JP2014202924A - Image forming apparatus, image forming system, and image forming control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To convey a sheet, which has been stopped due to a trouble, again without trouble.SOLUTION: An image forming apparatus includes: an image forming unit 150 which forms an image on a sheet; a conveyance unit 110 which conveys the sheet according to image forming operation; a detection unit 107 which detects a position of the sheet moving on a conveyance path of the conveyance unit and abnormal conveyance of the sheet; a control unit 101 which controls image formation and conveyance on the basis of a detection result of the detection unit. When the detection unit detects an abnormal condition and the sheet position detected by the detection unit corresponds to a preset re-conveyance prohibited position, the control unit 101 controls the sheet to continue moving as long as it is located in the re-conveyance prohibited position, and controls the sheet to stop moving when the sheet exits the re-conveyance prohibited position.

Description

  The present invention relates to an image forming apparatus, an image forming system, and an image forming control method, and in particular, purge processing is ensured by appropriately handling residual paper when residual paper remains in the apparatus or system when an abnormality occurs. It relates to technology that can be implemented.

  When an abnormality such as a paper jam occurs at any position in the image forming apparatus such as a copying machine, a printer, a facsimile machine, or a printing machine, the purge process is performed after the operation of the image forming apparatus is stopped. For example, there is a technique for collecting and discharging residual paper remaining in the image forming system in one paper discharge tray.

  Also, in the case of performing image formation using a large amount of paper, etc., after removing the paper in which an abnormality has occurred, it is possible to continue from the image formation on the page in which the abnormality has occurred, following the paper before the occurrence of the abnormality. It has also been proposed to eliminate the waste of paper by performing the image formation.

  As processing related to such abnormalities as paper jams, techniques related to the following patent documents have been proposed.

JP-A-10-152246 Japanese Patent Laid-Open No. 02-163244

  In the above Patent Document 1, when trouble such as a paper jam occurs, in order to minimize waste paper and downtime, when the trouble of the apparatus occurs, the apparatus drive including each transport unit based on the trouble detection signal. Is temporarily stopped, and when the driving of the apparatus is resumed, the recording material existing in the image forming conveyance unit is discharged out of the apparatus, and the image forming process is restarted from the recording material existing in the paper feeding conveyance unit. Yes.

Note that when trouble occurs, control is performed so that the paper position is temporarily stopped without considering the paper position and then purge processing is performed, but re-conveyance from the stop position is not taken into consideration.
In the above cited document 2, when a jam is detected, the paper transport system drive motor is stopped based on the off-timer value corresponding to the copy mode and the number of panel pitch divisions, so that the paper behind the jam paper slides. It has been proposed to prevent stopping between units.

Although the stop between the slide units is prevented, no consideration is given to the stop at other places and the re-conveyance from the stop place.
As a result of repeated investigations by the inventors of the present application, when a trouble occurs and the paper is temporarily stopped without considering the paper position, damage (curl, wrinkle, folding) of the paper staying at the stop position increases. As a result, it has been found that troubles such as jams may occur again when re-conveyance is started for the purge process.

However, in the conventional proposal, it is not considered that the re-transfer start is surely executed in such a situation.
The present invention has been made in view of such a problem, and can form an image forming apparatus, an image forming system, and an image forming control capable of re-transporting a sheet stopped when a trouble occurs without causing a trouble again. The aim is to realize the method.

That is, the present invention for solving the above-described problems is as follows.
(1) The present invention provides an image forming unit that forms an image on a sheet, a conveying unit that conveys the sheet according to an image forming operation, a position of the sheet that moves on a conveying path of the conveying unit, and the An image forming apparatus comprising: a detection unit that detects a paper conveyance abnormality; and a control unit that controls image formation and conveyance based on a detection result of the detection unit, wherein the control unit includes the detection unit If the paper position detected by the detection unit corresponds to a predetermined non-retransportable position when the abnormality is detected in step S1, the movement is performed while the paper is in the non-retransportable position. And the movement of the paper is stopped when the paper leaves the non-re-carryable position.

  (2) In the above (1), the control unit moves the sheet based on whether or not the leading end region in the sheet conveyance direction detected by the detection unit corresponds to the non-reconveyable position. Control whether to continue or stop.

  (3) In the above (1)-(2), the transport unit is configured to include a connecting unit that is connected from one transport path to the other transport path, and the re-transport disabled position is the connection The control unit determines that the leading end region in the transport direction determined according to the transport direction length of the coupling unit is the non-retransportable position among the sheets detected by the detection unit. Based on whether or not this is the case, it is controlled whether to continue or stop the movement of the sheet.

  (4) In the above (1)-(2), the transport unit is configured to have a curved portion that transports the paper in a curved shape or an arc shape toward the transport direction, and the non-re-transportable position is , And determined based on the position and curvature of the music part.

  (5) In the above (1)-(2), the image forming unit includes a fixing unit that fixes a visible image on a sheet, and the sheet is fixed in the non-re-conveyable position. It is determined based on the position held between the parts.

  (6) In the above (1)-(2), the transport unit includes a transport path switching unit that switches a plurality of different transport paths. Defined by position.

  (7) In the above (1)-(2), a pair of rollers having different characteristics for sandwiching the paper is provided at any position of the transport unit. It is determined based on the position sandwiched between the pair.

  (8) In the above (1)-(2), a plurality of drive rollers that are driven by different driving sources and transport the paper are provided at any position of the transport unit, and the re-transport disabled position is The position is determined based on the position where the sheet moves while straddling a plurality of driving rollers driven by different driving sources.

  (9) In the above (1) to (8), when the abnormality is detected, the control unit performs the preceding conveyance that moves in advance with respect to the non-re-conveyable position sheet existing at the non-re-conveyable position. If there is a sheet or a succeeding transport sheet that moves subsequently, and if the preceding transport sheet or the succeeding transport sheet can be moved to move the unretransportable position sheet, Control is performed to move the preceding transport sheet or the succeeding transport sheet so that the unconveyable position sheet can be moved.

  (10) In the above (1) to (9), the transport unit has a function of discharging the paper out of the image forming apparatus, and the control unit moves the paper in a position other than the non-re-transportable position. Then, control is performed so that the sheet remaining in the image forming apparatus and transportable is discharged.

According to each aspect described above, the following effects can be obtained.
(1) In the present invention, when an abnormality is detected by the detection unit, if the position of the sheet detected by the detection unit corresponds to a predetermined non-retransferable position, the sheet cannot be re-transported. Control is made to continue movement while the paper is in the position, and control is made to stop the movement of the paper when the paper leaves the non-re-carryable position. It becomes possible to carry again without generating.

  (2) In the above (1), whether to continue or stop the movement of the sheet is controlled based on whether or not the leading end area in the sheet conveyance direction detected by the detection unit corresponds to a non-re-conveyable position. As a result, regarding the re-transport trouble that is likely to occur at the front end of the paper, the paper stopped when the trouble occurs can be re-transported without causing any trouble again.

  (3) In the above (1)-(2), it is configured to include a connecting portion connected from one transport path to the other transport path, and the re-transport disabled position is determined based on the position of the connecting portion. And the movement of the paper is continued based on whether or not the leading end region in the transport direction determined according to the transport direction length of the connecting portion of the paper detected by the detection unit corresponds to the non-retransportable position. In order to control whether to stop or to stop, it is possible to re-transport the paper stopped at the time of occurrence of the trouble without causing the trouble again with respect to the trouble of re-conveying in which the leading end of the paper is likely to occur in the connection region of the conveying path.

  (4) In the above (1)-(2), the transport unit is configured to have a curved portion that transports the paper in a curved shape or an arc shape in the transport direction, and the non-retransportable position is a curved portion. By determining the position based on the position and the curvature of the sheet, it is possible to re-transport the paper stopped when the trouble occurs without causing a trouble again, regarding the trouble of the paper re-transport that is likely to occur at the curved portion of the transport unit.

  (5) In the above (1)-(2), the image forming unit is configured to include a fixing unit that fixes the visible image on the sheet, and the sheet is held between the fixing unit at the non-reconveyable position. By determining the position based on the position, the sheet that has been stopped when the trouble occurs can be re-transported again without causing any trouble, with respect to the trouble of re-transporting the sheet that is likely to occur at the fixing position of the fixing unit.

  (6) In the above (1)-(2), the conveyance unit is configured to include a conveyance path switching unit that switches a plurality of different conveyance paths, and the re-conveyance impossible position is determined by the position of the conveyance path switching unit. As a result, regarding the trouble of paper re-conveying that is likely to occur in the switching section of the plurality of conveying paths, it becomes possible to re-convey the paper that has stopped when the trouble occurs without causing trouble again.

  (7) In the above (1)-(2), a pair of rollers having different characteristics for sandwiching a sheet is provided at any position of the transport unit, and the sheet is sandwiched between the pair of rollers at a non-re-transportable position. By determining the position based on the position, it is possible to re-transport the paper stopped when the trouble occurs without causing the trouble again with respect to the trouble of the re-transport of the paper that is likely to occur at the different characteristic roller pair clamping position.

  (8) In the above (1)-(2), a plurality of driving rollers that are driven by different driving sources and transport the paper are provided at any position of the transport unit. By determining the position based on the position where the sheet moves while straddling a plurality of drive rollers driven by the source, the sheet that has been stopped when the trouble occurs can be re-established with respect to the trouble of sheet re-conveying that tends to occur at a position straddling different drive sources. It becomes possible to carry it again without causing any trouble.

  (9) In the above (1) to (8), when the abnormality is detected, the preceding conveyance sheet that moves in advance or the subsequent movement with respect to the non-reconveyable position sheet that exists in the non-retransferable position In the case where there is a subsequent transport sheet to be moved, and the movement of the non-retransportable position paper becomes possible by moving the preceding transport sheet or the subsequent transport sheet, the non-retransportable position sheet can be moved. In this way, by controlling the movement of the preceding conveyance sheet or the subsequent conveyance sheet, it becomes possible to move the sheet without being obstructed by the preceding conveyance sheet or the subsequent conveyance sheet. It becomes possible to carry it again without doing it.

  (10) In the above (1) to (9), the transport unit has a function of discharging the paper to the outside of the image forming apparatus. By controlling to discharge the remaining paper that can be transported, it is possible to transport the paper that has been stopped when a trouble occurs again to the outside of the apparatus without causing any trouble again.

It is a block diagram which shows the structure of embodiment of this invention. It is a block diagram which shows the structure of embodiment of this invention. It is explanatory drawing explaining the operation state of embodiment of this invention. It is explanatory drawing explaining the operation state of embodiment of this invention. It is explanatory drawing explaining the operation state of embodiment of this invention. It is explanatory drawing explaining the operation state of embodiment of this invention. It is explanatory drawing explaining the operation state of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is explanatory drawing explaining the operation state of embodiment of this invention. It is explanatory drawing explaining the operation state of embodiment of this invention. It is explanatory drawing explaining the operation state of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a section lineblock diagram explaining an operation state of an embodiment of the present invention. It is explanatory drawing explaining an example of the information table used for embodiment of this invention. It is a conveyance schematic diagram explaining the operation state of embodiment of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an image forming apparatus, an image forming system, and an image forming control method that perform residual paper discharge control according to the present invention will be described below in detail with reference to the drawings.
[Configuration of image forming apparatus and image forming system]
Here, as a first example of the embodiment, a configuration of an image forming apparatus and an image forming system capable of re-feeding a sheet stopped when a trouble occurs without causing a trouble again is shown in FIGS. This will be described in detail.

  Here, a paper feeding device 50 that can feed a plurality of types of stored paper as needed, an image forming device 100 that forms an image on the paper, and various types of paper processing on paper that has been image-formed by the image forming device 100 Assume that the sheet processing apparatus 200 that performs (punch processing, half-folding processing, stapling processing, etc.) and discharges it is arranged along the flow of the sheet.

  The image forming apparatus 100 of this embodiment can be applied to various types of image forming apparatuses. Here, however, a composite having functions of a scanner, a copier, a printer, and a facsimile apparatus connected to a network. The description will be continued with a specific example of a machine (MFP) or a copying machine. Also, description of general portions that are known as the image forming apparatus 100 and are not directly related to the characteristic operation and control of the present embodiment is omitted.

The detailed configuration of each part of each apparatus will be described below with reference to FIG. 1 as a system configuration diagram and FIG. 2 as a cross-sectional configuration diagram of the image forming system.
The sheet feeding device 50 includes a control unit 51 that controls each unit in the sheet feeding device 50, a communication unit 52 for communicating with other connected devices, and a plurality of sheet feeding units 55a to 55b (see FIG. 2). ) And a paper feeding unit 55 that feeds the paper stored in the paper.

  The image forming apparatus 100 controls each unit in the image forming apparatus 100 and controls the entire system as an image forming system, a communication unit 102 for communicating with other connected apparatuses, and a user An operation display unit 103 that performs operation input by the user and a status display of the image forming apparatus 100, a storage unit 104 that stores various setting values, programs, and the like, and sheets stored in paper feed trays 105a to 105c (see FIG. 2). And a sensor 107 as a detection unit for detecting an abnormality in an image formed on the sheet and a sheet conveyance condition (such as a sheet position and a sheet passage timing (carrying delay during conveyance)). A conveyance unit 110 that conveys paper in the apparatus, a document reading unit 120 that reads a document, and an image data storage unit 1 that stores image data and various data used when forming an image. 0, an image processing unit 140 that executes various image processes necessary for image formation, an image forming unit 150 that forms an image on a sheet based on an image formation command and image data, and an image formed sheet is inverted The reversing unit 180 is configured to include a double-sided conveyance unit 185 that conveys a sheet when a double-sided image is formed.

  As shown in FIG. 2, the image forming unit 150 includes an image carrier 151 on which a toner image is formed, a charging unit 152 that charges the image carrier 151 at a predetermined potential, and a charged image carrier 151. An exposure unit 153 that forms an electrostatic latent image by performing exposure according to image data, a developing unit 154 that develops the electrostatic latent image into a toner image, and a toner image on the image carrier 151 on a sheet. The image forming apparatus includes a transfer unit 155 for transferring, and a fixing unit 156 for fixing the toner image on the paper with heat and pressure.

  Although the sensor 107 as the detection unit is not shown in detail, a plurality of sensors are arranged along the respective positions of the paper feeding unit 105, the conveyance unit 110, the reversing unit 180, and the double-sided conveyance unit 185. The control unit 101 is notified of detection results such as the sheet presence position, passage position, and passage timing.

  The sheet processing apparatus 200 includes a control unit 201 that controls each unit in the sheet processing apparatus 200, a communication unit 202 that communicates with other connected apparatuses, and an image formed on the sheet and a conveyance condition of the sheet ( Sensor 207 serving as a detection unit for detecting abnormalities in the sub-scanning direction during conveyance, conveyance delay during conveyance, and the like, a conveyance unit 210 that conveys a sheet in the sheet processing apparatus 200, and a sheet A sheet processing unit 250 that performs various types of sheet processing, a sub-tray discharge unit 290S that discharges sheets to a sub-discharge tray 290s, and a main tray discharge unit 290M that discharges sheets to a main discharge tray 290m. Has been. As the paper processing in the paper processing apparatus 200, various processing such as punch processing, half-folding processing, stapling processing, and the like can be performed as necessary.

  The sensor 207 serving as a detection unit is not illustrated in detail, but a plurality of sensors are arranged along the positions of the transport unit 210 and the paper processing unit 250, and the presence position and passage position of the paper. , The detection result such as the passage timing is notified to the control unit 201. Furthermore, when an abnormality is determined from the detection result of the sensor 207, the control unit 201 notifies the control unit 101 of the abnormality detection result.

  Further, it is desirable that the above-described transport unit 110 and transport unit 210 not only transport the paper in the normal transport direction, but can also move the paper in the reverse direction when an abnormality described later is detected.

The control unit 101 controls image formation and conveyance based on the detection results of the sensor 107 and the sensor 207 serving as a detection unit. When an abnormality is detected, the content of the abnormality and the content of the apparatus are included. Depending on the position at the time of abnormality detection of each remaining paper,
If the position of the sheet detected by the sensors 107 and 207 when an abnormality is detected corresponds to a predetermined “non-reconveyable position”, the sheet remains in the non-reconveyable position. Controls the transport units 110 and 210 so as to continue the movement, and controls to stop the movement of the paper when the paper leaves the non-re-carryable position.
It has a function.

In addition, as shown in FIG. 3, for example, as shown in FIG.
-When the conveyance units 110 and 210 are configured to have a curved portion that conveys a sheet in a curved shape or an arc shape toward the conveyance direction, and where the curvature of the curved portion is equal to or greater than a predetermined value: curl ( (Curvature wrinkles) occurs (see FIGS. 2p2 and 2p6).
Position where the sheet is sandwiched between the pair of fixing rollers of the fixing unit 156: Curling or wrinkling occurs on the sheet (see p3 in FIG. 2).
The transfer units 110 and 210 are configured to have a plurality of different transfer path switching units (gates), and a gate area in which the plurality of transfer paths are switched: a part of the gate is pressed against the sheet and is placed on the sheet. Folding occurs (see FIG. 2 p5).
A position where the paper is sandwiched by a pair of rollers having different characteristics: When the hard roller and the soft roller are in contact with each other, curling or wrinkle is generated on the sandwiched paper when the soft roller is recessed (see FIGS. 2p7 and 4). In the case of rollers having extremely different diameters, the nipped paper may be recessed toward the small roller even if the rollers themselves do not deform. That is, characteristics such as various parameters, properties, and attributes such as diameter, hardness / softness, and temperature difference correspond to the characteristics of the roller.
-Position where the paper moves while straddling multiple drive rollers driven by different drive sources: The paper is pulled or pushed in due to the difference in the rising characteristics at the start of re-conveying, and curls and wrinkles occur (See FIG. 2, p1, p4).
-Position of the connecting part connected by a step or discontinuous part for transferring paper from one transport path to the other transport path: The end of the paper contacts the step or discontinuous part and curls or wrinkles occur (See FIGS. 5 to 6). Note that the step is not only a step shape but also a curved spread is treated as a step. In addition, the discontinuous portion means a portion where a part of the conveyance path is open. In addition, the connecting portion may occur not only between a plurality of devices but also between the same devices. Here, FIG. 5 shows an example of a connecting part in the same device, and FIG. 6 shows an example of a connecting part between other devices.
In each of the above cases, desirably, the leading end region in the paper conveyance direction corresponds to the above-described re-conveyance impossible position.
In the case of the above-described connecting portion, desirably, the leading end region (see FIG. 7B) in the paper transport direction, which is determined based on the transport direction length of the connecting region of the connecting portion (see FIG. 7A), Here, a state in which twice the length in the transport direction of the connection area is a determination target) exists in any position of the non-re-transfer position (connection portion).

  In other words, the “non-reconveyable position” is a position where various kinds of damage (curl, wrinkles, folds) are likely to occur in the paper staying at the stop position, and as a result, it is re-conveyed for purging after the stop. This means a position determined in advance as a position where a trouble such as a jam is likely to occur again.

  For this reason, the specific location and the cause of the non-re-transferable position are not limited to those shown in FIGS. 3 to 7, and are appropriately determined according to the configurations of the image forming apparatus 100 and the sheet processing apparatus 200. Determined.

  Although not shown here, the refeeding impossible position can be similarly determined in the paper feeding device 50 as well. In addition, when various apparatuses such as a reverse conveying apparatus and a reading apparatus that are not shown are connected as an image forming system, a non-reconveyable position is similarly determined as appropriate.

<Operation (1)>
Hereinafter, with reference to the flowchart of FIG. 8, the operation of the abnormality processing of the present embodiment for the image forming system shown in FIGS.

  The control unit 101 monitors the occurrence of a paper jam (jam), a conveyance abnormality, and the like regarding the conveyance of the sheet with respect to the detection result of the sensor 207 via the sensor 107 and the control unit 201. In the following description of the operation, a description will be continued by taking a jam as a specific example as a conveyance abnormality.

  Here, it is assumed that the control unit 101 determines that a paper jam has occurred at any position based on the detection results of the sensors 107 and 207 for the paper being conveyed (step S101 in FIG. 8). Here, the paper on which the jam has occurred is determined as the control target paper (step S102 in FIG. 8). The control unit 101 controls to stop the conveyance of the control target paper, and continues to convey the paper other than the control target paper until it is determined to be stopped by a determination described later (step S103 in FIG. 8). .

Then, the control unit 101 confirms whether or not there is a sheet on the upstream side next (subsequent) to the control target sheet (step S104 in FIG. 8).
Here, if there is no upstream sheet following the control target sheet (NO in step S104 in FIG. 8), the control unit 101 ends the abnormal process (end in FIG. 8). In this case, as normal jam processing, a message is displayed on the operation display unit 103 so as to remove the paper on which the jam has occurred.

  On the other hand, if there is a sheet on the upstream side that follows the control target paper (YES in step S104 in FIG. 8), the control unit 101 newly sets the upstream sheet that has been detected as the control target paper (FIG. 8). 8 (step S105 in FIG. 8), it is determined whether or not the control target paper can be transported (step S106 in FIG. 8). If the control target paper can be transported (YES in step S106 in FIG. 8). ), It is determined whether or not the control target paper is positioned at a re-conveyable position (step S107 in FIG. 8).

  Here, when the control target paper is not transportable (NO in step S106 in FIG. 8), or when the control target paper is transportable but is not positioned at the non-retransportable position (in FIG. 8). In step S107, the control unit 101 performs control to stop the conveyance of the control target paper (step S109 in FIG. 8).

  On the other hand, if the control target paper can be transported (YES in step S106 in FIG. 8), and if the control target paper is located in a non-retransportable position (YES in step S107 in FIG. 8). ), The control unit 101 controls to continue transporting the control target paper (step S108 in FIG. 8).

  Then, the control unit 101 determines whether the control target paper that has been controlled to continue transport can be transported continuously (step S106 in FIG. 8), and the control target paper is transported. If it is possible (YES in step S106 in FIG. 8), it is determined whether or not the control target paper is located in a re-conveyable position (step S107 in FIG. 8).

  That is, for the control target paper controlled so as to continue the conveyance (step S106 in FIG. 8), if the control target paper is out of the re-conveyance disabled position (NO in step S107 in FIG. 8), the conveyance is stopped. Control is performed (step S109 in FIG. 8).

Thereafter, the subsequent sheet is newly determined as a control target sheet (YES in step S104 in FIG. 8, S105), and the same processing is repeated (steps S106, S107, S108, and S109 in the figure). Here, if there is no subsequent sheet (NO in step S104 in FIG. 8), the process is terminated (END in FIG. 8).
The above operation will be described with reference to FIGS. 9 to 11 as the state of the sheet in the image forming system. In FIG. 9, the paper Pa is jammed before the main tray 290 m of the paper processing apparatus 200.

  At this time, the succeeding paper Pb is positioned at the non-reconveyable position p6 where the curvature of the curved portion is equal to or greater than a predetermined value (YES in step S107 in FIG. 8), and the control unit 101 sets the non-reconveyable position. Control is performed so as to continue the conveyance until the vehicle escapes (step S108 in FIG. 8).

  Further, the succeeding paper Pc is located at the non-re-carrying position p5 that is the gate area (YES in step S107 in FIG. 8), and the control unit 101 continues to carry until it escapes from the non-re-carrying position. Control is performed (step S108 in FIG. 8).

  Further, the succeeding paper Pd is located at a non-reconveyable position p3 that is nipped by the fixing roller by the fixing unit 156 (YES in step S107 in FIG. 8), and the control unit 101 sets the non-reconveyable position. Control is performed so as to continue the conveyance until the vehicle escapes (step S108 in FIG. 8).

  Further, the succeeding paper Pe is positioned at the non-reconveyable position p2 where the curvature of the curved portion is a predetermined value or more (YES in step S107 in FIG. 8), and the control unit 101 sets the non-reconveyable position. Control is performed so as to continue the conveyance until the vehicle escapes (step S108 in FIG. 8).

  By the continuous transport control at the non-retransportable position as described above, as shown in FIG. 10, the paper Pb escapes from the non-retransportable position p6, the paper Pc escapes from the non-retransportable position p5, and the paper Pd The conveyance disabled position p3 is escaped, and the paper Pe escapes from the reconveyance impossible position p2.

Then, after the jammed paper Pa is removed, as shown in FIG. 11, the papers Pb to Pe are discharged to the main tray 290m by a purge process.
<Operation (2)>
Hereinafter, with reference to the flowchart of FIG. 12, the operation (2) of the abnormality processing of the present embodiment for the image forming system shown in FIGS.

FIG. 12 is a modified example of the operation of the flowchart of FIG. 8 described above, and the same step number is assigned to the same step, and redundant description is omitted.
As an operation different from that in FIG. 8, when the control target paper can be transported (YES in step S106 in FIG. 8), it is determined whether or not the leading end area of the control target paper is located at a re-conveyable position. (Step S107 ′ in FIG. 8). This is especially true when the leading edge of the paper is damaged, and when the re-feed is started, the leading edge is bent or the curled paper is caught by a minute step or the like in the carrying path, causing a jam. This is because the possibility increases.

  For this reason, the conveyance continuation (step S108 in FIG. 12) and stop control (step S109 in FIG. 12) are performed so as not to be damaged with respect to the paper leading edge region where the influence of re-conveyance due to damage becomes large.

  The leading edge area of the control target paper may be determined in advance such as 10% or 20% on the leading edge side in the paper transport direction, or thin and soft depending on the flexibility (susceptibility to damage) of the paper. The sheet may be determined in advance so as to increase the leading end area. Further, as described with reference to FIG. 7, in the case of the connecting portion, the leading end region in the paper transport direction (see FIG. 7B) based on the transport direction length of the connection region of the connecting portion (see FIG. 7A). ) Reference, here, twice the length of the connected region in the transport direction may be determined.

  In this way, by controlling whether to continue or stop the movement of the paper based on whether or not the front end region in the paper transport direction corresponds to the non-retransportable position, the retransport that is likely to occur at the front end of the paper is controlled. With regard to trouble, it becomes possible to re-transport the paper stopped when trouble occurs without causing trouble again.

<Operation (3)>
Hereinafter, the operation (3) of the abnormality processing of the present embodiment for the image forming system shown in FIGS. 1 to 2 will be described with reference to the flowchart of FIG.

FIG. 13 is a further modified example of the operation of the flowchart of FIG. 8 described above, and the same step number is assigned to the same step, and redundant description is omitted.
As an operation different from that in FIG. 8, when the control target paper is not transportable (NO in step S106 in FIG. 13), the control unit 101 determines whether there is a preceding paper that can be transported with respect to the control target paper. (Step S110 in FIG. 13), control is performed so that the transportable preceding paper (YES in Step S110 in FIG. 13) is transported again by the longest distance within the possible range (Step S111 in FIG. 13).

  Then, it is possible to transport the control target paper (YES in step S106 in FIG. 13) for the determination of the preceding paper that can be transported and the re-transport of the longest possible distance (steps S110 to S111 in FIG. 13). Repeat until it becomes.

  That is, when the distance between the control target paper and the preceding paper is close and there is a risk of collision, the control target paper cannot be conveyed (NO in step S106 in FIG. 13, NO in S110). (YES), after the preceding paper is conveyed (step S111 in FIG. 13), the control target paper is controlled to continue conveyance (YES in step S106 in FIG. 13, YES in S107, S108). Here, the preceding paper desirably includes a plurality of preceding papers as well as the preceding preceding paper with respect to the control target paper.

  By such control, it becomes possible to move the control target paper without colliding with the paper in the close position without being obstructed, and the paper stopped when the trouble occurs can be transported again without causing trouble again. It becomes possible.

<Operation (4)>
Hereinafter, referring to the cross-sectional configuration diagram of FIG. 14, the sheet information table explanatory diagram of FIG. 15, and the conveyance state schematic diagram of FIG. 16, the state of control of this embodiment will be described using specific numerical values.

  In FIG. 14, the image forming apparatus 100 is shown as a center, and a specific example is a state in which the sensor 170a is disposed at the non-retransportable position p2 and the sensors 170b and 170c are disposed before and after the non-retransportable position p3. .

  In such an image forming apparatus 100, as shown in FIG. 15, three sheets (A4 (sheet length 210 mm)) of ID = 1 to 3 as the sheet ID are conveyed at a conveying speed of 400 mm at the conveying unit 110. / s, paper with ID = 1 is fed from paper feeder 105 at time 0 ms, paper with ID = 2 is fed from paper feeder 105 at time 500 ms, and paper with ID = 3 is fed at time 1000 ms. The control unit 101 controls to feed paper from the paper unit 105.

  In this case, the distance from the sheet feeding start position to the sensor 170a is 300 mm, the distance from the sensor 170a to the sensor 170b is 450 mm, the distance from the sensor 170b to the sensor 170c is 200 mm, the distance from the sensor 170c to the exit of the image forming apparatus is 100 mm, and the image is formed from the sheet feeding start position. The distance of the transport unit 110 to the apparatus exit is 1050 mm, the re-non-transferable position p2 is 400 mm including the sensor 170a position from the paper feed start position, and the re-non-transferable position p3 is 100 mm including the fixing roller clamping position between the sensors 170b to 170c. Suppose that

  Here, for the paper of ID = 1, in the above conditions, the on time of the sensor 170a is 750 ms, the off time is 1275 ms, the on time of the sensor 170b is 1875 ms, the off time is 2400 ms, and the on time of the sensor 170c is 2375 ms. -The off time is 2900ms and the specified time is calculated.

  For the paper with ID = 2, the ON time of the sensor 170a is 1250 ms, the OFF time is 1775 ms, the ON time of the sensor 170b is 2375 ms, the OFF time is 2900 ms, and the ON time of the sensor 170c is 2875 ms. The specified off time is 3400 ms.

  For the paper of ID = 3, the ON time of the sensor 170a is 1750 ms, the OFF time is 2275 ms, the ON time of the sensor 170b is 2875 ms, the OFF time is 3400 ms, and the ON time of the sensor 170c is 3375 ms. The off time is 3900 ms, and the prescribed time is calculated.

In such a state, the control unit 101 can detect that a conveyance abnormality such as a jam has occurred when the sheet does not pass during the above specified times.
In addition, the control unit 101 refers to the above specified time, information on the position where re-transfer is not possible (distance from the paper feed position) and the current time (elapsed time from the sensor passage time), and the control unit 101 detects when a jam occurs. In step S107, it can be determined whether or not the control target paper is in a re-conveyable position (step S107 in FIG. 8).

  Further, referring to the above specified time and information on the position where re-conveyance is not possible (distance from the paper feed position), the above-described conveyance continuation (step S108 in FIG. 8) is executed for a predetermined time. Then, it can be determined that the control target sheet has escaped from the re-conveyable position (NO in step S107 in FIG. 8).

Note that the position and number of the sensor 107, the position (distance) of each part, the speed, and the passing time shown in FIGS. 14, 15, and 16 are examples, and various modifications are possible.
[Other operations]
In the above description of the operation, it has been assumed that the normal conveyance in the forward direction toward the downstream side is performed as the conveyance continuation (step S108 in FIGS. 8, 12 and 13). However, the present invention is not limited to this, and it is also possible to perform reverse conveyance in the upstream direction depending on the relationship between the non-reconveyable position and the paper position. In other words, moving the paper in the forward or reverse direction so as to avoid the non-retransportable position can be treated as continuation of the conveyance, and the movement of the paper when the paper leaves the non-retransportable position. By controlling to stop the paper, it becomes possible to re-transport the paper stopped when the trouble occurs without causing the trouble again.

  In this case, as the operation (3), when the control target paper in FIG. 13 cannot be conveyed (NO in step S106 in FIG. 13), if the paper is moved in the reverse direction, the subsequent paper is also included. What is necessary is just to move to a reverse direction. By such control, it becomes possible to move the control target paper without being obstructed by the paper in the close position, and it is possible to re-transport the paper that has been stopped when the trouble occurs without causing any trouble again.

[Other Embodiments]
In the above description, various modifications such as the presence / absence of connection and the number of connections of the sheet feeding device 50, the image forming apparatus 100, and the sheet processing apparatus 200 can be variously modified, and the above-described embodiments can be applied. It is.

DESCRIPTION OF SYMBOLS 50 Paper feeder 100 Image forming apparatus 101 Control part 102 Communication part 103 Operation display part 104 Storage part 105 Paper feed part 107 Sensor 110 Conveyance part 120 Document reading part 130 Image data storage part 140 Image processing part 150 Image formation part 180 Inversion part 185 Double-sided conveyance unit 200 Paper processing device 201 Control unit 202 Communication unit 207 Sensor 250 Paper processing unit

Claims (23)

An image forming unit for forming an image on paper;
A transport unit that moves the paper according to an image forming operation;
A detection unit for detecting a position of the sheet moving on a conveyance path of the conveyance unit and an abnormality in conveyance of the sheet;
A control unit that controls image formation and conveyance based on a detection result of the detection unit;
An image forming apparatus having
When an abnormality is detected by the detection unit, if the position of the sheet detected by the detection unit corresponds to a predetermined non-retransportable position, the control unit re-transports the sheet. Control to continue the movement while the paper is in the impossible position, and to stop the movement of the paper when the paper leaves the non-re-carryable position,
An image forming apparatus. The control unit controls whether to continue or stop the movement of the sheet based on whether or not the leading end region in the sheet conveyance direction detected by the detection unit corresponds to the non-re-carrying position.
The image forming apparatus according to claim 1. The transport unit is configured to include a connecting unit that is coupled from one transport path to the other transport path,
The re-transport impossible position is determined based on the position of the connecting portion,
The control unit is based on whether or not a front end region in the transport direction determined according to the transport direction length of the connecting unit of the paper detected by the detection unit corresponds to the non-retransportable position. Control whether the paper movement continues or stops,
The image forming apparatus according to claim 1 or 2. The conveyance unit is configured to have a curved portion that conveys the paper in a curved shape or an arc shape toward the conveyance direction,
The re-carrying impossible position is determined based on the position and curvature of the music part,
The image forming apparatus according to claim 1 or 2. The image forming unit includes a fixing unit that fixes a visible image on a sheet,
The non-re-carrying position is determined based on a position where the sheet is clamped by the fixing unit.
The image forming apparatus according to claim 1 or 2. The transport unit is configured to include a transport path switching unit that switches between a plurality of different transport paths,
The re-transport impossible position is determined by the position of the transport path switching unit.
The image forming apparatus according to claim 1 or 2. A roller pair with different characteristics for sandwiching the paper is provided at any position of the transport unit,
The re-conveying impossible position is determined based on a position where the paper is sandwiched between the roller pair.
The image forming apparatus according to claim 1 or 2. A plurality of drive rollers that are driven by different drive sources and transport the paper are provided at any position of the transport unit,
The non-reconveyable position is determined based on a position where the sheet moves in a state of straddling a plurality of driving rollers driven by different driving sources.
The image forming apparatus according to claim 1 or 2. When the control unit has a preceding transport sheet that moves in advance or a succeeding transport sheet that moves subsequently with respect to the non-retransportable position sheet that exists in the non-retransportable position when an abnormality is detected. When the preceding transport sheet or the subsequent transport sheet can be moved by moving the non-re-transferable position sheet, the non-re-transfer non-position sheet can be moved. Control to move the preceding transport sheet or the subsequent transport sheet;
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The transport unit has a function of discharging the paper out of the image forming apparatus;
The control unit controls to discharge the sheet remaining in the image forming apparatus and transportable after the sheet is moved to a position other than the non-re-transportable position;
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. An image forming unit for forming an image on paper;
A paper processing unit that performs various types of paper processing on the paper on which an image is formed by the image forming unit;
A transport unit that moves the paper according to image forming and paper processing operations;
A detection unit for detecting a position of the sheet moving on a conveyance path of the conveyance unit and an abnormality in conveyance of the sheet;
A control unit that controls image formation and conveyance based on a detection result of the detection unit;
An image forming system comprising:
When an abnormality is detected by the detection unit, if the position of the sheet detected by the detection unit corresponds to a predetermined non-retransportable position, the control unit re-transports the sheet. Control to continue the movement while the paper is in the impossible position, and to stop the movement of the paper when the paper leaves the non-re-carryable position,
An image forming system. The control unit controls whether to continue or stop the movement of the sheet based on whether or not the leading end region in the sheet conveyance direction detected by the detection unit corresponds to the non-re-carrying position.
The image forming system according to claim 11. The transport unit is configured to include a connecting unit that is coupled from one transport path to the other transport path,
The re-transport impossible position is determined based on the position of the connecting portion,
The control unit is based on whether or not a front end region in the transport direction determined according to the transport direction length of the connecting unit of the paper detected by the detection unit corresponds to the non-retransportable position. Control whether the paper movement continues or stops,
The image forming system according to claim 11, wherein the image forming system is an image forming system. The conveyance unit is configured to have a curved portion that conveys the paper in a curved shape or an arc shape toward the conveyance direction,
The re-carrying impossible position is determined based on the position and curvature of the music part,
The image forming system according to claim 11, wherein the image forming system is an image forming system. The image forming unit includes a fixing unit that fixes a visible image on a sheet,
The non-re-carrying position is determined based on a position where the sheet is clamped by the fixing unit.
The image forming system according to claim 11, wherein the image forming system is an image forming system. The transport unit is configured to include a transport path switching unit that switches between a plurality of different transport paths,
The re-transport impossible position is determined by the position of the transport path switching unit.
The image forming system according to claim 11, wherein the image forming system is an image forming system. A roller pair with different characteristics for sandwiching the paper is provided at any position of the transport unit,
The re-conveying impossible position is determined based on a position where the paper is sandwiched between the roller pair.
The image forming system according to claim 11, wherein the image forming system is an image forming system. A plurality of drive rollers that are driven by different drive sources and transport the paper are provided at any position of the transport unit,
The non-reconveyable position is determined based on a position where the sheet moves in a state of straddling a plurality of driving rollers driven by different driving sources.
The image forming system according to claim 11, wherein the image forming system is an image forming system. When the control unit has a preceding transport sheet that moves in advance or a succeeding transport sheet that moves subsequently with respect to the non-retransportable position sheet that exists in the non-retransportable position when an abnormality is detected. When the preceding transport sheet or the subsequent transport sheet can be moved by moving the non-re-transferable position sheet, the non-re-transfer non-position sheet can be moved. Control to move the preceding transport sheet or the subsequent transport sheet;
The image forming system according to claim 11, wherein the image forming system is an image forming system. The transport unit has a function of discharging the paper out of the image forming system;
The control unit controls to discharge the paper that is left in the image forming system and can be transported after the paper is moved to a position other than the non-re-carryable position.
The image forming system according to claim 11, wherein the image forming system is an image forming system. An image forming unit for forming an image on paper;
A transport unit that transports the paper according to an image forming operation;
A detection unit for detecting a position of the sheet moving on a conveyance path of the conveyance unit and an abnormality in conveyance of the sheet;
A control unit that controls image formation and conveyance based on a detection result of the detection unit;
An image formation control method for controlling image formation in an image forming apparatus having
When an abnormality is detected by the detection unit, if the position of the sheet detected by the detection unit corresponds to a predetermined non-retransportable position, the control unit re-transports the sheet. Control to continue the movement while the paper is in the impossible position, and to stop the movement of the paper when the paper leaves the non-re-carryable position,
An image formation control method characterized by the above. When the control unit has a preceding transport sheet that moves in advance or a succeeding transport sheet that moves subsequently with respect to the non-retransportable position sheet that exists in the non-retransportable position when an abnormality is detected. When the preceding transport sheet or the subsequent transport sheet can be moved by moving the non-re-transferable position sheet, the non-re-transfer non-position sheet can be moved. Control to move the preceding transport sheet or the subsequent transport sheet;
The image formation control method according to claim 21, wherein: The transport unit has a function of discharging the paper out of the image forming apparatus;
The control unit controls to discharge the sheet remaining in the image forming apparatus and transportable after the sheet is moved to a position other than the non-re-transportable position;
23. The image formation control method according to claim 21-22.

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