Sheet processing device and image forming system

Abstract

To provide a sheet processing device for precisely aligning sheet bundles, which are loaded in a loading section, in the width direction.SOLUTION: A staple tray 60 is provided on which a plurality of sheets P are loaded as a sheet bundle PT. A side fence 63 is provided to press both ends in the width direction against the sheet bundle PT loaded in the staple tray 60 to align the width direction. Further, a first pressure sensor 93 is provided to detect the pressing force in the width direction applied to the sheet bundle PT by the side fence 63. The pressing force in the width direction applied by the side fence 63 is adjusted based on the detection result by the first pressure sensor 93.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a sheet processing apparatus that performs alignment processing on a sheet, and an image forming system including the same. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a technique for performing alignment processing (sorting processing) on ​​a sheet stack made up of a plurality of sheets in a sheet processing apparatus connected to an image forming apparatus such as a copier or a printer (see, for example, Patent Document 1).

[0003] On the other hand, Patent Document 1 discloses a technology in which a stack of sheets loaded on a staple tray (loading section) installed inside a post-processing device (sheet processing device) is pressed from above with a lever to align the stack in the height direction (loading direction). Furthermore, Patent Document 1 discloses a technique for detecting the pressure applied by a lever and controlling the amount of movement of the lever based on the detection result. Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional sheet processing devices do not have sufficient alignment accuracy (alignment accuracy) in the width direction of the sheet stack loaded on the stacking section, which can result in poor appearance. In particular, when a binding process is performed on a sheet stack that is misaligned in the width direction, it is difficult to correct the misalignment (appearance) later.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide a sheet processing device and an image forming system that can perform widthwise alignment of a stack of sheets loaded on a stacking section with high precision. [Means for solving the problem]

[0006] The sheet processing device of this invention comprises a loading section in which multiple sheets transported in a predetermined transport direction are stacked as a sheet bundle, a width direction alignment means for pressing both width direction ends of the sheet bundle loaded on the loading section perpendicular to the transport direction to align the sheet bundle in the width direction, and a detection means for detecting the width direction pressing force applied to the sheet bundle by the width direction alignment means, and the width direction pressing force applied by the width direction alignment means is adjusted based on the detection result by the detection means. Effect of the Invention

[0007] According to the present invention, it is possible to provide a sheet processing apparatus and an image forming system capable of aligning a sheet stack stacked on a stacking section in the width direction with high accuracy. [Brief description of the drawings]

[0008] [Figure 1] 1 is an overall configuration diagram showing an image forming system according to an embodiment of the present invention; [Diagram 2] 11A and 11B are diagrams illustrating an operation of a presser member in the binding device. [Diagram 3] 11A and 11B are diagrams illustrating an example of an operation of a side fence in the binding device. [Figure 4] 13A and 13B are diagrams illustrating another example of the operation of the side fences in the binding device. [Diagram 5] 11A and 11B are diagrams illustrating the operation of a side fence in the discharge device. [Figure 6] FIG. 2 is a block diagram showing a hardware configuration of a post-processing device. [Figure 7] 10 is a flowchart showing an example of control in the binding device. [Figure 8] 5 is a flowchart showing an example of control in the discharge device. [Figure 9] FIG. 11 is a configuration diagram showing a post-processing device in a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and the duplicated description will be appropriately simplified or omitted.

[0010] First, the overall configuration and operation of an image forming system 100 will be described with reference to FIG. In the present embodiment, the image forming apparatus 1 has a post-processing device 40 detachably installed therein, and constitutes one image forming system 100 together with the post-processing device 40 . The image forming apparatus 1 is a multifunction machine having a copy function, a printer function, and a scanner function. A personal computer is connected to the image forming apparatus 1 as a remote input device via a network. A user uses the personal computer to issue various commands to the image forming apparatus 1 through communication to perform desired printing (image forming operation), or manually operates operation buttons and operation keys displayed on the screen of an operation display panel 99 as an operation unit to issue various commands to perform desired printing (image forming operation). The post-processing device 40 is also provided with a binding device 50 and a discharge device 67 as sheet processing devices that perform alignment processing on a sheet bundle PT formed by stacking a plurality of sheets P.

[0011] As shown in FIG. 1, a scanner 13 (document reader) that optically reads image information of a document is provided on the upper portion of the image forming apparatus 1. An intermediate transfer belt 8 is provided at the center upper portion of the image forming apparatus 1. Photoconductor drums 2Y, 2M, 2C, and 2K (imaging units) corresponding to the respective colors (yellow, magenta, cyan, and black) are arranged side by side so as to face the intermediate transfer belt 8. Furthermore, the intermediate transfer belt 8 is pressed against a secondary transfer roller 15 (secondary transfer belt 16) below it to form a secondary transfer nip as an image forming unit.

[0012] 1, a charging unit 3, a developing unit 4, a cleaning unit 5, a discharging unit, etc. are arranged around the photoconductor drum 2K corresponding to black. Then, an image creation process (charging process, exposure process, developing process, transfer process, cleaning process, discharging process) is performed on the photoconductor drum 2K, and a black image is formed on the surface of the photoconductor drum 2K.

[0013] The other three photoconductor drums 2Y, 2M, and 2C have substantially the same configuration around them, and images corresponding to the respective toner colors are formed on the surfaces of the photoconductor drums 2Y, 2M, and 2C. Below, we will omit the description of the image formation process on the other three photoconductor drums 2Y, 2M, and 2C as appropriate, and will only describe the image formation process corresponding to black.

[0014] The photoconductor drum 2K is rotated by a main motor in the counterclockwise direction in Fig. 1. Then, at the position of the charging unit 3, the surface of the photoconductor drum 2K is uniformly charged (charging process). Thereafter, the surface of the photosensitive drum 2K reaches the irradiation position of the laser light emitted from the exposure unit 7, and an electrostatic latent image corresponding to black is formed by exposure scanning in the width direction (perpendicular to the paper surface of Figure 1, which is the main scanning direction) at this position (this is the exposure process).

[0015] When the image forming apparatus 1 is used as a copy machine, a latent image is formed on the photoconductor drum 2K by irradiation with laser light from the exposure unit 7 based on image information of an original document read by the scanner 13. On the other hand, when the image forming apparatus 1 is used as a printer, a latent image is formed on the photoconductor drum 2K by irradiation with laser light from the exposure unit 7 based on image information sent from a personal computer.

[0016] Thereafter, the surface of the photoconductor drum 2K reaches a position facing the developing unit 4, where the electrostatic latent image is developed to form a black toner image (this is the developing process). Thereafter, the surface of the photoconductor drum 2K reaches a position facing the intermediate transfer belt 8 and the primary transfer roller 6, and the toner image formed on the surface of the photoconductor drum 2K at this position is primarily transferred onto the surface of the intermediate transfer belt 8 (the primary transfer process). At this time, a small amount of untransferred toner remains on the photoconductor drum 2K.

[0017] Thereafter, the surface of the photoconductor drum 2K reaches a position facing the cleaning unit 5, and at this position, untransferred toner remaining on the photoconductor drum 2K is collected into the cleaning unit 5 by a cleaning blade (this is the cleaning process). Finally, the surface of the photoconductor drum 2K reaches a position facing a charge removing unit, where the residual potential on the photoconductor drum 2K is removed. Thus, a series of image forming processes carried out on the photosensitive drum 2K is completed.

[0018] The above-mentioned image forming process is performed on the surfaces of the other photoconductor drums 2Y, 2M, and 2C in the same manner as for the black photoconductor drum 2K. Then, the toner images of each color formed on the surface of each of the photoconductor drums 2Y, 2M, 2C, and 2K are primarily transferred onto the intermediate transfer belt 8 in a superimposed manner. In this manner, a color image is formed on the intermediate transfer belt 8.

[0019] Thereafter, the intermediate transfer belt 8, onto which the toner images of each color are superimposed and primarily transferred, reaches a position facing the secondary transfer roller 15 (secondary transfer belt 16). At this position, the secondary transfer facing roller 9 sandwiches the intermediate transfer belt 8 and the secondary transfer belt 16 between itself and the secondary transfer roller 15 to form a secondary transfer nip (image forming portion). Then, the four-color toner images formed on the intermediate transfer belt 8 are secondarily transferred onto a sheet P, such as paper, conveyed to the position of this secondary transfer nip (secondary transfer process). At this time, untransferred toner that has not been transferred to the sheet P remains on the intermediate transfer belt 8.

[0020] Thereafter, the intermediate transfer belt 8 reaches the position of an intermediate transfer cleaning unit, where untransferred toner and other adhering matter adhering to the surface of the intermediate transfer belt 8 is removed. Thus, a series of transfer processes carried out on the intermediate transfer belt 8 is completed.

[0021] Here, referring to Figure 1, the sheet P transported to the position of the secondary transfer nip (image forming section) is transported from a paper feed section 10 arranged below the image forming apparatus 1 via a transport path K1 on which a paper feed roller 11, a registration roller 12, etc. are arranged. More specifically, a plurality of sheets P, such as paper, are stored in a stack in the paper feed section 10. When the paper feed roller 11 is rotated counterclockwise in FIG. 1, the topmost sheet P is fed toward between the registration rollers 12 via a conveying path K1.

[0022] The sheet P conveyed to the registration rollers 12 is temporarily stopped at the roller nip of the registration rollers 12 that have stopped rotating. Then, the registration rollers 12 are rotated in synchronization with the color image on the intermediate transfer belt 8, and the sheet P is conveyed toward the secondary transfer nip (image forming section). In this way, the desired color image is transferred onto the sheet P.

[0023] Thereafter, the sheet P onto which the color image has been transferred at the secondary transfer nip position is transported by the secondary transfer belt 16, and after being separated from the secondary transfer belt 16, is transported by the transport belt 18 to the position of the fixing unit 19. Then, at this position, the color image transferred to the surface is fixed onto the sheet P by the heat and pressure of the fixing belt and pressure roller (fixing process). Thereafter, the sheet P is discharged to the outside of the image forming apparatus 1 by the sheet discharge rollers 25 via the discharge transport path K2. Furthermore, the sheets P discharged from the image forming apparatus 1 are transported inside the post-processing device 40, where they are subjected to processes (post-processing) such as punching, alignment, and binding. The sheets P that have been subjected to post-processing (sheet stack PT) are then discharged onto a discharge tray 68. The configuration and operation of the post-processing device 40 will be described in detail later. In this way, a series of image forming processes (image forming operations) in the image forming apparatus 1 is completed.

[0024] The post-processing device 40 will now be described in detail. First, the sheet P discharged from the image forming apparatus 1 is fed (conveyed) into the post-processing device 40 by the inlet rollers 51. When the user has previously selected the "normal processing mode" on the operation display panel 99, the conveying path is switched by the switching claw 73, and the sheet P is discharged directly onto the discharge tray 68 by the discharge roller pair 66 via the linear conveying path K15. At this time, if the user has additionally selected "perforation processing (punch processing)" in advance on the operation display panel 99, the perforation processing section 70 performs perforation processing on the sheet P as the sheet P passes through the perforation processing section 70. Furthermore, when the "normal processing mode" is selected in this manner, regardless of whether the "perforation processing" is selected, each time a plurality of sheets P are discharged one by one onto the discharge tray 68 by the discharge roller pair 66, a pair of side fences 69 (see FIG. 5) moves in the width direction (the direction perpendicular to the plane of FIG. 1, that is, the left-right direction in FIG. 5) to perform a widthwise alignment process (sorting process) on the sheet stack PT consisting of a plurality of sheets P. The pair of side fences 69 (jogger fences) are installed so as to be movable in the width direction on the discharge tray 68 of the discharge device 67 as a sheet processing device, which will be described in detail later with reference to FIG. 5 etc.

[0025] On the other hand, when the user has previously selected the "binding processing mode (staple mode)" on the operation display panel 99 of the image forming apparatus 1, the conveying path is switched by the switching claw 73, and the sheets P are sequentially conveyed via the conveying paths K11 and K13, and sequentially stacked on the staple tray 60 (loading section) of the binding device 50 (sheet processing device). 1 and 2, each time a sheet P (sheet stack PT) is placed on the tray surface of the staple tray 60 serving as a stacking section, a beating roller 58 disposed above the sheet P moves from a standby position to a position where it abuts against the uppermost sheet P, and the beating roller 58 is rotated counterclockwise in each of FIGS. 1 and 2, while a movable fence 61 (see FIG. 2) moves diagonally downward along the inclination of the staple tray 60, thereby conveying (moving) the sheet P toward a stopper section 62 (end fence). As a result, the rear ends (rear ends in the conveying direction) of the multiple sheets P (sheet stack PT) hit the stopper section 62, and the positions of the multiple sheets P in the conveying direction are aligned.

[0026] At this time, a pair of side fences 63 (see Figure 3) installed at both widthwise ends of the staple tray 60 move in the widthwise direction to sandwich the sheets P (sheet stack PT) each time a sheet P is placed on the staple tray 60 (or after the desired number of sheets P have been stacked), thereby aligning the widthwise position of the sheets P (sheet stack PT). Furthermore, a pressure member 59 (see FIG. 2) installed above the staple tray 60 moves in the stacking direction (height direction) so as to press down the sheets P (sheet stack PT) from above each time a sheet P is placed on the staple tray 60 (or after the desired number of sheets P have been stacked), thereby aligning the stacking direction (height direction) of the sheets P (sheet stack PT). The configurations and operations of the side fences 63 (jogger fences) and the pressing members 69 of the binding device 50 as the sheet processing device will be described in detail later with reference to FIGS. 2 and 3.

[0027] Then, the stapler 80 (stitching processing section) performs stitching processing on the rear end of the sheets P (sheet stack) whose conveying direction, width direction, and stacking direction (height direction) are aligned. Thereafter, the stapled sheets P (sheet stack PT) move diagonally upward along the inclination of the staple tray 60 due to the movement of the stopper portion 62, which also functions as a discharge claw, in the discharge direction, and after passing through the discharge conveying path K14, are discharged onto the discharge tray 68 by conveyance by a pair of discharge rollers 66. In addition, even in the binding processing mode, if the user has additionally selected "perforation processing" in advance on the operation display panel 99, the perforation processing section 70 performs perforation processing on the sheet P as the sheet P passes through the perforation processing section 70.

[0028] In addition, in the post-processing device 40 in this embodiment, a second transport path K12 (standby transport path) branching off from the transport path (which is the first transport path K11 and the merging transport path K13) from the position of the switching claw 73 to the staple tray 60 is provided midway along the transport path. The second transport path K12 is a transport path for temporarily waiting (evacuating) the sheet P (or a sheet stack) instead of directly transporting the sheet P to the staple tray 60 as a placement unit via the first transport path K11 and the junction transport path K13. Then, the sheet P transported from the first transport path K11 and the sheet P (including the sheet stack PT) that has been kept waiting on the second transport path K12 are overlapped and transported toward the staple tray 60 via the junction transport path K13 as appropriate and as necessary. As a result, even if the time (processing time) required for post-processing such as binding performed in the binding device 50 is longer than the time (printing time) required for continuous printing in the image forming device 1, it is not necessary to adjust the printing time of the image forming device 1 to be slower in accordance with the processing time of the binding device 50 by appropriately waiting the sheet P on the second transport path K12 to offset the time difference. Therefore, it is possible to reduce problems that complicate the control on the image forming device 1 side.

[0029] The configurations and operations of the characteristic sheet processing devices (the binding device 50 and the discharge device 67) in the post-processing device 40 of the present embodiment will be described in detail below. As described above with reference to FIG. 1 etc., the post-processing device 40 in this embodiment is provided with two sheet processing devices (the binding device 50 and the discharge device 67) that align the width direction of the sheet bundle PT. In particular, the binding device 50 aligns (aligns) the sheet stack PT in the width direction, as well as in the conveying direction (the direction along the inclined surface of the staple tray 60) and in the loading direction (the direction perpendicular to the tray surface of the staple tray 60, which is the height direction). In this embodiment, the alignment of the sheet stack PT is performed each time a sheet P forming the sheet stack PT is loaded onto the stacking section (the staple tray 60 or the discharge tray 68), but it may also be performed after the loading of the sheet stack PT consisting of the desired number of sheets P has been completed.

[0030] 2 to 4, the binding device 50 as a sheet processing device is provided with a staple tray 60 as a loading section, a pair of side fences 63 (jogger fences) as width-direction alignment means, a first pressure sensor 93 as detection means (first detection means), a first moving mechanism 96, a pressure member 59 as loading direction alignment means, a second pressure sensor 94 as second detection means, a second moving mechanism 97, a stopper section 62, a stapler 80 as a binding processing section, and the like.

[0031] The staple tray 60 functions as a stacking section on which a plurality of sheets P transported in a predetermined transport direction (a direction along the inclination of the tray surface of the staple tray 60) are stacked as a sheet bundle PT. The pair of side fences 63 function as widthwise alignment means for pressing both ends of the sheet stack PT loaded on the staple tray 60 (loading section) in the width direction (a direction perpendicular to the transport direction, a direction perpendicular to the paper surface in FIG. 2, and a left-right direction in FIGS. 3 and 4) to align the sheet stack PT in the width direction. The pair of side fences 63 are configured to be movable in the width direction. Furthermore, each of the pair of side fences 63 is formed to stand up in the loading direction. The pair of side fences 63 are configured to be movable in the width direction by a first moving mechanism 96 that is driven and controlled by the control unit 90. Specifically, the pair of side fences 63 are moved by the first moving mechanism 96 so as to increase or decrease the opposing distance between them. As the first moving mechanism, for example, one equipped with a pinion-rack mechanism can be used.

[0032] The first pressure sensor 93 is a pressure sensor that functions as a detection unit (first detection unit) that detects the pressing force in the width direction applied to the sheet stack PT by the side fence 63 (width direction aligning unit). The first pressure sensor 93 (detection means) is installed on the side fences 63 so as to be able to come into contact with the side surfaces of the sheet stack PT. Specifically, the first pressure sensor 93 is installed on the inner wall surfaces (surfaces facing the sheet stack PT) of the pair of side fences 63, respectively.

[0033] In this embodiment, the pressing force in the width direction by the pair of side fences 63 (width direction alignment means) is adjusted based on the detection result by the first pressure sensor 93 (detection means). In other words, based on the detection result by the first pressure sensor 93, the movement of the pair of side fences 63 in the width direction is controlled (the movement positions are adjusted). Specifically, the pair of side fences 63 are moved toward the sheet stack PT (the sheet stack PT on the staple tray 60) so that the detection result by the first pressure sensor 93 (detection means) reaches a predetermined value A. More specifically, as shown in Fig. 3A, the pair of side fences 63 wait for the reference position set to the position of the widthwise end within the movable range in the width direction. Then, every time a new sheet P is stacked on the staple tray 60, the side fence 63 moves from the reference position toward the widthwise center so as to contact the side of the sheet stack PT, as shown in Fig. 3B. Then, when the pressing force (contact pressure) detected by the first pressure sensor 93 reaches a predetermined value A, the control unit 90 controls the first moving mechanism 96 so that the movement of the side fence 63 stops (or stops after decelerating).

[0034] In this manner, in the binding device 50 (sheet processing device) in the present embodiment, the pressing force (movement position) in the width direction by the pair of side fences 63 is adjusted based on the detection result by the first pressure sensor 93. When the sheet stack PT is misaligned (not aligned) in the width direction, the repulsive force of the sheets PT acting on the side fences 63 becomes smaller and the balance of the repulsive forces acting on the left and right side fences 63 becomes uneven, compared to when the sheets are not misaligned. Therefore, by controlling the pressing force of the side fences 63, the sheet stack PT loaded on the staple tray 60 can be aligned in the width direction with high accuracy. In particular, in the binding device 50, the binding process is performed by the stapler 80 after the alignment process, and since the binding process is performed on the sheet stack PT that has been aligned with high precision in the width direction, the appearance after the binding process is also good.

[0035] In this embodiment, the above-mentioned "predetermined value A" can be changed based on at least one of the size, thickness, and number of sheets P constituting the sheet bundle PT. Specifically, when the width direction size of the sheet P is large, the repulsive force against the pressure of the side fence 63 is larger than when the width direction size is small, so the predetermined value A is set to a larger value. Also, when the transport direction size of the sheet P is large, a similar tendency is observed compared to when the transport direction size is small, so the predetermined value A is set to a larger value. Furthermore, when the sheet P is thick, the repulsive force against the pressure of the side fence 63 is greater than when the sheet P is thin, so the predetermined value A is set to be larger. Furthermore, when the number of sheets P is large, the repulsive force against the pressure of the side fence 63 is larger than when the number of sheets P is small, so the predetermined value A is set to a larger value. Information on the size, thickness, number of sheets P, etc. can be acquired based on sheet information input by the user via the operation display panel 99 (see FIG. 1).

[0036] Here, in this embodiment, under the control of the control unit 90, the pair of side fences 63 are moved by the first moving mechanism 96 toward the sheet stack PT so that the detection results of a pair of first pressure sensors 93 (pressure sensors) respectively installed on the pair of side fences 63 become approximately equivalent. 3, when the sheet stack PT is placed evenly in the width direction with respect to the central reference (the position indicated by the dashed line, which is half the distance between the pair of side fences 63) on the staple tray 60, when the pair of side fences 63 contact the sheet stack PT, approximately equal repulsive forces (pressing forces) are applied to the pair of first pressure sensors 93 from the beginning (the detection results become approximately equal). Therefore, while obtaining such approximately equal detection results, the pair of side fences 63 are moved until the detection results reach a predetermined value A. 4, when the sheet stack PT is placed unevenly in the width direction with respect to the center reference on the staple tray 60, the sheet stack PT first comes into contact with one of the pair of side fences 63. Then, the sheet stack PT also comes into contact with the other side fence 63, and finally, substantially equal repulsive forces are applied to both first pressure sensors 93 (the detection results become substantially equal), and the pair of side fences 63 are moved until such substantially equal detection results reach a predetermined value A. By controlling in this manner, it is possible to perform highly accurate alignment in the width direction of the sheet stack PT regardless of the presence or absence of deviation of the sheet stack PT from the center reference.

[0037] Here, referring to Figure 2 etc., the pressure member 59 functions as a loading direction alignment means for aligning the loading direction of the sheet stack PT loaded on the staple tray 60 (loading section) by pressing the upper surface in the loading direction (height direction). The pressing member 59 is a plate-like member that is movable in the stacking direction and contacts and applies a pressing force to the upper surface of the sheet stack PT on the staple tray 60 (the upper surface of the uppermost sheet P that is farthest from the tray surface and is the upper surface on the side closer to the stopper portion 62 (the rear end in the transport direction)). The pressing member 59 is moved in the stacking direction (the direction of the white arrow in FIG. 2(B) or the opposite direction) by a second moving mechanism 97 consisting of a motor mechanism or the like controlled by the control portion 90.

[0038] The second pressure sensor 94 is a pressure sensor that functions as a second detection unit that detects the pressing force in the stacking direction applied to the sheet stack PT by the pressing member 59 (stacking direction aligning unit). The second pressure sensor 94 (second detection means) is installed so as to be able to come into contact with the upper surface of the sheet stack PT on the staple tray 60. Specifically, the second pressure sensor 94 is installed at the tip of the pressing member 59 (the portion facing the sheet stack PT).

[0039] In this embodiment, the pressing force in the loading direction by the pressing member 59 (loading direction alignment means) is adjusted based on the detection result by the second pressure sensor 94 (second detection means). In other words, based on the detection result by the second pressure sensor 94, the movement of the pressing member 59 in the stacking direction is controlled (the movement position is adjusted). Specifically, the pressing member 59 is moved toward the sheet stack PT (the sheet stack PT on the staple tray 60) so that the detection result by the second pressure sensor 94 (second detection means) reaches a predetermined threshold value B. More specifically, as shown in Fig. 2(A), the pressing member 59 waits at a position farthest from the tray surface within the movable range in the stacking direction as a reference position. Then, every time a new sheet P is stacked on the staple tray 60, the pressing member 59 moves from the reference position in the stacking direction so as to contact the upper surface of the sheet stack PT as shown in Fig. 2(B). Then, when the pressing force (contact pressure) detected by the second pressure sensor 94 reaches a threshold value B, the control unit 90 controls the second moving mechanism 97 so that the movement of the pressing member 59 stops (or stops after decelerating).

[0040] In this manner, in the binding device 50 (sheet processing device) in the present embodiment, the pressing force (movement position) of the pressing member 59 in the stacking direction is adjusted based on the detection result of the second pressure sensor 94. When the sheet bundle PT is not aligned in the stacking direction (when it is bent), the repulsive force of the sheets PT acting on the pressing member 59 is smaller than when it is aligned. Therefore, by controlling the pressing force of the pressing member 59, it is possible to align the sheet bundle PT stacked on the staple tray 60 in the stacking direction with high accuracy. In particular, in the binding device 50, the binding process is performed by the stapler 80 after the alignment process, and since the binding process is performed on the sheet stack PT whose stacking direction is precisely aligned, defects in the binding process are unlikely to occur and the appearance after the binding process is good.

[0041] In this embodiment, the above-mentioned "threshold value B" can be changed based on at least one of the size, thickness, and number of sheets P constituting the sheet bundle PT. Specifically, when the width direction size or the transport direction size of the sheet P is large, the repulsive force against the pressure of the presser member 59 tends to be larger than when these sizes are small, so the threshold value B is set to be larger. Furthermore, when the sheet P is thick, the repulsive force against the pressure of the pressing member 59 is greater than when the sheet P is thin, and therefore the threshold value B is set to be larger. Furthermore, when the number of sheets P is large, the repulsive force against the pressure of the presser member 59 is larger than when the number of sheets P is small, and therefore the threshold value B is set to be larger.

[0042] As described above with reference to FIG. 2 and the like, the binding device 50 is provided with a stopper portion 62 that determines the position in the conveying direction of the sheet bundle PT loaded on the staple tray 60 (loading portion). In this embodiment, after the sheet stack PT is aligned in the width direction and the stacking direction while being positioned by the stopper portion 62, the stapler 80 (binding processing portion) performs binding processing on the sheet stack PT. Specifically, after the movement control of the side fence 63 based on the detection result of the first pressure sensor 93 and the movement control of the pressing member 59 based on the detection result of the second pressure sensor 94 are completed, the stapler 80 is driven under the control of the control unit 90, and the binding process is performed on the sheet stack PT whose width direction and stacking direction are aligned. Therefore, the binding process is performed on the sheet bundle PT whose width direction and stacking direction are aligned with high precision, and the binding process with a good appearance can be performed.

[0043] In the present embodiment, the binding device 50 is configured to adjust the pressing force in the width direction by the side fences 63 and the pressing force in the loading direction by the pressing member 59, but it can also be configured to adjust the pressing force in the conveying direction by the stopper portion 62 and the movable fence 61 (the movement position of the movable fence 61). In this case, a detection means is provided for detecting the pressure in the transport direction applied to the sheet stack PT by the stopper portion 62 or the movable fence 61, and the pressure in the transport direction is adjusted based on the detection result. Then, after the movement control of the side fence 63, the movement control of the pressure member 59, and the movement control of the movable fence 61 are completed, the stapler 80 is driven under the control of the control unit 90, and the binding process is performed on the sheet stack PT whose width direction, stacking direction, and conveying direction are aligned.

[0044] An example of the control performed by the binding device 50 will be described below with reference to FIG. First, when the user selects the "binding mode" via the operation display panel 99 (see FIG. 1), information (such as size, thickness, number of sheets, etc.) of the sheets P (the sheets P to be bound) set in the paper feed section 10 is obtained (step S1). Then, based on the sheet information acquired in step S1, a predetermined value A of the pressure to be detected by the first pressure sensor 93 is determined (step S2), and a threshold value B of the pressure to be detected by the second pressure sensor 94 is determined (step S3). Then, when the sheets P are placed (discharged) on the staple tray 60 (step S4), the first moving mechanism 96 starts moving the side fence 63 in the width direction (alignment process) (step S5). Then, when the pressing force detected by the first pressure sensor 93 reaches the predetermined value A determined in step S2, the first moving mechanism 96 stops moving the side fence 63 in the width direction (alignment process) (steps S6 and S7). In parallel with such widthwise alignment processing, when the sheets P are placed (discharged) onto the staple tray 60 (step S4), the second moving mechanism 97 starts moving the presser member 69 in the stacking direction (alignment processing) (step S8). Then, when the pressing force detected by the second pressure sensor 94 reaches the threshold value B determined in step 3, the second moving mechanism 97 stops moving the presser member 69 in the stacking direction (alignment processing) (steps S9, S10). Then, when such alignment processing in the width direction and stacking direction is performed for the desired number of sheets, the stapler 80 performs binding processing on the sheet bundle PT of the desired number of sheets (steps S11, S12), and this flow ends. The above-mentioned "predetermined value A" and "threshold value B" may be changed in accordance with an increase in the number of sheets in the sheet stack PT.

[0045] The discharge device 67 as a sheet processing device will be described in detail below. Referring to Figure 5, the discharge device 67 as a sheet processing device is provided with a discharge tray 68 as a stacking section, a pair of side fences 69 (jogger fences) as widthwise alignment means, a pressure sensor 95 as detection means, a moving mechanism 98, and the like. The discharge tray 68 functions as a stacking section on which a plurality of sheets P transported in a predetermined transport direction are stacked as a sheet bundle PT. The discharge tray 68 is a tray onto which the sheets transported in the transport direction (the direction in which the sheets are discharged by the pair of discharge rollers 66) are discharged. The pair of side fences 69 function as widthwise alignment means for pressing both ends in the width direction (a direction perpendicular to the conveying direction, i.e., the left-right direction in FIG. 5) of the sheet stack PT loaded on the discharge tray 68 (loading section) to align the sheet stack in the width direction. The pair of side fences 69 are configured to be movable in the width direction. Also, each of the pair of side fences 69 is formed to stand up in the loading direction. The pair of side fences 69 are configured to be movable in the width direction by a moving mechanism 98 that is driven and controlled by the control unit 90. Specifically, the pair of side fences 69 are moved by the moving mechanism 98 so as to increase or decrease the opposing distance between them. As the moving mechanism, for example, one equipped with a pinion-rack mechanism can be used.

[0046] The pressure sensor 95 functions as a detection unit that detects the pressing force in the width direction applied to the sheet stack PT by the side fence 69 (width direction alignment unit). The pressure sensor 95 (detection means) is installed on the side fence 69 so as to be able to come into contact with the side surface of the sheet stack PT. Specifically, the pressure sensor 95 is installed on the inner wall surfaces (surfaces facing the sheet stack PT) of the pair of side fences 69, respectively.

[0047] In this embodiment, the pressing force in the width direction by the pair of side fences 69 (width direction alignment means) is adjusted based on the detection result by the pressure sensor 95 (detection means). In other words, based on the detection result by the pressure sensor 95, the movement of the pair of side fences 69 in the width direction is controlled (the movement positions are adjusted). Specifically, the pair of side fences 69 are moved toward the sheet stack PT so that the detection result by the pressure sensor 95 (detection means) reaches a predetermined value A'. More specifically, as shown in Fig. 5(A), the pair of side fences 69 wait for the reference position to be the endmost position in the width direction within the movable range in the width direction. Then, every time a new sheet P is stacked on the discharge tray 68, the side fence 69 moves from the reference position toward the center in the width direction so as to contact the side of the sheet stack PT, as shown in Fig. 5(B). Then, the control unit 90 controls the moving mechanism 98 so that the movement of the side fences 69 stops (or stops after decelerating) when the pressing force (contact pressure) detected by the pressure sensor 95 reaches a predetermined value A'.

[0048] In this manner, in the discharge device 67 (sheet processing device) according to the present embodiment, the pressing force (movement position) in the width direction by the pair of side fences 69 is adjusted based on the detection result by the pressure sensor 95. This allows the sheet stack PT stacked on the discharge tray 68 to be aligned in the width direction with high accuracy.

[0049] Here, in the discharge device 67 as well, similarly to the binding device 50, the above-mentioned "predetermined value A'" can be changed based on at least one of the size, thickness, and number of sheets P constituting the sheet bundle PT. Also, in the discharge device 67, similarly to the binding device 50, the control unit 90 controls the pair of side fences 69 to be moved by the moving mechanism 98 toward the sheet stack PT so that the detection results of a pair of pressure sensors 95 respectively installed on the pair of side fences 69 become approximately equal.

[0050] An example of the control performed by the discharge device 67 will be described below with reference to FIG. First, when the user selects the "normal processing mode" via the operation display panel 99 (see FIG. 1), information (such as size, thickness, number of sheets, etc.) of the sheets P (the sheets P to be bound) set in the paper feed section 10 is obtained (step S1). Then, based on the sheet information acquired in step S1, a predetermined value A' of the pressing force to be detected by the pressure sensor 95 is determined (step S13). Then, when the sheets P are placed (discharged) onto the discharge tray 68 (step S14), the movement mechanism 98 starts moving the side fence 69 in the width direction (alignment process) (step S15). Then, when the pressing force detected by the pressure sensor 95 reaches the predetermined value A' determined in step S13, the movement mechanism 98 stops moving the side fence 69 in the width direction (alignment process) (steps S16 and S17). Then, when such widthwise alignment processing is performed for the desired number of sheets and the job is completed (steps S17 and S18), this flow ends. The above-mentioned "predetermined value A'" may be variable in accordance with an increase in the number of sheets in the sheet stack PT.

[0051] Hereinafter, the hardware configuration of the post-processing device 40 will be briefly described with reference to FIG. The control unit 90 of the post-processing device 40 includes a CPU 201 (Central Processing Unit), a RAM 202 (Random Access Memory), a ROM 203 (Read Only Memory), a HDD 204 (Hard Disk Drive), etc., and an I / F 250 is connected via a common bus 251. The CPU 201 is a calculation means and controls the overall operation of the post-processing device 40. The RAM 202 is a volatile storage medium capable of reading and writing information at high speed, and is used as a working area when the CPU 201 processes information. The ROM 203 is a read-only non-volatile storage medium in which programs such as firmware are stored. The HDD 204 is a non-volatile storage medium capable of reading and writing information and has a large storage capacity, and stores an OS (Operating System), various control programs, application programs, etc. The post-processing device 40 processes a control program stored in the ROM 203, an information processing program (application program) loaded from a storage medium such as the HDD 204 to the RAM 202, and the like, by using a calculation function provided in the CPU 201. This processing constitutes a software control unit (control unit 90) including various functional modules of the post-processing device 40. The combination of the software control unit thus constituted and the hardware resources mounted on the post-processing device 40 constitutes a functional block that realizes the functions of the post-processing device 40. That is, the CPU 201, the RAM 202, the ROM 203, and the HDD 204 constitute a controller 200 that controls the operation of the post-processing device 40. I / F250 is an interface that connects the conveying roller pairs 51, 67, 53-57, the switching claw 73, the first moving mechanism 96 (side fence 63), the first pressure sensor 93, the movable fence 61, the stopper portion 62, the hitting roller 58, the second moving mechanism 97 (pressing member 59), the second pressure sensor 94, the stapler 80, the moving mechanism 98 (side fence 69) of the discharge device 67, and the pressure sensor 95 of the discharge device 67 to the common bus 251. Through the I / F 250, the controller 200 operates the conveying roller pairs 51, 67, 53-57, the switching claw 73, the first moving mechanism 96 (side fence 63), the first pressure sensor 93, the movable fence 61, the stopper portion 62, the hitting roller 58, the second moving mechanism 97 (pressing member 59), the second pressure sensor 94, the stapler 80, the moving mechanism 98 (side fence 69) of the discharge device 67, and the pressure sensor 95 of the discharge device 67.

[0052] <Modification> As shown in Figure 9, the post-processing device 40 in the modified example differs from that in Figure 1 in that it does not have a punch processing unit 70, that an upper conveying path K20 is provided in addition to the straight conveying path K15 as a conveying path used in the normal processing mode, and that it is configured to be able to execute a folding processing mode. 9, the post-processing device 40 in the modified example is provided with an upper transport path K20 that extends upward so as to branch off from the straight transport path K15. Then, depending on the user's selection, in the normal processing mode, the sheet P is discharged directly onto the discharge tray 68B (second discharge tray) via the straight transport path K15, or the sheet P is discharged directly onto the first discharge tray 68A via the upper transport path K20. Here, in addition to the second discharge device 67B (second discharge tray 68B), the first discharge device 67A (first discharge tray 68A) also has pressure sensors (detection means) installed on the side fences 69A, 69B, similar to the discharge device 67 (discharge tray 68) in Fig. 5, and the pressing force in the width direction by the pair of side fences 69A, 69B (width direction alignment means) is adjusted based on the detection result by the pressure sensor. This allows the sheet bundles PT stacked on the first and second discharge trays 68A, 68B to be aligned in the width direction with high accuracy.

[0053] As shown in FIG. 9, a mechanism for folding the sheet stack PT is provided at the lower left portion of the post-processing device 40 in the modified example. When the user operates the operation display panel 99 to select the "folding mode," the sheet P passes through the linear conveying path K15 (or the conveying paths K12 to K14 for binding processing) and is discharged partway to the position of the second discharge device 67B, where it is switched back (inverted) and guided to the vertical conveying path K21. The sheet P conveyed to the vertical conveying path K21 is conveyed to a position where the center of the sheet P faces the sheet folding blade 76. At this time, the leading edge of the sheet P abuts against the second stopper portion 75 (configured to be movable in the conveying direction by a moving mechanism, not shown). Then, when a desired number of sheets P in such a state are stacked to form a sheet bundle PT, the sheet bundle PT is folded at its center by a sheet folding blade 76 moving leftward in Fig. 9, and the folded portion is pressed against the sheet folding rollers 77, thereby performing a folding process. Thereafter, the folded sheet bundle PT is transported by a pair of discharge rollers and discharged onto the third discharge tray 68C of the third discharge device 67C. In addition, a saddle stitching processing section for performing saddle stitching processing in the center of the sheet bundle PT can be provided on the vertical transport path K21.

[0054] As described above, the binding device 50 (or the discharge device 67) as the sheet processing device in this embodiment is provided with the staple tray 60 (or the discharge tray 68) as a stacking unit on which a plurality of sheets P conveyed in a predetermined conveying direction are stacked as a sheet bundle PT. In addition, the side fence 63 (or the side fence 69) is provided as a widthwise alignment means for pressing both ends in the widthwise direction perpendicular to the conveying direction of the sheet bundle PT stacked on the staple tray 60 (or the discharge tray 68) to align the widthwise direction. In addition, the first pressure sensor 93 (or the pressure sensor 95) is provided as a detection means for detecting the widthwise pressing force applied to the sheet bundle PT by the side fence 63 (or the side fence 69). Based on the detection result by the first pressure sensor 93 (or the pressure sensor 95), the widthwise pressing force by the side fence 63 (or the side fence 69) is adjusted. This allows the sheet stack PT loaded on the staple tray 60 (or the discharge tray 68) to be aligned in the width direction with high accuracy.

[0055] In this embodiment, the present invention is applied to the sheet processing devices (such as the binding device 50 and the discharge device 67) of the post-processing device 40 connected to a color image forming device 1, but the present invention can also be applied to the sheet processing devices of the post-processing device connected to a monochrome image forming device. Furthermore, in this embodiment, the present invention is applied to the sheet processing devices 50, 67 of the post-processing device 40 connected to an electrophotographic image forming device 1, but the application of the present invention is not limited to this, and the present invention can also be applied to the sheet processing devices of post-processing devices connected to other types of image forming devices (for example, inkjet image forming devices, stencil printing devices, etc.). Furthermore, in this embodiment, the present invention is applied to an image forming system 100 in which a post-processing device 40 and an image forming device 1 are installed, but the present invention can also be applied to an independent device that is an independent post-processing device (sheet processing device) to which the image forming device 1 is not connected. In addition, in this embodiment, the present invention is applied to the binding device 50 and the discharge device 67 of the post-processing device 40, but the present invention can also be applied only to the binding device 50, or only to the discharge device 67. In addition, in this embodiment, the present invention is applied to the sheet processing devices 50 and 67 installed in the post-processing device 40, but the present invention can naturally be applied to sheet processing devices installed in other devices or to devices that are independent as sheet processing devices. Even in such cases, the same effects as those of this embodiment can be obtained.

[0056] It is clear that the present invention is not limited to the present embodiment, and that the present embodiment may be modified as appropriate within the scope of the technical concept of the present invention in addition to the modifications suggested in the present embodiment. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and may be any number, position, shape, etc. suitable for implementing the present invention.

[0057] In this specification, the term "sheet" is defined to include not only paper but also all sheets that are the subject of processing such as alignment processing. [Explanation of symbols]

[0058] 1 Image forming device, 40 Post-processing device, 50 Binding device (sheet processing device), 58 Beating Roller, 59 Holding member (loading direction alignment means), 60 Staple tray (loading area), 61 Movable fence, 62 Stopper portion, 63 Side fence (width direction alignment means), 67 Discharge device (sheet processing device), 68 discharge tray (loading section), 69 Side fence (widthwise alignment means), 80 Stapler (stapling processing section), 93 first pressure sensor (detection means, first detection means), 94 second pressure sensor (second detection means), 95 Pressure sensor (detection means), 96 first moving mechanism, 97 Second movement mechanism, 98 movement mechanism; 100 Image forming system, P sheet, PT sheet bundle.

[0059] The present invention can also be embodied in the following combinations of Supplementary Notes 1 to 10. (Appendix 1) a stacking section on which a plurality of sheets conveyed in a predetermined conveying direction are stacked as a sheet bundle; a width direction alignment unit that aligns the sheet bundle in the width direction by pressing both ends of the sheet bundle in the width direction perpendicular to the conveying direction, the sheet bundle being stacked on the stacking unit; a detection means for detecting a pressing force in the width direction applied to the sheet stack by the width direction alignment means; Equipped with The sheet processing apparatus further comprises: a width-direction alignment unit that adjusts a pressing force in the width direction based on a detection result from the detection unit; (Appendix 2) a loading direction aligning means for aligning the loading direction of the sheet bundle by pressing an upper surface in a loading direction of the sheet bundle loaded on the loading section; a second detection means for detecting a pressing force in the stacking direction applied to the sheet bundle by the stacking direction alignment means; Equipped with 2. The sheet processing apparatus according to claim 1, wherein the pressing force in the stacking direction by the stacking direction aligning means is adjusted based on a detection result by the second detection means. (Appendix 3) The loading direction aligning means is a pressing member movable in the loading direction, the second detection means is a pressure sensor that is installed on the pressing member so as to be capable of contacting an upper surface of the sheet stack, 3. The sheet processing apparatus according to claim 2, wherein the pressing member is moved toward the sheet stack so that the detection result by the second detection means reaches a predetermined threshold value. (Appendix 4) 4. The sheet processing apparatus according to claim 3, wherein the threshold value is changed based on at least one of a thickness, a size, and a number of sheets constituting the sheet stack. (Appendix 5) 5. The sheet processing apparatus according to claim 2, wherein the stacking unit is a discharge tray onto which the sheet transported in the transport direction is discharged. (Appendix 6) The width direction alignment means is a pair of side fences movable in the width direction, the detection means is a pressure sensor that is installed on the side fence so as to be capable of coming into contact with a side surface of the sheet stack, The sheet processing apparatus according to any one of claims 1 to 5, wherein the pair of side fences are moved toward the sheet stack so that the detection result by the detection means reaches a predetermined value. (Appendix 7) 7. The sheet processing apparatus according to claim 6, wherein the predetermined value is changed based on at least one of a size, a thickness, and a number of sheets constituting the sheet stack. (Appendix 8) The pressure sensors are installed on the pair of side fences, The sheet processing apparatus according to claim 6 or 7, characterized in that the pair of side fences are moved toward the sheet stack so that the detection results of the pair of pressure sensors respectively installed on the pair of side fences become approximately equal. (Appendix 9) a stopper portion for determining a position in the conveying direction of the sheet bundle loaded on the loading portion; a binding processing section that performs a binding process on the sheet stack after the sheet stack is aligned in the width direction and the stacking direction while being positioned at the stopper section; 9. The sheet processing apparatus according to claim 1, further comprising: (Appendix 10) An image forming system comprising: an image forming apparatus that forms an image on a sheet; and a sheet processing apparatus according to any one of appendices 1 to 9 that performs post-processing on the sheet on which the image has been formed by the image forming apparatus. [Prior art documents] [Patent documents]

[0060] [Patent Document 1] JP 2008-63042 A

Claims

1. a stacking section on which a plurality of sheets conveyed in a predetermined conveying direction are stacked as a sheet bundle; a width direction alignment unit that aligns the sheet bundle in the width direction by pressing both ends of the sheet bundle in the width direction perpendicular to the conveying direction, the sheet bundle being stacked on the stacking unit; a detection means for detecting a pressing force in the width direction applied to the sheet stack by the width direction alignment means; Equipped with The sheet processing apparatus further comprises: a width-direction alignment unit that adjusts a pressing force in the width direction based on a detection result from the detection unit;

2. a loading direction aligning means for aligning the loading direction of the sheet bundle by pressing an upper surface in a loading direction of the sheet bundle loaded on the loading section; a second detection means for detecting a pressing force in the stacking direction applied to the sheet stack by the stacking direction aligning means; Equipped with 2. The sheet processing apparatus according to claim 1, wherein the pressing force in the stacking direction by the stacking direction aligning means is adjusted based on the detection result by the second detection means.

3. The loading direction aligning means is a pressing member movable in the loading direction, the second detection means is a pressure sensor that is installed on the pressing member so as to be capable of contacting an upper surface of the sheet stack, 3. The sheet processing apparatus according to claim 2, wherein the pressing member is moved toward the sheet stack so that the detection result by the second detection means reaches a predetermined threshold value.

4. The sheet processing apparatus according to claim 3 , wherein the threshold value is changed based on at least one of a thickness, a size, and a number of sheets constituting the sheet bundle.

5. The sheet processing apparatus according to claim 2 , wherein the stacking unit is a discharge tray onto which the sheet conveyed in the conveying direction is discharged.

6. The width direction alignment means is a pair of side fences movable in the width direction, the detection means is a pressure sensor that is installed on the side fence so as to be capable of coming into contact with a side surface of the sheet stack, 3. The sheet processing apparatus according to claim 1, wherein the pair of side fences are moved toward the sheet stack so that the detection result by the detection means reaches a predetermined value.

7. 7. The sheet processing apparatus according to claim 6, wherein the predetermined value is changed based on at least one of the size, thickness, and number of sheets constituting the sheet stack.

8. The pressure sensors are installed on the pair of side fences, 7. The sheet processing apparatus according to claim 6, wherein the pair of side fences are moved toward the sheet stack so that the detection results of the pair of pressure sensors respectively installed on the pair of side fences become approximately equal.

9. a stopper portion for determining a position in the conveying direction of the sheet bundle loaded on the loading portion; a binding processing section that performs a binding process on the sheet stack after the sheet stack is aligned in the width direction and the stacking direction while being positioned at the stopper section; 3. The sheet processing apparatus according to claim 1, further comprising:

10. 3. An image forming system comprising: an image forming apparatus that forms an image on a sheet; and the sheet processing apparatus according to claim 1, that performs post-processing on the sheet on which the image has been formed by the image forming apparatus.

Images