JP3984976B2 - Sheet conveying apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to sheet processing in an image forming apparatus such as a copying machine, a printer, and a facsimile machine.

  In a conventional image forming apparatus, when a jam occurs on a sheet being conveyed, a control for immediately stopping a clutch and a drive motor for transmitting drive to the conveyance system is common. Then, a sheet stopped on the conveyance path is detected by a sensor arranged to detect the passage of the sheet, and a unit of the conveyance path to which the sensor belongs is displayed on the display unit. Accordingly, the user is configured to remove the stopped jam sheet.

  In recent years, in order to improve the removability of a sheet when a jam occurs, a sheet conveying path is divided into a plurality of units, and an apparatus in which these units are configured to be detachable from the apparatus body has begun to be provided. Yes.

JP-A-62-283348

  However, in the apparatus constituted by a plurality of units that can be attached to and detached from the apparatus main body as described above, if the conveyance drive system is immediately stopped when a jam occurs, it extends over both adjacent units that are detachably divided. One sheet may stop. At that time, when only one unit was pulled out, there was a problem such as the sheet being torn. Further, as the size of the apparatus is reduced, the sheet conveyance path is curved in a complicated manner, and it is difficult to remove the jammed sheet.

  Here, Japanese Patent Laid-Open No. 62-283348 (Patent Document 1) describes a configuration in which a sheet material is carried into a unit that is pulled out from the apparatus main body when a jam occurs. That is, a configuration is described in which the conveyance is continued until the entire sheet is wound around the transfer drum, instead of immediately stopping the sheet conveyance even when a jam occurs. As a result, the jam processing can be performed easily and quickly.

  The present invention solves the above-mentioned problem by another configuration, and stops the sheet at a position where it can be easily taken out on the sheet conveyance path when the sheet is jammed. An object of the present invention is to provide an image forming apparatus provided with this.

A typical configuration of the present invention for achieving the above-described objects includes a plurality of conveyance rollers that convey a sheet in a sheet conveyance path, a conveyance abnormality detection unit that detects a conveyance abnormality of the sheet in the sheet conveyance path, and constitutes a part outside of the apparatus can be pulled out transport unit of the sheet conveying path, and an image forming means for forming a toner image on a sheet in passing through the said transport unit, there is one of said plurality of transport rollers Te, Ri upstream side der in the transport unit, and said image forming means is disposed upstream of the position for forming an image on a sheet, registration rollers for feeding the sheet to the image forming unit, the conveyor anda stop control means for stopping the plurality of conveying rollers when the abnormality detection unit detects the abnormal conveyance of the sheet, said stop control means, the resist roller The way the transport unit is pulled out from the apparatus, stop and conveyed to the sheet on the downstream side is stopped while holding the trailing end of the sheet by the registration rollers while sandwiching only the rear end of the seat Te It is characterized by making it.

According to the present invention, since the conveyance is stopped so that the conveyance unit is pulled out with the rear end portion of the sheet held between the registration rollers, the sheet is reliably accommodated in the conveyance unit. For this reason, it is possible to reliably prevent the sheet from being damaged when pulling out the transport unit, and to easily remove the sheet after the transport unit is pulled out. Further, since the sheet is sandwiched, the sheet is not disturbed when the conveyance unit is pulled out, and is not left in the apparatus main body, so that damage to the sheet can be prevented more reliably. Further, when the sheet is removed after the conveyance unit is pulled out, the trailing edge of the sheet is held only by the registration roller. For example, the user moves the sheet in the downstream direction in the sheet conveyance direction and moves the registration roller. Therefore, the sheet can be easily removed.

  An embodiment of a copying machine adopting an electrophotographic system as an example of a sheet conveying apparatus and an image forming apparatus having the same will be specifically described with reference to the drawings. 1 is a schematic configuration diagram of a copying machine provided with a sheet conveying device, FIG. 2 is a block diagram of a control device of the copying machine provided with a sheet conveying device, FIG. 3 is a diagram showing an arrangement configuration of an operation panel, and FIG. FIG. 5 is a perspective view showing a detachable unit and an openable / closable unit provided in the apparatus main body, FIG. 6 is a perspective view showing an open / closed state of the upper right door unit, and FIG. FIG. 8 is a flowchart showing the control of the sheet feeding operation task, FIG. 9 is a flowchart showing the control of the sheet feeding task, and FIG. 10 is the control of the jam display task. FIG. 11 is a flowchart showing control of sheet removal processing, FIG. 12 is a flowchart showing control of a jam post-processing task, and FIG. 13 is a flowchart showing control of jam monitoring. It is over door.

  In FIG. 1, a copying machine 1 includes a circulation type automatic document feeder 2 (RDF) for automatically feeding a document, and an image forming apparatus main body 3. The automatic document feeder 2 is connected to the apparatus main body 3. Are combined.

  The apparatus main body 3 includes an original table glass 5 serving as an original table on an upper portion thereof, and an optical system 6 serving as an image reading unit below the original table glass 5. The optical system 6 includes an exposure lamp 6a, a scanning mirror 6b, a zoom lens 6c, and a motor (not shown). The exposure lamp 6a illuminates the original, and the reflected light from the original is irradiated to the photosensitive drum 7a serving as a toner image carrier by the scanning mirror 6b and the zoom lens 6c. There are the following two methods for irradiating the photosensitive drum 7a with the reflected light from the original. One method is to move the optical system 6 such as the exposure lamp 6a while the original is fixed on the platen glass 5, and to the original while the optical system 6 such as the exposure lamp 6a is fixed. There is a method of moving a document on the glass plate 5 (hereinafter referred to as “scanning”).

  Below the optical system 6, an image forming unit 7 as image forming means is arranged. The image forming unit 7 includes a photosensitive drum 7a that is rotatably arranged in the direction of arrow a, a high-pressure unit 7b that is arranged around the photosensitive drum 7a, a blank exposure unit 7c, a potential sensor 7d, and a developing device. 7e, a transfer charger 7f, a separation charger 7g, and a cleaning device 7h. The photosensitive drum 7a is rotationally driven by a main motor (not shown) and is corona-charged by the high-voltage unit 7b. Then, the reflected light of the original is irradiated from the optical system 6 to form an electrostatic latent image. The electrostatic latent image is developed by the developing device 7e and visualized as a toner image.

  On the other hand, the lower part of the apparatus main body 3 is provided with a feeding cassette 9 of a first cassette 9a, a second cassette 9b, a third cassette 9c, and a fourth cassette 9d. The cassettes 9a to 9d are provided with pickup rollers 10a to 10d for feeding out the sheets S accommodated therein. Further downstream, separation roller pairs 11a to 11d for separating and feeding the sheets S respectively fed by the pickup rollers 10a to 10d are arranged, and the uppermost sheet S is separated one by one. The separated sheet S is conveyed to a registration roller 13 provided in front of the image forming unit 7 by conveyance rollers 12a to 12d arranged further downstream.

  In the vicinity of the image forming unit 7, a multi-manual feeding device 14 for manually feeding the sheet S to the image forming unit 7 is disposed. Further, downstream of the image forming unit 7, a conveyance belt 15 that conveys the image-formed sheet S further downstream, and a fixing device 16 that serves as a fixing unit are provided. The fixing device 16 fixes the toner image on the sheet S by heating and pressing the sheet nipped and conveyed by the fixing rollers 16a and 16b. A discharge flapper 17 is provided in the vicinity of the downstream side of the fixing device 16, and a discharge path A 1 for discharging the sheet S to the outside of the apparatus main body 3 and double-side recording or recording on one sheet S. The mode is appropriately switched to the re-transport route A2 when performing multiplex recording. A discharge roller 19 is provided in the discharge path A1.

  A transport path 20 connected to the re-transport path A2 is provided below the fixing device 16. Downstream of the transport path 20, a temporary storage tray 23 that temporarily stores the sheet S that has been transported after image formation, a temporary storage tray discharge roller 21 that discharges the sheet S thereto, and a temporary storage tray 23. A discharge sensor 22 is provided for detecting the sheet S discharged to the front. The discharge sensor 22 also functions as a sheet detection unit that detects the passage of the sheet S and a conveyance abnormality detection unit that detects a conveyance abnormality of the sheet S. In the vicinity of the discharge sensor 22, a refeed device 34 that sequentially refeeds the sheets S stored in the temporary storage tray 23 is provided.

  In the vicinity of the feeding opening of the temporary storage tray 23, a refeed roller 31 for refeeding the stored sheet S is disposed. Further, a refeed / send roller 32 and a refeed / separation belt 33 are in contact with the downstream side, so that the sheets S are separated and re-fed one by one. As shown in FIG. 1, the temporary storage tray 23 has a structure inclined at a predetermined angle to assist in reaching the refeed separation belt 33 when the stored sheet S is refeeded. ing.

  Near the downstream side of the refeed / feed roller 32 and the refeed separation belt 33, a multiple flapper 36 is disposed. A reverse conveyance path 37 and a conveyance path 39 are provided downstream of the multiple flapper 36. The reverse conveyance path 37 extends upward, and the image of the conveyed sheet S is recorded so that multiple images are recorded on the recording surface of the sheet S when performing multiple recording on one recording surface of the sheet S. This is to reverse the forming surface once. The conveyance path 39 extends downward, and is used for reversing the image forming surface of the sheet S and conveying the other recording surface to the image forming unit 7 again when performing double-sided recording. Then, the sheet S is conveyed to the reverse conveyance path 37 or the conveyance path 39 by appropriately switching the multiple flapper 36 according to the recording purpose.

  Conveying rollers 40a to 40d are sequentially arranged in the conveying path 39. Further, at a predetermined position on the sheet conveyance path disposed in the apparatus main body 3, there is a sheet detection unit that detects the passage of the sheet S, and a conveyance abnormality detection unit that detects a conveyance abnormality of the sheet S in the sheet conveyance path. Sensors 50 to 58 that also serve as the above are disposed.

  FIG. 2 shows a block diagram of the control device. The control device 100 controls the entire apparatus of the copier 1, but as a control program procedure or module, a sheet conveyance control means, a stop control means for forcibly stopping a transfer sheet during image formation, and the like. Implementing means. The control device 100 includes a CPU 101 that controls the entire copying machine 1 in accordance with control means stored in a read-only memory (ROM 102), a ROM 102 that stores a control procedure (control program) of the control device 100, storage of input data, Random access memory (RAM 103) which is a main storage device used as a working storage area, etc., and input / output of control signals from the CPU 101 to driving means such as a main motor, and signals from sensors and the like to be sent to the CPU 101 Processor 104 (I / O) and the like.

  FIG. 3 shows an arrangement configuration example of the operation panel 200 provided in the apparatus main body 3. In FIG. 3, the user mode key 601 indicates that the operator (user) is ON / OFF for automatic sorting, ON / OFF for front-side sorter, ON / OFF for both sides of skipping, ON / OFF for feeder manual feed auto start, and cassette auto Selection ON / OFF, buzzer ON / OFF setting, slightly smaller mode change, preheat mode setting, specification setting initialization, standard mode change, auto clear time change, auto power off time change, weekly timer , Setting of day / time, zoom fine adjustment, feeder cleaning, wire cleaning, etc.

  The all reset key 610 is pressed when returning to the standard mode. A copy start key 605 (copy start key) is pressed to start copying. A clear key 604 is used to cancel the set number of copies. A stop key 609 is pressed to interrupt continuous copying. After copying at the time when this key is pressed, the copying operation of the apparatus is stopped.

  A numeric keypad 608 is pressed to set the number of copies. A guide key 602 is used to display a description of functions corresponding to various keys on the message display 615. The preheating key 607 is pressed when the preheating mode is set. This key is a self-illuminating key provided with a light emitting element such as a light emitting diode, and is lit in the preheating mode.

  The interrupt key 606 is interrupted during a copying operation and is pressed when making another copy. This key is also a self-illuminating key, similar to the preheating key 607 described above, and is lit when an interrupt is accepted, and remains lit during interrupt copying.

  The message display 615 is display means for displaying the operation procedure of the apparatus. The message display 615 has an LCD (liquid crystal) type touch panel and displays characters and figures with 240 × 320 dots to display various information regarding copying.

  In the standard state, the message display 615 is set to a standard scaling key, equal magnification key, zoom key, slightly smaller key, sheet selection key, copy density key, sorter key for selecting the sorter function, and duplex copy mode. In addition to double-sided keys for copying, frame erase, binding margin, cover / interleaf, reduced layout, enlarged layout, OHP sheet insertion, continuous page copying, multiple copies, mixed originals, photographs, mode memory, etc. An application mode key for setting a mode is displayed. When a portion corresponding to each key is touched, a window related to the content is further displayed. In addition, an operation procedure when a sheet is jammed or an error is displayed.

  FIGS. 4A to 4F are explanatory diagrams of the document reading operation by flow reading. First, when the document D is set on the automatic document feeder 2 (see FIG. 4A) and the copy start key 605 is turned on, the second document D2 in which the automatic document feeder 2 is positioned at the lowest position is displayed in FIG. While feeding to the document reading unit 4 from the right side of a), the apparatus body 3 moves the optical system 6 to the center of the document table glass 5, and locks the optical system 6 by an optical system locking means (not shown) (FIG. 4 ( b)).

  When the second document D2 is transported to just before the optical system 6 (see FIG. 4C), the automatic document feeder 2 sends an image signal to the apparatus body 3, and the apparatus body 3 turns on the exposure lamp 6a. The registration roller 13 is controlled in accordance with the image signal (see FIG. 4D).

  At this time, the first document D1 placed on the second document D2 is fed to the document reading unit 4 from the right side of the figure following the second document D2, and is supplied to the second document D2. Subsequently, the first document D1 is exposed, and the second document D2 is discharged from the left side of the drawing (see FIG. 4E). Then, the optical system 6 returns to the home position, and the first document D1 is discharged from the left side of the drawing (see FIG. 4F).

FIG. 5 divides the sheet conveyance path in the apparatus main body 3 as a plurality of conveyance units, and each of these conveyance units constitutes a part of the sheet conveyance path and can be attached to and detached from the apparatus main body 3 or can be opened and closed. It is a perspective view which shows an example comprised. 6 is a perspective view showing an open state of the upper right door unit 311 in FIG. 5, and FIG. 7 is a perspective view showing a state in which the fixing conveyance unit 301 in FIG.

  As shown in FIGS. 5 to 7, the fixing conveyance unit 301 is integrated with the parts from the registration roller 13 to the discharge roller 19. The fixing and conveying unit 301 includes a plurality of sheet conveying means such as a registration roller 13, a conveying belt 15, and a discharge roller 19, but the first sheet disposed on the upstream side in the conveying direction inside the fixing and conveying unit 301. The registration roller 13 corresponds to the conveying means. In the temporary storage tray unit 302, the temporary storage tray 23 and the refeed device 34 are integrated. The refeed conveyance unit 303 is integrated with conveyance rollers 40 a to 40 d for conveying the sheet S re-fed from the temporary storage tray 23. The sheet feeding cassette units 304 to 307 include the first to fourth cassettes 9a to 9d, respectively. Each of the units is configured so as to be integrated and pulled out forward (front side in the figure) and detachable from the apparatus main body 3.

  In addition, the manual cover unit 310 is configured to be able to open and close the conveyance path of the multi manual feeder 14. The upper right door unit 311 and the lower right door unit 312 are configured to be able to be opened and closed by dividing the conveyance path extending upward from the apparatus main body 3 on which the conveyance rollers 12a to 12d are arranged. The manual feed cover unit 310 and the door units 311 and 312 can be opened and closed with the back side in the figure as a fulcrum.

  As described above, each unit is configured to be detachable or openable / closable with respect to the apparatus main body 3, and includes a unit detachment detecting means and a unit opening detecting means (not shown) for detecting that each unit has been detachably attached or opened. ing. The removal / release state of each unit detected by these detection means is transmitted to the control device 100.

  The control device 100 includes unit recognition means (not shown) inside, and detects the unit at which the sheet S is currently located in response to detection information from the sensors 22 and 50 to 58 described above. In addition, when a conveyance abnormality occurs in the sheet S conveyed in each unit, the control device 100 recognizes the unit to which the sheet S in which the conveyance abnormality has occurred and also displays a message display 615 (LCD) on the operation panel 200. ) And instruct the optimal processing procedure.

  Next, the control system of the copying machine 1 configured as described above will be described in detail. FIG. 8 is a flowchart of a control task for controlling the sheet S feeding operation of the apparatus body 3. First, when the copy start key 605 is turned on, a sheet feeding task for controlling the conveyance of the sheet S is activated (step S101). Then, the position count value Cc corresponding to the position where the sheet feeding cassette units 304 to 307 are arranged on the sheet conveyance path is set in the position counter C of the sheet feeding task (step S102).

  The position counter C is a sheet position counter that recognizes the current position (front end position) of the sheet S on the sheet conveyance path in the apparatus main body 3, and sets the position of the registration roller 13 to “0” on the upstream side (sheet feeding). Side) takes a negative value, and the downstream side (sheet discharge side) takes a positive value. The position counter C is counted up by an encoder clock or an internal timer clock of a main motor (not shown) that drives a conveying means such as a conveying roller arranged on the sheet conveying path in the apparatus main body 3, Is processed by In the position counter C counted up by the encoder clock, the count value Cc corresponding to the position where the sheet feeding cassette units 304 to 307 are arranged is from the position of the sheet feeding cassette units 304 to 307 to the registration roller 13. A value obtained by dividing the actual distance in the conveyance path by the movement distance per pulse of the encoder clock is set. The position counter C is configured to indicate a value calculated in the same manner as the above setting method.

  Next, the value obtained by subtracting the position count value Cc corresponding to the arrangement position of the sheet feeding cassette units 304 to 307 from the count value Cp of the position counter C in the previous sheet feeding task control is fed on the sheet conveyance path. It waits until it becomes larger than the count value Cb corresponding to the sheet interval distance between the preceding sheet and the succeeding sheet (step S103). If there is a request for feeding the next sheet S, the next sheet feeding task is started (step S101), and if there is no request for feeding the next sheet S, the sheet feeding task is ended.

  Next, a specific operation of the sheet feeding task will be described. FIG. 9 is a flowchart illustrating the operation of the sheet feeding task. First, when the sheet feeding task is activated, it is checked whether the sheet S passes any one of the sensors 22 and 50 to 58 disposed on the conveyance path (step S201). When any one of the sensors 22, 50 to 58 passes, the value of the position counter C is corrected (updated) to an absolute position counter value Ca corresponding to the arrangement position of the sensors 22, 50 to 58 (step S202). Further, the conveying means such as the conveying roller to be driven next disposed on the sheet conveying path is turned on, and the conveying means such as the conveying roller already passed is turned off (step S203).

  Next, the sensors 22 and 50 to 58 check whether or not a jam has occurred in the sheet S being conveyed (step S204). When a jam occurs on the sheet conveyance path, the current value Cx of the position counter C is determined based on the fixing conveyance unit 301, the temporary storage tray unit 302, the refeed conveyance unit 303, the sheet supply on the sheet conveyance path. Which position of each unit such as the feeding cassette units 304 to 307, the manual feed cover unit 310, the upper right door unit 311 and the lower right door unit 312 belongs is calculated (step S205).

  The sheet stop position determining means provided in the control device 100 determines the optimum stop position of the sheet S based on the count information of the position counter C, and is set in advance optimally for the sheet S to stop in the unit to which it belongs. The stop position count value Cs of the position counter C corresponding to the set position is output. Then, the current position count value Cx is subtracted from the stop position count value Cs (step S206), and the process waits for the difference position count value Cd corresponding to the difference to elapse (step S207). Thereafter, the stop control unit turns off the conveyance unit such as the conveyance roller being driven to stop the sheet S at a predetermined stop position (step S208). After stopping the sheet S that is the cause of the conveyance abnormality, the stop control unit similarly sequentially stops the sheets positioned on the upstream side in the sheet conveyance direction from the sheet S stopped in the sheet conveyance path.

  In other words, the sheet conveying apparatus according to the present embodiment recognizes the current position of the sheet by the position counter indicating the absolute position of the sheet on the sheet conveying path when the conveyance abnormality detecting unit detects the conveyance abnormality of the sheet, and stops the sheet. Position determining means determines an optimum stop position of the sheet. Then, the stop control means stops the sheet at the stop position determined by the sheet stop position determining means. Thereby, the sheet can be stopped at the optimum stop position.

  For example, the sheet S immediately before the registration roller 13 or the sheet S passing through the registration roller 13 is stopped in a state where the vicinity of the rear end of the sheet SR is sandwiched between the registration rollers 13 as shown in FIG. Since the rear end of the sheet SR is stopped at a position where the trailing end of the sheet SR completely enters the fixing conveyance unit 301 shown in FIG. 1, the sheet SR is not damaged even if the fixing conveyance unit 301 is pulled out. Further, since the sheet SR stops while being sandwiched by the registration rollers 13, when the fixing conveyance unit 301 is pulled out, the sheet SR is surely pulled out together with the fixing conveyance unit 301 without being exposed, and is adsorbed by the photosensitive drum 7a. And does not remain on the main body. Further, since only the vicinity of the rear end of the sheet SR is sandwiched between the registration rollers 13, for example, the user can easily remove the sheet SR by moving the sheet SR in the downstream direction in the sheet conveyance direction.

  Even if the sheet SR is the maximum length in the sheet conveyance direction among the sheets S used in the image forming apparatus, when the sheet SR stops at a predetermined stop position, By setting the distance between the registration roller 13 and the fixing rollers 16a and 16b so that the leading ends are not sandwiched between the fixing rollers 16a and 16b, the removal of the sheet SR becomes easy. Even when the distance between the registration roller 13 and the fixing rollers 16a and 16b is relatively short, the fixing rollers 16a and 16b are stopped before the leading edge of the sheet SR reaches the fixing rollers 16a and 16b. Also good. In that case, when the sheet SR is stopped at a predetermined stop position, the sheet SR is curved between the fixing device 16 and the photosensitive drum 7a.

  Next, it is checked whether or not there is a succeeding sheet S upstream from the stopped sheet S (step S209). If there is a subsequent sheet S, the occurrence of jamming of the preceding sheet S is notified to the sheet feeding task of the subsequent sheet S (step S210). If there is no subsequent sheet S, it is checked whether or not the current position count value Cx has passed the count value Ci of the position counter C corresponding to the arrangement position of the separation charger 7g (step S211).

  When the current position count value Cx passes the arrangement position count value Ci of the separation charger 7g, the primary charge, the developing bias, the post charge, the transfer charge, and the separation charge are turned off in this order. Post-rotation control for high pressure is started (step S212), control is transferred to the next task, and the sheet feeding task is terminated. This task is activated for a certain time or as needed.

  Next, display control displayed on the operation panel 200 when a jam of the sheet S on the sheet conveyance path occurs will be described. FIG. 10 is a flowchart for controlling the jam display task. When a jam occurs in the sheet S conveyed on the sheet conveyance path, a jam display task is activated. First, the sheet feeding task described above is the number n of sheets S remaining on the sheet conveyance path in the apparatus main body 3 (excluding the number of sheets S normally stored in the sheet feeding cassette units 304 to 307). The sheet removal task count Tn (n times) related to the jam processing is calculated from the information (step S301).

  Then, the number Ui of each unit on the sheet conveyance path where each sheet S is stopped is calculated (step S302). This unit number Ui is a first unit number and a second unit number that determine the priority order of jam processing in the case where the sheet S is inevitably stopped between adjacent units for some reason. These two unit numbers are assigned.

  For example, the sheet S stopped immediately before the registration roller 13 is the first unit number in which the jam processing for the upper right door unit 311 shown in FIG. 6 is the priority processing order, and the jam processing for the fixing conveyance unit 301 shown in FIG. Is the second unit number in post-processing order. In other words, by instructing the operator to preferentially process the unit corresponding to the first unit number, the jammed sheet S can be efficiently and easily removed.

  Next, it is determined whether or not there is a unit Up to be removed preferentially. This is because if the sheet S of the priority unit Up is not removed first, the sheet S to be removed is damaged, the stop position of the jammed sheet S or the like cannot be accurately determined, or unavoidably adjacent. This is advantageous when the sheet S stops between the units.

  First, “1” is set to a temporary variable i for counting the number n of removed sheets S remaining on the sheet conveyance path in the apparatus main body 3 (step S303). While determining that the temporary variable i reaches the number n to be removed (step S304), it is checked whether or not it is a preset priority unit Up (step S305). If it is a priority unit Up, the priority unit Up presence flag is set (step S306), the temporary variable i is incremented (sequentially adding “1”) (step S307), and the sheet is removed by Tn times corresponding to the number n of removal. Repeat the task. If the above-mentioned priority unit Up presence flag is set (step S308), a sheet removal process described later is executed (step S309), and the sheets S to be preferentially removed are sequentially removed.

  Next, the removal process is similarly performed on the remaining sheets S. First, “1” is set to the temporary variable i (step S310). While determining that the temporary variable i reaches the number n to be removed (step S311), a sheet S removal process described later is executed (step S312), and the temporary variable i is incremented (sequentially adding “1”) (step S313). ). When the sheet removal task is repeated Tn times corresponding to the number n of removed sheets, the sheet removal task control operation is terminated.

  Next, the sheet S removal process will be described. FIG. 11 is a flowchart showing the control of the sheet removal process. The display order determining means provided in the control device 100 determines the display order of the jam processing target units recognized by the unit recognition means described above, and the display control means operates the display means to cause a jam processing procedure on the message display 615. Is displayed.

  First, a display for prompting jam processing of the first unit number that is the priority processing order is displayed on the message display 615 (LCD) of the operation panel 200 (step S401), and the operator attaches / detaches or opens / closes the first unit. (Step S402). When the first unit is detached or opened / closed, the sensor provided in the first unit can detect the sheet S, that is, before the first unit is detached or opened / closed, Detects whether the sheet S is detected and whether the sensor is turned off by attaching / detaching or opening / closing the first unit (step S403).

  If the detection of the sensor is valid and the sensor is OFF, the operator recognizes that the sheet S has been removed and the removal of the sheet S has been completed, and the control of the sheet removal process ends. In other states, that is, when the detection of the sensor is not effective or the sensor is ON, it is recognized that the removal of the sheet S is incomplete. In this case, in step S404, it is checked whether or not the second unit number that is the post-processing order is set (step S404). If the second unit number is not set, the sensor detection is performed. Is valid (step S405), and if the detection of the sensor is valid, it waits for the first unit to be detached or opened again (step S402).

  If the second unit number is set, a message prompting the processing of the second unit number is displayed on the message display 615 of the operation panel 200 (step S406), and the operator detaches the second unit. Or it waits for opening and closing (step S407). When the second unit is attached / detached / opened / closed, the sensor in the second unit detects the sheet S and checks whether the sensor is turned off by attaching / detaching / opening / closing the second unit. (Step S408).

  If the sensor can detect the sheet S and the sensor is OFF, it is recognized that the removal of the sheet S is completed as described above, and the control of the sheet removal process is ended. In other states, that is, when the detection of the sensor is not effective or / and the sensor is ON, it is recognized that the removal of the sheet S is incomplete. In this case, in step S409, it is determined whether or not the detection of the sensor is effective. If the detection of the sensor is not effective, it is recognized that the removal of the sheet S is completed, and control of the sheet removal processing is performed. Exit. If the detection by the sensor is valid, the process waits for the second unit to be attached or detached again (step S407).

  Next, jam post-processing task control for reusing the sheet S remaining in the temporary storage tray 23 when a jam occurs will be described. FIG. 12 is a flowchart of the jam post-processing. When the unit recognition means recognizes that the sheet S remains in the temporary storage tray 23, the display control means provided in the control device 100 operates the display means on the message display 615. The sheet S in the temporary storage tray 23 is displayed to be processed.

  First, it is checked whether or not the sheet S remains in the temporary storage tray 23 (step S501). If the sheet S does not remain in the temporary storage tray 23, normal recovery data is calculated (step S506). To do.

  Further, if the sheet S remains in the temporary storage tray 23, it is checked whether or not the temporary storage tray 23 has been detached after all the jam processing (step S502). If the temporary storage tray 23 has been removed, the process display of the temporary storage tray 23 is displayed (step S503), and waiting for the temporary storage tray 23 to be removed by the operator (step S504). After the temporary storage tray 23 is attached and detached, the processing display is repeated until there is no sheet S in the temporary storage tray 23 (step S505), and when there is no sheet S in the temporary storage tray 23, recovery data is calculated (step S506). ), The jam post-processing task control operation is terminated. When the operator removes the temporary storage tray 23 in spite of the state where the sheet S in the temporary storage tray 23 can be reused, the processing is displayed as being unusable.

  Next, the control of the monitoring unit that monitors the occurrence of a jam, particularly the control when the copy operation is in the flow-reading mode will be described. FIG. 13 is a flowchart of jam monitoring control. First, the process waits for the copy start key 605 to be pressed (step S601). When the copy start key 605 is pressed, it is determined from the document size, the copy magnification, and the like whether or not the scanning operation is possible (step S602).

  Then, if the flow reading operation is possible, the flow reading mode flag is set (step S603). If the flow reading mode flag is set (step S604), the detection unit (not shown) monitors occurrence of a jam in the circulation type automatic document feeder 2 (RDF) (step S605). If a jam occurs in the automatic document feeder 2, the sheet feeding task during image formation is notified that a jam has occurred (step S606). Monitoring is continued until the copying is completed (step S607), and when the copying is completed, the monitoring unit ends the operation for monitoring the occurrence of a jam.

  That is, when a jam occurs in the automatic document feeder 2 in the flow reading mode, the jamming is forcibly stopped with respect to the sheet S during image formation corresponding to this document, so that the image formation is not completed. It is possible to prevent the sheet S from being discharged outside the apparatus.

  The present invention can be used in an image forming apparatus that forms an image by conveying a sheet.

1 is a schematic configuration diagram of a copying machine including a sheet conveying device. FIG. 3 is a block diagram of a control device of a copying machine including a sheet conveying device. It is a figure which shows the arrangement configuration of an operation panel. It is explanatory drawing of the original reading operation | movement by flow reading. It is a perspective view which shows the detachable unit with which the apparatus main body was equipped, and the unit which can be opened and closed. It is a perspective view which shows the open state of an upper right door unit. FIG. 6 is a perspective view illustrating a state in which the fixing conveyance unit is pulled out and detached from the apparatus main body. 10 is a flowchart illustrating control of a sheet feeding operation task. 10 is a flowchart illustrating control of a sheet feeding task. It is a flowchart which shows control of a jam display task. It is a flowchart which shows control of a sheet removal process. It is a flowchart which shows control of a jam post-processing task. It is a flowchart which shows control of jam monitoring.

Explanation of symbols

A1 ... discharge path A2 ... reconveying path C ... position counter D ... document S ... sheet 1 ... copying machine 2 ... automatic document feeder 3 ... image forming apparatus body 4 ... document reading section 7 ... image forming section 9 ... feeding cassette
13… Registration roller
16… Fixer
22… discharge sensor
23… Temporary storage tray
34… Refeed device
50-58 ... Sensor
100 ... Control device
200… Operation panel
301… Fixing transport unit
302… Temporary storage tray unit
303… Re-feed transport unit
304 to 307 ... Sheet feeding cassette unit
310… Bypass cover unit
311… Upper right door unit
312… Lower right door unit
615 Message display

Claims (4)

A plurality of conveying rollers for conveying the sheet in the sheet conveying path;
A transport abnormality detection means for detecting abnormal conveyance of sheets of the sheet conveying path,
A transport unit which can be pulled out partially constructed device outside of the sheet conveying path,
Image forming means for forming a toner image on a sheet passing through the conveying unit;
A one of said plurality of transport rollers, the transport direction upstream side der in the transfer unit is, is and disposed on the upstream side of a position where the image forming unit forms an image on a sheet, said image forming means A registration roller that feeds the sheet to
Stop control means for stopping the plurality of transport rollers when the transport abnormality detecting means detects a sheet transport abnormality,
It said stop control means, wherein the registration roller to the conveyance unit while holding the only trailing end of the sheet is pulled out from the apparatus, in order to stop while holding the trailing end of the sheet at the registration roller An image forming apparatus, wherein a sheet is conveyed downstream and stopped . It said image forming means comprises a toner image bearing member for bearing a toner image to be transferred to a sheet, a fixing unit configured to fix the toner image on the sheet,
The stop control means is configured so that the conveyance unit is pulled out of the apparatus in a state where only the rear end portion of the sheet is sandwiched by the registration rollers when the conveyance abnormality detection means detects the conveyance abnormality of the sheet. The image forming apparatus according to claim 1, wherein the image forming apparatus is stopped in a state where the trailing edge of the sheet is held by a roller, and the fixing unit is stopped before the sheet reaches the fixing unit. It said image forming means comprises a toner carrying member for carrying a toner image to be transferred to a sheet,
Fixing means for fixing the toner image to a sheet;
The distance between the registration roller and the fixing unit is such that the leading end of the sheet is upstream of the fixing unit in the sheet conveying direction, with the trailing end of the sheet having the longest conveying direction held between the registration rollers. The image forming apparatus according to claim 1, wherein the image forming apparatus is set so as to be positioned in the position.   The image forming apparatus according to claim 2, wherein the fixing unit is provided in the transport unit.

Images