JP2015151216A - Sheet processing device, control method thereof, and image formation device equipped with the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that, when a curled sheet is continued to be loaded in a tray, a sheet bundle may prevent discharging of a following sheet to cause jamming, and even if a jam process is performed after occurrence of jamming, the curled sheet bundle that remains in the tray may clog discharge of a sheet, to cause jamming again.SOLUTION: If a sheet bundle remains in a tray, a control is made so that, when a following sheet is discharged and loaded in the tray, by increasing a falling amount of the tray that can be lifted, the sheet that is discharged to the tray does not hit against the curled sheet bundle. Thus, repeated occurrence of jamming because of a curled sheet bundle that remains in the tray can be prevented.

Description

  The present invention relates to a sheet processing apparatus, a control method therefor, and an image forming apparatus including the apparatus, and more particularly, for example, a sheet processing apparatus that discharges a sheet on which an image is formed according to an electrophotographic method and stacks the sheet on a tray. The present invention relates to a method and an image forming apparatus including the apparatus.

  In a sheet processing apparatus having a movable tray that is disposed on or next to an image forming unit in an image forming apparatus and that stacks sheets formed with an image formed in the image forming unit, the image-formed sheet is discharged onto the tray. When loading, the following troubles may occur. That is, the sheet discharge is hindered by the curled state of the sheet bundle already loaded on the tray, and the sheet discharged later may be repeatedly jammed at the discharge port.

  In order to improve this, conventionally, as disclosed in Patent Document 1, for example, the number of sheets passed until a jam occurs on the same sheet conveyance path is counted, and the number of sheets conveyed on the same path is counted as the count. When it reaches, it is switched to another transport path.

JP 2011-180289 A

  However, in Patent Document 1 of the above-described conventional example, the conveyance path switching control is performed based on the assumption that the same number of sheets that have passed through the same conveyance path before the occurrence of the previous jam occurs again this time. The following problems will occur. In other words, jams do not occur every time the same number of sheets are ejected. Therefore, although the effect of avoiding jam occurrence is low, it is convenient for the user to eject the jams through an unintended route. It ’s bad and inconvenient.

  The present invention has been made in view of the above-described conventional example, and includes a sheet processing apparatus, a control method thereof, and the apparatus that prevent jamming due to curled stacked sheets remaining on a tray and improve user convenience. An object of the present invention is to provide an image forming apparatus.

  In order to achieve the above object, the image forming apparatus of the present invention has the following configuration.

  That is, a sheet processing apparatus that processes a sheet to be discharged, the transport unit configured to transport the sheet, the tray that stacks the discharged sheet, the tray that is movable in the stacking direction, and the transport A holding unit that holds, as a history, the number of conveyance jams that have occurred in the past due to conveyance by the unit, a first detection unit that detects whether or not a sheet is stacked on the tray, and detection by the first detection unit Control means for controlling the tray to move away from the sheet discharge port while varying the amount of movement of the tray based on the number of previous transport jams held by the holding means. It is characterized by.

  According to another aspect of the present invention, the sheet processing apparatus having the above-described configuration, a supply unit that supplies a sheet, an image forming unit that forms an image on the sheet supplied by the supply unit, and the image forming unit The image forming apparatus includes: a discharge unit that discharges the sheet on which the image is formed to the sheet processing apparatus.

  According to another aspect of the present invention, there is provided a control method for a sheet processing apparatus that includes a tray that discharges sheets, stacks the discharged sheets, and is movable in a stacking direction of the sheets. A transporting process for transporting the sheet, a holding process for storing in the memory the number of transporting jams that have occurred in the past by transporting in the transporting process, and a detecting process for detecting whether or not a sheet is stacked on the tray Based on the detection in the detection step and the number of previous jams held in the memory in the holding step, the tray moves away from the sheet discharge port while varying the amount of movement of the tray. And a control means for controlling to move the sheet processing apparatus.

  Therefore, according to the present invention, it is possible to prevent the occurrence of a jam due to the curled and stacked sheets remaining on the tray, thereby improving the convenience for the user.

1 is a cross-sectional view illustrating a configuration of an image forming apparatus including a sheet treatment apparatus that is a typical embodiment of the present invention. It is a sectional side view explaining the structure of a sheet processing apparatus. 3 is a block diagram illustrating a control configuration of the sheet processing apparatus. FIG. , 6 is a flowchart illustrating sheet conveyance control processing. It is a figure which shows the relationship between a jam count value and tray downward amount.

  Hereinafter, preferred embodiments of the present invention will be described more specifically and in detail with reference to the accompanying drawings.

  FIG. 1 is a side sectional view showing a configuration of a copying machine including a sheet processing apparatus according to a typical embodiment of the present invention. In FIG. 1, a copying machine includes an image forming unit 1 that forms an image on a recording medium such as a sheet-like cut sheet according to an electrophotographic method, an automatic document feeder (ADF) 3 provided on the upper side of the copying machine, and an image. A sheet processing apparatus 100 that performs processing of a sheet discharged from the forming unit 1 is included.

  A document table 2 on which an image document is placed is provided below the ADF 3, and cassettes 10 to 13 on which a plurality of types of sheets are stacked are provided below the image forming unit 1.

  In the copying machine having such a configuration, when an image original is read to form an image, first, the originals stacked on the ADF 3 are sequentially conveyed onto the platen glass 31 one by one. Next, when the document is conveyed to a predetermined position on the platen glass 31, the reader unit 30 irradiates the document with light, reads the reflected light, performs photoelectric conversion, performs image processing, and outputs a digital image signal. Generated.

  Based on the image signal generated by reading the image of the document in this way, the exposure control unit 17 is driven to scan the photosensitive drum 18 charged with the beam light. As a result, an electrostatic latent image is formed on the photosensitive drum 18, and this latent image is developed by the developing device 20, and a toner image is formed on the photosensitive drum 18.

  Next, in synchronization with the leading edge of the toner image, the sheet is conveyed from one of the cassettes 10 to 13 by the conveyance roller 14, and the toner image is transferred to the sheet by the transfer drum 19. Thereafter, the toner image transferred to the sheet is fixed by the fixing unit 21, and then the sheet is discharged to the sheet processing apparatus 100.

  Note that the sheet supply need not be from the cassettes 10 to 13 but may be performed from the sheets stacked on the manual feed tray 15.

  When image formation is performed on both sides of the sheet, the sheet having the image transferred on one side is once returned to the duplex unit 4 through the duplex conveying path 29, and then the sheet is reversed and the image is again displayed. It is conveyed to the forming unit 1.

  FIG. 2 is a side sectional view for explaining the configuration of the sheet processing apparatus 100.

  Next, with reference to FIG. 2, an operation for discharging an image-formed sheet will be described.

  The sheet discharged from the fixing unit 21 reaches the conveyance roller 103 by the relay pass roller 102. Further, the sheet is discharged onto the tray 107 by the conveyance roller 103. The tray 107 is a tray that is movable in the vertical direction. When the sheet is discharged onto the tray by the conveying roller 103, the sheet upper surface detection sensor 141 is turned off, and then the tray 107 is located at a position where it has been lowered by a certain distance. When the sheet that has passed the conveyance roller 103 is discharged onto the tray 107, the tray 107 is raised to a position where the sheet upper surface detection sensor 141 can be turned on.

  Here, when the arm 105 moves from the position of the solid line in FIG. 2 to the position of the dotted line, the alignment roller 104 attached to the arm 105 comes into contact with the upper surface of the sheet discharged onto the tray 107. Then, the sheet is aligned by rotating the alignment roller 104 (counterclockwise) in a direction in which the sheet is moved to the right in FIG.

  FIG. 3 is a block diagram illustrating a configuration of the control unit of the sheet processing apparatus 100.

  In FIG. 3, a one-chip controller 310 includes a CPU 311, ROM 312, RAM 313, and I / O port 314. Needless to say, a memory other than the ROM 312 and the RAM 313 may be provided.

  The controller 310 controls the relay path motor 112 that drives the relay path roller 102, the transport motor 113 that drives the transport roller 103, and the alignment motor 114 that drives the alignment roller 104. The controller 310 further controls an arm solenoid 115 that drives the arm 105 that moves the alignment roller 104 in the vertical direction and a tray motor 130 that moves the tray 107 in the vertical direction.

  The controller 310 further includes an intermediate path sensor 143 disposed on the upstream side in the transport direction, as shown in FIG. 2, and a transport path sensor 140 disposed on the downstream side, of the two sensors that detect passage of the sheet in the transport path. Control and receive their output. The controller 310 further includes a sheet upper surface detection sensor 141 for detecting that the upper surface of the sheet bundle stacked on the tray 107 is in a position for receiving the next sheet, and a sheet presence / absence sensor 142 for detecting the presence / absence of a sheet on the tray 107. Control and receive their output. The controller 310 is connected to a communication unit 320 that communicates with the image forming unit 1.

  The arrangement interval between the intermediate path sensor 143 and the conveyance path sensor 140 is set in consideration of the length in the conveyance direction of the cut sheet that can be processed by the sheet processing apparatus 100.

  As can be understood from the above configuration, this sheet processing apparatus uses one conveyance path for discharging an image-formed sheet to the outside of the apparatus.

  Next, sheet conveyance control executed by the copying machine configured as described above, particularly the sheet processing apparatus 100, will be described with reference to flowcharts. Here, as an example of the sheet, a sheet of a predetermined size (for example, A4, A3, B4, etc.) is supplied from the cassettes 10 to 13 or the manual feed tray 15.

  4 to 5 are flowcharts showing the sheet conveyance control process.

  First, in step S <b> 101, the communication unit 320 with the image forming unit 1 is used to wait for a notice of sheet carry-in notice from the image forming unit 1. When the notification is received, the process proceeds to step S102, where the relay path motor 112 starts to be driven, and the relay path roller 102 is rotated to start the sheet conveying operation.

  Next, in step S103, based on the sensor output of the sheet presence / absence sensor 142 (first detection means), it is checked whether there is a sheet discharged to the tray 107. If it is determined that there is no sheet, the process advances to step S104 to clear the value of the conveyance jam count stored in the RAM 313 to zero. Thereafter, the process proceeds to step S105. On the other hand, if it is determined that there is a sheet, the process proceeds to step S105.

  The conveyance jam count is a counter that holds the number of jams that occurred in the past as a history, and the count value is held as long as the discharged sheets are stacked on the tray 107.

  In step S105, the process waits until the leading edge of the sheet conveyed to the sheet processing apparatus 100 reaches the intermediate path sensor 143 (second detection means). Here, when it is detected that the sheet has arrived, the process proceeds to step S106, and the time based on the sheet size information received from the image forming unit 1 via the communication unit 320 in advance is set as a timer value. The relay jam timer (first time measuring means) is started. In step S110, the process waits until the leading edge of the sheet reaches the conveyance path sensor 140 (third detection means). Here, when the arrival of the sheet is detected, the process proceeds to step S111 as a trigger, and the time based on the sheet size information received from the image forming unit 1 via the communication unit 320 in advance is set as a timer value to convey the jam. A timer (second timing means) is started.

  Furthermore, in step S112, the driving of the conveyance motor 113 is started, and preparation for sheet conveyance by the conveyance roller 103 is made. In step S113, it is checked whether or not the value of the conveyance jam count stored in the RAM 313 is “0”. If it is determined that the value is “0”, the process proceeds to step S114 to set a descending distance of 5 mm (normal value), and then the process proceeds to step S116. On the other hand, if it is determined that the value is other than “0”, the process proceeds to step S115 to set the descending distance 15 mm. In step S116, the tray 107 starts to descend according to the set value.

  In this embodiment, after the sensor output of the sheet upper surface detection sensor 141 is turned off, the drive pulse to the tray motor 130 using the stepping motor is counted, and the amount of tray lowering is known by converting the count value to a distance. be able to.

  In step S117, the process waits until the tray lowering amount reaches the set distance (5 mm or 15 mm), and when the set distance is reached, the process proceeds to step S118 and stops moving the tray 107.

  In step S120, it is checked whether the trailing edge of the sheet has passed the intermediate path sensor 143. If it is determined that the sheet has not passed, the process proceeds to step S121 to check whether the relay jam timer set in step S106 has timed out. If it is determined that a time-out has occurred, the process proceeds to step S127 to stop all driving, and in step S140, the image forming unit 1 is notified of the occurrence of a jam via the communication unit 320. Thereby, the operation of the sheet conveyance control is once ended. When the jam is released, the sheet conveyance control starts again from step S101. On the other hand, if it is determined that the relay jam timer has not timed out, the process returns to step S120 and waits for the passage of the intermediate path sensor 143 at the trailing edge of the sheet. In step S120, if the intermediate path sensor 143 detects passage of the trailing edge of the sheet, the process proceeds to step S123, and the operation of the relay jam timer is stopped.

  In step S124, it is checked whether the trailing edge of the sheet has passed the conveyance path sensor 140. If it is determined that the sheet has not passed, the process proceeds to step S125, and it is checked whether or not the conveyance jam timer set in step S111 has timed out. If it is determined that a time-out has occurred, the process proceeds to step S 126, and “1” is added to the conveyance jam count set in the RAM 313 inside the controller 310. Then, the process proceeds to step S127, and the same process as when the relay jam timer times out is executed. On the other hand, if it is determined that the conveyance jam timer has not timed out, the process returns to step S124 to wait for the conveyance path sensor 140 at the trailing edge of the sheet to pass. In step S124, when the conveyance path sensor 140 detects the passage of the trailing edge of the sheet, the process proceeds to step S128, and the operation of the conveyance jam timer is stopped.

  Next, in step S129, the tray motor 130 is driven to start raising the tray 107. In step S130, after the start of raising the tray, the process monitors the sensor output of the sheet upper surface detection sensor 141, and continues monitoring if the output is OFF. If the output of the sheet upper surface detection sensor is ON (sheet upper surface detection is possible), the process proceeds to step S131, the tray motor 130 is stopped, and the tray 107 is stopped from rising.

  Further, in step S132, the arm solenoid 115 is turned ON, and at the same time, the aligning motor 104 is driven in the direction in which the aligning roller 104 rotates in the sheet pulling direction, and the aligning roller 104 is lowered. Further, in step S133, the alignment roller 104 comes into contact with the upper surface of the newly stacked sheet, and the uppermost sheet is pulled back (to the right in FIG. 2) to align the sheets on the tray 107.

  In step S134, it is checked whether or not a predetermined amount of pullback has been completed by counting drive pulses to the alignment motor 114 using the stepping motor. If it is determined that the predetermined amount of pullback has been completed, the process proceeds to step S135, and the driving of the alignment motor 114 is stopped. At the same time, in step S136, the arm solenoid 115 is turned off. As a result, the alignment roller 104 moves away from the sheet bundle on the tray 107 to make it easier for the user to take the sheet.

  Finally, in step S137, it is checked whether there is a sheet to be subsequently discharged. This is done by confirming whether or not the sheet information transmitted from the image forming unit 1 via the communication unit 320 has been received. Here, if there is sheet information, it is determined that there is a sheet to be subsequently discharged, and the process returns to step S101. On the other hand, if there is no sheet information, it is determined that there is no sheet to be subsequently discharged, and the process proceeds to step S138, where all motor driving is stopped and a series of sheet conveyance control is terminated.

  Therefore, as described above, according to the embodiment, the lowering amount of the tray can be made different according to the presence / absence of the sheet discharged to the tray and the number of the past occurrences of the jam. As a result, the tray lowering amount can be reduced when there is no sheet discharged to the tray or when the count of occurrence of conveyance jam is zero. On the other hand, the tray lowering amount can be increased when there is a sheet discharged to the tray or when the count number of occurrence of the conveyance jam is not zero.

  In this way, by changing the distance of the tray from the sheet discharge port, the curl bundle stacked on the tray due to the curl of the sheet generated by the jam closes the sheet discharge port, and the jam occurs repeatedly. This can be prevented.

  In the embodiment described above, if the jam count value is “0”, the descending distance is set to 5 mm, and if it is not “0”, the descending distance is set to 15 mm. It is not limited. For example, as shown in FIG. 6, the setting may be changed so as to change the tray lowering amount according to the value of the jam count.

  In addition, in the configuration according to this embodiment, since there is one discharge path, it is possible to improve the inconvenience that sheets are discharged from different discharge paths as in the conventional case and the user is confused.

  In the embodiment described above, the image forming unit conforming to the electrophotographic method is used, but the present invention is not limited thereto. For example, an image forming unit using another recording method such as an inkjet method or a sublimation method may be used. Further, in the embodiment described above, a copying machine is used as an image forming apparatus. However, the present invention is a single-function printer that forms an image by image data transferred from a host device or a multifunction printer having a facsimile communication function. It is also applicable to the device.

Claims (10)

A sheet processing apparatus for processing to discharge a sheet,
Conveying means for conveying the sheet;
A tray on which discharged sheets are stacked, the tray being movable in the stacking direction of the sheets,
Holding means for holding, as a history, the number of conveyance jams that occurred in the past due to conveyance by the conveyance means;
First detecting means for detecting whether or not sheets are stacked on the tray;
Based on the detection by the first detection means and the number of previous transport jams held by the holding means, the tray is moved away from the sheet discharge port while varying the amount of movement of the tray. And a control means for controlling the sheet processing. Second detection means for detecting the sheet by the conveying means;
Triggered by the detection of the leading edge of the sheet by the second detection means, further comprising a first time measuring means for measuring time based on the size of the sheet, and time measurement,
The control means considers that a jam has occurred in the sheet when the trailing edge of the sheet is not detected by the second detection means and the timing by the first timing means has timed out. The sheet processing apparatus according to claim 1. A third detection unit that is disposed downstream of the second detection unit with respect to the conveyance direction by the conveyance unit and detects the sheet;
Triggered by the detection of the leading edge of the sheet by the third detection means, further comprising a second time measuring means for measuring time based on the size of the sheet,
The control means determines that a jam has occurred in the sheet when the trailing edge of the sheet is not detected by the third detecting means, and the timing by the second timing means has timed out, The sheet processing apparatus according to claim 2, wherein the number of conveyance jams held in the holding unit is added.   The control unit is configured to remove the tray when the sheet conveyed by the conveying unit is detected by the second detecting unit and the third detecting unit, respectively, at the leading end and the trailing end of the sheet. The sheet processing apparatus according to claim 3, wherein the sheet processing apparatus is controlled to be moved to a discharge port. The control means includes
When the first detection unit detects that a sheet is stacked on the tray, the amount of lowering the tray is increased according to the number of previous transport jams held by the holding unit,
When the first detection unit detects that no sheet is stacked on the tray, the number of previous transport jams held by the holding unit is cleared to zero, and the amount by which the tray is lowered is reduced. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is controlled as follows.   The sheet processing apparatus according to claim 1, wherein the conveyance unit has a single sheet conveyance path. The sheet processing apparatus according to any one of claims 1 to 6,
Supply means for supplying a sheet;
Image forming means for forming an image on the sheet supplied by the supply means;
An image forming apparatus comprising: a discharge unit configured to discharge a sheet on which an image is formed by the image forming unit to the sheet processing apparatus.   The image forming apparatus according to claim 7, wherein the image forming unit forms an image according to an electrophotographic method.   The image forming apparatus according to claim 7, wherein the sheet processing apparatus further includes a communication unit that communicates information about a sheet size with the image forming apparatus. A control method for a sheet processing apparatus that includes a tray that discharges sheets, stacks the discharged sheets, and is movable in a stacking direction of the sheets,
A conveying step for conveying the sheet;
A holding step of holding in the memory the number of conveyance jams that occurred in the past due to conveyance in the conveyance step as a history;
A detection step of detecting whether or not sheets are stacked on the tray;
Based on the detection in the detection step and the number of previous jams held in the memory in the holding step, the tray is moved away from the sheet discharge port while varying the amount of movement of the tray. And a control means for controlling the sheet processing apparatus.

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