Sheet loading device and image forming system including the device

Abstract

To solve the problem in which, conventionally, the loading of already loaded sheets is impaired when sheets of different widths are loaded, due to the fact that the end part of the already loaded sheets in the sheet width direction interferes with an alignment plate, depending on the sheet width (loading position) of the already loaded sheets and the alignment waiting position of the alignment plate for receiving subsequent sheets provided on a loading tray.SOLUTION: When sheets of different widths are loaded, by relatively shifting the alignment waiting position of the alignment plate and the dispensing position of the subsequent sheet to the loading tray, interference between the end part of the already loaded sheet in the sheet width direction and the alignment plate is avoided.SELECTED DRAWING: Figure 18

Description

Technical Field

[0001] The present invention relates to a sheet stacking device having a function of aligning sheets stacked on a stacking tray and an image forming system including the device.

Background Art

[0002] In a sheet stacking device that stacks printed sheets discharged from an image forming apparatus on a tray, there is a demand for a performance of aligning those sheets with high accuracy on the tray. In Patent Document 1, it is proposed to provide an aligning member on the stacking tray and move the aligning member toward and away from the end face of the sheet parallel to the discharge direction of the sheet to align the positions of the end faces of the sheets, thereby stacking the sheets stacked on the stacking tray in an aligned manner.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, as shown in FIG. 20, consider a case (mixed loading of different widths) where a sheet (subsequent sheet) having a sheet width W2 (W2 < W1) different from the sheet width W1 of the sheets (already stacked sheets) stacked on the stacking tray 2101 is stacked on the already stacked sheets and the subsequent sheets having the sheet width W2 are aligned. The alignment plates A and B provided on the stacking tray 2101 are configured to be able to perform mixed loading of different widths by once moving upward away from the stacking tray 2101 and then moving downward again after moving to a position a predetermined amount away in the sheet width direction from the end in the sheet width direction of the sheet discharged onto the stacking tray 2101 even when the position in the sheet width direction of the sheet to be stacked is changed. However, when the alignment plate is lowered to receive the subsequent sheet, depending on the sheet width (loading position) of the already loaded sheet and the lowered position of the alignment plate for receiving the subsequent sheet, there is a risk that the alignment plate may interfere with the end portion of the already loaded sheet in the sheet width direction, thereby impairing the loadability of the already loaded sheet.

[0005] Therefore, in the present invention, when it is recognized that the end portion of the already loaded sheet in the sheet width direction on the loading tray interferes with the alignment plate on the loading tray during mixed loading of different widths, the position of the alignment plate and the discharge position of the subsequent sheet onto the loading tray are relatively shifted to avoid interference between the end portion of the already loaded sheet in the sheet width direction and the alignment plate, and the object is to prevent the loadability of the already loaded sheet from being impaired.

Means for Solving the Problems

[0006] In order to solve the above problems, the sheet loading device of the present invention includes a loading port for loading sheets, a conveying means for conveying the sheets loaded from the loading port in a predetermined conveying direction, a shifting means for shifting the sheets conveyed by the conveying means in a sheet width direction orthogonal to the predetermined conveying direction, a discharging means for discharging the sheets conveyed by the conveying means in a predetermined discharging direction, a loading tray on which the sheets discharged by the discharging means are loaded, a moving member disposed on the loading tray and movable in a sheet width direction and a sheet thickness direction respectively orthogonal to the predetermined discharging direction, an aligning means for moving the sheets discharged onto the loading tray by the discharging means by the moving member to align the sheets, a receiving position moving means for moving the aligning means to a receiving position for receiving the sheets discharged onto the loading tray by the discharging means, a recognizing means for recognizing whether or not there is interference between at least one side surface in the sheet width direction orthogonal to the predetermined discharging direction of the already loaded sheet already loaded on the loading tray and the receiving position moving means when discharging a sheet having a sheet width different from that of the already loaded sheet onto the loading tray by the discharging means, and a control means for controlling the shifting means and the receiving position moving means to move the discharging position of the sheet discharged by the discharging means and the sheet receiving position in the sheet width direction orthogonal to the predetermined discharging direction so that the recognizing means does not recognize interference between the already loaded sheet and the receiving position moving means when the recognizing means recognizes interference between the already loaded sheet and the receiving position moving means.

Effect of the Invention

[0007] According to the present invention, when mixed loading of different widths, by relatively shifting the position of the alignment plate on the loading tray and the discharging position of the subsequent sheet onto the loading tray, it is possible to avoid interference between the end portion in the sheet width direction of the already loaded sheet and the alignment plate and prevent the loading property of the already loaded sheet from being impaired.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

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Figure 11

Figure 12

Figure 13

Figure 14

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Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the present invention according to the claims, and not all combinations of the features described in the present embodiment are essential for the solution means of the present invention. Note that the sheet processing apparatus according to the present invention may be included in the image forming apparatus described later, or may be included in the sheet loading apparatus, or may constitute the image forming apparatus or the sheet loading apparatus.

[0010] FIG. 1 is a configuration diagram showing a cross-sectional structure of a main part of an image forming system according to an embodiment of the present invention.

[0011] This image forming system includes an image forming apparatus 10 and a finisher 500 as a sheet loading apparatus. The image forming apparatus 10 includes an image reader 200 that reads an image from a document, and a printer 350 that forms (prints) the read image on a sheet.

[0012] The original document feeding device 100 feeds the documents set upward on the document tray 101 one by one in order from the first page, conveys them through a curved path through a predetermined reading position on the platen glass 102, and then discharges them to the discharge tray 112. At this time, the scanner unit 104 is fixed at a predetermined reading position, and when the document passes through the reading position, the image of the document is read by the scanner unit 104. When the document passes through the reading position, the document is irradiated with the light of the lamp 103 of the scanner unit 104, and the reflected light from the document is guided to the lens 108 through the mirrors 105, 106, and 107. The light that has passed through this lens 108 is imaged on the imaging surface of the image sensor 109, converted into image data, and output. The image data output from the image sensor 109 is input as a video signal to the exposure unit 110 of the printer 350.

[0013] The exposure unit 110 of the printer 350 outputs a modulated laser beam based on the video signal input from the image reader 200. This laser beam is irradiated onto the photosensitive drum 111 while being scanned by the polygon mirror 119, and an electrostatic latent image corresponding to the scanned laser beam is formed on the photosensitive drum 111. The electrostatic latent image on this photosensitive drum 111 is developed by the developer supplied from the developing unit 113 and visualized as a visible image. In this embodiment, the 1D type image forming apparatus 10 having one developing unit 113 and one photosensitive drum 111 will be described as an example. However, the present invention is not limited to this, and the image forming apparatus 10 may have developing units for C (cyan), M (magenta), Y (yellow), and K (black) and photosensitive drums.

[0014] The sheets used for printing are taken out one by one from the paper feed tray 114 or the paper feed tray 115 equipped in the printer 350 by the rotation of the pickup roller 127 or 128. The sheets taken out in this way are conveyed to the position of the registration roller 126 by the rotation of the paper feed roller 129 or the paper feed roller 130. In FIG. 1, for the sake of convenience of explanation, only two paper feed trays are shown, but the printer 350 may be provided with other paper feed trays (not shown). Also, a configuration may be such that an optional paper feeding device (not shown) is connected to the printer 350 to add more paper feed trays. When the leading edge of the sheet reaches the position of the registration roller 126 in this way, the registration roller 126 is rotationally driven at a predetermined timing, and the sheet is conveyed between the photosensitive drum 111 and the transfer unit 116. Thereby, the developer image formed on the photosensitive drum 111 is transferred onto the fed sheet by the transfer unit 116. The sheet onto which the developer image has been transferred in this way is conveyed to the fixing unit 117, and the fixing unit 117 fixes the image on the sheet by heating and pressing the sheet. The sheet that has passed through the fixing unit 117 is discharged from the printer 350 toward the outside (finisher 500) via the flapper 121 and the discharge roller 118. When forming images on both sides of the sheet, the sheet is conveyed to the duplex conveyance path 124 via the reverse path 122 and is conveyed again to the position of the registration roller 126.

[0015] Next, with reference to FIG. 2, the configuration of the controller that controls the entire image forming system according to the present embodiment and the overall system block diagram will be described. FIG. 2 is a block diagram showing the configuration of the controller that controls the entire image forming system according to the embodiment.

[0016] The controller has a CPU circuit section 900, and the CPU circuit section 900 has a CPU 901, a ROM 902, and a memory section 903. The memory section 903 is composed of a RAM and an HDD. The CPU 901 is a CPU that controls the entire image forming system, and the ROM 902 in which a control program is written and the memory section 903 for temporarily storing various data are connected via an address bus and a data bus (not shown). The CPU 901 comprehensively controls each control section 911, 921, 922, 931, 941, 951 and the external I / F 904 according to the control program stored in the ROM 902. The memory section 903 temporarily holds control data and is used as a work area for arithmetic processing associated with control.

[0017] The original document feeding control unit 911 drives and controls the original document feeding device 100 based on an instruction from the CPU circuit unit 900. The image reader control unit 921 performs drive control for the above-described scanner unit 104, image sensor 109, etc., and transfers the image signal output from the image sensor 109 to the image signal control unit 922. The image signal control unit 922 performs various processes after converting the analog image signal from the image sensor 109 into a digital signal, converts this digital signal into a video signal, and outputs it to the printer control unit 931. The image signal control unit 922 also performs various processes on the digital image signal input from the computer 905 via the external I / F 904, converts this digital image signal into a video signal, and outputs it to the printer control unit 931. The processing operation by this image signal control unit 922 is controlled by the CPU circuit unit 900. The printer control unit 931 controls the exposure unit 110 and the printer 350 based on the input video signal, and performs image formation, sheet conveyance, etc. The finisher control unit 951 is mounted on the finisher 500 and performs drive control of the finisher 500 by exchanging information with the CPU circuit unit 900. The control details will be described later. The operation display control unit 941 exchanges information between the operation display unit 400 in FIG. 1 and the CPU circuit unit 900. The operation display unit 400 has a plurality of keys for setting various functions related to image formation, a display unit for displaying information indicating the set state, etc. The operation display unit 400 outputs a key signal corresponding to the operation of each key to the CPU circuit unit 900, and displays the corresponding information on the operation display unit 400 based on a signal from the CPU circuit unit 900.

[0018] FIG. 3 is a diagram for explaining the operation display unit 400 of the image forming apparatus according to the embodiment.

[0019] On the operation display unit 400, there are arranged a start key 402 for starting the image forming operation, a stop key 403 for interrupting the image forming operation, numeric keys 404 to 413 for performing setting input, etc., a clear key 415, a reset key 416, and the like. Also, a display unit 420 having a touch panel formed on the upper part is arranged, and soft keys can be created on the screen of this display unit 420.

[0020] In this image forming apparatus, as post-processing modes, it has various processing modes such as non-sort, sort, shift sort, and staple sort (binding mode). The setting of such processing modes and the like is performed by an input operation from the operation display unit 400. For example, when setting the post-processing mode, when the "Finishing" key 417, which is a soft key, is selected on the initial screen shown in FIG. 3, a menu selection screen is displayed on the display unit 420, and the post-processing mode is set using this menu selection screen.

[0021] Next, the configuration of the finisher 500 will be described with reference to FIG. 4. FIG. 4 is a diagram for explaining the configuration of the finisher 500 according to the embodiment. FIG. 4(A) is a front view of the finisher 500, and FIG. 4(B) is a view of the stacking trays 700 and 701 of the finisher 500 as seen from the sheet discharge direction side.

[0022] First, an explanation will be given with reference to FIG. 4(A).

[0023] The finisher 500 sequentially takes in the sheets discharged from the image forming apparatus 10, performs post-processing such as aligning the plurality of taken-in sheets and bundling them into one bundle, and stapling the rear end of the bundled sheet stack with staples. The finisher 500 takes in the sheets discharged from the image forming apparatus 10 into the conveyance path 520 by the conveyance roller pair 511. The sheets taken into the interior by the conveyance roller pair 511 are conveyed via the conveyance roller pairs 512, 513, and 514. Conveyance sensors 570, 571, 572, and 573 are provided on the conveyance path 520, each detecting the passage of the sheet. The conveyance roller pair 512 is provided in the shift unit 580 together with the conveyance sensor 571.

[0024] The shift unit 580 can move the sheet in the sheet width direction orthogonal to the sheet conveyance direction by a shift motor M5 (Fig. 5) described later. By driving the shift motor M5 with the conveying roller pair 512 holding the sheet, the sheet can be offset in the width direction while being conveyed. In the shift sort mode, the position of the sheet bundle is shifted in the width direction for each part. As the offset amount, for example, 15 mm (front shift) to the front side or 15 mm (rear shift) to the rear side with respect to the center position in the width direction is set. When there is no shift designation, the sheet is discharged to the same position as the front shift.

[0025] When the finisher 500 detects that the sheet has passed through the shift unit 580 based on the input from the conveyance sensor 571, it drives the shift motor M5 to return the shift unit 580 to the center position. Between the conveying roller pairs 513 and 514, a switching flapper 540 is arranged to guide the sheet that is reversely conveyed by the conveying roller pair 514 to the buffer path 523 (Fig. 14). The switching flapper 540 is driven by a solenoid SL1 (Fig. 5) described later.

[0026] Between the conveying roller pairs 514 and 515, a switching flapper 541 for switching between conveying to the upper paper discharge path 521 or the lower paper discharge path 522 is arranged. The switching flapper 541 is driven by a solenoid SL2 described later. When the switching flapper 541 switches to the upper paper discharge path 521 side, the sheet is guided to the upper paper discharge path 521 by the conveying roller pair 514 that is rotationally driven by the buffer motor M2 (Fig. 5). Then, it is discharged to the stacking tray 701 by the conveying roller pair 515 that is rotationally driven by the paper discharge motor M3 (Fig. 5). A conveying sensor 574 is provided on the upper paper discharge path 521 to detect the passage of the sheet. Also, when the switching flapper 541 switches to the lower paper discharge path 522 side, the sheet is guided to the lower paper discharge path 522 by the conveying roller pair 514 that is rotationally driven by the buffer motor M2. The sheet is further guided to the processing tray 630 by the conveying roller pairs 516 - 518 that are rotationally driven by the paper discharge motor M3. Conveying sensors 575 and 576 are provided on the lower paper discharge path 522 to detect the passage of the sheet. The sheet guided to the processing tray 630 is discharged onto the processing tray 630 or the stacking tray 700 according to the post - processing mode by the bundled paper discharge roller pair 680 that is rotationally driven by the bundled paper discharge motor M4 (Fig. 5).

[0027] Also, as shown in FIG. 4(B), on the loading tray 701, there are alignment plates 711a (first alignment plate) and 711b (second alignment plate), which are alignment units that abut against both ends (side ends) of the sheet discharged onto the loading tray 701 to align the width direction of the sheet. These alignment plates 711a and 711b are indicated by reference numeral 711 in FIG. 4(A). Similarly, on the loading tray 700, there are alignment plates 710a and 710b for aligning the sheet width direction of the sheet discharged onto the loading tray 700. These alignment plates 710a and 710b are indicated by reference numeral 710 in FIG. 4(A). These alignment plates 710a and 710b can be moved in the sheet width direction by lower tray alignment motors M11 and M12 (FIG. 5), which will be described later. In FIG. 4(A), the alignment plate 710a is arranged on the front side and the alignment plate 710b is arranged on the back side. Also, the alignment plates 711a and 711b are similarly driven by upper tray alignment motors M9 and M10 (FIG. 5), which will be described later. In FIG. 4(A), the alignment plate 711a is arranged on the front side and the alignment plate 711b is arranged on the back side. Also, the alignment plates 710 and 711 are moved vertically by an alignment plate lifting motor M13 (FIG. 5) for the upper tray and an alignment plate lifting motor M14 (FIG. 5) for the lower tray, which will be described later. Then, it moves up and down around the alignment plate shaft 713 between the actual alignment position (FIG. 6(A)) where the alignment process is performed and the initial position (FIG. 6(B)) in the standby state.

[0028] The loading trays 700 and 701 can be lifted by tray lifting motors M15 and M16 (FIG. 5), which will be described later. The paper surface detection sensors 720 and 721 (FIG. 4(A)), which will be described later, detect the loading trays 700 and 701 or the top surface of the sheet on the loading trays 700 and 701. The finisher 500 rotates and drives the tray lifting motors M15 and M16 in response to the input from the paper surface detection sensors 720 and 721, so as to always control the top surface of the aforementioned loading trays 700 and 701 or the sheet on the loading trays 700 and 701 to be at a certain position. Also, the presence or absence of the sheet on the loading trays 700 and 701 is detected by a paper presence / absence detection sensor 730 or 731 (FIG. 4(A)).

[0029] Next, the configuration of the finisher control unit 951 that drives and controls the finisher 500 will be described with reference to FIG. 5. FIG. 5 is a block diagram showing the configuration of the finisher control unit 951 according to the embodiment.

[0030] The finisher control unit 951 includes a CPU 952, a ROM 953, a RAM 954, etc. The finisher control unit 951 communicates with the CPU circuit unit 900, performs data exchange such as sending and receiving commands, job information, and sheet transfer notifications, and executes various programs stored in the ROM 953 to drive and control the finisher 500. Next, various inputs and outputs provided in the finisher 500 will be described.

[0031] The finisher 500 includes an inlet motor M1, a buffer motor M2, a paper discharge motor M3, a shift motor M5, solenoids SL1 and SL2, and transport sensors 570 to 576 for rotationally driving the transport roller pairs 511 to 513 for sheet transport. Further, the finisher 500 includes a bundle paper discharge motor M4 for driving the bundle paper discharge roller 680, and alignment motors M6 and M7 for driving the moving member 641 as means for driving various members of the processing tray 630 (FIG. 4(A)). Furthermore, the finisher 500 includes a swing guide motor M8 for driving the swing guide up and down. Also, the finisher 500 includes tray lift motors M15 and M16 for raising and lowering the stacking trays 700 and 701, paper surface detection sensors 720 and 721, and paper presence / absence detection sensors 730 and 731. Additionally, the finisher 500 includes upper tray alignment motors M9 and M10, lower tray alignment motors M11 and M12, an upper tray alignment plate lift motor M13, and a lower tray alignment plate lift motor M14 for aligning the sheets on the stacking trays 700 and 701.

[0032] Next, the flow of the non-sorting mode sheets will be described with reference to FIGS. 3, 7, 10, 11, and 14. When the user presses the "Paper Selection" key 418 on the operation display unit 400 of the image forming apparatus 10 on the initial screen shown in FIG. 3, a paper feed stage selection screen as shown in FIG. 11 is displayed on the display unit 420. Here, the user selects the sheet to be used for the job. Here, it is assumed that the "A4" size of the first paper feed stage is selected. FIG. 11 is a diagram showing an example of the paper feed stage selection screen, where the "A4" size is selected.

[0033] Also, when the user selects the "Finishing" key 417, which is a soft key, on the operation display unit 400 of the image forming apparatus 10 on the initial screen shown in FIG. 3, a finishing menu selection screen as shown in FIG. 10(A) is displayed on the display unit 420. Here, as shown in FIG. 10(A), when the user presses the OK button in a state where the "Non-Sorting" key is selected, the non-sorting mode is set.

[0034] When the non-sorting mode is specified by the user and a job is input, the CPU 901 of the CPU circuit unit 900 notifies the CPU 952 of the finisher control unit 951 of information regarding the job, such as the size of the sheet and that the non-sorting mode is selected.

[0035] FIG. 14 is a diagram for explaining the conveyance of sheets in the finisher according to the embodiment, and parts common to the above-described FIG. 4(A) are denoted by the same reference numerals.

[0036] When the sheet P is discharged from the image forming apparatus 10 to the finisher 500, the CPU 901 of the CPU circuit section 900 notifies the CPU 952 of the finisher control section 951 to start the transfer of the sheet. Further, the CPU 901 notifies the CPU 952 of the finisher control section 951 of sheet information such as the shift information and sheet width information of the sheet P. Note that the sheet width information is assumed to be stored in advance in the ROM 902 or the memory section 903 for each sheet size. For example, the width of an A4 size sheet is 297 mm, the width of an A4R size sheet is 210 mm, the width of a B5 size sheet is 257 mm. Also, the width of a letter size sheet is 279.4 mm. Since the A3 size sheet can only be conveyed with the short side at the front, the width of the A3 size sheet is 297 mm. When the CPU 952 receives the notification of the start of sheet transfer, it rotationally drives the inlet motor M1, the buffer motor M2, and the paper discharge motor M3. As a result, the conveying roller pairs 511, 512, 513, 514, 515 shown in FIG. 14 are rotationally driven, and the sheet P discharged from the image forming apparatus 10 is taken into the finisher 500 and conveyed. Note that when the non-sort mode is selected by the user as the finishing (post-processing mode), the shift operation by the shift unit 580 is not performed.

[0037] When the switching flapper 541 is rotationally driven to the position shown in FIG. 14 by the solenoid SL2, the sheet P is guided to the upper paper discharge path 521. Then, when the conveyance sensor 574 detects the passage of the rear end of the sheet P, the CPU 952 rotationally drives the paper discharge motor M3 so that the conveying roller pair 515 conveys the sheet P at a speed suitable for stacking, and discharges the sheet P onto the stacking tray 701.

[0038] Next, the alignment operation in the non-sort mode will be described with reference to FIG. 7. FIG. 7 is a diagram for explaining the positions of the alignment plates 711a and 711b when the stacking tray 701 is viewed from the sheet discharge direction side in the non-sort mode.

[0039] As shown in FIG. 7(A), a pair of alignment plates 711a and 711b are waiting at the initial position before the job starts. When the job starts, as shown in FIG. 7(B), the front alignment plate 711a moves from the center position of the loading tray 701 to the alignment standby position that is separated from the center of the sheet width by a length of W / 2 and a predetermined retraction amount M. Then, the alignment plate 711a waits at this alignment standby position until the sheet is discharged. On the other hand, the rear alignment plate 711b is waiting at the alignment standby position that is separated from the center position of the loading tray 701 by a length of W / 2 and a predetermined retraction amount M, similar to the alignment plate 711a. When the sheet P is discharged onto the loading tray 701 and a predetermined time has elapsed, as shown in FIG. 7(C), the front alignment plate 711a and the rear alignment plate 711b move by a predetermined pushing amount M in the direction of the center of the loading tray 701 to align the sheet P. When the sheet P is aligned in this way and a predetermined time has elapsed, the alignment plate 711a and the alignment plate 711b retract to the alignment standby position as shown in FIG. 7(D).

[0040] Next, the flow of sheets in the sort mode will be described with reference to FIGS. 3, 8, 10, and 14. When the user selects the "Finishing" key 417, which is a soft key, on the operation display unit 400 of the image forming apparatus 10 in the initial screen shown in FIG. 3, a finishing menu selection screen as shown in FIG. 10(B) is displayed on the display unit 420. Here, as shown in FIG. 10(B), when the user presses the OK button while the "Sort" key is selected, the sort mode is set.

[0041] Also, when offsetting the sheet bundles for each part, in FIG. 10(B), when the user presses the OK button while the "Shift" key is selected, the shift mode is set.

[0042] When a job is input after the sorting mode is specified by the user, the CPU 901 in the CPU circuit unit 900 notifies the CPU 952 in the finisher control unit 951 of information related to the job, such as the sheet size and the selected sorting mode. In this embodiment, after the sheets are discharged in one print job, a shift operation is performed so that the discharge position of the sheets printed in the next print job is different from that of the sheets in the previous job. Such a shift operation for each print job is referred to as an inter-job shift.

[0043] When the sheet P is discharged from the image forming apparatus 10 to the finisher 500, the CPU 901 in the CPU circuit unit 900 notifies the CPU 952 in the finisher control unit 951 to start the delivery of the sheet. Further, the CPU 901 notifies the CPU 952 in the finisher control unit 951 of sheet information such as the shift information and the sheet width information of the sheet P. When receiving the notification of the start of sheet delivery, the CPU 952 rotationally drives the inlet motor M1, the buffer motor M2, and the paper discharge motor M3. As a result, the conveying roller pairs 511, 512, 513, 514, 515 shown in FIG. 14 are rotationally driven, and the sheet P discharged from the image forming apparatus 10 is taken into the finisher 500 and conveyed. When the conveyance path sensor 571 detects the sheet P, it means that the conveying roller pair 512 holds the sheet P, so the CPU 952 drives the shift motor M5 to move the shift unit 580 and offset the sheet in the width direction. If the shift information among the sheet information notified from the CPU 901 is "no shift specified", it is uniformly offset by 15 mm to the front side.

[0044] When the switching flapper 541 is rotationally driven to the position shown in FIG. 14 by the solenoid SL2, the sheet P is guided to the upper paper discharge path 521. When the conveyance sensor 574 detects the passage of the rear end of the sheet P, the CPU 952 rotationally drives the paper discharge motor M3 so that the conveying roller pair 515 conveys the sheet P at a speed suitable for stacking, and discharges the sheet P onto the stacking tray 701.

[0045] Next, taking the forward shift operation as an example, the alignment operation in the sorting mode will be described with reference to FIG. 8. FIG. 8 is a diagram for explaining the positions of the alignment plates 711a and 711b when the loading tray 701 is viewed from the sheet discharge direction side.

[0046] As shown in FIG. 8(A), the pair of alignment plates 711a and 711b are waiting at the initial positions before the job starts. When the job starts, as shown in FIG. 8(B), the forward alignment plate 711a moves from the center position of the loading tray 701 to an alignment standby position that is separated by a predetermined retraction amount M from the forward sheet end position X1, which is at a distance obtained by adding the shift amount Z to half the sheet width W / 2. Then, the alignment plate 711a waits at this alignment standby position until the sheet is discharged. On the other hand, the rear alignment plate 711b waits at an alignment standby position that is separated by a predetermined retraction amount M from the rear sheet end position X2, which is at a distance obtained by subtracting the shift amount Z from half the sheet width W / 2, from the center position of the loading tray 701. Then, when the sheet P is discharged onto the loading tray 701 and a predetermined time has elapsed, as shown in FIG. 8(C), the forward alignment plate 711a moves by a predetermined pushing amount 2M in the direction of the center of the loading tray and abuts the sheet P against the stationary rear alignment plate 711b. As a result, the sheet P is moved by the retraction amount M toward the alignment plate 711b side. When the sheet P is thus abutted against the alignment plate 711b and a predetermined time has elapsed, the alignment plate 711a retracts to the alignment standby position as shown in FIG. 8(D). At this time, in the sheet width direction, the alignment plate 711a retracts by an amount 2M, which is twice the retraction amount M, in the direction away from the sheet P, and waits until the next sheet is discharged onto the loading tray 701. Here, when the offset amount Z is 15 mm and the retraction amount M is 5 mm, during the alignment operation, the forward alignment plate 711a pushes the sheet P in by 5 mm, so the offset amount of the sheet after the alignment operation becomes 10 mm. By repeating the above operations, the alignment of the sheet P is performed every time the sheet P is discharged onto the loading tray 701.

[0047] Next, the flow of sheets in shift sort mode will be described with reference to FIGS. 3, 9, 10, and 14. On the finishing menu selection screen shown in FIG. 10(C), when the "Sort" key and the "Shift" key are selected and the OK button is pressed, the shift sort mode is set. When the user designates the shift sort mode and a job is input, the CPU 901 of the CPU circuit section 900 notifies the CPU 952 of the finisher control section 951 that the shift sort mode has been selected. Hereinafter, the operation of the shift sort mode when the number of sheets constituting one "section" is three will be described.

[0048] When the sheet P is discharged from the image forming apparatus 10 to the finisher 500, the CPU 901 of the CPU circuit section 900 notifies the CPU 952 of the finisher control section 951 to start the transfer of the sheet. When receiving the notification of the start of sheet transfer, the CPU 952 rotationally drives the inlet motor M1, the buffer motor M2, and the paper discharge motor M3. As a result, the conveying roller pairs 511, 512, 513, 514, 515 shown in FIG. 14 are rotationally driven, and the sheet P discharged from the image forming apparatus 10 is taken into the finisher 500 and conveyed. When the conveying path sensor 571 detects that the conveying roller pair 512 has clamped the sheet P, the CPU 952 drives the shift motor M5 to move the shift unit 580 to offset the sheet. At this time, if the sheet shift information notified from the CPU 901 is "front", it is offset by 15 mm to the front side, and if it is "rear", it is offset by 15 mm to the rear side. The switching flapper 541 is rotationally driven to the position shown in FIG. 14 by the solenoid SL2, and the sheet P is guided to the upper paper discharge path 521. When the conveyance sensor 574 detects the passage of the rear end of the sheet P, the CPU 952 rotationally drives the paper discharge motor M3 so that the conveying roller pair 515 rotates at a speed suitable for stacking the sheet P, and discharges the sheet P to the stacking tray 701.

[0049] The operation of the alignment plate during shifting will be described with reference to Fig. 9 by taking the case where the shifting direction is changed from the front to the back as an example. Fig. 9 is a diagram for explaining the position of the alignment plate when viewed from the sheet discharge direction side during shift sorting of the loading tray 701.

[0050] Fig. 9(A) shows the position of the alignment plate after sheet alignment, indicating a state where the operation of the front alignment plate 711a retracting from the sheet has ended (corresponding to Fig. 8(D) described above). After that, as shown in Fig. 9(B), the alignment plates 711a and 711b are separated by a predetermined amount in a direction away from the loading tray 701 upward.

[0051] Next, the alignment plates 711a and 711b move to the alignment standby position for the next sheet in the sheet width direction. Here, it shows a case where the next sheet to be discharged is shifted and loaded on top of the sheets already loaded on the loading tray 701 in a state where its position is shifted to the back side of the stacked sheet bundle. As shown in Fig. 9(C), the front alignment plate 711a moves from the center position of the loading tray 701 to the alignment standby position, which is further away from the front sheet end position X1 by a distance obtained by subtracting the shift amount Z from half of the sheet width W / 2 by a predetermined retraction amount M. On the other hand, the rear alignment plate 711b moves from the center position of the loading tray 701 to the alignment standby position, which is further away from the rear sheet end position X2 by a distance obtained by adding the shift amount Z to half of the sheet width W / 2 by a predetermined retraction amount M.

[0052] When the movement of the alignment plate to the alignment standby position is thus completed, as shown in Fig. 9(D), the alignment plates 711a and 711b move downward by a predetermined amount in a direction approaching the loading tray 701 and wait until the next sheet is discharged onto the loading tray 701. At this time, the alignment plate 711a is in contact (touching) with the upper surface of the topmost sheet of the loaded sheets.

[0053] Next, as shown in FIG. 9(E), the sheet P is discharged onto the stacking tray 701. Then, when a predetermined time has elapsed, as shown in FIG. 9(F), the alignment plate 711b moves a predetermined pushing amount 2M in the central direction of the stacking tray 701 and abuts the sheet P against the alignment plate 711a. In this state, when a predetermined time has elapsed, as shown in FIG. 9(G), the alignment plate 711b retracts a predetermined pushing amount 2M in the direction opposite to the center of the stacking tray 701 and waits until the next sheet is discharged onto the stacking tray 701. Note that the operation (reciprocating operation) of moving the alignment plate 711b a predetermined pushing amount 2M in the central direction of the stacking tray 701 and retracting a predetermined pushing amount 2M in the direction opposite to the center of the stacking tray 701 may be performed only once, or may be repeated a predetermined number of times.

[0054] As described above, when the position in the width direction of the sheet to be stacked is changed, the alignment plate is once separated upward from the stacking tray, the alignment position by the alignment plate is changed, and then it descends again to prepare for aligning the next sheet to be discharged. And every time a sheet is discharged onto the already stacked sheet, an operation of aligning the sheet at the shifted position is performed.

[0055] Still, in this case, the alignment plate 711a that abuts (contacts) the upper surface of the uppermost sheet of the stacked sheets does not move, and the alignment plate 711b moves in a direction orthogonal to the sheet conveyance direction to perform the alignment operation of the newly discharged sheet. Thereby, it is possible to prevent the upper surface of the uppermost sheet of the stacked sheets from rubbing against the alignment plate 711a and getting dirty, or at least to reduce such dirt.

[0056] When the "Paper Discharge Destination Selection" key is selected on the finishing menu selection screen shown in FIG. 10(A), a paper discharge destination selection screen as shown in FIG. 10(D) is displayed on the display unit 420. Here, when the user selects a paper discharge destination and presses the OK button, the paper discharge destination is selected (in FIG. 10(D), "Upper Tray" is selected), and again, a finishing menu selection screen as shown in FIG. 10(A) is displayed on the display unit 420.

[0057] Next, different-width mixed loading will be described, in which a plurality of types of sheets with different widths are loaded on the loading tray. When the "Paper Selection" key 418 is pressed on the screen of FIG. 3, the feeding stage selection screen shown in FIG. 11 is transitioned to. Here, when the user selects the "Automatic Selection" key, an automatic paper selection mode is set in which sheets of a size corresponding to the size of the original document are automatically selected. Also, on the screen of FIG. 3, when the user presses the "Application Mode" key 419, the selection screen for the application mode shown in FIG. 12(A) is transitioned to. Here, when the user presses the "Original Size Mixed Loading" key, the original size mixed loading screen shown in FIG. 12(B) is transitioned to. Here, when the user selects the "Different Width" key and presses the OK button, the different-width mixed loading mode is set. In this state, when the user presses the start key 402 of the operation display unit 400, a plurality of original documents loaded in the original document feeding device 100 are fed one by one, and the feeding stage for storing the sheets corresponding to the size of each original document is automatically selected and the copy process is executed. In this way, the printed sheets corresponding to the size of each original document are fed, and a plurality of sheets with different widths are mixed and loaded on the loading tray.

[0058] Also, not only when copying the image of the original document, but also when receiving and printing data created by a computer, if pages with different image sizes are mixed, a plurality of printed sheets with different widths will be mixed and loaded on the loading tray.

[0059] The above different-width mixed loading is an example that occurs in one print job. Next, different-width mixed loading that occurs in two print jobs will be described.

[0060] When the user selects the "Paper Selection" key 418 on the screen shown in Fig. 3, the system transitions to the paper feed stage selection screen shown in Fig. 11. Assume that the user selects the "A4" paper feed stage here. In this state, when printing is executed, printed sheets of A4 size are loaded onto the stacking tray. Next, assume that the user selects the "Paper Selection" key 418 on the screen of Fig. 3 and selects the "B5" paper feed stage on the screen shown in Fig. 11. If printing is executed without changing the sheet discharge destination here, sheets of B5 size printed in the subsequent job are loaded on top of the printed A4-size sheets loaded on the stacking tray in the previous printing job.

[0061] Also, not only when copying the image of the original document, but also when receiving and printing data created on a computer, if the sizes of the sheets used in each printing job are different, multiple sheets with different widths will be loaded on the stacking tray in a mixed state.

[0062] Next, the procedure for setting a partition sheet inserted to make the separation position of the work product clear at the time of job switching (including when switching users, etc.) will be described.

[0063] When the user presses the "Application Mode" key 419 on the screen of Fig. 3, the system transitions to the application mode selection screen shown in Fig. 13(A). When the user selects "Partition Paper" and presses the OK button here, the system transitions to the partition sheet selection screen shown in Fig. 13(B). On this screen, the user selects the paper feed stage containing the partition sheet. In Fig. 13(B), the paper feed stage 1 in which the A4-size partition sheet is set is selected. When the user presses the OK button here, the A4 size set in paper feed stage 1 is set as the partition sheet.

[0064] As described above, when sheets of different widths are loaded together (including the case where a partition sheet is inserted), in order to receive the subsequent sheet, after separating the alignment plate upward from the stacking tray (if already separated, no action is taken), it moves to a position a predetermined amount away from the end of the sheet in the sheet width direction of the sheet to be discharged onto the stacking tray, and then descends again, so that it can be prepared for aligning the subsequent sheet.

[0065] However, in the conventional control during mixed loading of sheets of different widths, when the alignment plate is lowered to receive the subsequent sheet, depending on the sheet width (loading position) of the already loaded sheet and the lowered position of the alignment plate for receiving the subsequent sheet, there is a risk that the alignment plate interferes with the end of the already loaded sheet in the sheet width direction, thereby impairing the loadability of the already loaded sheet.

[0066] As a specific example, the case of mixed loading of 8.8 x 11.7 inches (sheet length 297.2 mm, sheet width 223.5 mm) and 8.5 x 11 inches (sheet length 279.4 mm, sheet width 215.9 mm) will be described. In this example, the 8.8 x 11.7 - inch sheet is inserted as a partition sheet to clearly indicate the separation position of the workpieces at the time of job switching (including when switching by the user, etc.). FIG. 15 is an explanatory diagram when viewing the position of the sheet at that time from above the stacking tray. Also, as the post - processing mode, the non - sort mode described above is set, and as the paper discharge destination, the upper tray described above is set.

[0067] FIG. 16 is an operation explanatory diagram during mixed loading of sheets of different widths by conventional control. It will be described from the state where an 8.8 x 11.7 - inch partition sheet is loaded on the stacking tray 701 as the already loaded sheet until an 8.5 x 11 - inch sheet is loaded on the stacking tray 701 as the subsequent sheet and aligned by the alignment plates 711a and 711b. Unless otherwise specified, the following operations are executed by the CPU 952 provided in the finisher control unit 951 described above.

[0068] Figs. 16(A) and (B) show a state where an 8.8 x 11.7-inch partition sheet is loaded on the loading tray 701 as a pre-loaded sheet. Fig. 16(A) is a view when looking from above the loading tray 701, and Fig. 16(B) is a view when looking from the sheet discharge direction. At this time, the alignment plates 711a and 711b are waiting at the above-described initial positions.

[0069] Figs. 16(C), (D), (E), and (F) are operation explanatory views when moving the alignment plates 711a and 711b to the alignment standby positions to receive an 8.5 x 11-inch sheet as a subsequent sheet. Figs. 16(C) and (E) are views when looking from above the loading tray 701, and Figs. 16(D) and (F) are views when looking from the sheet discharge direction. At this time, after the alignment plates 711a and 711b move to a position a predetermined amount away from the position where the subsequent sheet (8.5 x 11 inches) is discharged, they perform a descending operation to receive the subsequent sheet. However, in this example, a state is shown where interference occurs between the end portion in the sheet width direction of the pre-loaded sheet (8.8 x 11.7 inches) and the alignment plate when it descends. Thus, in the control during mixed loading of different widths in the prior art, there is a risk of deteriorating the loadability of the pre-loaded sheet depending on the sheet width (loading position) of the pre-loaded sheet and the descending position of the alignment plate for receiving the subsequent sheet. Also, Figs. 16(G) and (H) show the operations when receiving the subsequent sheet and performing the alignment operation thereafter.

[0070] Next, the present invention for solving the above problems will be described. FIG. 18 is a flowchart of a process for determining the sheet discharge position according to the present invention and the alignment standby position of the alignment plates 711a and 711b for receiving subsequent sheets. FIGS. 17 and 19 are respectively an operation explanatory diagram and a flowchart during mixed loading of different widths according to the present invention. The state where an 8.8x11.7-inch partition sheet is loaded on the loading tray 701 as the already loaded sheet, and then an 8.5x11-inch sheet is loaded on the loading tray 701 as the subsequent sheet and aligned by the alignment plates 711a and 711b will be described. Also, as the post-processing mode, the non-sort mode described above is set, and as the paper discharge destination, the upper tray described above is set. Note that, unless otherwise specified, the following operations are executed by the CPU 952 provided in the finisher control unit 951 described above.

[0071] When the job is started, the CPU 952 first executes a process for determining the sheet discharge position according to the present invention in FIG. 18 and the alignment standby positions of the alignment plates 711a and 711b for receiving subsequent sheets.

[0072] In S101, the CPU 952 acquires the sheet information notified from the controller CPU circuit unit 900. The sheet information includes information such as sheet width information, post-processing mode, and paper discharge destination. Also, the job information may be the sheet information of a single job or the sheet information of a job spanning multiple sheets.

[0073] Subsequently, the CPU 952 determines the shift amount of the sheet from the sheet information acquired in S101 (S102). In this example, since the non-sort mode is selected as the post-processing mode, the shift amount is determined to be 0 mm (it is determined that the shift operation by the shift unit 580 is not performed). Thus, by determining the shift amount of the sheet, as a result, the discharge position of the sheet onto the loading tray 701 is also determined.

[0074] In S103, the CPU 952 determines the alignment standby position from the sheet information acquired in S101 (in this embodiment, it is determined as a position that is a predetermined amount away from the end in the sheet width direction of the sheet discharged onto the stacking tray 701 in the sheet width direction).

[0075] Next, the CPU 952 acquires the information of the already stacked sheets on the stacking tray 701 stored in the RAM 954 (S104), and determines in S105 whether or not an already stacked sheet is stacked on the stacking tray 701. If it is determined that an already stacked sheet is stacked (S105: Y), the process proceeds to S106. If it is determined that no already stacked sheet is stacked (S105: N), the process ends as it is.

[0076] Subsequently, in S106, the CPU 952 determines whether or not the end in the sheet width direction of the already stacked sheet on the stacking tray 701 interferes with the alignment plates 711a and 711b. If it is determined that the end in the sheet width direction of the already stacked sheet interferes with the alignment plates 711a and 711b (S106: N), the process proceeds to S107. If it is determined that there is no interference (S106: Y), the process ends as it is (in this embodiment, when a partition sheet of 8.8 x 11.7 inches is stacked on the stacking tray 701 as the already stacked sheet and then a sheet of 8.5 x 11 inches is stacked on the stacking tray 701 as the subsequent sheet as it is, interference with the alignment plates 711a and 711b occurs, so the process proceeds to S107).

[0077] Furthermore, in S107, the CPU 952 determines whether it is possible to relatively move either one or both of the sheet discharge position (the shift amount of the sheet), the alignment standby position of the alignment plates 711a and 711b so that the end in the sheet width direction of the already stacked sheet does not interfere with the alignment plates 711a and 711b.

[0078] In S107, when it is determined that the movement of the sheet discharge position (sheet shift amount) and the alignment plates 711a and 711b is not possible (S107: N), the CPU 952 determines to prohibit the alignment operation by the alignment plates 711a and 711b in S110 and ends the process (in this embodiment, since the movement of the sheet discharge position (sheet shift amount) and the alignment plates 711a and 711b is possible, the process proceeds to S108). Cases where it is determined that the movement of the sheet discharge position (sheet shift amount) and the alignment plates 711a and 711b is not possible include cases where there are limits in the drivable area of the alignment plates 711a and 711b or the movable area of the shift unit 580.

[0079] Note that in S107, when the CPU 952 determines that the movement of the sheet discharge position (sheet shift amount) and the alignment plates 711a and 711b is possible (S107: Y), in S108, the sheet shift amount (sheet discharge position) is changed, and in S109, the alignment standby positions of the alignment plates 711a and 711b are changed (however, it is possible that only one of them is changed), and the process ends.

[0080] Regarding the changed sheet shift amount (sheet discharge position) and the alignment standby positions of the alignment plates 711a and 711b, there are no particular restrictions as long as they are determined in a positional relationship such that the ends in the sheet width direction of the already loaded sheet do not interfere with the alignment plates 711a and 711b. Generally, it is desirable to determine them so that the movement amount of each is reduced. Also, the ends in the sheet width direction of the already loaded sheet and the alignment plates 711a and 711b interfere in many cases where the difference between the sheet width of the already loaded sheet and the sheet width of the subsequent sheet is relatively small (in this embodiment, already loaded sheet: sheet width 223.5 mm, subsequent sheet: sheet width 215.9 mm). In that case, instead of simply reducing the movement amount, considering the stacking property, the movement amounts may be determined so that the ends in the sheet width direction of the already loaded sheet and the ends in the sheet width direction of the subsequent sheet are aligned and stacked on the stacking tray 701. Similarly, when acquiring sheet information of a job spanning multiple sheets in S101, the movement amounts may be determined so as to align the ends in the sheet width direction of the sheets to be stacked on the stacking tray 701.

[0081] Next, after determining the sheet discharge position and the alignment standby positions of the alignment plates 711a and 711b for subsequent sheet reception in the process of starting the job and determining the sheet discharge position and the alignment standby positions, the operation from the state where an 8.8x11.7-inch partition sheet is loaded on the loading tray 701 as the already loaded sheet to loading an 8.5x11-inch sheet on the loading tray 701 as the subsequent sheet and aligning it with the alignment plates 711a and 711b will be described according to the operation explanatory diagram of FIG. 17 and the flowchart of FIG. 19.

[0082] FIG. 17(A) shows a state where an 8.8x11.7-inch partition sheet is loaded on the loading tray 701 as the already loaded sheet. At this time, the alignment plates 711a and 711b are waiting at the above-described initial positions.

[0083] In S201, when a sheet is discharged from the image forming apparatus 10 to the finisher 500, the CPU 952 conveys the sheet into the finisher 500 to receive the sheet.

[0084] Subsequently, the CPU 952 performs a shift operation by the shift unit 580 based on the shift amount of the sheet determined in S102 or S108 (S202). In S203, the CPU 952 moves the alignment plates 711a and 711b based on the alignment standby positions of the alignment plates 711a and 711b determined in S103 or S109. In this embodiment, the shift amount of the sheet and the alignment standby positions of the alignment plates 711a and 711b are determined so that the ends of the already loaded sheet in the sheet width direction do not interfere with the alignment plates 711a and 711b (so that the ends of the already loaded sheet in the sheet width direction are aligned with the ends of the subsequent sheet in the sheet width direction). FIGS. 17(B), (C), (D), and (E) show the states at that time. Note that FIGS. 17(B) and (D) are views when looking from above the loading tray 701, and FIGS. 17(C) and (E) are views when looking from the sheet discharge direction.

[0085] Thereafter, the CPU 952 discharges the subsequent sheet onto the stacking tray 701 at S204, and performs an alignment operation by the alignment plates 711a and 711b at S205 (Figs. 17(F) and (G) show the states at that time).

[0086] As described above, in the present invention, when sheets of different widths are mixed and loaded, by relatively shifting the position of the alignment plate on the stacking tray and the discharge position of the subsequent sheet onto the stacking tray, interference between the end portion of the already loaded sheet in the sheet width direction and the alignment plate is avoided, and it becomes possible to prevent the loadability of the already loaded sheet from being impaired.

[0087] Note that the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the scope of the present invention. All technical matters included in the technical idea described in the claims are the subject of the present invention. The above embodiments are merely illustrative examples, and those skilled in the art can realize various alternative examples, modification examples, variation examples, or improvement examples from the content disclosed in this specification, and these are included in the technical scope described in the appended claims.

Explanation of Reference Numerals

[0088] 10 Image forming apparatus 500 Finisher 580 Shift unit 701 Stacking tray 711a First alignment plate 711b Second alignment plate

Claims

1. An inlet for loading a sheet, Conveying means for conveying the sheet loaded from the inlet in a predetermined conveying direction, Shifting means for shifting the sheet conveyed by the conveying means in a sheet width direction orthogonal to the predetermined conveying direction, Discharging means for discharging the sheet conveyed by the conveying means in a predetermined discharging direction, A stacking tray on which the sheet discharged by the discharging means is stacked, A moving member for aligning the sheet, which is arranged on the stacking tray and is movable in a sheet width direction and a sheet thickness direction orthogonal to the predetermined discharging direction respectively, Aligning means for aligning the sheet discharged onto the stacking tray by the discharging means by the moving member, Receiving position moving means for moving the aligning means to a receiving position where the sheet discharged onto the stacking tray by the discharging means is received, When discharging a sheet having a sheet width different from the sheet width of the already stacked sheet already stacked on the stacking tray onto the stacking tray by the discharging means, recognition means for recognizing whether or not at least one side surface in the sheet width direction orthogonal to the predetermined discharging direction of the already stacked sheet interferes with the receiving position moving means, When the recognition means recognizes that the already stacked sheet interferes with the receiving position moving means, the control means for controlling the shifting means and the receiving position moving means to move the discharging position of the sheet discharged by the discharging means and the sheet receiving position in the sheet width direction orthogonal to the predetermined discharging direction so that the recognition means recognizes that the already stacked sheet does not interfere with the receiving position moving means, A sheet stacking device comprising the above.

2. The control means, The sheet stacking device according to claim 1, wherein the shifting means, the receiving position moving means, and the aligning means are controlled so as to align an end surface in the sheet width direction orthogonal to the predetermined discharging direction of the already stacked sheet and an end surface in the sheet width direction orthogonal to the predetermined discharging direction of the sheet discharged by the discharging means.

3. When at least one or more of the planned sheets to be stacked on the stacking tray have different sheet widths, further comprising second recognition means for recognizing whether or not at least one side surface in the sheet width direction orthogonal to the predetermined discharging direction of the planned sheet to be stacked interferes with the receiving position moving means, The control means, The sheet loading device according to claim 1, wherein the shift means, the receiving position moving means, and the aligning means are controlled so that an end surface in the sheet width direction orthogonal to the predetermined discharge direction of the planned loading sheet and an end surface in the sheet width direction orthogonal to the predetermined discharge direction of the sheet discharged by the discharging means are aligned.

4. A loading port for loading a sheet; Conveying means for conveying the sheet loaded from the loading port in a predetermined conveying direction; Shifting means for shifting the sheet conveyed by the conveying means in a sheet width direction orthogonal to the predetermined conveying direction; Discharging means for discharging the sheet conveyed by the conveying means in a predetermined discharging direction; A loading tray on which the sheet discharged by the discharging means is loaded; A moving member disposed on the loading tray and movable in a sheet width direction and a sheet thickness direction, both of which are orthogonal to the predetermined discharging direction; Aligning means for moving the sheet discharged onto the loading tray by the discharging means by the moving member to align the sheet; Receiving position moving means for moving the aligning means to a receiving position of the sheet discharged onto the loading tray by the discharging means; When a sheet having a sheet width different from the sheet width of the already loaded sheet on the loading tray is discharged onto the loading tray by the discharging means, recognition means for recognizing whether or not at least one side surface in the sheet width direction orthogonal to the predetermined discharging direction of the already loaded sheet interferes with the receiving position moving means; and second control means for prohibiting the aligning means and the receiving position moving means when the recognition means recognizes that the already loaded sheet and the receiving position moving means interfere with each other. A sheet loading device comprising the same.

5. An image forming apparatus for forming an image on a sheet; An image forming system comprising the sheet loading device according to any one of claims 1 to 4.

Images