JP6319154B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  Conventionally, an image forming apparatus of a process in which an electrostatic latent image is formed on the surface of a charged photosensitive drum, then the electrostatic latent image is converted into a toner image by a developing device, transferred to a sheet, and then fixed by a fixing device. Is well known.

  In such an image forming apparatus, there is a case in which a so-called jam occurs, in which a sheet conveyed along a predetermined mechanism portion is jammed inside the mechanism portion or between adjacent mechanism portions. When a jam occurs, the image forming operation of the image forming apparatus normally stops. Thereafter, when the paper jammed inside the image forming apparatus is removed by the operator, the image forming operation of the image forming apparatus is resumed. In this manner, when an jam occurs, an action of removing a jammed sheet by an operator is hereinafter referred to as jam processing.

  When a jam occurs, if the paper is long paper and the long paper is straddling the boundary of the mechanism that can be pulled out, the operator pulls the long paper from the manual paper feed section or paper discharge section. Jam processing to pull out, or jam processing to cut out a long sheet at a manual paper feed port and then pull out a freely drawable mechanism portion. Note that when a jam occurs, a paper cutting operation or a paper rewinding operation is performed according to the leading edge position of the paper (for example, see Patent Document 1).

JP 2003-50490 A

  In the prior art, if a jam occurs in the middle of passing a long paper, the long paper may not be confirmed from the paper feed unit or the paper discharge unit depending on the stop position of the long paper. In this case, since the presence of the long paper is not confirmed, the operator cannot perform the jam processing for pulling out the long paper. Further, even if the operator cuts the long paper near the paper feed port, there is a risk that the long paper may straddle the boundary portion because there is a distance from the boundary portion of the pullable mechanism portion. . In this case, if the operator tries to pull out the mechanism that can be pulled out, the paper may get entangled in the middle of the transport path, the paper cannot be pulled out, the jammed paper cannot be removed, and the jammed paper may remain in the machine.

  Note that the technique disclosed in Patent Document 1 cuts a sheet in vain because a sheet cutting operation or a sheet rewinding operation is performed according to the leading end position of the sheet when the sheet conveyance function is stopped. There is nothing. However, in the technique described in Patent Document 1, when the sheet conveyance function is stopped and the sheet is straddling between the conveyance units, if the operator pulls out a conveyance unit that can be pulled out among the conveyance units, the sheet is not removed. There is a risk of entanglement in the middle of the transport path.

  Therefore, even in the conventional technique as described in Patent Document 1, depending on the situation when the paper transport function is stopped, the restoration work is reliably and easily performed by the operator when the paper transport function is restored. There is a fear that it cannot be made.

  The present invention has been made in order to solve the conventional problems, and an object of the present invention is to provide an image that allows a worker to perform the restoration work reliably and easily at the time of restoration work of the paper transport function by the operator. It is to provide a forming apparatus.

In order to achieve the above object, an image forming apparatus according to the present invention includes a first transport unit, a second transport unit, and a third transport unit that are provided adjacent to each other to form a paper transport path. An image forming apparatus in which the second transport unit can be pulled out, a determination unit that determines whether or not the paper transport function is stopped, and the paper transport function is stopped by the determination unit A calculation unit that obtains the amount of the sheet straddling the first conveying unit or the amount of the sheet striking the third conveying unit with reference to the second conveying unit. Depending on the amount of paper straddling calculated by the arithmetic unit, a part of the paper is moved to the inside of the second transport unit, and the paper straddling with the first transport unit, or JP that and a mechanism control unit to eliminate the spanning of said sheet and said third conveyor section To.

  According to this image forming apparatus, the restoration work can be surely and easily performed at the time of the restoration work of the paper transport function by the operator.

In the image forming apparatus according to the present invention, the first conveyance unit, the second conveyance unit, and the third conveyance unit are provided adjacent to each other to form a sheet conveyance path, and the second conveyance unit An image forming apparatus in which a part can be pulled out, a determination unit that determines whether or not the paper transport function has stopped, and a determination unit that determines that the paper transport function has stopped An arithmetic unit that obtains the amount of paper straddling the first transport unit or the amount of paper straddling the third transport unit on the basis of the second transport unit; and Depending on the calculated amount of paper straddling, a part of the paper is moved to the outside of the second transport unit, and the straddling portion of the paper with the first transport unit, or the third further comprising a mechanism control unit that the state pulling the straddling portions of the sheet between the conveying section, the Preferred.

  According to this image forming apparatus, the restoration work can be surely and easily performed at the time of the restoration work of the paper transport function by the operator.

  In the image forming apparatus according to the aspect of the invention, the mechanism control unit may move the end portion of the sheet to the second conveyance unit when the amount of the sheet straddling is within an accommodation range of the second conveyance unit. It is preferable to move inward.

  According to this image forming apparatus, the amount of sheets that can be accommodated can be accommodated in the second conveyance unit.

  In the image forming apparatus according to the present invention, the sheet is transported in the order of the first transport unit, the second transport unit, and the third transport unit, and the mechanism control unit includes: When the rear end side of the sheet straddles the first transport unit, it is preferable that the rear end of the sheet is moved to the inside of the second transport unit.

  According to this image forming apparatus, when the second transport unit is pulled out, it is possible to improve the state where the paper is entangled due to the straddling of the paper between the first transport unit and the second transport unit. it can.

  In the image forming apparatus according to the present invention, the sheet is transported in the order of the first transport unit, the second transport unit, and the third transport unit, and the mechanism control unit includes: When the leading end side of the sheet straddles the third transport unit, it is preferable that the leading end of the sheet is moved to the inside of the second transport unit.

  According to this image forming apparatus, when the second transport unit is pulled out, it is possible to improve the state where the paper is entangled due to the straddling of the paper between the second transport unit and the third transport unit. it can.

  In the image forming apparatus according to the aspect of the invention, the mechanism control unit may move the edge of the sheet to the outside of the second conveyance unit when the amount of the sheet straddling is not within the accommodation range of the second conveyance unit. It is preferable to move it.

  According to this image forming apparatus, the amount of paper that cannot be accommodated can be pulled toward the outside of the second transport unit.

  In the image forming apparatus according to the present invention, the sheet is transported in the order of the first transport unit, the second transport unit, and the third transport unit, and the mechanism control unit includes: When the rear end side of the sheet straddles the first transport unit, it is preferable that the rear end of the sheet is moved to the upstream side of the second transport unit.

  According to the image forming apparatus, when the second transport unit is pulled out, the sheet straddling between the first transport unit and the second transport unit can be easily cut.

  In the image forming apparatus according to the present invention, the sheet is transported in the order of the first transport unit, the second transport unit, and the third transport unit, and the mechanism control unit includes: When the leading end side of the sheet straddles the third transport unit, it is preferable that the leading end of the sheet is moved to the downstream side of the second transport unit.

  According to this image forming apparatus, when the second transport unit is pulled out, the sheet straddling between the second transport unit and the third transport unit can be easily cut.

  In the image forming apparatus according to the present invention, the second transport unit includes a transfer roller that forms a transfer nip, a fixing roller that is provided downstream of the transfer roller and forms a fixing nip, and the transfer roller. An upstream conveying roller that moves the trailing edge of the sheet, and a downstream conveying roller that moves downstream of the fixing roller and moves the leading edge of the sheet, and The mechanism control unit moves at least one of a portion between the upstream conveyance roller and the transfer roller and a portion between the fixing roller and the downstream conveyance roller of the sheet. It is preferable not to let it.

  According to this image forming apparatus, even when an unfixed image is present on the sheet when moving the trailing end side of the sheet and when moving the leading end side of the sheet after the jam occurs, the inside of the second transport unit is not stained. Can be moved to.

  In the image forming apparatus according to the present invention, the second conveyance unit further includes a registration roller provided between the upstream conveyance roller and the transfer roller, and the mechanism control unit Of the paper, when the portion between the transport roller on the upstream side and the transfer roller is not moved, the registration roller is preferably brought into a pressure-bonded state.

  According to this image forming apparatus, even when an unfixed image is present on the sheet when moving the trailing end side of the sheet and when moving the leading end side of the sheet after the jam occurs, the inside of the second transport unit is not stained. It is possible to reliably carry out the movement.

  In the image forming apparatus according to the aspect of the invention, the second transport unit may further include a fixing paper discharge roller provided between the fixing roller and the downstream transport roller, and the mechanism control unit may When the portion of the sheet between the fixing roller and the downstream transport roller is not moved, the fixing discharge roller is preferably brought into a pressure-bonded state.

  According to this image forming apparatus, even when an unfixed image is present on the sheet when moving the trailing end side of the sheet and when moving the leading end side of the sheet after the jam occurs, the inside of the second transport unit is not stained. It is possible to reliably carry out the movement.

  In the image forming apparatus according to the aspect of the invention, the first transport unit may include a transport roller that transports the paper to the second transport unit, and the most downstream of the transport rollers in the first transport unit. It is preferable that at least one of the upstream-side transport roller and the upstream-side transport roller has a nip formed in the entire width direction of the sheet.

  According to this image forming apparatus, it is possible to improve the difficulty of cutting due to the flapping of the paper on the trailing edge side of the paper.

  In the image forming apparatus according to the present invention, the third transport unit includes a transport roller that transports the paper transported from the second transport unit, and is the most downstream side of the downstream transport rollers. It is preferable that at least one of the transport roller and the transport roller on the uppermost stream side among the transport rollers in the third transport unit has a nip formed in the entire width direction of the paper.

  According to this image forming apparatus, it is possible to improve the difficulty of cutting due to the flapping of the paper at the leading end side of the paper.

  In the image forming apparatus according to the present invention, the image forming apparatus further includes a cutting unit that cuts the paper, and the cutting unit is located on the most downstream side of the first conveying unit and the most upstream side of the second conveying unit. It is preferable that at least one and at least one of the most downstream side of the second transport unit and the most upstream side of the third transport unit are provided.

  According to this image forming apparatus, when the second transport unit is pulled out, the rear end side of the sheet and the front end side of the sheet can be reliably cut.

  In the image forming apparatus according to the aspect of the invention, it is preferable that the cutting unit is capable of cutting the paper when the second transport unit is pulled out.

  According to this image forming apparatus, the sheet can be reliably and easily cut when the second transport unit is pulled out.

  In the image forming apparatus according to the aspect of the invention, it is preferable that the cutting unit is released from a state in which the sheet can be cut when the second transport unit is returned to the original position.

  According to this image forming apparatus, when the second transport unit is returned to the original position, it is possible to promptly shift to the paper transport operation.

  According to the present invention, it is possible to reliably and easily perform the restoration work at the time of restoration work of the paper transport function by the operator.

1 is a configuration diagram schematically illustrating a configuration of an image forming apparatus 1 according to an embodiment. 2 is a diagram illustrating an example of a functional configuration of an image forming apparatus 1 according to the present embodiment. FIG. It is a figure which shows an example of operation | movement of the conveyance guides 201a and 201b of the boundary part 81. FIG. It is a figure which shows an example of operation | movement of the conveyance guides 201c and 201d of the boundary part 82. FIG. FIG. 10 is a diagram illustrating an example of an operation for moving the paper P inside the second transport unit 12 at the boundary portion 81. FIG. 10 is a diagram for explaining an example of an operation for moving the paper P to the inside of the second transport unit 12 at the boundary portion 82. 6 is a diagram illustrating an example of an operation for moving the paper P to the outside of the second transport unit 12 at the boundary portion 81. FIG. 6 is a diagram illustrating an example of an operation of moving the paper P to the outside of the second transport unit 12 at the boundary portion 82. FIG. 4 is a flowchart for explaining an operation example of the image forming apparatus 1.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

  FIG. 1 is a configuration diagram schematically illustrating a configuration of an image forming apparatus 1 according to the present embodiment. In the image forming apparatus 1, the first transport unit 11, the second transport unit 12, and the third transport unit 13 are provided adjacent to each other to form a transport path for the paper P, and the second transport unit 12. Can be pulled out freely. Here, the paper P is basically transported in the order of the first transport unit 11, the second transport unit 12, and the third transport unit 13. Further, sensors 50 a to 50 h are arranged in the second transport unit 12. If any of the sensors 50a to 50h is not particularly specified, the sensor 50a is referred to as a sensor 50.

  The first transport unit 11 includes a transport roller 21 that is provided on the upstream side of the second transport unit 12 and transports the paper P to the second transport unit 12. In the first transport unit 11, the straddling amount La is obtained by calculation based on the transport speed and the like after the paper P is detected by the sensor 50. For example, the straddling amount La may be calculated based on the time required for the conveyance function of the paper P to stop after a part of the paper P passes the sensor 50 and the conveyance speed of the paper P. Whether or not the transport function of the paper P is stopped is determined when the paper P is not detected by the second sensor 50 even after a predetermined time has elapsed after the paper P passes through the first sensor 50. What is necessary is just to determine with the conveyance function of no.

  In FIG. 1, only one transport roller 21 is provided on the most upstream side of the first transport unit 11, but actually, the first transport unit 11 includes a plurality of transport rollers 21. The conveyance roller 21 is provided.

  The third transport unit 13 includes a transport roller 41 that is provided on the downstream side of the second transport unit 12 and transports the paper P transported from the second transport unit 12. In the third transport unit 13, the straddling amount Lb is obtained by calculation based on the transport speed of the paper P after the paper P is detected by the sensor 50, similarly to the straddling amount La.

  In FIG. 1, it is illustrated that only one transport roller 41 is provided on the most downstream side of the third transport unit 13, but actually, the third transport unit 13 includes a plurality of transport rollers 41. The conveyance roller 41 is provided.

  Next, the 2nd conveyance part 12 is demonstrated. The second transport unit 12 is provided between the first transport unit 11 and the third transport unit 13. The second transport unit 12 includes a transfer roller 35, a fixing roller 36, upstream transport rollers 31, 32, 33, downstream transport rollers 38, 39, and the like. The transfer roller 35 forms a transfer nip. The fixing roller 36 is provided on the downstream side of the transfer roller 35 and forms a fixing nip. The upstream conveying rollers 31, 32, and 33 are provided on the upstream side of the transfer roller 35 and move the rear end of the paper P. The downstream transport rollers 38 and 39 are provided on the downstream side of the fixing roller 36 and move the leading edge of the paper P.

  The conveyance path of the paper P between the transfer roller 35 and the fixing roller 36 is an unfixed image conveyance path 83. The unfixed image conveyance path 83 is for conveying the paper P on which an unfixed image is formed. A reverse conveyance path 84 for reversing the paper P is provided below the transfer roller 35 and the fixing roller 36. The reverse conveyance path 84 is a path used when the front and back of the paper P are reversed.

  The second transport unit 12 includes a registration roller 34. The registration roller 34 is provided between the transport rollers 31, 32, 33 on the upstream side and the transfer roller 35. The second transport unit 12 includes a fixing paper discharge roller 37. The fixing paper discharge roller 37 is provided between the fixing roller 36 and the transport rollers 38 and 39 on the downstream side.

  The second transport unit 12 is provided with a region for storing the paper P. Specifically, on the upstream side of the second transport unit 12 and between the transport roller 31 and the transport roller 32, a region for storing the paper P is provided in the storage range LA. Further, on the downstream side of the second transport unit 12, a region for storing the paper P is provided in the storage range LB between the transport roller 38 and the transport roller 39.

  Here, in the case where the portion between the transport rollers 31, 32, 33 and the transfer roller 35 on the upstream side of the paper P is not moved, the registration roller 34 is brought into a pressure-bonded state. Further, when the portion of the paper P between the fixing roller 36 and the downstream transport rollers 38 and 39 is not moved, the fixing paper discharge roller 37 is brought into a pressure-bonded state.

  Of the transport roller 21 in the first transport unit 11, the transport roller 21 on the most downstream side and the transport roller 31 on the most upstream side of the transport rollers 31, 32, 33 on the upstream side in the second transport unit 12 At least one nip is formed in the entire width direction of the paper P. In addition, at least one of the most downstream transport roller 39 of the downstream transport rollers 38 and 39 and the most upstream transport roller 41 of the transport rollers 41 in the third transport unit 13 is the width direction of the paper P. A nip is formed over the entire area.

  As shown in FIG. 1, a cutting unit 71 is provided on the most upstream side of the second conveyance unit 12, and a cutting unit 72 is provided on the most downstream side of the second conveyance unit 12. The cutting units 71 and 72 are for cutting the paper P. The cutting units 71 and 72 are capable of cutting the paper P when the second transport unit 12 is pulled out. Further, the cutting units 71 and 72 are released from a state in which the paper P can be cut when the second transport unit 12 is returned to the original position.

  That is, the cutting units 71 and 72 only need to be able to perform the cutting operation of the paper P when the second transport unit 12 is pulled out. Therefore, the arrangement location of the cutting units 71 and 72 is not limited to the second transport unit 12. Specifically, the cutting part 71 should just be provided in at least one among the most downstream side of the 1st conveyance part 11, and the most upstream side of the 2nd conveyance part 12. FIG. Moreover, the cutting part 72 should just be provided in at least one among the most downstream side of the 2nd conveyance part 12, and the most upstream side of the 3rd conveyance part 13. FIG.

  Here, the image forming apparatus 1 forms an image by an electrophotographic method, for example. Although not shown, the image forming apparatus 1 forms a full-color image by arranging a plurality of photosensitive drums facing one intermediate transfer belt 6 in the vertical direction, so-called tandem color image formation. Device. The image forming apparatus 1 mainly includes a document reading device (not shown), four sets of image forming units (not shown), and a fixing roller 36.

  The document reading device scans and exposes an image of a document with the optical system of the scanning exposure device, reads the reflected light with a line image sensor, and obtains an image signal. The image signal is processed as an image reading value after being subjected to processing such as A / D conversion, shading correction, and compression. The image data to be processed is not limited to the data read by the document reading device, but for example, a personal computer (not shown) connected to the image forming device 1, received from another image forming device, or a semiconductor memory It may be read from a portable recording medium.

  The four sets of image forming units are provided above the transfer roller 35, and form an image forming unit that forms a yellow (Y) image, an image forming unit that forms a magenta (M) image, and a cyan (C) image. The image forming unit is formed with an image forming unit that forms a black (K) image. Each image forming unit includes a photosensitive drum, a charging unit arranged around the photosensitive drum, an optical writing unit, a developing device, and a drum cleaner.

  The surface of each of the photosensitive drums is uniformly charged by the charging unit, and a latent image is formed by scanning exposure by the optical writing unit. The developing device develops the latent image on the photosensitive drum by developing with toner. As a result, an image (toner image) of a predetermined color corresponding to any of yellow, magenta, cyan, and black is formed on each photosensitive drum. The images formed on the respective photosensitive drums are sequentially transferred to predetermined positions on the rotating intermediate transfer belt 6 by the primary transfer roller.

  The image transferred onto the intermediate transfer belt 6 is transferred to the paper P conveyed at a predetermined timing by a transfer roller 35 that functions as a secondary transfer roller. The transfer roller 35 is disposed in pressure contact with the intermediate transfer belt 6 to form a transfer nip.

  The fixing roller 36 performs a fixing process on the paper P on which the image is transferred. The fixing rollers 36 are pressed against each other to form a fixing nip. One or both of the fixing rollers 36 are heated by a heater. Specifically, the transferred image is fixed on the paper P through the action of the pressure applied by the pair of fixing rollers 36 and the heat of the fixing roller 36. The sheet P on which the fixing process has been performed by the fixing roller 36 is discharged out of the second transport unit 12 through the fixing discharge roller 37 and the transport rollers 38 and 39.

  When image formation is performed also on the back surface of the paper P, the paper P on which image formation has been performed on the front surface of the paper P is reversed and conveyed by a switching gate provided between the fixing paper discharge roller 37 and the conveyance roller 38. It is conveyed to the path 84. In the reverse conveyance path 84, the rear end of the conveyed paper P is nipped by the reverse roller, and then reversely fed to reverse the front and back of the paper P. The paper P whose front and back are reversed is transported by a plurality of transport rollers, and is joined to a transport path on the upstream side of the transfer position in order to provide image formation on the other surface.

  FIG. 2 is a diagram illustrating an example of a functional configuration of the image forming apparatus 1 according to the present embodiment. A controller 100 in FIG. 2 controls the operation of the image forming apparatus 1. The controller 100 can be realized using a microcomputer mainly composed of a CPU, a ROM, a RAM, and an I / O interface.

  As shown in FIG. 2, the controller 100 includes a determination unit 111, a calculation unit 112, and a mechanism control unit 113. In addition, the controller 100 is provided with a timer unit 114 and a nonvolatile memory 115. The controller 100 performs various controls based on the detection results of the sensors 50a to 50h.

  The determination unit 111 determines whether the transport function of the paper P has stopped. The time measuring unit 114 measures the elapsed time, and is used for determining whether the stride amount La, the stride amount Lb, and the paper P transport function are stopped.

  Specifically, the time measuring unit 114 is an elapsed time after the first sensor 50 detects a part of the paper P when the first sensor 50 detects a part of the paper P. The time is measured, and the time measurement result is transmitted to the determination unit 111. Whether the determination unit 111 has passed through the second sensor 50 after a predetermined time has elapsed since a part of the paper P passed through the first sensor 50 based on the time measurement result of the time measuring unit 114. It is to determine whether or not. As described above, the determination unit 111 determines whether the transport function of the paper P is stopped based on the detection result of the sensor 50 and the time measurement result of the time measurement unit 114.

  When the determination unit 111 determines that the conveyance function of the paper P is stopped, the calculation unit 112 uses the second conveyance unit 12 as a reference, and the amount La of the sheet P over the first conveyance unit 11 or the first 3 is obtained as a stride amount Lb of the sheet P to the third transport unit 13.

  Specifically, the time measuring unit 114 measures the time from when a part of the paper P passes the first sensor 50 until the conveyance function of the paper P stops as the conveyance time of the paper P. The result is transmitted to the determination unit 111. The time measurement result is transmitted from the determination unit 111 to the calculation unit 112 together with the determination result of whether or not the conveyance function of the paper P is stopped. The calculation unit 112 obtains the straddling amount La or the straddling amount Lb of the paper P based on the transport speed of the paper P and the transport time.

  The mechanism control unit 113 moves a part of the paper P to the inside of the second transport unit 12 in accordance with the straddling amounts La and Lb of the paper P calculated by the calculation unit 112. Further, the mechanism control unit 113 moves a part of the paper P to the outside of the second transport unit 12 according to the stride amounts La and Lb calculated by the calculation unit 112. That is, the mechanism control unit 113 moves a part of the paper P to the inside or the outside of the second transport unit 12 according to the stride amounts La and Lb calculated by the calculation unit 112.

  Specifically, the mechanism control unit 113 sets the end of the paper P to the second transport unit 12 when the straddling amounts La and Lb of the paper P are within the accommodation ranges LA and LB of the second transport unit 12. It is moved inward. On the other hand, when the straddling amounts La and Lb of the paper P are not within the accommodation ranges LA and LB of the second transport unit 12, the mechanism control unit 113 moves the end portion of the paper P to the outside of the second transport unit 12. Is.

  More specifically, in the mechanism control unit 113, the straddling amount La of the paper P is within the accommodation range LA of the second transport unit 12, and the rear end side of the paper P straddles the first transport unit 11. In this case, the rear end of the paper P is moved to the inside of the second transport unit 12. When the stride amount Lb of the paper P is within the accommodation range LB of the second transport unit 12 and the leading end side of the paper P straddles the third transport unit 13, the mechanism control unit 113 sets the front end of the paper P. It moves to the inside of the 2nd conveyance part 12. FIG.

  When the stride amount La of the paper P is not within the accommodation range LA of the second transport unit 12 and the rear end side of the paper P is straddling the first transport unit 11, the mechanism control unit 113 is The end is moved to the upstream side of the second transport unit 12. When the stride amount Lb of the paper P is not within the accommodation range LB of the second transport unit 12 and the front end side of the paper P straddles the third transport unit 13, the mechanism control unit 113 sets the front end of the paper P. It moves to the downstream side of the 2nd conveyance part 12. FIG.

  The mechanism control unit 113 is located in the portion of the paper P between the upstream transport rollers 31, 32, 33 and the transfer roller 35, and between the fixing roller 36 and the downstream transport rollers 38, 39. At least one of the parts is not moved.

  Specifically, the mechanism control unit 113 causes the registration roller 34 to be in a pressure-bonded state when the portion of the paper P between the upstream-side transport rollers 31, 32, 33 and the transfer roller 35 is not moved. It is. The mechanism control unit 113 causes the fixing paper discharge roller 37 to be in a pressure-bonded state when the portion of the paper P between the fixing roller 36 and the downstream transport rollers 38 and 39 is not moved.

  Next, a configuration for forming a slack in the paper P when a part of the paper P is accommodated inside the second transport unit 12 will be described with reference to FIGS. FIG. 3 is a diagram illustrating an example of the operation of the conveyance guides 201a and 201b in the boundary portion 81. FIG. 4 is a diagram illustrating an example of the operation of the conveyance guides 201c and 201d in the boundary portion 82. Although not shown in FIG. 2, the second transport unit 12 is provided with transport guides 201a to 201d as shown in FIGS.

  Specifically, as illustrated in FIG. 3, a transport guide 201 a and a transport guide 201 b are provided between the downstream transport roller 38 and the downstream transport roller 39. The conveyance guide 201a and the conveyance guide 201b are rotatable, and a space for loosening the paper P is provided by opening the conveyance guide 201a when the paper P is accommodated. The operation of the conveyance guides 201a and 201b and the operation of the conveyance rollers 38 and 39 on the downstream side cooperate with each other, so that the paper P is accommodated in the accommodation range LB. Specifically, after the conveyance guides 201a and 201b are opened, the sheet P is reversely moved by the conveyance roller 39 on the downstream side, and the conveyance roller 38 is stopped, so that the sheet P is loosened and falls within the accommodation range LB. Will be housed.

  As shown in FIG. 4, a transport guide 201 c and a transport guide 201 d are provided between the upstream transport roller 31 and the upstream transport roller 32. The conveyance guide 201c and the conveyance guide 201d are rotatable, and when the paper P is accommodated, the conveyance guide 201c and the conveyance guide 201d are opened to provide a space for loosening the paper P. The operation of the transport guides 201c and 201d and the operation of the transport rollers 31 and 32 on the upstream side cooperate with each other, so that the paper P is stored in the storage range LA. Specifically, after the transport guides 201c and 201d are opened, the paper P is advanced by the upstream transport roller 31 and the transport roller 32 is stopped, so that the paper P is loosened and stored in the storage range LA. Will be.

  Next, a state in which a part of the paper P is accommodated inside the second transport unit 12 will be described with reference to FIGS. FIG. 5 is a diagram illustrating an example of an operation for moving the paper P inside the second transport unit 12 at the boundary 81. FIG. 6 is a diagram illustrating an example of an operation of moving the paper P inside the second transport unit 12 at the boundary portion 82.

  As shown in FIG. 5, of the paper P, the leading end side of the paper P is accommodated in the accommodation range LB between the downstream conveyance roller 38 and the downstream conveyance roller 39. Specifically, the transport roller 38 stops and the transport rollers 39 and 41 cause the leading edge of the paper P to run backward, whereby the leading edge side of the paper P is moved to the inside of the second transport unit 12. If the straddling amount Lb of the paper P is not 0 or less during the reverse running operation of the leading end of the paper P, the backward running operation of the leading end of the paper P is continued, and if the straddling amount Lb of the paper P is 0 or less, the paper The reverse movement of the tip of P stops. Further, before the backward movement operation of the leading edge of the paper P, the transport guides 201a and 201b are in an open state, a space for accommodating the slack shape of the paper P is formed, and the paper P is accommodated in the accommodation range LB. The

  As shown in FIG. 6, among the paper P, the rear end side of the paper P is accommodated in the accommodation range LA between the upstream conveyance roller 31 and the upstream conveyance roller 32. Specifically, the transport roller 32 stops and the transport rollers 21 and 31 advance the rear end of the paper P, whereby the rear end side of the paper P is moved to the inside of the second transport unit 12. If the stride amount La of the paper P is not less than or equal to 0 during the advancing operation of the paper P, the advancing operation of the rear end of the paper P is continued, and if the straddle amount La of the paper P is 0 or less, the paper The advancing operation at the rear end of P stops. In addition, the transport guides 201c and 201d are opened before the trailing edge of the sheet P is advanced, so that a space for accommodating the slack shape of the sheet P is formed, and the sheet P is accommodated in the accommodation range LA. The

  Next, a state in which a part of the paper P is moved to the outside of the second transport unit 12 will be described with reference to FIGS. FIG. 7 is a diagram illustrating an example of an operation for moving the paper P to the outside of the second transport unit 12 at the boundary portion 81. FIG. 8 is a diagram illustrating an example of an operation for moving the paper P to the outside of the second transport unit 12 at the boundary portion 82.

  As shown in FIG. 7, of the paper P, the leading end side of the paper P is moved to the downstream side of the second transport unit 12. Specifically, when the transport roller 41 advances the leading end of the paper P, the leading end side of the paper P is moved to the outside of the second transport unit 12. During the advancing operation of the leading edge of the paper P, the straddling portion of the leading edge of the paper P is pulled and stopped.

  As shown in FIG. 8, the rear end side of the paper P among the paper P is moved to the upstream side of the second transport unit 12. Specifically, the transport roller 21 moves the rear end of the paper P backward, so that the rear end side of the paper P is moved to the outside of the second transport unit 12. When the backward movement of the rear end of the paper P is performed, the straddle portion of the rear end of the paper P is pulled and stopped.

  Next, an example of the paper P transport function will be described with reference to FIG. FIG. 9 is a flowchart for explaining an operation example of the image forming apparatus 1.

  In step S11, it is determined whether or not the transport function of the paper P has been stopped. When the transport function of the paper P is stopped (YES in step S11), the process proceeds to step S12. On the other hand, when the transport function of the paper P does not stop (NO in step S11), when the paper P is transported, the operation of determining whether or not the transport function of the paper P is stopped is repeated.

  In step S12, the straddling amounts La and Lb of the paper P are obtained, and in step S13, it is determined whether or not the straddling amounts La and Lb of the paper P are present. When there are the straddling amounts La and Lb of the paper P (YES in step S13), the process proceeds to step S14. On the other hand, when there are no straddling amounts La and Lb of the paper P (NO in step S13), the process proceeds to step S20, and in step S20, the lock mechanism is released, and the operator performs an operation of pulling out the second transport unit 12. Become.

  The determination of whether or not the sheet P has the straddling amounts La and Lb is performed for each of the straddling amounts La and Lb of the sheet P. If the straddling amount La of the sheet P is larger than 0, the straddling amount of the sheet P is determined. It is determined that there is La. The stride amount Lb of the paper P is similarly determined.

  In step S14, it is determined whether or not the straddling amounts La and Lb of the paper P are within the accommodation range. When the straddling amounts La and Lb of the paper P are within the accommodation ranges LA and LB (YES in step S14), the process proceeds to step S15, and an operation of moving the paper P to the inside of the second transport unit 12 is performed. On the other hand, when the straddling amounts La and Lb of the paper P are not within the accommodation ranges LA and LB (NO in step S14), the process proceeds to step S23, and the operation of moving the paper P to the outside of the second transport unit 12 is performed.

  Note that the determination whether or not the straddling amounts La and Lb of the paper P are within the accommodation ranges LA and LB is performed for each of the straddling amounts La and Lb of the paper P, and the straddling amount La of the paper P is the accommodation range. If it is equal to or less than LA, it is determined that the straddling amount La of the paper P is within the accommodation range LA. The stride amount Lb of the paper P is similarly determined.

  In step S15, it is determined whether or not the straddling amount La of the paper P is less than or equal to the accommodation range LA. If the straddling amount La of the paper P is less than or equal to the accommodation range LA (step S15 YES), an operation of advancing the trailing edge of the paper P is performed in step S16, and the straddling amount La of the paper P is 0 or less in step S17. It is determined whether or not there is, and an operation of advancing the trailing edge of the paper P is performed until the straddling amount La of the paper P becomes 0 or less.

  In step S18, it is determined whether or not the straddling amount Lb of the paper P is less than or equal to the accommodation range LB. When the straddling amount Lb of the paper P is equal to or less than the accommodation range LB (step S18 YES), the process proceeds to step S21. If the straddling amount Lb of the paper P is not less than or equal to the accommodation range LB (NO in step S18), the process proceeds to step S19. In step S19, the paper P is stopped, and in step S20, the operation described above is performed.

  On the other hand, when the straddling amount La of the paper P is not less than the accommodation range LA (step S15 NO), the process proceeds to step S21. In step S21, an operation of reversing the leading edge of the paper P is performed. In step S22, it is determined whether or not the straddling amount Lb of the paper P is 0 or less, and the straddling amount Lb of the paper P becomes 0 or less. The operation of reversing the leading edge of the paper P is performed. Next, the process proceeds to step S19. In step S19, the operation described above is performed, and in step S20, the operation described above is performed.

  In step S23, it is determined whether or not the straddling amount La of the paper P is larger than the accommodation range LA. When the straddling amount La of the paper P is larger than the accommodation range LA (YES in step S23), an operation of reversing the rear end of the paper P is performed in step S24, and the straddling portion of the rear end of the paper P is pulled in step S25. The state is stopped and the process proceeds to step S26. In step S26, it is determined whether or not the straddling amount Lb of the paper P is larger than the accommodation range LB. When the straddling amount Lb of the paper P is larger than the accommodation range LB (step S26 YES), the process proceeds to step S28, and when the straddling amount Lb of the paper P is not larger than the accommodation range LB (step S26 NO), the process proceeds to step S27.

  On the other hand, when the straddling amount La of the paper P is not larger than the accommodation range LA (step S23 NO), the process proceeds to step S28. In step S28, the leading edge of the paper P is advanced. In step S29, the straddling portion of the leading edge of the paper P is pulled and stopped, and the process proceeds to step S27. In step S <b> 27, an operation is performed to release the lock mechanism and to make the cutting units 71 and 72 severable.

  From the above description, in the image forming apparatus 1, the first conveyance unit 11, the second conveyance unit 12, and the third conveyance unit 13 are provided adjacent to each other, and the conveyance path of the paper P is formed. . Of the first transport unit 11, the second transport unit 12, and the third transport unit 13, the second transport unit 12 can be pulled out.

  When it is determined that the conveyance function of the paper P has been stopped, the image forming apparatus 1 uses the second conveyance unit 12 as a reference, according to the amount La of the sheet P to the first conveyance unit 11, or the first A part of the paper P is moved to the inside of the second transport unit 12 according to the amount Lb of the paper P straddling the third transport unit 13.

  Thereby, even if the 2nd conveyance part 12 is pulled out, the paper P does not get tangled in the middle of a conveyance path | route. Therefore, the recovery work can be surely and easily performed when the operator performs the recovery work of the paper P transport function.

  Here, when the straddling amounts La and Lb of the paper P are within the accommodation ranges LA and LB of the second transport unit 12, the end of the paper P is moved to the inside of the second transport unit 12. Thereby, the straddling amounts La and Lb of the paper P that can be accommodated can be accommodated in the second transport unit 12.

  Specifically, when the rear end side of the paper P straddles the first transport unit 11, the rear end of the paper P is moved to the inside of the second transport unit 12. 11, the span La of the paper P to 11 is improved. Thereby, when the second transport unit 12 is pulled out, the state where the paper P is entangled due to the span La of the paper P between the first transport unit 11 and the second transport unit 12 is improved. Can do.

  In addition, when the leading end side of the sheet P straddles the third transport unit 13, the leading end of the sheet P is moved to the inside of the second transport unit 12, and thus the sheet P to the third transport unit 13. The stride Lb is improved. Thereby, when the second transport unit 12 is pulled out, the state where the paper P is entangled due to the straddling Lb of the paper P between the second transport unit 12 and the third transport unit 13 is improved. Can do.

  Further, when it is determined that the conveyance function of the paper P is stopped, the image forming apparatus 1 uses the second conveyance unit 12 as a reference, according to the stride amount La of the paper P to the first conveyance unit 11. Alternatively, a part of the paper P is moved to the outside of the second transport unit 12 according to the stride amount Lb of the paper P to the third transport unit 13.

  Thus, when the second transportable portion 12 that can be pulled out is pulled out, the sheet P is pulled by the movement of the second transport portion 12 to the outside, so that the cutting operation can be easily performed. it can. As a result, the paper P does not get tangled in the middle of the transport path. Therefore, the recovery work can be surely and easily performed when the operator performs the recovery work of the paper P transport function.

  Here, when the straddling amounts La and Lb of the paper P are not within the accommodation ranges LA and LB of the second transport unit 12, the end of the paper P is moved to the outside of the second transport unit 12. Thereby, the straddling amounts La and Lb of the paper P that cannot be accommodated can be pulled toward the outside of the second transport unit 12.

  Specifically, when the rear end side of the paper P straddles the first transport unit 11, the rear end of the paper P is moved to the upstream side of the second transport unit 12. The sheet P straddling between the section 11 and the second transport section 12 is in a tension state. Thereby, when the 2nd conveyance part 12 is pulled out, the paper P straddling between the 1st conveyance part 11 and the 2nd conveyance part 12 can be cut | disconnected easily.

  Further, when the leading end side of the paper P straddles the third transport unit 13, the leading end of the paper P is moved to the downstream side of the second transport unit 12. The sheet P straddling between the three transport units 13 is in a tension state. Thereby, when the 2nd conveyance part 12 is pulled out, the paper P straddling between the 2nd conveyance part 12 and the 3rd conveyance part 13 can be cut | disconnected easily.

  Furthermore, since at least one of the part between the conveyance rollers 31, 32, 33 and the transfer roller 35 and the part between the fixing roller 36 and the conveyance rollers 38, 39 of the paper P is not moved, When it is determined that the conveyance function of the paper P is stopped, even if there is an unfixed image on the paper P, the paper P does not move. As a result, even when an unfixed image is present on the paper P when the paper trailing edge side and the paper leading edge side are moved after the jam occurs, the inside of the second transport unit 12 is moved without being stained. be able to.

  Further, when the portion of the paper P between the transport rollers 31, 32, 33 and the transfer roller 35 is not moved, the registration roller 34 can press the paper P in order to bring the registration roller 34 into a pressure-bonded state. . As a result, even when an unfixed image is present on the paper P when the paper trailing edge side and the paper leading edge side are moved after the jam occurs, the inside of the second transport unit 12 is moved without being stained. Can be carried out reliably.

  In addition, when the portion of the paper P between the fixing roller 36 and the transport rollers 38 and 39 is not moved, the fixing paper discharge roller 37 presses the paper P in order to bring the fixing paper discharge roller 37 into a pressure-bonded state. Can do. As a result, even when an unfixed image is present on the paper P when the paper trailing edge side and the paper leading edge side are moved after the jam occurs, the inside of the second transport unit 12 is moved without being stained. Can be carried out reliably.

  Further, since at least one of the transport roller 21 in the first transport unit 11 and the transport roller 31 on the most upstream side has a nip formed in the entire width direction of the paper P, the first transport unit 11 and the first transport unit 31 Even if the rear end side of the paper P straddles between the second transport unit 12, if the rear end of the paper P is moved to the upstream side of the second transport unit 12, the rear end side of the paper P Will be in tension without fluttering. Accordingly, it is possible to improve the difficulty of cutting due to the flapping of the paper P on the rear end side of the paper P.

  Further, since at least one of the most downstream transport roller 39 and the transport roller 41 in the third transport unit 13 has a nip formed in the entire width direction of the paper P, the second transport unit 12 and Even if the leading end side of the sheet P straddles the third conveying unit 13, if the leading end of the sheet P is moved downstream of the second conveying unit 12, the leading end side of the sheet P is It will be in tension without fluttering. Thereby, it is possible to improve the difficulty of cutting due to flapping of the paper P on the leading end side of the paper P.

  The cutting unit 71 includes at least one of the most downstream side of the first conveyance unit 11 and the most upstream side of the second conveyance unit 12, the most downstream side of the second conveyance unit 12, and the third conveyance. It is provided on at least one of the most upstream sides of the portion 13. Therefore, even if the rear end side of the paper P straddles between the first transport unit 11 and the second transport unit 12, the rear end of the paper P is moved to the upstream side of the second transport unit 12. If the rear end side of the paper P is pulled without flapping, the paper P can be reliably cut. Further, even if the leading end side of the paper P straddles between the second transport unit 12 and the third transport unit 13, the leading end of the paper P is moved to the downstream side of the second transport unit 12, If the leading end side of the paper P is pulled without flapping, the paper P can be reliably cut. Thereby, when the 2nd conveyance part 12 is pulled out, the rear end side of the paper P and the front end side of the paper P can be cut | disconnected reliably.

  Further, since the cutting units 71 and 72 are in a state in which the paper P can be cut when the second transport unit 12 is pulled out, the cutting operation of the paper P is performed when the second transport unit 12 is pulled out. It will be. Thereby, when the 2nd conveyance part 12 is pulled out, the paper P can be cut | disconnected reliably and easily.

  Further, when the second transport unit 12 is returned to the original position, the cutting units 71 and 72 are released from a state in which the paper P can be cut, and thus the second transport unit 12 is returned to the original position. Sometimes the cutting operation of the paper P is not performed. As a result, when the second transport unit 12 is returned to the original position, it is possible to promptly shift to the transport operation of the paper P.

  As described above, according to the image forming apparatus 1 according to the present embodiment, the first conveyance unit 11, the second conveyance unit 12, and the third conveyance unit 13 are provided adjacent to each other, and In the image forming apparatus 1 in which the transport path is formed and the second transport unit 12 can be pulled out, a determination unit 111 that determines whether the transport function of the paper P is stopped, and a determination unit 111 When it is determined that the conveyance function of the paper P has been stopped, the amount La of the paper P straddling the first conveyance unit 11 or the paper P to the third conveyance unit 13 with the second conveyance unit 12 as a reference. And a mechanism for moving a part of the sheet P to the inside of the second transport unit 12 according to the stride amounts La and Lb of the sheet P calculated by the calculation unit 112. And a control unit 113. Thereby, at the time of the restoration work of the conveyance function of the paper P by the operator, the restoration work can be performed reliably and easily.

  Further, the first transport unit 11, the second transport unit 12, and the third transport unit 13 are provided adjacent to each other to form a transport path for the paper P, and the second transport unit 12 can be pulled out. If the image forming apparatus 1 is a determination unit 111 that determines whether or not the conveyance function of the paper P has been stopped, and the determination unit 111 determines that the conveyance function of the paper P has been stopped, the second processing is performed. The calculation unit 112 that obtains the amount La of the sheet P to the first conveyance unit 11 or the amount Lb of the sheet P to the third conveyance unit 13 on the basis of the conveyance unit 12, and the calculation unit 112 A mechanism control unit 113 that moves a part of the sheet P to the outside of the second transport unit 12 according to the calculated straddling amounts La and Lb of the sheet P is provided. Thereby, at the time of the restoration work of the conveyance function of the paper P by the operator, the restoration work can be performed reliably and easily.

  Further, the mechanism control unit 113 moves the end of the paper P to the inside of the second transport unit 12 when the straddling amounts La and Lb of the paper P are within the accommodation ranges LA and LB of the second transport unit 12. It is something to be made. Thereby, the straddling amounts La and Lb of the paper P that can be accommodated can be accommodated in the second transport unit 12.

  Further, the paper P is transported in the order of the first transport unit 11, the second transport unit 12, and the third transport unit 13, and the mechanism control unit 113 transfers the first transport unit 11 to the first transport unit 11. When the rear end side of the paper P is straddling, the rear end of the paper P is moved to the inside of the second transport unit 12. Thereby, when the second transport unit 12 is pulled out, it is possible to improve the state in which the paper P is tangled due to the straddling of the paper P between the first transport unit 11 and the second transport unit 12. it can.

  Further, the paper P is transported in the order of the first transport unit 11, the second transport unit 12, and the third transport unit 13, and the mechanism control unit 113 transfers the third transport unit 13 to the third transport unit 13. When the leading end side of the sheet P is straddling, the leading end of the sheet P is moved to the inside of the second transport unit 12. Thereby, when the second transport unit 12 is pulled out, it is possible to improve the state in which the paper P is entangled due to the straddling of the paper P between the second transport unit 12 and the third transport unit 13. it can.

  Further, the mechanism control unit 113 moves the edge of the paper P to the outside of the second transport unit 12 when the straddling amounts La and Lb of the paper P are not within the accommodation ranges LA and LB of the second transport unit 12. Is. Thereby, the straddling amounts La and Lb of the paper P that cannot be accommodated can be pulled toward the outside of the second transport unit 12.

  Further, the paper P is transported in the order of the first transport unit 11, the second transport unit 12, and the third transport unit 13, and the mechanism control unit 113 transfers the first transport unit 11 to the first transport unit 11. When the rear end side of the paper P is straddling, the rear end of the paper P is moved to the upstream side of the second transport unit 12. Thereby, when the 2nd conveyance part 12 is pulled out, the paper P straddling between the 1st conveyance part 11 and the 2nd conveyance part 12 can be cut | disconnected easily.

  Further, the paper P is transported in the order of the first transport unit 11, the second transport unit 12, and the third transport unit 13, and the mechanism control unit 113 transfers the third transport unit 13 to the third transport unit 13. When the leading end side of the sheet P is straddling, the leading end of the sheet P is moved to the downstream side of the second transport unit 12. Thereby, when the 2nd conveyance part 12 is pulled out, the paper P straddling between the 2nd conveyance part 12 and the 3rd conveyance part 13 can be cut | disconnected easily.

  The second transport unit 12 is provided on the downstream side of the transfer roller 35 that forms the transfer nip, the transfer roller 35, the fixing roller 36 that forms the fixing nip, and on the upstream side of the transfer roller 35, Upstream conveying rollers 31, 32, 33 for moving the rear end of the sheet P, and downstream conveying rollers 38, 39 provided on the downstream side of the fixing roller 36 for moving the leading end of the sheet P, The mechanism control unit 113 is located in the portion of the paper P between the upstream transport rollers 31, 32, 33 and the transfer roller 35, and between the fixing roller 36 and the downstream transport rollers 38, 39. At least one of the parts is not moved. As a result, even when an unfixed image is present on the paper P when the paper trailing edge side and the paper leading edge side are moved after the jam occurs, the inside of the second transport unit 12 is moved without being stained. be able to.

  The second transport unit 12 further includes a registration roller 34 provided between the upstream transport rollers 31, 32, 33 and the transfer roller 35, and the mechanism control unit 113 includes the paper P When the portion between the upstream conveying rollers 31, 32, 33 and the transfer roller 35 is not moved, the registration roller 34 is brought into a pressure-bonded state. As a result, even when an unfixed image is present on the paper P when the paper trailing edge side and the paper leading edge side are moved after the jam occurs, the inside of the second transport unit 12 is moved without being stained. Can be carried out reliably.

  The second transport unit 12 further includes a fixing paper discharge roller 37 provided between the fixing roller 36 and the downstream transport rollers 38 and 39, and the mechanism control unit 113 includes the paper P When the portion between the fixing roller 36 and the downstream transport rollers 38 and 39 is not moved, the fixing paper discharge roller 37 is brought into a pressure-bonded state. As a result, even when an unfixed image is present on the paper P when the paper trailing edge side and the paper leading edge side are moved after the jam occurs, the inside of the second transport unit 12 is moved without being stained. Can be carried out reliably.

  The first transport unit 11 includes a transport roller that transports the paper P to the second transport unit 12, and among the transport rollers in the first transport unit 11, the transport roller 21 on the most downstream side and the upstream roller At least one of the transport rollers 31 on the most upstream side of the transport rollers 31, 32, 33 has a nip formed in the entire width direction of the paper P. Accordingly, it is possible to improve the difficulty of cutting due to the flapping of the paper P on the rear end side of the paper P.

  The third transport unit 13 includes a transport roller that transports the paper P transported from the second transport unit 12, and the most downstream transport roller 39 and the third of the downstream transport rollers 38 and 39. At least one of the most upstream side transport rollers 41 among the transport rollers in the transport unit 13 has a nip formed in the entire width direction of the paper P. Thereby, it is possible to improve the difficulty of cutting due to flapping of the paper P on the leading end side of the paper P.

  In addition, it further includes cutting units 71 and 72 for cutting the paper P, and the cutting units 71 and 72 are at least one of the most downstream side of the first conveyance unit 11 and the most upstream side of the second conveyance unit 12; It is provided on at least one of the most downstream side of the second conveyance unit 12 and the most upstream side of the third conveyance unit 13. Thereby, when the 2nd conveyance part 12 is pulled out, the rear end side of the paper P and the front end side of the paper P can be cut | disconnected reliably.

  In addition, the cutting units 71 and 72 are capable of cutting the paper P when the second transport unit 12 is pulled out. Thereby, when the 2nd conveyance part 12 is pulled out, the paper P can be cut | disconnected reliably and easily.

  Further, the cutting units 71 and 72 are released from a state in which the paper P can be cut when the second transport unit 12 is returned to the original position. As a result, when the second transport unit 12 is returned to the original position, it is possible to promptly shift to the transport operation of the paper P.

  The image forming apparatus according to the present invention has been described above based on the embodiment. However, the present invention is not limited to this, and modifications may be made without departing from the spirit of the present invention.

  For example, an example of a configuration for forming a full-color image has been described. In this case, it is sufficient that the transfer roller 35 is in contact with a photosensitive drum (not shown) and a transfer nip is formed.

  In addition, in the present embodiment, an example in which the transport rollers 21, 31, 32, 33, 38, 39, and 41 are provided has been described. However, the present invention is not limited thereto, and different numbers and arrangement configurations may be used.

  Moreover, although the example in which the reverse conveyance path | route 84 was provided in the 2nd conveyance part 12 was demonstrated, not only this but the reverse conveyance path | route 84 does not need to be provided in the 2nd conveyance part 12. FIG.

  Moreover, although an example of the configuration of the transport guides 201a to 201d has been described, the present invention is not limited to this, and any configuration is acceptable as long as the paper P can be stored in the storage ranges LA and LB.

  Moreover, although the example provided with the sensors 50a-50h was demonstrated, not only this but a different number and arrangement | positioning structure may be sufficient.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 6 Intermediate transfer belt 11 1st conveyance part 12 2nd conveyance part 13 3rd conveyance part 21,31-33,38,39,41 Conveyance roller 34 Registration roller 35 Transfer roller 36 Fixing roller 37 Fixing Paper discharge roller 50, 50a-50h Sensor 71, 72 Cutting part 81, 82 Boundary part 83 Unfixed image conveyance path 84 Reverse conveyance path 100 Controller 111 Determination part 112 Calculation part 113 Mechanism control part 114 Timing part 115 Non-volatile memory 201a- 201d Conveyance guide P Paper La, Lb Amount span LA, LB Accommodation range

Claims (16)

An image forming apparatus in which a first transport unit, a second transport unit, and a third transport unit are provided adjacent to each other to form a sheet transport path, and the second transport unit can be pulled out freely. Because
A determination unit for determining whether or not the sheet conveyance function is stopped;
When the determination unit determines that the sheet conveyance function has stopped, the amount of the sheet straddling the first conveyance unit or the third conveyance unit with the second conveyance unit as a reference A calculation unit for determining the amount of sheet straddling
Depending on the amount of paper straddling computed by the computing unit, a part of the paper is moved to the inside of the second transport unit, and the straddling of the paper with the first transport unit, or the A mechanism control unit that eliminates the straddling of the sheet with the third transport unit ;
An image forming apparatus comprising: An image forming apparatus in which a first transport unit, a second transport unit, and a third transport unit are provided adjacent to each other to form a sheet transport path, and the second transport unit can be pulled out freely. Because
A determination unit for determining whether or not the sheet conveyance function is stopped;
When the determination unit determines that the sheet conveyance function has stopped, the amount of the sheet straddling the first conveyance unit or the third conveyance unit with the second conveyance unit as a reference A calculation unit for determining the amount of sheet straddling
Depending on the amount of paper straddling calculated by the arithmetic unit, a part of the paper is moved to the outside of the second transport unit, and the straddling portion of the paper with the first transport unit, or A mechanism control unit for pulling the sheet straddling part with the third transport unit ;
An image forming apparatus comprising:   The mechanism control unit is configured to move an end portion of the sheet to the inside of the second conveyance unit when the amount of the sheet straddling is within an accommodation range of the second conveyance unit. The image forming apparatus according to claim 1. The paper is transported in the order of the first transport unit, the second transport unit, and the third transport unit,
The mechanism control unit is configured to move the rear end of the sheet to the inside of the second transport unit when the rear end side of the sheet straddles the first transport unit. The image forming apparatus according to claim 3. The paper is transported in the order of the first transport unit, the second transport unit, and the third transport unit,
The mechanism control unit is configured to move the leading end of the sheet to the inside of the second conveying unit when the leading end side of the sheet straddles the third conveying unit. The image forming apparatus according to 3.   The mechanism control unit is configured to move an end portion of the sheet to the outside of the second conveyance unit when the amount of the sheet straddling is not within an accommodation range of the second conveyance unit. The image forming apparatus according to claim 2. The paper is transported in the order of the first transport unit, the second transport unit, and the third transport unit,
The mechanism control unit is configured to move the trailing end of the sheet to the upstream side of the second conveying unit when the trailing end of the sheet straddles the first conveying unit. The image forming apparatus according to claim 6. The paper is transported in the order of the first transport unit, the second transport unit, and the third transport unit,
The mechanism control unit is configured to move the leading end of the sheet to the downstream side of the second conveying unit when the leading end side of the sheet straddles the third conveying unit. Item 7. The image forming apparatus according to Item 6. The second transport unit is
A transfer roller that forms a transfer nip; and
A fixing roller provided on the downstream side of the transfer roller and forming a fixing nip;
An upstream conveying roller that is provided upstream of the transfer roller and moves a rear end of the paper; and
A downstream conveying roller that is provided downstream of the fixing roller and moves the leading edge of the paper;
With
The mechanism control unit includes at least one of a portion of the paper between the upstream conveyance roller and the transfer roller, and a portion between the fixing roller and the downstream conveyance roller. The image forming apparatus according to claim 1, wherein the image forming apparatus is not moved. The second transport unit is
Further comprising a registration roller provided between the transport roller on the upstream side and the transfer roller,
The said mechanism control part makes the said registration roller into a crimping | compression-bonding state, when not moving the part between the said upstream conveyance roller and the said transfer roller among the said sheets. The image forming apparatus according to 9. The second transport unit is
A fixing discharge roller provided between the fixing roller and the downstream transport roller;
The mechanism control unit is configured to cause the fixing paper discharge roller to be in a pressure-bonded state when the portion of the paper between the fixing roller and the downstream transport roller is not moved. The image forming apparatus according to claim 9. The first transport unit includes a transport roller that transports the paper to the second transport unit,
At least one of the most downstream conveyance roller of the conveyance rollers in the first conveyance unit and the most upstream conveyance roller of the upstream conveyance rollers has a nip formed in the entire width direction of the sheet. The image forming apparatus according to claim 7, wherein the image forming apparatus is an image forming apparatus. The third transport unit includes a transport roller that transports the paper transported from the second transport unit,
At least one of the downstream-side transport roller among the downstream-side transport rollers and the most upstream-side transport roller among the transport rollers in the third transport unit has a nip formed in the entire width direction of the sheet. The image forming apparatus according to claim 8, wherein the image forming apparatus is an image forming apparatus. A cutting unit for cutting the paper;
The cutting unit includes at least one of the most downstream side of the first transport unit and the most upstream side of the second transport unit, and the most downstream side of the second transport unit and the third transport unit. The image forming apparatus according to claim 12, wherein the image forming apparatus is provided on at least one of the most upstream sides.   The image forming apparatus according to claim 14, wherein the cutting unit is in a state where the sheet can be cut when the second transport unit is pulled out.   The image forming apparatus according to claim 14, wherein the cutting unit is released from a state in which the sheet can be cut when the second transport unit is returned to the original position.

Images