Post-processing device and image formation apparatus

Abstract

To provide a post-processing device in which miniaturization is attained compared to the case where, by using a device which executes an overlapping operation on large recording media at passages where an overlapping operation is executed on small recording media, the passages in the device is extended according to the large recording media.SOLUTION: A post-processing device comprises: a first passage 10 for receiving recording media each having an image formed and guiding the same to a discharge part 112; a second passage 20 branched from the first passage 10, receiving the recording medium PA in the first passage 10 to clear the first passage 10, and guiding the recording media PA, PB to be post-processed to a storage part 411 for temporarily storing them; and a third passage 30 branched from the second passage 20, utilizable upon executing an operation of overlapping the recording medium PB in the first passage 10 and the recording medium PA in the second passage 20 each other by utilizing the first passage 10 and the second passage 20, and into which a tip part P2 of the recording medium PA progressing from the first passage 10 to the second passage 20 enters.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a post-processing device and an image forming apparatus. [Background technology]

[0002] For example, Patent Document 1 discloses a paper post-processing device that includes a first transport path that guides incoming paper to a first post-processing means, a first waiting path that branches off from a branching point of the first transport path and a second waiting path that is formed continuously with the first waiting path and merges with the first transport path, a transport waiting path that allows paper to be transported to the first post-processing means to wait on the first waiting path and the second waiting path, a second transport path that branches off from the branching point of the first waiting path and guides paper that is transported to the first waiting path to the second post-processing means, a first path switching means that is provided at the branching point of the first transport path and switches and connects the first transport path to either the first waiting path or the first post-processing means, and a second path switching means that is provided at the branching point of the first waiting path and switches and connects the first waiting path to either the second waiting path or the second transport path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-184177 Summary of the Invention [Problem to be solved by the invention]

[0004] Consider a case where recording media of different sizes are handled when superimposing recording media using a path within an apparatus that performs post-processing on recording media on which an image has been formed. If a large recording medium is superimposed on a path that is used for superimposing small recording media, it is necessary to ensure that the path length within the apparatus is long enough to accommodate the large recording medium, which results in an increase in the size of the apparatus. The object of the present invention is to make the device smaller in size compared to a case where a path within the device is extended to accommodate the large recording medium in a device that performs the superimposition operation of a large recording medium on a path that performs the superimposition operation of a small recording medium. [Means for solving the problem]

[0005] The invention described in claim 1 is a post-processing device comprising: a first path that receives a recording medium on which an image has been formed and guides it to an ejection section; a second path that branches off from the first path and receives the recording medium on the first path to free up the first path, the second path guiding the recording medium to be post-processed to a storage section that temporarily stores the recording medium; and a third path that branches off from the second path and can be used when using the first path and the second path to overlap the recording medium on the first path and the recording medium on the second path, the third path into which the leading end of the recording medium traveling from the first path to the second path enters. The invention described in claim 2 is the post-processing device described in claim 1, characterized in that the third path has a portion that overlaps with the second path in a height direction. The invention described in claim 3 is the post-processing device described in claim 2, characterized in that the portion of the third path is located in an area separated by the portion of the first path that accepts the recording medium and the second path. The invention described in claim 4 is the post-processing device described in claim 3, characterized in that the third path is provided on the side where the storage section is located when the inside of the device is divided by the second path and a virtual extension line of the second path. The invention described in claim 5 is the post-processing device described in claim 1, characterized in that when the second path is divided at the branching position of the third path into a first part which is the part on the storage section side and a second part which is the part on the opposite side from the storage section, the angle formed between the third path and the first part is smaller than the angle formed between the third path and the second part. The invention described in claim 6 is the post-processing device described in claim 1, characterized in that the leading edge enters the third path when the recording medium satisfies predetermined conditions indicating its outer shape. The invention described in claim 7 is a post-processing device comprising: a first path that receives a recording medium on which an image has been formed and guides it to an ejection section; a second path that branches off from the first path and receives the recording medium on the first path to free the first path, the second path guiding the recording medium to a storage section that temporarily stores the recording medium to be post-processed; and a third path that can be used when a recording medium is stored in the storage section and the first and second paths are used to overlap the recording medium on the first path and the recording medium on the second path, the third path branching off from the second path at a position that does not interfere with the recording medium in the storage section and into which the leading end of the recording medium traveling from the first path to the second path enters. The invention described in claim 8 is the post-processing device described in claim 7, characterized in that it is provided with a switching member that is located at a position where the third path branches off from the second path and switches the direction in which the recording medium travels. The invention described in claim 9 is the post-processing device described in claim 8, characterized in that the switching member guides the recording medium to the third path during the overlapping operation, and switches the direction in which the recording medium moves from the third path to the storage section when the overlapping operation is completed. The invention described in claim 10 is an image forming apparatus including the post-processing device described in claim 1 or 7. [Effects of the Invention]

[0006] According to the invention of claim 1, the device can be made smaller than when a path within the device is extended to accommodate a large recording medium in a device that performs the overlapping operation of a small recording medium on a path used for the overlapping operation of a large recording medium. According to the invention of claim 2, the height dimension of the device can be reduced compared to when the third path does not have a configuration in which the third path has a portion that overlaps with the second path in the height direction. According to the invention of claim 3, the third path portion can be more easily positioned within the device than when it does not have a configuration in which it is located in an area separated by the receiving side portion of the first path for the recording medium and the second path. According to the invention of claim 4, the third path can allow recording media that have been superimposed using the third path to enter the storage section more smoothly than when the third path is not provided on the side where the storage section is located when the inside of the device is divided by the second path and a virtual extension line of the second path. According to the invention of claim 5, when the second path is divided at the branching position of the third path into a first part which is the part on the storage section side and a second part which is the part on the opposite side from the storage section, the angle between the third path and the first part is smaller than the angle between the third path and the second part, so that the recording medium can enter the third path from the second path more smoothly than when the configuration is not provided. According to the invention of claim 6, the third path allows the device to be made smaller than when it does not have a configuration in which the tip enters when the recording medium satisfies predetermined conditions indicating its outer shape. According to the invention of claim 7, in an apparatus that performs the overlapping operation of a large recording medium on a path that performs the overlapping operation of a small recording medium, the apparatus can be made smaller than when the path within the apparatus is extended to accommodate the large recording medium. According to the invention of claim 8, the configuration can be simplified compared to a case where the third path is provided at a position where it branches off from the second path and does not include a switching member that switches the direction in which the recording medium moves. According to the invention of claim 9, the switching member guides the recording medium to the third path during the overlapping operation, and when the overlapping operation is completed, switches the direction in which the recording medium moves from the third path to the storage section, allowing post-processing and the overlapping operation to be performed in parallel, compared to a case in which the switching member is not provided with a configuration in which the switching member guides the recording medium to the third path during the overlapping operation and switches the direction in which the recording medium moves from the third path to the storage section when the overlapping operation is completed. According to the invention of claim 10, in an apparatus that performs the overlapping operation of a large recording medium on a path that performs the overlapping operation of a small recording medium, the apparatus can be made smaller than when the path within the apparatus is extended to accommodate the large recording medium. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 2]FIG. 2 is a diagram illustrating a first example of conveyance of a recording medium. [Figure 3] FIG. 2 is a diagram illustrating a first example of conveyance of a recording medium. [Figure 4] FIG. 10 is a diagram illustrating a second example of conveyance of a recording medium. [Figure 5] FIG. 10 is a diagram illustrating a second example of conveyance of a recording medium. [Figure 6] FIG. 10 is a diagram illustrating a second example of conveyance of a recording medium. [Figure 7] FIG. 10 is a diagram illustrating a second example of conveyance of a recording medium. [Figure 8] FIG. 10 is a diagram illustrating a second example of conveyance of a recording medium. [Figure 9] FIG. 10 is a diagram illustrating a second example of conveyance of a recording medium. [Figure 10] FIG. 10 is a diagram illustrating a third example of conveyance of a recording medium. [Figure 11] 10 is a flowchart showing an example of gate control. [Figure 12] FIG. 2 is a diagram illustrating the relationship between a first route, a second route, and a third route. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. <Image forming apparatus 100> First, a description will be given of the configuration of an image forming apparatus 100 according to this embodiment. Fig. 1 is a schematic diagram showing the configuration of an image forming apparatus 100 according to this embodiment.

[0009] In the drawings, the arrow UP indicates the top of the device, and the arrow DO indicates the bottom of the device. In addition, the arrow LH indicates the left of the device, and the arrow RH indicates the right of the device. In addition, the arrow FR indicates the front of the device, and the arrow RR indicates the rear of the device. These directions are defined for the convenience of explanation, and the device configuration is not limited to these directions. In addition, in each direction of the device, the word "device" may be omitted. That is, for example, "above the device" may be simply referred to as "upper", and "below the device" may be simply referred to as "lower".

[0010] In the following description, the term "vertical direction" may be used to mean "both upward and downward," "either upward or downward," or "height direction." The height direction here refers to the direction of arrows UP and DO. The term "left and right direction" may be used to mean "both right and left" or "either right or left." The term "left and right direction" can also be referred to as the lateral, horizontal, or horizontal direction. The "front-rear direction" may mean "both forward and backward" or "either forward or backward." The "front-rear direction" may also be referred to as the lateral, transverse, or horizontal direction. The up-down direction, left-right direction, and front-rear direction are directions that intersect with each other, specifically, directions that are perpendicular to each other.

[0011] In addition, the symbol "x" inside a "circle" in the figure indicates an arrow pointing from the front to the back of the page. In addition, the symbol "·" inside a "circle" in the figure indicates an arrow pointing from the back to the front of the page. Furthermore, the dimensional ratios of the parts shown in the drawings in the up-down, left-right, and front-rear directions may differ from the actual dimensional ratios.

[0012] The image forming apparatus 100 shown in Fig. 1 is an apparatus that forms an image on a recording medium P (see Fig. 2), and as shown in Fig. 1, includes an image forming unit 101 and a post-processing unit 102. Each unit of the image forming apparatus 100, specifically the image forming unit 101 and the post-processing unit 102, will be described below.

[0013] <Image forming unit 101> 1 is a component that forms an image on a recording medium P. As the image forming unit 101, for example, an electrophotographic image forming unit that forms an image on the recording medium P using toner is used.

[0014] In an electrophotographic image forming unit, for example, the steps of charging, exposing, developing, transferring, and fixing are performed to form an image on a recording medium P. Specifically, in an electrophotographic image forming unit, for example, the steps of charging, exposing, developing, and transferring are performed to form an image on a transfer body, and the image is transferred from the transfer body to the recording medium P, and then the image is fixed to the recording medium P, thereby forming an image on the recording medium P.

[0015] Note that the image forming unit is not limited to the electrophotographic image forming unit described above, but may be, for example, an inkjet image forming unit, and various other image forming units can be used. In the inkjet image forming unit, for example, an image is formed on the recording medium P by ejecting ink droplets from an ejection unit onto the recording medium P.

[0016] <Post-processing device 102> The post-processing device 102 shown in Figure 1 is a device that performs post-processing, which is processing performed on a recording medium P on which an image has been formed by the image forming unit 101, and is equipped with a first post-processing unit 103 and a second post-processing unit 104. The post-processing device 102 also includes a control unit 105 that controls each unit. The control unit 105 includes, for example, a CPU, a RAM, a ROM, and the like.

[0017] The first post-processing unit 103 of the post-processing device 102 performs, as post-processing, a binding process in which a plurality of recording media P are bound by a stapler, but is not limited to this. For example, the first post-processing unit 103 may perform a cutting process in which the recording media P are cut, a punching process in which holes are punched in the recording media P, or any other process that is performed on the recording media P on which an image has been formed. The second post-processing unit 104 of the post-processing device 102 performs post-processing such as binding and folding on the central portion in the conveying direction of the plurality of recording media P to produce a booklet. Note that the binding and folding processes may be referred to as saddle stitching hereinafter.

[0018] The post-processing device 102 also includes a receiving section 111 that receives a recording medium P on which an image has been formed by the image forming section 101, and a first discharging section 112 that discharges the recording medium P that has been received by the receiving section 111 and post-processed by the first post-processing section 103. Furthermore, the post-processing device 102 includes a second discharge section 113 that discharges the recording medium P that has been received by the receiving section 111 and post-processed by the second post-processing section 104. The first ejection section 112 is an example of an ejection section.

[0019] In the post-processing device 102, the receiving section 111 and the first discharge section 112 are located on the upper side of the device, and the second discharge section 113 is located on the lower side of the device. The receiving section 111 is provided on the left side of the post-processing device 102, and the first discharge section 112 and the second discharge section 113 are provided on the right side of the post-processing device 102.

[0020] The post-processing device 102 includes a first path 10, which is a path for transporting the recording medium P received by the receiving unit 111 to the first discharge unit 112, and a second path 20, which branches off from a branch point 14 of the first path 10, extends downward, and transports the recording medium P to the second post-processing unit 104. To explain further, the recording medium P proceeding to the second post-processing unit 104 on the second path 20 is post-processed by the second post-processing unit 104 as described above, and is discharged to the second discharge unit 113 as a booklet.

[0021] In addition to the first path 10 and the second path 20 described above, the post-processing device 102 also includes a third path 30 that branches off from the branch point 23 of the second path 20 and extends obliquely downward. To explain further, in this embodiment, the third path 30 is provided on the image forming unit 101 side, i.e., the receiving unit 111 side, of the second path 20, in consideration of effective use of the internal layout of the post-processing device 102 and mitigating the degree of bending of the recording medium P when transported to the third path 30. However, the position of the third path 30 is not limited to this, and a configuration is also possible in which the third path 30 is provided on the opposite side of the second path 20 from the image forming unit 101 side. This allows the leading edge of the recording medium P transported on the third path 30 to protrude from the outer surface of the post-processing device 102, making it possible to accommodate recording media P that are longer in the transport direction. In FIG. 1, the path of the recording medium P is indicated by a thick line.

[0022] The first path 10 is provided with a transport roll 11, a transport roll 12 located closer to the first discharge section 112 than the transport roll 11, and a first detection section 13 located between the transport roll 11 and the transport roll 12. In this embodiment, the transport roll 12 is provided at a branch point 14 of the first path 10. The first detection unit 13 detects an end, for example, the leading end, of the recording medium P transported along the first path 10.

[0023] The transport roll 11 can control the transport speed of the recording medium P. Furthermore, the transport roll 11 can control the transport timing of transporting the recording medium P on the first path 10 based on the detection result of the first detection unit 13. The transport rolls 12 are capable of rotating forward and backward, and are capable of switching back the recording medium P on the first path 10. That is, when the transport rolls 12 rotate forward, the recording medium P is discharged to the first discharge section 112. When the transport rolls 12 rotate backward, the recording medium P switched back on the first path 10 is transported to the second path 20.

[0024] Note that the term "switchback" used here refers to switching the conveyance direction or traveling direction of the recording medium P to the opposite direction. That is, when the traveling direction is one way, the leading end of the recording medium P becomes the trailing end when the traveling direction is switched back and the recording medium P travels in the other direction, which is the opposite direction. The leading end and trailing end of the recording medium P before the switchback become the trailing end and leading end, respectively, after the switchback.

[0025] The second path 20 is provided with a transport roll 21 and a second detection unit 22 located closer to the branch point 14 of the first path 10 than the transport roll 21. The second detection unit 22 detects the end, for example, the leading end, of the recording medium P transported along the second path 20.

[0026] Like the transport rolls 12 of the first path 10 described above, the transport rolls 21 are reversible and can switch back the recording medium P in the second path 20. That is, when the transport rolls 21 rotate in the forward direction, the recording medium P is transported downward. When the transport rolls 21 rotate in the reverse direction, the recording medium P that has been switched back in the second path 20 is returned from the branch point 14 to the first path 10.

[0027] The operation of returning the recording medium P on the second path 20 to the first path 10 is performed in synchronization with the timing at which the first detection unit 13 detects the recording medium P received by the receiving unit 111. As a result, the preceding recording medium P on the second path 20 and the following recording medium P on the first path 10 overlap each other on the first path 10. On the second path 20, it is possible to transport a stack of multiple recording media P in this way, and by repeating this, it is possible to create a stack of a larger number of sheets.

[0028] In this way, the post-processing device 102 according to the present embodiment can perform a stacking operation, which is an operation of stacking the recording media P sequentially received by the receiving unit 111 onto one another to form a bundle of multiple sheets. The bundle of recording media P stacked by this stacking operation is transported to the second post-processing unit 104 described above, where post-processing is performed.

[0029] To explain further, if the recording medium P received by the receiving section 111 is not subjected to an overlapping operation and post-processing is not performed in the second post-processing section 104, it is discharged from the first path 10 to the first discharge section 112. In addition, if the recording medium P accepted by the receiving section 111 is to be post-processed in the second post-processing section 104 after the overlapping operation, it is transported from the first path 10 to the second path 20, post-processed in the second post-processing section 104, and discharged as a booklet to the second discharge section 113.

[0030] It is also possible that the recording medium P received by the receiving section 111 is discharged to the first discharge section 112 after a superposition operation is performed, or that the recording medium P is not superposed and is subjected to post-processing by the second post-processing section 104 in a single sheet state before being discharged to the second discharge section 113. In addition, in this embodiment, the recording medium P received by the receiving unit 111 is transported to the second post-processing unit 104 via the first path 10 and the second path 20, but a modified example is also possible in which an additional path (not shown) is provided for transporting the recording medium P received by the receiving unit 111 directly to the second path 20 without passing through the first path 10.

[0031] The third path 30 is provided with a chute 31, a stopper 32, a gate 33, and a motor 34 that drives the gate 33. Although the motor 34 is a dedicated drive source for driving only the gate 33, the present invention is not limited to this, and it is also possible to use the motor 34 as a drive source for driving the transport rolls 21, for example.

[0032] The chute 31 is a plate-like member that guides the recording medium P that has entered the third path 30, and holds the recording medium P on its upper surface. The chute 31 is composed of a first member 31a and a second member 31b. The portion where the first member 31a and the second member 31b are connected to each other is formed in a smooth arc shape.

[0033] The stopper 32 is a member that defines the moving end of the recording medium P that has entered the third path 30, and is provided at the end of the second member 31b that is far from the first member 31a. The stopper 32 is provided in the third path 30, and the third path 30 is not a through path but a dead-end path. Therefore, the recording medium P that has entered the third path 30 exits the third path 30 by reversing.

[0034] Here, when the recording medium P enters the third path 30, the rear end of the recording medium P is held by the transport roll 21. When the recording medium P that has entered the third path 30 is held by the transport roll 21, the leading end of the recording medium P is positioned so as not to come into contact with the stopper 32. Then, if the recording medium P that has entered the third path 30 is no longer held by the transport roll 21, the stopper 32 prevents the recording medium P from falling out of the third path 30.

[0035] Gate 33 is provided at branch point 23 of second path 20, and switches the direction in which recording medium P travels on second path 20. The recording medium P may travel in either the third path or the paper stacking unit 411. In this embodiment, the gate 33 is rotatable about a rotation axis 33a. More specifically, the gate 33 rotates about the rotation axis 33a by receiving a driving force from the motor 34, and thereby changes its posture so that the direction in which the recording medium P moves changes.

[0036] Such a change in posture can be made from a posture that blocks the second path 20 (see FIG. 1) to a posture that does not block the second path 20, or from a posture that does not block the second path 20 to a posture that blocks the second path 20 (see FIG. 1). That is, the former is a case where the recording medium P is guided from the second path 20 to the paper stacking unit 411, and the latter is a case where the recording medium P is guided to the third path 30.

[0037] 1 is in a position blocking the second path 20, the recording medium P from the first path 10 proceeds to the third path 30. On the other hand, when the gate 33 is in a position not blocking the second path 20, the recording medium P from the first path 10 proceeds straight along the second path 20 toward the paper stacking unit 411 of the second post-processing unit 104. The gate 33 is an example of a switching member.

[0038] Next, the configuration of the second post-processing unit 104 will be described. As described above, the recording medium P is transported to the second post-processing unit 104 via the second path 20, where it is saddle-stitched and the produced booklet is discharged to the second discharge unit 113. Note that the "stack of recording media P" or simply "stack" also includes a stack consisting of a single recording medium P.

[0039] 1, the second post-processing section 104 is provided with a compile tray 41, a guide 42, a feed roll 43, an end guide 44, a paper alignment member 45, a stapler 46, a folding knife 47, and a folding roll 48. The operation of each section of the second post-processing section 104 is controlled by the control section 105. For example, the opening and closing mechanism of the end guide 44 and the operation of the folding knife 47 and the folding roll 48 are controlled by the control section 105.

[0040] The compile tray 41 holds the recording media P that are sequentially conveyed from the image forming apparatus 100. This creates a stack of one or more recording media P. The number of sheets in the stack of recording media P is specified by the settings of the printing process to be executed. In this specification, the term "sheet stack" also includes a stack consisting of one recording medium P. The compile tray 41 has a plate-shaped paper stacking portion 411 having a size corresponding to the recording medium P. The paper stacking unit 411 is a member for stacking a stack of recording media P to be saddle-stitched. The second path 20 guides the recording media P to the paper stacking unit 411. The paper stacking unit 411 is an example of a storage unit that temporarily stores recording media to be post-processed.

[0041] The guide 42 is disposed at a position facing the compile tray 41, and guides the recording medium P fed from the feed roll 43. The guide 42 is disposed along the compile tray 41 with a gap between it and the compile tray 41.

[0042] The feed roll 43 feeds the recording medium P conveyed from the image forming apparatus 100 toward the compile tray 41. When printing processing is performed on multiple sheets of recording medium P, the feed roll 43 feeds the recording medium P a number of times corresponding to the number of sheets to be printed.

[0043] The end guide 44 includes an abutment portion 441 against which the lower end of the stack of recording media P abuts, and an opening / closing mechanism 442 that can apply pressure to and hold the recording media P whose lower end abuts against the abutment portion 441. The abutment portion 441 is configured to be movable in the vertical direction A. This allows the position of the recording media P to be changed depending on the processing to be performed on the stack of recording media P, that is, the binding processing and folding processing.

[0044] The opening and closing mechanism 442 is movable in a direction intersecting the up-down direction A, and is configured to be able to change the storage width for storing the recording media P. That is, the opening and closing mechanism 442 is movable in the thickness direction of the stack of recording media P. More specifically, the opening and closing mechanism 442 is capable of selecting either a closed state in which it moves in a direction that narrows the storage width and clamps and pressurizes the stack of recording media P when performing post-processing, or an open state in which it moves in a direction that widens the storage width and allows the recording media P to be inserted and removed without clamping the stack of recording media P.

[0045] The paper alignment member 45 is a tamper that presses, i.e., tamps, the stack of sheets stacked on the compile tray 41 to align the stack of sheets. The paper alignment member 45 may have a configuration that presses the stack from above to align the stack in the vertical direction together with the abutment portion 441 of the end guide 44. The paper alignment member 45 may perform the operation of aligning the recording media P every time the recording media P are transported onto the compile tray 41, or may align the sheets after the number of recording media P determined by the settings of the print process has been stacked on the compile tray 41.

[0046] The stapler 46 performs a binding process on the stack of sheets of paper loaded on the compile tray 41. In this embodiment, the description will be made assuming a binding process in which a stack of sheets of paper is bound using staples, but instead of using staples, a mechanism in which sheets of paper are bound by pressing them together may also be used.

[0047] The folder knife 47 presses the stack of recording media P. The folder knife 47 is disposed at a position opposite to the compile tray 41. The folding knife 47 has a protrusion 471 that is configured to be able to advance and retreat toward the compile tray 41 across the width of the recording media P. When the protrusion 471 is in the retracted position, the folding knife 47 is positioned so as not to come into contact with the stacks stacked on the compile tray 41. When the protrusion 471 is advanced toward the compile tray 41, the folding knife 47 passes through the opening of the compile tray 41 and reaches the folding roll 48 provided on the back side of the compile tray 41. Therefore, when the protrusion 471 advances toward the compile tray 41 with a stack stacked on the compile tray 41, the folding knife 47 comes into contact with the surface of the stack and presses the stack toward the opening of the compile tray 41. As a result, the stack of recording media P is bent at the position pressed by the protrusion 471 of the folding knife 47, forming a bent portion.

[0048] Next, various examples of conveyance of the recording medium P in the post-processing device 102 will be described. In the explanation of various conveyance examples, in consideration of the case where a switchback is performed, the leading end of the recording medium P when received by the receiving unit 111 of the post-processing device 102 will be described as the first end P1, and the trailing end will be described as the second end P2. In addition, to distinguish between the recording media P in the overlapping operation, one alphabet will be added after "P", and it will be assumed that recording medium PB is conveyed after recording medium PA. In addition, in the drawings explaining various transport examples, the first path 10, the second path 20, and the third path 30 along which the recording medium P is transported are indicated by dashed lines, and the recording medium P to be transported is indicated by a solid line. Hereinafter, a first example, a second example, and a third example of conveying the recording medium P will be described.

[0049] <First transport example> First, a first transport example will be described. In the first transport example, the recording medium P is transported to the first discharge section 112 via the first path 10. 2 and 3 are diagrams for explaining a first example of conveyance of the recording medium P, and show the conveyance of the recording medium P in chronological order.

[0050] In the first transport example, as shown in Fig. 2, the recording medium P received by the receiving unit 111 of the post-processing device 102 is transported along the first path 10, during which post-processing is performed by the first post-processing unit 103. The post-processed recording medium P continues along the first path 10 and is discharged from the first discharge unit 112 as shown in Fig. 3. In the first transport example, the recording medium P does not switch back.

[0051] In the first conveyance example, one recording medium P is discharged from the first discharge unit 112 after being subjected to post-processing by the first post-processing unit 103, but this is not limiting. That is, it is also possible that the recording medium P is discharged from the first discharge unit 112 without being subjected to post-processing by the first post-processing unit 103. It is also conceivable that the recording media P are discharged as a bundle from the first discharge section 112. That is, in the first transport example, the overlapping operation that also uses the second path 20 is not performed, but it is also conceivable that a plurality of recording media P are discharged from the first discharge section 112 by performing the overlapping operation.

[0052] <Second transport example> Next, a second transport example will be described. In the second transport example, the recording media PA and PB are discharged to the second discharge unit 113 via the first path 10 and the second path 20, and an overlapping operation is performed on the recording media PA and PB. 4, 5, 6, 7, 8 and 9 are diagrams illustrating a second example of conveyance of the recording media PA and PB, and are shown in chronological order.

[0053] 4, when the leading end of the recording medium PA received in the receiving section 111 of the post-processing device 102 is the first end P1 and the trailing end is the second end P2, the recording medium PA stops once when the second end P2 reaches the position of the conveying roll 12. In other words, the recording medium PA stops at a position where the second end P2 has passed the branch point 14. The first end P1 of the recording medium PA is located outside the apparatus from the first discharge section 112.

[0054] Thereafter, the recording medium PA switches back and is transported from the branch point 14 to the second path 20, as shown in Fig. 5. The second end P2 of the recording medium PA becomes the leading end, and the first end P1 becomes the trailing end. In the case shown in FIG. 5, the second end P2 of the recording medium PA is located on the transport roll 21 of the second path 20, and the first end P1 is located on the transport roll 12 of the first path .

[0055] 5, the gate 33 of the third path 30 is in a position that blocks the second path 20. Therefore, when the recording medium PA advances further along the second path 20 from the state shown in the figure, the recording medium PA is guided by the gate 33 away from the second path 20 and into the third path 30, as shown in FIG.

[0056] 6, the recording medium PA is held by the transport roll 21. The second end P2 of the recording medium PA is separated from the stopper 32 of the third path 30. The second end P2 of the recording medium PA is located on the third path 30, and the first end P1 is located on the transport roll 21 of the second path 20. The third path 30 is a transport path that can be used when performing the overlapping operation.

[0057] 6, the recording medium PA is transported from the first path 10 to the second path 20 and the third path 30, and the first path 10 is empty. That is, since the recording medium PB following the recording medium PA can be transported, the recording medium PB is received in the receiving section 111, and the first end P1, which is the leading end, is proceeding along the first path 10.

[0058] 7, first end portions P1, which are the leading ends of the recording medium PA and the recording medium PB, are overlapped on the first path 10. The second end portion P2 of the recording medium PA is located on the second path 20, and the second end portion P2 of the recording medium PB is located on the first path 10. At the timing when the following recording medium PB passes the branch point 14 of the first path 10, the preceding recording medium PA returns from the second path 20 to the first path 10 via the branch point 14, thereby performing the overlapping operation.

[0059] 8, the recording medium PA and the recording medium PB are overlapped on the first path 10. The first end P1 of the recording medium PA and the recording medium PB is located outside the apparatus from the first discharge section 112, as in the case of FIG.

[0060] The overlapping recording media PA and recording media PB switch back, and in the case shown in Figure 9, they enter the second path 20 from the branch point 14 of the first path 10. The gate 33 of the third path 30 is in a position that blocks the third path 30. Therefore, as shown in Figure 9, the recording media PA and recording media PB do not proceed to the third path 30 at the branch point 23 of the second path 20, but proceed along the second path 20 and are transported to the second post-processing unit 104.

[0061] Here, consider the case where, when the above-described operation of superposing the recording media PA and the recording media PB is performed, a stack of recording media P has already been transported to the second post-processing unit 104. The above-described Fig. 6 shows a state in which the stack of recording media P is transported to the second post-processing unit 104, and the following description will be made using Fig. 6.

[0062] 6, if the recording medium PA is not retracted from the first path 10 using the third path 30, the second end P2 of the recording medium PA is not on the third path 30 but on the second path 20. Therefore, depending on the length of the recording medium P in the second post-processing unit 104 and the length of the recording medium PA, the second end P2 of the recording medium PA may interfere with the recording medium P in the second post-processing unit 104. As a measure to prevent such interference, it is possible to limit the length of the recording media P, PA, and PB handled by the post-processing device 102 to a short length, or to increase the path length of the second path 20 of the post-processing device 102. However, such measures may limit the uses of the post-processing device 102 or increase the size of the device.

[0063] Therefore, in this embodiment, a configuration is adopted in which the third path 30 can be used when overlapping the recording medium PA and the recording medium PB using the first path 10 and the second path 20, thereby preventing limitations on use and an increase in the size of the device. The second end P2, which is the tip of the preceding recording medium PA, is inserted into the third path 30, and even if the recording medium PA and the recording medium PB are long and a stack of recording media P has already been transported to the post-processing device 102, the overlapping operation can be performed.

[0064] <Third transport example> Fig. 10 is a diagram illustrating a third transport example of the recording medium P. Fig. 10 corresponds to Fig. 6 of the second transport example, which shows a case where an overlapping operation is performed on the recording media PA and PB. 10, the recording media PA and PB are smaller in size than those in the second conveyance example. Therefore, the recording media PA that has been switched back on the first path 10 and conveyed to the second path 20 does not need to be guided to the third path 30 to interfere with the recording media P in the paper stacking unit 411, even if a stack of recording media P is already loaded on the paper stacking unit 411. Therefore, in the third transport example, the gate 33 is not changed to a position that blocks the second path 20. As shown in FIG.

[0065] In addition, in cases where the size of the recording medium P in the paper stacking section 411 is small, or even when the size is large as in the second transport example, if there is no risk of interference with the recording medium P in the paper stacking section 411, it is possible to perform control so as not to guide the recording medium to the third path 30.

[0066] FIG. 11 is a flowchart showing an example of control of the gate 33. In the control example shown in FIG. 11, when the control unit 105 (see FIG. 1) of the post-processing device 102 receives a signal indicating that the recording medium P (see FIG. 2) is to be transported, it determines whether to perform overlay control, which is control to perform an overlay operation on the recording medium P to be transported (step 101).

[0067] When overlay control is performed (Yes in step 101), the control unit 105 (see FIG. 1) then determines whether the recording medium PA to be conveyed is equal to or larger than a predetermined size (step 102). The predetermined size here is determined according to the path length of the post-processing device 102, and as an example, is a size larger than A4, excluding B5 size.

[0068] If the recording medium PA to be transported is equal to or larger than the predetermined size (Yes in step 102), the control unit 105 (see FIG. 1) drives the motor 34 to switch the gate 33 so that the gate 33 blocks the second path 20 and the recording medium PA proceeds to the third path 30 (step 103). When the recording medium PA is equal to or larger than the predetermined size, this is an example of a case where the recording medium satisfies the predetermined condition indicating the outer shape. After that, the overlapping operation is started (step 104).

[0069] When the overlapping operation is completed (step 105), the control unit 105 (see FIG. 1) drives the motor 34 to switch the gate 33 so that the gate 33 closes the third path 30 and the recording media P proceeds to the second path 20 (step 106). As a result, the stack of recording media P is transported to the second post-processing unit 104. The bundle of conveyed recording media P is subjected to post-processing in the second post-processing section 104, whereby the bundle is saddle-stitched, and is then discharged to the second discharge section 113 (see FIG. 1) (step 108), completing the series of processes.

[0070] If overlay control is not performed (No in step 101) or if the recording medium PA to be transported is not equal to or larger than a predetermined size (No in step 102), the control unit 105 (see Figure 1) proceeds to step 106 and switches the gate to the second path 20 so that the recording medium PA is not guided to the third path 30.

[0071] FIG. 12 is a diagram illustrating the relationship between the first path 10, the second path 20, and the third path 30. As shown in FIG. 12, the first path 10 has an overlapping portion ΔH where the first path 10 overlaps with the second path 20 in the height direction, i.e., in the directions of the arrows UP and DO. The overlapping portion ΔH is the portion where a range H1 of the first path 10 and a range H2 of the second path 20 overlap with each other in the height direction.

[0072] More specifically, if the first path 10 is divided at the branch point 14, with the receiving section 111 side being the receiving side portion 10A and the first discharge section 112 side being the discharge side portion 10B, the overlapping portion ΔH is located within the diagonally shaded area 106 separated by the receiving side portion 10A of the first path 10 and the second path 20. The overlapping portion ΔH is an example of a portion whose position in the height direction overlaps with the second path. The region 106 is an example of a partitioned region.

[0073] Furthermore, the third path 30 is provided on the side where the paper stacking unit 411 of the post-processing device 102 is located when the interior of the second post-processing unit 104 is divided by the second path 20 and an imaginary extension line 24 extending downward from the second path 20. Since the third path 30 and the paper stacking unit 411 are located on the same side of the second path 20 and the imaginary extension line 24 of the second path 20, the curled state of the recording medium P when it enters the third path 30 does not hinder it from entering the paper stacking unit 411.

[0074] To explain further, consider a case where second path 20 is divided at branch point 23 into first portion 20A, which is the portion on the paper stacking unit 411 side, and second portion 20B, which is the portion on the opposite side from paper stacking unit 411. Comparing angle θa between third path 30 and first portion 20A of second path 20 and angle θb between third path 30 and second portion 20B of second path 20, angle θa is smaller than angle θb. In other words, θa<θb. Note that third path 30 can be recognized as roughly a single arc shape, and is not, for example, S-shaped, and therefore has few points of curvature change.

[0075] <Additional Notes> (((1))) a first path that receives the recording medium on which the image is formed and guides it to a discharge section; a second path branching from the first path to receive the recording medium on the first path and free up the first path, the second path guiding the recording medium to be post-processed to a storage section that temporarily stores the recording medium; a third path that branches off from the second path and can be used when performing an operation of overlapping a recording medium on the first path and a recording medium on the second path using the first path and the second path, the third path being into which a leading end of a recording medium traveling from the first path to the second path enters; A post-processing device comprising: (((2))) the third path has a portion that overlaps with the second path in a height direction; The post-processing device according to (((1))) is characterized in that (((3))) the portion of the third path is located in an area separated by a portion of the first path on the receiving side of the recording medium and the second path; The post-processing device according to (((2))) is characterized in that (((4))) The third path is provided on the side where the storage section is located when the inside of the device is divided by the second path and a virtual extension line of the second path. The post-processing device according to (((3))) is characterized in that (((5))) When the second path is divided at a branching position of the third path into a first part which is a part on the side of the storage section and a second part which is a part on the opposite side of the storage section, an angle formed between the third path and the first portion is smaller than an angle formed between the third path and the second portion; The post-processing device according to any one of ((1))) to ((4))) above. (((6))) the third path is entered by the leading end when the recording medium satisfies a predetermined condition indicating an outer shape of the recording medium; The post-processing device according to any one of ((1))) to (((5))) above. (((7))) a first path that receives the recording medium on which the image is formed and guides it to a discharge section; a second path branching from the first path to receive the recording medium on the first path and free up the first path, the second path guiding the recording medium to be post-processed to a storage section that temporarily stores the recording medium; a third path that can be used when performing an operation of overlapping the recording medium on the first path and the recording medium on the second path using the first path and the second path when a recording medium is stored in the storage section, the third path branching off from the second path at a position that does not interfere with the recording medium in the storage section and into which a leading end of the recording medium traveling from the first path to the second path enters; A post-processing device comprising: (((8))) a switching member that is provided at a position where the third path branches off from the second path and switches the direction in which the recording medium advances; The post-processing device according to (((7))) is characterized in that (((9))) The switching member is During the overlapping operation, the recording medium is guided to the third path; When the overlapping operation is completed, the direction in which the recording medium travels is switched from the third path to the storage section. The post-processing device according to (((8))) is characterized in that (((10))) An image forming apparatus including the post-processing device according to (((1))) or (((7))).

[0076] According to the invention (((1))), in an apparatus that performs the overlapping operation of a large recording medium on a path that performs the overlapping operation of a small recording medium, the apparatus can be made smaller than when the path within the apparatus is extended to accommodate the large recording medium. According to the invention (((2))), the third path can reduce the height dimension of the device compared to when the third path does not have a configuration in which the third path has a portion that overlaps with the second path in the height direction. According to the invention (((3))), the third path portion can be more easily positioned within the device than when it does not have a configuration in which it is located in an area separated by the receiving side portion of the first path for the recording medium and the second path. According to the invention (((4))), the third path is configured to be provided on the side where the storage section is located when the inside of the device is divided by the second path and a virtual extension line of the second path, so that recording media that have been superimposed using the third path can enter the storage section more smoothly than if the third path were not provided on the side where the storage section is located when the inside of the device is divided by a virtual extension line of the second path. According to the invention (((5))), when the second path is divided at the branching point of the third path into a first part which is the part on the storage section side and a second part which is the part on the opposite side from the storage section, the angle between the third path and the first part is smaller than the angle between the third path and the second part, so that the recording medium can enter the third path from the second path more smoothly than in the case where the angle is not smaller than the angle between the third path and the second part. According to the invention (((6))), the third path allows the device to be made smaller than when the device does not have a configuration in which the leading end enters when the recording medium satisfies predetermined conditions indicating its outer shape. According to the invention (((7))), in an apparatus that performs the overlapping operation of a large recording medium on a path that performs the overlapping operation of a small recording medium, the apparatus can be made smaller than when the path within the apparatus is extended to accommodate the large recording medium. According to the invention (((8))), the configuration can be simplified compared to a configuration that does not include a switching member that is provided at a position where the third path branches off from the second path and switches the direction in which the recording medium moves. According to the invention (((9))), the switching member guides the recording medium to the third path during the overlapping operation, and when the overlapping operation is completed, switches the direction in which the recording medium moves from the third path to the storage section, allowing post-processing and the overlapping operation to be performed in parallel, compared to a case in which the switching member is not provided with a configuration in which the switching member guides the recording medium to the third path during the overlapping operation and switches the direction in which the recording medium moves from the third path to the storage section when the overlapping operation is completed. According to the invention of (((10))), in an apparatus that performs the overlapping operation of a large recording medium on a path that performs the overlapping operation of a small recording medium, the apparatus can be made smaller than when the path within the apparatus is extended to accommodate the large recording medium. [Explanation of symbols]

[0077] 10...first path, 10A...receiving side portion, 14, 23...branch point, 20...second path, 20A...first portion, 20B...second portion, 24...imaginary extension line, 30...third path, 33...gate, 100...image forming apparatus, 101...image forming section, 102...post-processing device, 104...second post-processing section, 106...area, 111...receiving section, 112...first discharge section, 411...paper stacking section, P, PA, PB...recording medium, P1...first end, P2...second end, ΔH...overlapping portion, θa, θb...angle

Claims

1. a first path that receives the recording medium on which the image is formed and guides it to a discharge section; a second path branching from the first path to receive the recording medium on the first path and free up the first path, the second path guiding the recording medium to be post-processed to a storage section that temporarily stores the recording medium; a third path that branches off from the second path and can be used when performing an operation of overlapping a recording medium on the first path and a recording medium on the second path using the first path and the second path, the third path being into which a leading end of a recording medium traveling on the second path from the first path enters; A post-processing device comprising:

2. the third path has a portion that overlaps with the second path in a height direction; 2. The post-processing device according to claim 1, wherein the post-processing device is a paper feeder.

3. the portion of the third path is located in an area separated by a portion of the first path on the receiving side of the recording medium and the second path; 3. The post-processing device according to claim 2.

4. The third path is provided on the side where the storage section is located when the inside of the device is divided by the second path and a virtual extension line of the second path.

4. The post-processing device according to claim 3.

5. When the second path is divided at a branching position of the third path into a first portion which is a portion on the side of the storage section and a second portion which is a portion on the opposite side of the storage section, an angle formed between the third path and the first portion is smaller than an angle formed between the third path and the second portion; 2. The post-processing device according to claim 1, wherein the post-processing device is a paper feeder.

6. the third path is entered by the leading end when the recording medium satisfies a predetermined condition indicating an outer shape of the recording medium; 2. The post-processing device according to claim 1, wherein the post-processing device is a paper feeder.

7. a first path that receives the recording medium on which the image is formed and guides it to a discharge section; a second path branching from the first path to receive the recording medium on the first path and free up the first path, the second path guiding the recording medium to be post-processed to a storage section that temporarily stores the recording medium; a third path that can be used when performing an operation of overlapping the recording medium on the first path and the recording medium on the second path using the first path and the second path when a recording medium is stored in the storage section, the third path branching off from the second path at a position that does not interfere with the recording medium in the storage section, and into which a leading end of the recording medium traveling from the first path to the second path enters; A post-processing device comprising:

8. a switching member that is provided at a position where the third path branches off from the second path and switches the direction in which the recording medium advances; The post-processing device according to claim 7 .

9. The switching member is During the overlapping operation, the recording medium is guided to the third path; When the overlapping operation is completed, the direction in which the recording medium travels is switched from the third path to the storage section. The post-processing device according to claim 8 .

10. An image forming apparatus comprising the post-processing device according to claim 1 or 7.

Images