retries is less than 3 (S216: YES), the process returns to S207 to retry the paper feeding operation. That is, as described with reference to FIG. 3, the electromagnetic clutch is engaged again after a predetermined release time hb. If it is determined that the sheet sensor is not detected by any sheet sensor of any sheet feeding tray and the number of retries is three (S216: NO), a sheet feeding error is detected (S217), and an execution tray determination process is performed. Exit.

  Returning to FIG. 4, after the execution tray determination process in S107, it is determined whether a paper feed error has occurred (S108). When the process returns from S217 in FIG. 5, it is determined that a paper feed error has occurred (S108: YES), an error message indicating no sheet is issued (S109), and the paper feed process is terminated.

On the other hand, when the process returns from S205 or S213 in FIG. 5, it is not a paper feed error because the execution tray has been successfully determined. If it is determined that there is no paper feed error (S108: NO), the sheet is conveyed from the determined execution tray to the image forming unit 10 (S105), and the paper feed process is terminated. That is, the sheet fed by the sheet feeding operation started in S204 or S207 of FIG. 5 is further conveyed, supplied to the image forming unit 10, and printed. If there is a next page in the print job, the paper feeding process is executed again to supply the next sheet. When all pages have been printed, the print job processing ends.

[Example of the first embodiment]
Next, an example in which the above-described first form paper feed process is executed will be described with reference to the timing charts of FIGS. These drawings show changes in the signals of the electromagnetic clutches and the sheet sensors after the determination at S101 or S102 of FIG. 4 is YES and the processing proceeds to the execution tray determination process of FIG. Each of these figures is an example of the order of the first tray 12, the second tray 13, and the third tray 14 in descending order of the priority of the paper feed trays.

  FIGS. 6 to 10 show examples in which the simultaneous sheet feeding operation is executed by proceeding to S207 because the first priority sheet sensor is OFF. In the example of FIGS. 6 to 8, there is no sheet feeding tray in which the sheet sensor is turned on at the start of the simultaneous sheet feeding operation, and all three electromagnetic clutches are connected at time t 1, and the three sheet feeding trays are connected. In this example, the paper feeding operation is started at the same time. When the signal of the electromagnetic clutch is changed from OFF to ON, the electromagnetic clutch is connected, and the paper feeding operation is started on the corresponding tray.

  The example of FIG. 6 is a timing chart when a sheet is detected by the first sheet sensor 56 at time t2 after the sheet feeding operation is started at time t1. Time t2 is within a specified time ha (see FIG. 3) from time t1. Since the first tray 12 is the first priority paper feed tray, the first tray 12 is determined as the execution tray at time t2. Therefore, after time t2, the sheet feeding operation of the second tray 13 and the third tray 14 that have not become the execution tray is stopped. The sheet feeding operation of the first tray 12 that has become the execution tray is continued for a predetermined conveyance time and stopped at time t3. The fed sheet is conveyed to the image forming unit 10 by the first conveying roller pair 52 and the like as described above after time t3. Time t4 is the time when the trailing edge of the sheet passes the detection position of the first sheet sensor 56.

  The example of FIG. 7 is a timing chart in the case where the sheet is not detected by the first sheet sensor 56 of the first tray 12 by the time t5 when the specified time ha has elapsed after the sheet feeding operation is started at the time t1. It is. Instead, the sheet is detected by the third sheet sensor 58 of the third tray 14 at time t6 between time t1 and time t5. Therefore, although the priority order is low, the third tray 14 is determined as the execution tray because it is the only tray in which the sheet is detected by time t5. Accordingly, the sheet feeding operation of the first tray 12 and the second tray 13 is stopped at time t5. The sheet feeding operation of the third tray 14 is continued for a predetermined conveyance time until time t7, similarly to the first tray 12 in the example of FIG. Further, the sheet passes through the third sheet sensor 58 at time t8. The transport time may be different for each tray or the same time.

  In the example of FIG. 8, after the sheet feeding operation is started at time t1, a sheet is detected by the third sheet sensor 58 of the third tray 14 at time t9, and then at time t10 within a specified time ha from time t1. This is an example in which a sheet is further detected by the first sheet sensor 56 of the first tray 12. Since the third tray 14 in which the sheet is detected at time t9 is not the first priority paper feed tray, the paper feed operation is continued until the specified time ha has elapsed. Then, when a sheet is detected in the first tray 12 that is ranked first in the priority order at time t10, the first tray 12 is determined as the execution tray. The sheet feeding operation of the second tray 13 and the third tray 14 that have not become the execution tray is stopped after t10, but the third sheet sensor 58 remains on.

  For example, FIG. 9 is a continuation of FIG. 8 and shows an example in which the simultaneous sheet feeding operation is executed in a state where the third sheet sensor 58 remains on. Since the third tray 14 is not the first priority sheet sensor, the feeding operation of the first tray 12 and the second tray 13 other than the third tray 14 is started at time t1. Since the third sheet sensor 58 is on, the feeding operation of the third tray 14 is not started. Then, as shown in the example of FIG. 8, since the sheet is detected by the first sheet sensor 56 of the first tray 12 at the time t11 within the specified time ha from the time t1, the first tray 12 is determined as the execution tray. Paper is fed from the first tray 12. If neither the first sheet sensor 56 nor the second sheet sensor 57 is turned on within the specified time ha, the third tray 14 in which a sheet is detected is determined as the execution tray.

  FIG. 10 is an example of a timing chart in the case of continuous paper feeding in the first form of paper feeding processing. In the case of a multi-page print job, if it is determined in S101 in FIG. 4 that the print job is within the first specified page from the start of the print job, the execution tray determination process is repeated. In FIG. 10, the third tray 14 is determined as the execution tray for the first sheet as in the example of FIG. 7, and the first tray 12 is determined for the second sheet as in the example of FIG. It is an example when it determines to an execution tray.

  Since the execution tray determination process is repeated with the paper feeding operation within the first specified page from the start of the print job, the paper feeding from the first tray 12 failed due to, for example, slipping of the first electromagnetic clutch 23 during the first connection. Even in this case, the first sheet can be fed from another sheet feeding tray. Therefore, productivity is high. Further, if there is no paper feed error for the second sheet, paper is fed from the first tray 12 having a high priority, so that the paper tray having a high priority can be preferentially used.

  As described above in detail, the printer 100 according to the first embodiment has a plurality of paper feed rollers that feed paper from each paper feed tray and a paper fed from each paper feed tray. When printing a print job having a plurality of sheet sensors for detecting the presence or absence of a sheet and not specifying a sheet feeding tray, the sheet feeding operation is simultaneously performed from each sheet feeding tray. Then, based on the detection result of each sheet sensor, an execution tray for supplying the sheet conveyed to the image forming unit 10 is determined. Further, the sheet is conveyed from the paper feed tray determined as the execution tray to the image forming unit 10. On the other hand, the sheet feeding operation of the sheet feeding trays other than the sheet feeding tray determined as the execution tray is stopped. Therefore, the determination of the presence or absence of sheets in the paper feed tray can be performed simultaneously on a plurality of paper feed trays, and an improvement in productivity can be expected as compared with the case of sequentially judging each paper feed tray.

[Second form]
Next, the procedure of paper feed processing in the printer 100 of the second embodiment will be described with reference to the flowchart of FIG. In the paper feed process of the second form, the above-described (B) early detection order tray determination process is executed as a tray determination process method. The paper feed process of the second form is different from the paper feed process of the first form only in the contents of the execution tray determination process (S107 in FIG. 4), and the procedure of the paper feed process (FIG. 4). Is the same. The same processes as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  When the execution tray determination process is started, the printer 100 according to the second embodiment first determines whether there is a paper feed tray whose sheet sensor is already turned on (S301). As in the previous example, if the simultaneous paper feeding operation is performed, sheets may be fed from paper feeding trays other than the execution tray, so the sheet sensor may remain on. .

  In this embodiment, when it is determined that there is a sheet feeding tray whose sheet sensor is already turned on (S301: YES), the sheet feeding tray whose sheet sensor is turned on is determined as an execution tray (S302). Then, the execution tray feeding operation is started (S303), and the execution tray determination process is ended. When there are a plurality of sheet feeding trays whose sheet sensors are already turned on, one sheet feeding tray is determined according to a predetermined priority order.

  On the other hand, when it is determined that there is no sheet feeding tray whose sheet sensor is already turned on (S301: NO), the sheet feeding operation of all the sheet feeding trays is started (S305). Then, it is determined whether or not a sheet is detected by the sheet sensor of any of the sheet feeding trays (S307).

  When it is determined that no sheet is detected by any sheet sensor of the sheet feeding tray (S307: NO), it is determined whether or not a timeout has occurred (S210). Further, as in the first embodiment, the paper feeding operation is retried (S214, S215, S216). If no sheet is detected even after retrying (S216: NO), a paper feed error is detected (S217), and the execution tray determination process is terminated.

  On the other hand, if a sheet is detected in any of the sheet feeding trays during the sheet feeding operation up to three times (S307: YES), the sheet feeding tray in which the sheet is detected is determined as the execution tray ( S309). Further, the sheet feeding operation of the sheet feeding trays other than the execution tray is stopped (S213), and the execution tray determination process is ended.

[Example of the second embodiment]
Next, an example in which the above-described second form paper feed process is executed will be described with reference to the timing charts of FIGS.

  The example of FIG. 12 is an example in which there is no sheet sensor turned on at the start of processing, and NO is made in S301 and the process proceeds to S305. That is, in this example, all three electromagnetic clutches are connected at time t1, and the sheet feeding operation is started simultaneously with the three sheet feeding trays. Since the third sheet sensor 58 is turned on first among the three sheet sensors, the third tray 14 is determined as the execution tray. Note that, as the second sheet, the simultaneous sheet feeding operation is executed again, the first sheet sensor 56 is first turned on, and the sheet is fed from the first tray 12.

  The example of FIG. 13 is an example in which the third sheet sensor 58 is turned on at the start of processing. In this example, since YES is obtained in S301, the sheet feeding operation of the first tray 12 and the second tray 13 in which the sheet sensor is not turned on is not started. Then, the third tray 14 is determined as the execution tray, and the feeding operation from the third tray 14 is started at time t1.

  As described above in detail, also by the printer 100 of the second embodiment, the presence / absence of a sheet in the paper feed tray is simultaneously determined in a plurality of paper feed trays to be conveyed to the image forming unit 10. The execution tray for supplying the sheets to be processed can be determined at an early stage. This can be expected to improve productivity. In particular, in the second embodiment, since the paper feed tray from which the sheet is detected at an early stage is preferentially determined as the execution tray, the productivity is higher than that in the first embodiment. On the other hand, in the first embodiment, since the execution tray is determined based on the priority order, it is possible to expect appropriate use of the sheet feeding tray as compared with the second embodiment.

  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 or a FAX. Further, the present invention is not limited to the electrophotographic method but can be applied to an ink jet printer. Further, the present invention can be applied not only to a monochrome printer but also to a color printer.

  Further, for example, the simultaneous paper feeding operation includes an operation that is not exactly simultaneous. That is, the sheet feeding operations in S207 and S305 are not limited to those in which the sheet feeding operations are started at the plurality of sheet feeding trays at the same time, and may include the time during which they are simultaneously operated. For example, the sheet feeding operation for the next sheet feeding tray may be started within the specified time ha of the sheet feeding tray that started the operation in advance. Alternatively, after operating one paper feed tray, another paper feed tray may be operated during the retry period.

  In each of the above embodiments, each of the three paper feed trays is fed by one main motor and three electromagnetic clutches. However, the present invention is not limited to this configuration. For example, the motors may not be common. For example, the number of paper feed trays is not limited to three, and a plurality of paper feed trays may be provided. It is only necessary to start or stop the sheet feeding operation for each sheet feeding tray, and the sheet feeding tray is not limited to one using an electromagnetic clutch.

  In addition, for example, a configuration for detecting opening and closing of the paper feed tray may not be provided. Alternatively, it may be configured such that only one of the trays is opened / closed and the opened / closed tray cannot be specified. For example, if the user accepts pressing of the start button after opening or closing any tray, the printer that resumes operation can determine that the tray has been opened or closed based on the pressing of the start button. In this case, the user may specify a tray that has been opened or closed, or a configuration that cannot be specified. Such a configuration is also an example of the second opening / closing detection unit.

  Further, for example, S101 and S102 in FIG. 4 may not be provided, or only one of them may be provided. For example, the execution tray determination process may be executed every time paper is fed. Alternatively, the execution tray determination process may be executed only on the first page from the start of the print job and not executed on the second and subsequent pages. In addition, if the execution tray determination process is executed in the first print job after the power is turned on, it may not be executed until one of the paper feed trays is opened or closed.

  Further, for example, in the first embodiment, the sheet feeding operation may be started in all sheet feeding trays in S207 without performing the determination in S203 of FIG. Further, for example, in the second embodiment, the determination in S301 of FIG. 11 may not be performed. That is, regardless of whether the sheet sensor is on or off at the start of processing, first, the sheet feeding operation may be started in all the sheet feeding trays. For example, as long as the sheet that has started to be fed is backed up to the sheet feeding tray, the sheet feeding operation may be executed every time in all the sheet feeding trays.

  Further, for example, in the first embodiment, the determination in S208 of FIG. 5 may not be performed. The execution tray may be determined based on the priority order from all the sheet feeding trays in which the sheet is detected after waiting for the timeout from the start of the operation. 5 and FIG. 11, the specified time ha until time out in S210 may be different for each paper feed tray depending on the configuration. In that case, the timeout may be determined for each tray, or the timeout may be determined based on the timeout of the paper feed tray having the longest specified time ha.

  For example, the number of sheet feeding operations including retry is not limited to three. In addition, for example, each sheet feeding tray may have a configuration for detecting the presence or absence of a stored sheet.

  The processing disclosed in the embodiments 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 the embodiment can be realized in various modes such as a recording medium or a method recording a program for executing the processing.

DESCRIPTION OF SYMBOLS 10 Image formation part 12, 13, 14 1st-3rd tray 21 Main motor 22, 25, 28 1st-3rd paper feed roller 23, 26, 29 1st-3rd electromagnetic clutch 31 CPU
52 First to Third Conveying Roller Pairs 56 First to Third Sheet Sensors 100 Printer

Claims (11)

An image forming unit for forming an image on paper;
A plurality of storage units for storing paper;
A plurality of paper feed units for feeding paper from each of the plurality of storage units;
A transport unit configured to transport a sheet fed by one of the plurality of sheet feed units to the image forming unit;
A plurality of detection units corresponding to each of the plurality of paper supply units, and detecting a fed sheet at a position upstream of the transport unit;
A control unit;
With
The controller is
A simultaneous paper feed process for performing a paper feed operation in another paper feed unit when performing a paper feed operation in one of the plurality of paper feed units;
After the simultaneous paper feed process is started, one of the plurality of storage units is determined to be an execution storage unit that supplies paper to be conveyed to the image forming unit, based on detection results of the plurality of detection units. Decision processing,
The paper fed from the execution storage unit determined in the determination process is transported to the image forming unit by the transport unit, and the paper feeding operation of the paper storage unit of the storage unit other than the execution storage unit is performed. Transport processing to stop,
An image forming apparatus characterized in that The image forming apparatus according to claim 1,
The controller is
In the determination process, the execution accommodating unit is determined based on a detection result of each of the detection units after a specified time has elapsed after starting the paper supply operation by the simultaneous paper supply process. Image forming apparatus. The image forming apparatus according to claim 2,
The controller is
In the determination process, when there are a plurality of detection units that detect paper before the specified time elapses, the storage unit having a shorter transport distance to the image forming unit has a priority as the execution storage unit. An image forming apparatus characterized by having a high value. In the image forming apparatus according to claim 2 or 3,
Comprising a plurality of open / close detection units for detecting that each of the storage units has been opened and closed;
The controller is
In the determination process, when there are a plurality of detection units that detect a sheet until the specified time elapses, the storage unit that is detected to be opened and closed by the open / close detection unit is the open / close detection unit. The image forming apparatus is characterized in that the execution unit is higher in priority than the storage unit that has not been detected to be opened and closed. In the image forming apparatus according to any one of claims 2 to 4,
The image forming apparatus according to claim 1, wherein the specified time is a time set for each of the housing units. The image forming apparatus according to any one of claims 2 to 5,
The controller is
In the determination process, when the detection unit of the storage unit having the highest priority among the plurality of storage units detects a sheet, the storage unit does not wait for the specified time to elapse. Is determined as the execution accommodating portion. The image forming apparatus according to claim 1,
The controller is
After starting the paper feeding operation by the simultaneous paper feeding process in the determination process, the storage unit in which the detection unit first detects the paper among the plurality of storage units is determined as the execution storage unit. An image forming apparatus. In the image forming apparatus according to any one of claims 1 to 7,
The controller is
The execution storage unit is determined in the determination process, and the paper fed from the execution storage unit in the transport process is transported toward the image forming unit. , Execute the simultaneous paper feeding process,
An image forming apparatus that executes the determination process and the transport process again with the execution of the simultaneous paper feeding process again. The image forming apparatus according to claim 8,
The controller is
From the start of processing of one job until the prescribed amount of image formation is performed, the simultaneous paper feed process is executed every time the paper is fed, and the determination process and the transport process are executed every time the simultaneous paper feed process is executed. An image forming apparatus. The image forming apparatus according to any one of claims 1 to 9,
A second opening / closing detection unit for detecting that at least one of the plurality of accommodating units is opened / closed;
The controller is
The image forming apparatus, wherein the simultaneous sheet feeding process is executed on condition that at least one of the plurality of storage units is detected to be opened and closed by the second opening / closing detection unit. In the image forming apparatus according to any one of claims 1 to 10,
The controller is
Before performing the paper feeding operation in the simultaneous paper feed process, it is determined whether any of the plurality of detection units detects a paper, and corresponds to the detection unit detecting the paper. An image forming apparatus, wherein a sheet feeding operation of the sheet feeding unit is not performed.

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