Paper loading device and image forming apparatus

Abstract

To provide a paper loading device capable of improving availability while suppressing paper damage and fence breakage.SOLUTION: A paper loading device 2 includes a tray 21, a bottom plate 27, a fence 28, a paper sensor 22, a tray sensor, and a control device. When the tray sensor detects the opening of the tray 21, the control device moves the fence 28 toward the outside of the tray 21. Furthermore, when the tray sensor 23 detects the tray 21 is closed, the control unit moves the fence 28 to a position aligned with the edge of a paper stack PS and moves the bottom plate 27 to align the center of the paper stack PS with a paper transport center CC.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a paper stacking device and an image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in image forming apparatuses and associated paper feed devices, a technique is known in which paper set in a paper stacking tray is automatically moved to a position where it can be fed, in order to facilitate paper replenishment and paper setting. Summary of the Invention [Problem to be solved by the invention]

[0003] However, with conventional paper transport means, there is a risk that the fence that holds the paper in place may break, or that paper not placed in a case may be damaged by the force of the fence. For example, Japanese Patent Application Laid-Open No. 11-301860 discloses a paper storage case intended to reduce the effort required for setting paper. However, this technology does not eliminate the risk of the fence breaking or the paper being damaged when a large amount of paper is loaded.

[0004] The present disclosure provides a paper stacking device and an image forming apparatus that can improve availability while suppressing damage to paper and breakage of a fence. [Means for solving the problem]

[0005] One aspect of the present disclosure provides a paper loading device comprising: an openable / closable tray; a movable bottom plate positioned at the bottom of the tray on which a stack of paper is placed; a fence positioned on the bottom plate and movable to a position along the edge of the stack of paper; a paper sensor that detects the position of the stack of paper placed on the bottom plate; a tray sensor that detects the opening and closing of the tray; and a control device that moves the bottom plate and the fence based on the detection results of the paper sensor and the tray sensor, wherein the control device moves the fence toward the outside of the tray when the tray sensor detects that the tray is open, and moves the fence to a position along the edge of the stack of paper and moves the bottom plate to align the center of the stack of paper with the center of paper transport in the tray when the tray sensor detects that the tray is closed.

[0006] Another aspect of the present disclosure provides an image forming apparatus including the paper stacking device of the above aspect. [Effects of the Invention]

[0007] According to the above aspects of the present disclosure, it is possible to provide a paper stacking device and an image forming apparatus that can improve availability while suppressing damage to paper and breakage of the fence. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram of an image forming apparatus and a paper stacking device according to a first embodiment. [Figure 2] FIG. 2 is a block diagram of a paper stacking device according to the first embodiment. [Figure 3] FIG. 2 is a schematic plan view of the paper stacking device of the first embodiment. [Figure 4] 10 is a flowchart of a procedure for setting a stack of paper sheets by the paper stacking device of the first embodiment. FIG. [Figure 5] 10 is a flow chart of centering a stack of paper sheets by the paper stacking device of the first embodiment. FIG. [Figure 6] 3A and 3B are schematic plan views showing the operation of the paper stacking device of the first embodiment. [Figure 7]FIG. 10 is a schematic plan view of a paper stacking device according to a second embodiment. [Figure 8] FIG. 10 is a flowchart of a procedure for setting a stack of paper sheets by the paper stacking device of the second embodiment. [Figure 9] 10 is an example of a display screen of the image forming apparatus according to the second embodiment. [Figure 10] FIG. 11 is a flow chart of aligning edges of a stack of paper sheets by the paper sheet loading device of the third embodiment. [Figure 11] 10 is an example of a display screen of the image forming apparatus according to the third embodiment. [Figure 12] 10 is an example of a display screen of the image forming apparatus according to the third embodiment. [Figure 13] 10 is an example of a display screen of the image forming apparatus according to the third embodiment. [Figure 14] FIG. 11 is a flowchart of a procedure for setting a stack of paper sheets using the paper stacking device of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the invention will be described with reference to the drawings.

[0010] [Embodiment 1] 1 is a block diagram showing a first embodiment of an image forming apparatus and a paper stacking device according to the present disclosure. The image forming apparatus 1 of this embodiment is a device that prints characters and images on paper, such as a copier, printer, or multifunction device. The image forming apparatus 1 includes, for example, a paper stacking device 2, a paper transport device 3, a printing device 4, a UI device 5, and a control device 6.

[0011] The paper stacking device 2 stores a stack of paper sheets PS (see FIG. 3) in which paper sheets to be printed are stacked, and supplies the paper sheets to the paper transporting device 3. The paper transporting device 3 takes out and transports paper sheets one by one from the stack of paper sheets PS stored in the paper stacking device 2. The printing device 4 prints characters and images on the paper sheets transported by the paper transporting device 3. The UI device 5 is a user interface device that includes, for example, a display device and an input device.

[0012] The UI device 5, for example, displays information to a user of the image forming apparatus 1 and accepts operations from the user. The control device 6 is configured by, for example, a central processing unit (CPU), memories such as ROM and RAM, a timer, and one or more microcontrollers including an input / output unit, and controls each part of the image forming apparatus 1 by loading a program stored in the ROM into the RAM by the CPU and executing the program.

[0013] Fig. 2 is a block diagram of the paper stacking device 2 that constitutes the image forming apparatus 1. Fig. 3 is a schematic plan view of the paper stacking device 2 that constitutes the image forming apparatus 1. Details will be described later, but the paper stacking device 2 of this embodiment is mainly characterized by having the following configuration.

[0014] The paper stacking device 2 includes a tray 21, a bottom plate 27, a fence 28, a paper sensor 22, a tray sensor 23, and a control device 26. The tray 21 is provided so as to be able to open and close. The bottom plate 27 is located at the bottom of the tray 21, and a stack of paper PS is placed on it. The fence 28 is located on the bottom plate 27 and is provided so as to be able to move to a position along the edge of the stack of paper PS. The paper sensor 22 detects the position of the stack of paper PS placed on the bottom plate 27. The tray sensor 23 detects whether the tray 21 is open or closed.

[0015] The control device 26 moves the bottom plate 27 and the fence 28 based on the detection results of the paper sensor 22 and the tray sensor 23. Specifically, when the tray sensor 23 detects that the tray 21 is open, the control device 26 moves the fence 28 toward the outside of the tray 21. Furthermore, when the tray sensor 23 detects that the tray 21 is closed, the control device 26 moves the fence 28 to a position along the edge of the paper stack PS and moves the bottom plate 27 to align the center of the paper stack PS with the paper transport center CC.

[0016] The paper stacking device 2 of this embodiment will be described in detail below with reference to FIGS. 4 to 6 in addition to FIGS. 2 and 3. FIG.

[0017] 2, the paper loading device 2 includes a paper sensor 22, a tray sensor 23, a bottom plate moving device 24, a fence moving device 25, and a control device 26. The control device 6 of the image forming apparatus 1 may be used as the control device 26 of the paper loading device 2. The paper loading device 2 also includes a tray 21, a bottom plate 27, and a fence 28, as shown in FIG.

[0018] 3 shows a three-dimensional Cartesian coordinate system having an X axis parallel to the opening / closing direction of the tray 21, a Y axis parallel to the paper transport direction in which paper is removed from the paper stack PS and transported, and a Z axis parallel to the vertical direction. In the following description, in the X axis direction in which the tray 21 opens and closes, the negative side is called the "front side" and the positive side is called the "rear side."

[0019] Tray 21 is, for example, a drawer-type paper tray that is provided in an openable and closable manner in image forming apparatus 1. Tray 21 can be opened, for example, by pulling it out toward the front (negative direction of the X-axis) and can be closed by pushing it in toward the back (positive direction of the X-axis). Tray 21 is, for example, a large-capacity paper tray that can accommodate a stack of paper sheets PS, which is made up of several thousand sheets of paper stacked together.

[0020] As described above, bottom plate 27 is disposed at the bottom of tray 21, and stack of sheets PS is placed on it. Bottom plate 27 is provided so as to be movable in the opening / closing direction (X-axis direction) of tray 21, for example, by bottom plate moving device 24. Bottom plate 27 is also provided so as to be movable up and down in the vertical direction (Z-axis direction) by bottom plate moving device 24, for example, and lifts stack of sheets PS to a position where they can be fed to sheet feeding section 31 of sheet transport device 3.

[0021] As described above, the fence 28 is disposed on the bottom plate 27 and is movable to a position along the edge of the stack of paper-sheets PS. The fence 28 includes, for example, a front side fence 28fs disposed on the front side of the stack of paper-sheets PS to prevent the paper from slipping forward, and a rear side fence 28rs disposed on the rear side of the stack of paper-sheets PS to prevent the paper from slipping backward. The fence 28 also includes, for example, an end fence 28e disposed on the rear side of the stack of paper-sheets PS in the conveying direction (positive direction of the Y axis) in which the paper feed unit 31 of the paper conveying device 3 feeds the paper from the stack of paper-sheets PS to prevent the paper from slipping backward.

[0022] Hereinafter, the side edge on the front side of the stack of sheets PS in the opening / closing direction of the tray 21 will be referred to as the front side edge of the stack of sheets PS. Also, the side edge on the rear side of the stack of sheets PS in the opening / closing direction of the tray 21 will be referred to as the rear side edge of the stack of sheets PS. Also, the front side edge of the stack of sheets PS in the paper transport direction (positive direction of the Y axis) by the paper feed unit 31 will be referred to as the leading edge of the stack of sheets PS. Also, the rear side edge of the stack of sheets PS in the paper transport direction will be referred to as the trailing edge of the stack of sheets PS.

[0023] The front side fence 28fs is movable, for example, by the fence moving device 25, between a retracted position at the outermost edge of the front side of the bottom plate 27 shown in Fig. 3 and a pressing position along the front edge of the paper stack PS. The rear side fence 28rs is movable, for example, by the fence moving device 25, between a retracted position at the outermost edge of the rear side of the bottom plate 27 shown in Fig. 3 and a pressing position along the rear edge of the paper stack PS.

[0024] 3, between a retracted position at the outermost edge of the bottom plate 27 at the rear side in the paper transport direction and a holding position along the rear end of the paper stack PS, for example, by the fence moving device 25. Also, the end fence 28e is movable in the opening / closing direction of the tray 21 (X-axis direction) between a position on the front side and a position on the back side of the bottom plate 27, for example, by the fence moving device 25.

[0025] The side fences 28fs and 28rs can have lengths at their maximum equal to the front and rear sides, respectively, of the bottom plate 27. Similarly, the end fence 28e can have a length at their maximum equal to the rear side of the bottom plate 27 in the paper transport direction.

[0026] As described above, the paper sensor 22 detects the position of the paper stack PS placed on the bottom plate 27 of the tray 21. The paper sensor 22 includes, for example, a front edge sensor 22fs that detects the front edge of the paper stack PS, a rear edge sensor 22rs that detects the rear edge of the paper stack PS, and a rear edge sensor 22e that detects the rear edge of the paper stack PS. The paper sensor 22 also includes, for example, a center deviation sensor 22c that detects a front center deviation Fx, which is the distance from the transport center CC of the tray 21 to the front edge of the paper stack PS, and a rear center deviation Rx, which is the distance from the transport center CC of the tray 21 to the rear edge of the paper stack PS.

[0027] The front edge sensor 22fs, the rear edge sensor 22rs, and the rear edge sensor 22e are provided on the surfaces of the front side fence 28fs, the rear side fence 28rs, and the end fence 28e that face the stack of sheets PS, respectively. The front edge sensor 22fs, the rear edge sensor 22rs, and the rear edge sensor 22e move together with the front side fence 28fs, the rear side fence 28rs, and the end fence 28e, respectively.

[0028] These front edge sensor 22fs, rear edge sensor 22rs, and rear edge sensor 22e are contact sensors that detect the position of the sheet stack PS placed on the bottom plate 27 by coming into contact with the front edge, rear edge, and rear edge of the sheet stack PS, respectively. Note that the sheet sensor 22 may also include, for example, a non-contact sensor that detects the position of the sheet stack PS placed on the bottom plate 27.

[0029] The center deviation sensor 22c detects the front-side center deviation Fx (see FIG. 6) by detecting the distance from the conveyance center CC of the tray 21 to the front-side side fence 28fs using, for example, a resistance change amount due to a slide resistor or a variable resistor. Similarly, the center deviation sensor 22c detects the distance from the conveyance center CC of the tray 21 to the rear-side side fence 28rs to detect the rear-side center deviation Rx (see FIG. 6).

[0030] The front center deviation Fx is the distance from the transport center CC of the tray 21 to the front end of the sheet stack PS, and the rear center deviation Rx is the distance from the transport center CC of the tray 21 to the rear end of the sheet stack PS. The center deviation sensor 22c may detect the front center deviation Fx and the rear center deviation Rx by detecting the positions of the front end and the rear end of the sheet stack PS using, for example, a distance sensor.

[0031] The tray sensor 23 is, for example, an open / close detection sensor that is configured to be turned on when the tray 21 is pulled out and open, and turned off when the tray 21 is pushed in and closed.

[0032] The bottom plate moving device 24 includes, for example, a power source such as a motor and a power transmission device such as gears, and moves the bottom plate 27 under the control of the control device 26. Similarly, the fence moving device 25 includes, for example, a power source such as a motor and a power transmission device such as gears, and moves the fence 28 under the control of the control device 26. The power source of the fence moving device 25 may include an elastic member such as a spring.

[0033] 4 is a flow diagram showing the procedure for setting a stack of sheets of paper in the paper loading device 2. When setting a stack of sheets of paper PS in the paper loading device 2, the user of the image forming apparatus 1 pulls out the tray 21 of the paper loading device 2 from the image forming apparatus 1 and opens the tray 21. Then, the tray sensor 23 detects that the tray 21 has been opened, and outputs the detection result to the control device 26 of the paper loading device 2.

[0034] When the control device 26 of the paper stacking device 2 receives a detection result from the tray sensor 23 indicating that the tray 21 is open, the control device 26 starts the flow of the paper stack setting procedure shown in Fig. 4 and moves and retracts the fence 28 toward the outside of the tray 21 (step S01). As a result, the fence 28, including the side fences 28fs, 28rs and the end fence 28e, moves to a retracted position at the outermost edge of the bottom plate 27, as shown in Fig. 3.

[0035] The user of the image forming apparatus 1 pulls out the tray 21 from the image forming apparatus 1 until the tray 21 is fully open (step S02), and places a new stack of sheets PS on the bottom plate 27 of the tray 21 (step S03). After that, the user pushes the tray 21 back into the image forming apparatus 1 to close the tray 21 (step S04). As a result, the tray sensor 23 detects that the tray 21 is closed, and outputs the detection result to the control device 26 of the paper stacking device 2.

[0036] Then, the control device 26 determines whether or not there is a stack of sheets PS in the tray 21, for example, based on the detection result of the sheet sensor 22, etc. (step S05). For example, suppose that the tray 21 becomes empty and the user closes the tray 21 in step S04 without placing the stack of sheets PS on the bottom plate 27 of the tray 21 in step S03. In this case, the control device 26 determines in step S05 that there is no stack of sheets PS in the tray 21 (NO), and ends the flow of the sheet stack setting procedure shown in FIG. 4.

[0037] On the other hand, if the control device 26 determines in step S05 that the sheet stack PS is in the tray 21 (YES), it controls the fence moving device 25 to start moving the fence 28 (step S06). At this time, the control device 26 may move the side fences 28fs, 28rs first and then the end fence 28e, or may move the side fences 28fs, 28rs and the end fence 28e simultaneously. Also, one of the rear and front side fences 28fs, 28rs may be fixed and the other moved.

[0038] Next, the control device 26 determines whether the fence 28 has moved to a position along the edge of the paper-sheet bundle PS (step S07). If the control device 26 determines in step S07 that the fence 28 has not moved to a position along the edge of the paper-sheet bundle PS (NO), it continues moving the fence 28 and repeats step S07. If the control device 26 determines in step S07 that the fence 28 has moved to a position along the edge of the paper-sheet bundle PS (YES), it ends the movement of the fence 28 (step S08).

[0039] Specifically, suppose that the front edge of the stack of sheets PS is detected by the front edge sensor 22fs after the control device 26 starts moving the front side fence 28fs in step S06. In this case, the control device 26 determines in step S07 that the front side fence 28fs has moved to a position along the front edge of the stack of sheets PS (YES), and ends the movement of the front side fence 28fs in step S08.

[0040] Also, suppose that the rear edge of the stack of sheets PS is detected by the rear edge sensor 22rs after the control device 26 starts moving the rear side fence 28rs in step S06. In this case, the control device 26 determines in step S07 that the rear side fence 28rs has moved to a position along the rear edge of the stack of sheets PS (YES), and ends the movement of the side fence 28rs in step S08.

[0041] Similarly, suppose that the rear end of the stack of sheets PS is detected by the rear end sensor 22e after the control device 26 starts moving the end fence 28e in step S06. In this case, the control device 26 determines in step S07 that the end fence 28e has moved to a position along the rear end of the stack of sheets PS (YES), and ends the movement of the end fence 28e in step S08.

[0042] The side fences 28fs, 28rs and end fence 28e may be moved one by one in any order, or all may be moved simultaneously, or any combination of two may be moved simultaneously with the other one moved before or after them.

[0043] Thereafter, the control device 26 determines whether the center of the paper stack PS is at the center CC of paper transport by the paper feed unit 31 of the paper transport device 3, for example, based on the detection result of the center deviation sensor 22c (step S09). If the control device 26 determines in step S09 that the front side center deviation Fx and the rear side center deviation Rx are equal and the center of the paper stack PS is at the transport center CC (YES), it ends the flow of the paper stack setting procedure shown in FIG.

[0044] On the other hand, if the control device 26 determines in step S09 that the front side center deviation Fx and the rear side center deviation Rx are not equal and the center of the paper stack PS is not at the transport center CC (NO), it moves the bottom plate 27 of the tray 21 to align the center of the paper stack PS with the transport center CC (step S10). Thereafter, the control device 26 ends the flow of the paper stack setting procedure shown in FIG.

[0045] Fig. 5 is a flow diagram showing the procedure of step S10 for aligning the center of the sheet stack PS with the conveyance center CC of the tray 21. Fig. 6 is a schematic plan view of the tray 21 showing the operation of the sheet stacking device 2 in step S10.

[0046] 5, the control device 26 starts measuring the amount of deviation of the sheet stack PS from the conveyance center CC of the tray 21 (step S1001). In step S1001, the control device 26 acquires the front-side center deviation Fx and the rear-side center deviation Rx of the sheet stack PS detected by the center deviation sensor 22c, for example, as shown in Fig. 6. The control device 26 constantly monitors the front-side center deviation Fx and the rear-side center deviation Rx of the sheet stack PS, for example, from the start to the end of step S10.

[0047] 6, the control device 26 moves the bottom plate 27 in the direction of arrow A1 to transition from the state shown in the upper diagram, in which the center of the sheet stack PS is deviated from the conveyance center CC, to the state shown in the lower diagram, in which the center of the sheet stack PS is aligned with the conveyance center CC, as shown by arrow A2. Specifically, the control device 26 determines the movement direction of the bottom plate 27 based on the front-side center deviation Fx and the rear-side center deviation Rx, and moves the bottom plate 27 in that movement direction.

[0048] The control device 26, for example, determines whether the front side center deviation Fx is greater than the rear side center deviation Rx (step S1002), and if the determination result is positive (YES), controls the bottom plate moving device 24 to start moving the bottom plate 27 toward the rear side (step S1003).

[0049] On the other hand, if the determination result of step S1002 is negative (NO), the control device 26 determines whether the front-side center deviation Fx is smaller than the rear-side center deviation Rx (step S1004). If the determination result of step S1004 is positive (YES), the control device 26 controls the bottom plate moving device 24 to start moving the bottom plate 27 toward the front side (step S1005), and if the determination result of step S1004 is negative (NO), the control device 26 ends step S10.

[0050] 4, in step S09 before step S10, if the front-side center deviation Fx is equal to the rear-side center deviation Rx and the center of the paper stack PS coincides with the conveyance center CC, step S10 is not started. Therefore, the determination result in step S1004 in FIG. 5 is not usually negative (NO).

[0051] Therefore, when the determination result of step S1002 is negative (NO), the control device 26 may skip step S1004 and proceed to step S1005, in which the control device 26 starts moving the bottom plate 27 toward the front side. After starting the movement of the bottom plate 27 in step S1003 or step S1005, the control device 26 determines whether the front-side center deviation Fx and the back-side center deviation Rx have become equal (step S1006).

[0052] If the control device 26 determines in step S1006 that the front side center deviation Fx is not equal to the rear side center deviation Rx (NO), it continues to move the bottom plate 27 and repeats the determination of step S1006. On the other hand, if the control device 26 determines in step S1006 that the front side center deviation Fx and the rear side center deviation Rx are equal (YES), it controls the bottom plate moving device 24 to stop the movement of the bottom plate 27 (step S1007).

[0053] 6, for example, in the state shown in the upper diagram, where the center of the stack of sheets PS is shifted toward the rear from the center of transport CC, the bottom plate 27 can be moved toward the front as indicated by arrow A1, resulting in a transition to the state shown in the lower diagram, where the center of the stack of sheets PS is aligned with the center of transport CC as indicated by arrow A2. In this state, the end fence 28e is positioned offset from the center of transport CC. Therefore, the control device 26 moves the end fence 28e so that the center of the end fence 28e is aligned with the center of transport CC.

[0054] The control device 26, for example, acquires the front-side center deviation Fx and the rear-side center deviation Rx measured before moving the bottom plate 27, and sets these as the front-side initial deviation Fx0 and the rear-side initial deviation Rx0. The control device 26 determines, for example, whether the front-side initial deviation Fx0 is greater than the rear-side initial deviation Rx0 (step S1008).

[0055] If the determination result of step S1008 is affirmative (YES), the control device 26 controls the fence moving device 25 to start moving the end fence 28e toward the rear (step S1010). If the determination result of step S1008 is negative (NO), the control device 26 controls the fence moving device 25 to start moving the end fence 28e toward the front (step S1011).

[0056] After starting the movement of the end fence 28e in step S1010 or step S1011, the control device 26 determines whether the movement amount of the end fence 28e is equal to or greater than the movement amount Mx of the bottom plate 27 (step S1013). If the determination result of step S1013 is negative (NO), the control device 26 continues the movement of the end fence 28e and repeats the determination of step S1013.

[0057] When the determination result in step S1013 becomes affirmative (YES), the control device 26 controls the fence moving device 25 to stop the movement of the end fence 28e (step S1014), and ends the flow of step S10 shown in Fig. 5. As a result, for example, as shown in the lower diagram in Fig. 6, the center of the end fence 28e that has shifted from the conveyance center CC due to the movement of the bottom plate 27 can be returned to the conveyance center CC.

[0058] The operation of the image forming apparatus 1 and the paper stacking device 2 of this embodiment will be described below in comparison with the prior art.

[0059] In conventional paper stacking devices, when replenishing or loading a stack of paper, a fence that holds down the edge of the stack of paper must be moved to a predetermined position by a user. In contrast, a technology is known in which the fence is moved as far away from the stack of paper as possible when the user opens the tray, and then automatically moved toward the stack of paper when the user loads the stack of paper into the tray and closes it. While this technology does not require the user to move the fence to a predetermined position, if the center of the stack of paper is offset from the center of paper transport in the tray, the fence must be used to push the stack of paper back to align the center of the stack of paper with the center of transport.

[0060] However, in a large-capacity paper stacking device that can accommodate stacks of several thousand sheets, the weight of the stack of sheets increases, making it difficult to align the center of the stack of sheets with the center of conveyance by pushing the stack of sheets with the fence. Furthermore, if you try to forcefully push the stack of sheets with the fence, there is a risk that the fence or its movement mechanism will be damaged, or that the fence will get caught in the stack of sheets, damaging the sheets.

[0061] In contrast, the paper stacking device 2 of this embodiment includes a tray 21, a bottom plate 27, a fence 28, a paper sensor 22, a tray sensor 23, and a control device 26. The tray 21 is openable and closable. The bottom plate 27 is located at the bottom of the tray 21 and has a stack of paper PS placed thereon. The fence 28 is located on the bottom plate 27 and is movable to a position along the edge of the stack of paper PS. The paper sensor 22 detects the position of the stack of paper PS placed on the bottom plate 27. The tray sensor 23 detects whether the tray 21 is open or closed. The control device 26 moves the bottom plate 27 and the fence 28 based on the detection results of the paper sensor 22 and the tray sensor 23. Specifically, when the tray sensor 23 detects that the tray 21 is open, the control device 26 moves the fence 28 toward the outside of the tray 21. Furthermore, when the tray sensor 23 detects that the tray 21 is closed, the control device 26 moves the fence 28 to a position along the edge of the paper stack PS and moves the bottom plate 27 to align the center of the paper stack PS with the paper transport center CC.

[0062] With this configuration, the paper stacking device 2 of this embodiment can align the center of the paper stack PS with the paper transport center CC by moving the bottom plate 27 of the tray 21. Therefore, there is no need to push the paper stack PS with the fence 28, and the movement of the fence 28 can be stopped when the fence 28 moves to a position along the edge of the paper stack PS. This prevents the fence 28 from applying excessive force to the paper stack PS, preventing damage to the fence 28 or the fence moving device 25 and the fence 28 from digging into the paper stack PS. Therefore, the paper stacking device 2 of this embodiment can improve availability while preventing damage to the sheets of the paper stack PS and damage to the fence 28.

[0063] In addition, in the paper stacking device 2 of this embodiment, the fence 28 includes side fences 28fs, 28rs that can be moved laterally to a position along the side edge of the paper stack PS, and an end fence 28e that can be moved forward and backward to a position along the rear edge of the paper stack PS.

[0064] With this configuration, when the user closes the tray 21, the control device 26 can automatically move the front side fence 28fs and the rear side fence 28rs to positions that align with the front and rear edges of the stack of sheets PS. Furthermore, when the user closes the tray 21, the control device 26 can automatically move the end fence 28e, which is located at the rear of the stack of sheets PS in the paper transport direction of the stack of sheets PS, to a position that aligns with the rear edge of the stack of sheets PS. This allows the front edge, rear edge, and rear edge of the stack of sheets PS to be held down by the front side fence 28fs, the rear side fence 28rs, and the rear end fence 28e in the paper transport direction, respectively. Furthermore, by moving the end fence 28e in the same manner as the bottom plate 27, skew of the stack of sheets PS can be prevented.

[0065] Furthermore, the image forming apparatus 1 of this embodiment is equipped with the above-described paper stacking device 2. Therefore, according to the image forming apparatus 1 of this embodiment, similar to the above-described paper stacking device 2, it is possible to improve availability while suppressing damage to the sheets of the paper stack PS and breakage of the fence 28.

[0066] As described above, according to this embodiment, it is possible to provide the image forming apparatus 1 and the paper stacking device 2 that can improve availability while suppressing damage to the paper and breakage of the fence 28.

[0067] [Embodiment 2] Next, a second embodiment of an image forming apparatus and a paper stacking device according to the present disclosure will be described with reference to Figs. 7 to 9, with reference to Figs. 1 and 2 described in the first embodiment above. Fig. 7 is a schematic plan view showing the second embodiment of the paper stacking device according to the present disclosure. Fig. 8 is a flow chart showing the procedure for setting a stack of paper sheets in the paper stacking device 2 of this embodiment. Fig. 9 is an example of a display screen displayed on the UI device 5 of the image forming apparatus 1 of this embodiment.

[0068] The image forming apparatus 1 and paper stacking device 2 of this embodiment differ from the image forming apparatus 1 and paper stacking device 2 of the first embodiment described above mainly in that the paper sensor 22 of the paper stacking device 2 includes a leading edge sensor 22p that detects the leading edge of the paper stack PS. The other configurations of the image forming apparatus 1 and paper stacking device 2 of this embodiment are similar to the configurations of the image forming apparatus 1 and paper stacking device 2 of the first embodiment described above. Therefore, in this embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and descriptions thereof will be omitted.

[0069] Leading edge sensor 22p is provided, for example, at the front end of tray 21 in the paper transport direction by paper feed unit 31 of paper transport device 3. Leading edge sensor 22p is a contact sensor that detects the position of the leading edge of paper stack PS by coming into contact with the leading edge of paper stack PS on the opposite side from the trailing edge in the paper transport direction, similar to front edge sensor 22fs, rear edge sensor 22rs, and rear edge sensor 22e. Note that leading edge sensor 22p may also be a non-contact sensor that detects the position of the leading edge of paper stack PS placed on bottom plate 27, for example.

[0070] In the paper stacking device 2 of this embodiment, when the paper stack setting procedure shown in Fig. 8 is started, steps S01 to S08 are performed in the same manner as the paper stack setting procedure of the first embodiment shown in Fig. 4. As a result, the fence 28 moves to a position along the edge of the paper stack PS. In this state, the control device 26 determines, for example, based on the detection result of the leading edge sensor 22p, whether or not the leading edge of the paper stack PS is at an abutment position where it abuts against the front edge of the tray 21 (step S11).

[0071] If the determination result of step S11 is positive (YES), the control device 26 performs steps S09 and S10 similar to those of the first embodiment described above, and ends the flow of the paper stack setting procedure shown in Fig. 8. On the other hand, if the determination result of step S11 is negative (NO), the control device 26 notifies that the leading edge of the paper stack PS has not abutted against the front edge of the tray 21 (step S12).

[0072] In step S12, the control device 26 causes a pop-up display PU to be displayed on the display device 51 constituting the UI device 5 of the image forming device 1 via the control device 6 of the image forming device 1, as shown in, for example, Figures 1 and 9. The pop-up display PU includes, for example, a notification that the leading edge of the paper stack PS has not been detected, the reason for this, and a response that the user should take. Thereafter, the control device 26 ends the flow of the paper stack setting procedure shown in, for example, Figure 8.

[0073] As described above, in the paper stacking device 2 of this embodiment, the control device 26 detects that the leading edge of the paper stack PS in the paper transport direction has abutted against the front edge of the tray 21 based on the detection result of the paper sensor 22.

[0074] With this configuration, the image forming apparatus 1 and paper stacking device 2 of this embodiment can notify the user that the stack of paper sheets PS is not set correctly and can prompt the user to set the stack of paper sheets PS correctly. This allows the user to avoid a situation where the leading edge of the stack of paper sheets PS does not reach the paper feed unit 31 of the paper transport device 3. Therefore, according to this embodiment, as with the first embodiment described above, it is possible to provide the image forming apparatus 1 and paper stacking device 2 that can improve availability while suppressing damage to paper sheets and breakage of the fence 28.

[0075] [Embodiment 3] Next, a third embodiment of the image forming apparatus and paper stacking device according to the present disclosure will be described with reference to Figs. 1 to 6 described in the first embodiment above and Figs. 10 to 13. Fig. 10 is a flow diagram showing the flow of step S20 in which the paper stacking device 2 of this embodiment aligns the end faces of the paper stack PS. Figs. 11 to 13 are examples of display screens displayed on the UI device 5 of the image forming apparatus 1 of this embodiment.

[0076] The image forming apparatus 1 and paper stacking device 2 of this embodiment differ from the image forming apparatus 1 and paper stacking device 2 of the previously described first embodiment in that the control device 26 has a function of aligning the edges of the stack of paper sheets PS. Other configurations of the image forming apparatus 1 and paper stacking device 2 of this embodiment are similar to the configurations of the image forming apparatus 1 and paper stacking device 2 of the previously described first embodiment. Therefore, in this embodiment, parts that are similar to those of the first embodiment are given the same reference numerals as those of the first embodiment, and descriptions thereof will be omitted.

[0077] For example, after the flow of the paper stack setting procedure shown in Fig. 4 is completed, the control device 26 starts the flow of step S20 for aligning the end faces of the paper stack PS shown in Fig. 10. For example, before starting the flow of step S20 shown in Fig. 10, the control device 26 causes the display device 51 constituting the UI device 5 of the image forming device 1 to display a setting screen including screen displays D1 to D5 shown in Fig. 11 via the control device 6 of the image forming device 1.

[0078] Screen display D1 displays the number of the tray 21 for which the edges of the paper stack PS are to be aligned. Screen display D2 displays the operation content corresponding to step S20 for aligning the edges of the paper stack PS. Screen displays D3 and D4 display buttons for selecting options related to the operation content displayed on screen display D2. Screen display D5 displays buttons for executing the operation content displayed on screen display D2. Note that screen displays D1 to D5 are merely examples, and the control device 26 can display screen displays that combine the elements required for each paper feed unit 31 and paper stacking device 2, for example.

[0079] Display device 51 includes, for example, a touch panel, and detects that the user has touched a position corresponding to screen display D1 to screen display D5. For example, the user can set the option for the operation of aligning the edges of stack of paper sheets PS to "weak" or "strong" by touching a position corresponding to screen display D3 or screen display D4 on display device 51. In addition, the user can start the flow of step S20 shown in FIG. 10 by control device 26 by touching a position corresponding to screen display D5 on display device 51.

[0080] 10 based on a user operation, the control device 26 determines whether the option setting set by the user via the UI device 5 of the image forming apparatus 1 is "strong" (step S2001). If the determination result of step S2001 is positive (YES), the control device 26 sets the pushing amount and the number of pushing times to "strong" (step S2002), and if the determination result of step S2001 is negative (NO), the control device 26 sets the pushing amount and the number of pushing times to "weak" (step S2003).

[0081] Here, the number of pushes refers to the number of times the fence 28 is pushed against the end of the paper stack PS, and the push amount refers to the drive time or number of drive pulses of the fence moving device 25 that pushes the fence 28 against the end of the paper stack PS. The number of pushes and the push amount when the setting is "strong" are greater than the number of pushes and the push amount when the setting is "weak."

[0082] Thereafter, the control device 26 sets the number of times the fence 28 has been pressed against the paper-sheet stack PS, that is, the number of pressing executions n, to zero (step S2004), and controls the fence moving device 25 to move the fence 28 toward the paper-sheet stack PS (step S2005). Thereafter, the control device 26 determines whether the movement amount of the fence 28 is equal to or greater than the set pushing amount (step S2006).

[0083] Here, the fence 28 may be pressed against the edge of the paper stack PS and not actually move, so the movement amount of the fence 28 in step S2006 is, for example, the drive time or number of drive pulses of the fence moving device 25 that presses the fence 28 against the edge of the paper stack PS, similar to the push amount.

[0084] If the determination result of step S2006 is negative (NO), the control device 26 continues to move the fence 28 toward the paper-sheet stack PS, pressing the fence 28 against the end of the paper-sheet stack PS, and repeats the determination of step S2006. If the determination result of step S2006 is positive (YES), the control device 26 controls the fence moving device 25 to move the fence 28 away from the end of the paper-sheet stack PS (step S2007).

[0085] In addition, the control device 26 determines whether the fence 28 has separated from the stack of sheets PS based on the detection results of the sheet sensors 22, such as the front edge sensor 22fs, the rear edge sensor 22rs, and the rear edge sensor 22e (step S2008).

[0086] If the determination result of step S2008 is negative (NO), the control device 26 continues to move the fence 28 in the direction away from the stack of paper-sheets PS and repeats the determination of step S2008. If the determination result of step S2008 is positive (YES), the control device 26 increases the number of pressing executions n to n+1, which is the previous number of pressing executions n plus 1 (step S2009), and determines whether the number of pressing executions n has become equal to or greater than the set number of pressing executions (step S2010).

[0087] If the determination result of step S2010 is negative (NO), the control device 26 repeats steps S2005 to S2010. On the other hand, if the determination result of step S2010 is positive (YES), the control device 26 controls the fence moving device 25 to move the fence 28 toward the stack of paper-sheets PS (step S2011). Furthermore, based on the detection result of the paper sensor 22, the control device 26 determines whether the fence 28 has moved to a position along the edge of the stack of paper-sheets PS (step S2012).

[0088] If the determination result of step S2012 is negative (NO), the control device 26 controls the fence moving device 25 to continue moving the fence 28 toward the paper stack PS, and repeats the determination of step S2012. On the other hand, if the determination result of step S2012 is positive (YES), the control device 26 controls the fence moving device 25 to stop the movement of the fence 28 (step S2013), and ends the flow of step S20 for aligning the end faces of the paper stack PS shown in FIG.

[0089] 10 is completed, the user may fine-tune the position of the fence 28 to adjust how much the fence 28 holds down the edge of the paper stack PS. In this case, the control device 26, for example, via the control device 6 of the image forming apparatus 1, causes the display device 51 to display screen displays D1, D2, D5, D6 to D8 as shown in FIG. 12 based on the user's operation on the UI device 5 of the image forming apparatus 1.

[0090] Screen display D1 displays, for example, the number of the tray 21 for which the degree of holding of the edge of the paper stack PS by the fence 28 is to be adjusted. Screen display D2 displays, for example, the operation content corresponding to the operation of adjusting the degree of holding of the edge of the paper stack PS. Screen display D5 displays a button for executing the operation content displayed on screen display D2. Screen displays D6 and D7 display buttons for selecting the direction of the edge of the paper stack PS for fine-tuning the position of the fence 28. Screen display D8 displays the amount of movement when fine-tuning the position of the fence 28.

[0091] For example, the user touches a position corresponding to screen display D6 or screen display D7 of display device 51 to select at least one of side fences 28fs, 28rs and end fence 28e of fence 28 to be fine-adjusted via the touch panel of display device 51. In addition, the user can set the amount of movement of fence 28 to be fine-adjusted by touching a position corresponding to screen display D8 of display device 51 and inputting a numerical value via the input device of UI device 5.

[0092] The amount of movement for fine-tuning the position of the fence 28 can be set in 1 mm increments, for example. Note that, for the amount of movement of the fence 28, a positive value represents the amount of movement away from the paper stack PS, and a negative value represents the amount of movement toward the paper stack PS. Note that the resolution of the amount of movement of the fence 28 is not limited to 1 mm increments. Also, the setting screen shown in FIG. 12 is an example, and elements required for each paper feed unit 31 and paper stacking device 2 may be combined.

[0093] When the user touches a position corresponding to screen display D5 on display device 51, control device 26 controls fence moving device 25 to move fence 28 based on settings input by the user via UI device 5 of image forming apparatus 1 and acquired via control device 6 of image forming apparatus 1. This allows the user to fine-tune the position of fence 28 and adjust how well fence 28 holds down the edge of stack of paper sheets PS.

[0094] 10, the user may fine-tune the position of the stack of sheets PS by fine-tuning the position of the bottom plate 27. In this case, the control device 26, for example, causes the display device 51 to display screen displays D1, D2, D5, and D8 as shown in FIG. 13 based on the user's operation on the UI device 5 of the image forming apparatus 1 via the control device 6 of the image forming apparatus 1.

[0095] Screen display D1 displays, for example, the number of the tray 21 for which the position of the paper stack PS is to be finely adjusted. Screen display D2 displays, for example, the operation content corresponding to the operation of finely adjusting the position of the bottom plate 27. Screen display D5 displays a button for executing the operation content displayed on screen display D2. Screen display D8 displays the amount of movement when finely adjusting the position of the bottom plate 27.

[0096] The amount of movement in fine adjustment of the position of the bottom plate 27 can be set in 1 mm increments, for example. Note that, for the amount of movement of the bottom plate 27, a positive value represents the amount of movement toward the rear (positive direction of the X axis), and a negative value represents the amount of movement toward the front (negative direction of the X axis). Furthermore, the resolution of the amount of movement of the bottom plate 27 is not limited to 1 mm increments. Furthermore, the setting screen shown in FIG. 13 is an example, and elements required for each paper feed unit 31 and paper stacking device 2 may be combined.

[0097] When the user touches a position corresponding to screen display D5 on display device 51, control device 26 controls bottom plate moving device 24 to move bottom plate 27 based on the settings input by the user via UI device 5 of image forming apparatus 1 and acquired via control device 6 of image forming apparatus 1. This allows the user to fine-tune the position of bottom plate 27, thereby fine-tuning the position of stack of paper sheets PS.

[0098] As described above, in the paper stacking device 2 of this embodiment, the control device 26 moves the fence 28 so as to press it against the edge of the paper stack PS multiple times while aligning the center of the paper stack PS with the paper transport center CC. With this configuration, the image forming apparatus 1 and paper stacking device 2 of this embodiment can not only achieve the same effects as the image forming apparatus 1 and paper stacking device 2 of the first embodiment described above, but can also align the edge of the paper stack PS stored in the tray 21 with the fence 28. As a result, the fence 28 can accurately hold the edge of the paper stack PS, preventing transport problems such as paper feed failures, double paper feeds, or paper skew.

[0099] Furthermore, in the paper stacking device 2 of this embodiment, the control device 26 aligns the center of the paper stack PS with the conveyance center CC and moves the fence 28 to a position along the edge of the paper stack PS, and then fine-tunes the position of the fence 28. With this configuration, the image forming apparatus 1 and paper stacking device 2 of this embodiment can adjust the degree to which the fence 28 holds the edge of the paper stack PS. As a result, a gap can be provided between the fence 28 and the edge of the paper stack PS, preventing conveyance problems such as paper non-feeding, double paper feed, or paper skew.

[0100] Furthermore, in the paper stacking device 2 of this embodiment, the control device 26 fine-tunes the position of the bottom plate 27 while aligning the center of the paper stack PS with the conveyance center CC and moving the fence 28 to a position along the edge of the paper stack PS. With this configuration, the image forming apparatus 1 and paper stacking device 2 of this embodiment can fine-tune the position of the paper stack PS without applying load to the fence 28 or the fence moving device 25. Furthermore, by fine-tuning the position of the bottom plate 27 to fine-tune the position of the paper stack PS, it is possible to prevent conveyance problems such as paper feed failures, paper double feeds, or paper skew caused by hardware factors such as individual differences between devices, wear on the rollers of the paper conveying device 3, or special paper.

[0101] [Embodiment 4] Finally, a third embodiment of an image forming apparatus and a paper stacking device according to the present disclosure will be described with reference to Fig. 14, with reference to Figs. 1 to 3, 5, and 6 described in the first embodiment above. Fig. 14 is a flow chart showing a procedure for setting a paper stack in the paper stacking device 2 of this embodiment.

[0102] The image forming apparatus 1 and paper stacking device 2 of this embodiment differ from the image forming apparatus 1 and paper stacking device 2 of the first embodiment described above in that, when the tray sensor 23 detects that the tray 21 is open, the control device 26 moves the bottom plate 27 toward the front in the opening direction of the tray 21. The other configurations of the image forming apparatus 1 and paper stacking device 2 of this embodiment are similar to the configurations of the image forming apparatus 1 and paper stacking device 2 of the first embodiment described above. Therefore, in this embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and descriptions thereof will be omitted.

[0103] When the control device 26 receives a detection result from the tray sensor 23 indicating that the tray 21 is open, the control device 26 starts the flow of the paper stack setting procedure shown in Fig. 14 and moves the fence 28 toward the outside of the tray 21 to retract it (step S01). Thereafter, the control device 26 controls the bottom plate moving device 24 to move the bottom plate 27 toward the front (step S13). Thereafter, the control device 26 goes through steps S02 to S10 similar to those in the first embodiment, and ends the flow of the paper stack setting procedure shown in Fig. 14.

[0104] As described above, in the paper stacking device 2 of this embodiment, when the tray sensor 23 detects that the tray 21 is open, the control device 26 moves the bottom plate 27 toward the front in the opening direction of the tray 21. With this configuration, the bottom plate 27 of the tray 21 moves to a position closer to the user who has pulled out the tray 21. This allows the user to easily place the stack of paper PS on the bottom plate 27.

[0105] The image forming apparatus and the paper stacking device according to the present disclosure have been described in detail above. However, the image forming apparatus and the paper stacking device according to the present disclosure are not limited to the above-described embodiments. Various modifications or substitutions may be applied to the above-described embodiments without departing from the scope of the present disclosure. [Explanation of symbols]

[0106] 1. Image forming device 2 Paper stacking device 21 Tray 22 Paper sensor 23 Tray sensor 26 Control device 27 Bottom plate 28 Fence 28fs Side Fence 28rs side fence 28e End Fence CC transport center PS Paper stack [Prior art documents] [Patent documents]

[0107] [Patent Document 1] Japanese Patent Application Publication No. 11-301860

Claims

1. Openable tray and a movable bottom plate disposed at the bottom of the tray on which a stack of sheets is placed; a fence disposed on the bottom plate and movable to a position along an edge of the stack of paper; a paper sensor that detects the position of the paper stack placed on the bottom plate; a tray sensor that detects whether the tray is open or closed; a control device that moves the bottom plate and the fence based on detection results of the paper sensor and the tray sensor, the control device moves the fence toward the outside of the tray when the tray sensor detects that the tray is open, and moves the fence to a position along the edge of the stack of paper when the tray sensor detects that the tray is closed, and moves the bottom plate to align the center of the stack of paper with the center of paper transport in the tray. Paper loading device.

2. the control device detects, based on the detection result of the paper sensor, that the leading edge of the paper stack in the paper transport direction has abutted against the front edge of the tray; The paper stacking device according to claim 1 .

3. the control device moves the fence so as to press the fence against the end of the paper stack multiple times while aligning the center of the paper stack with the conveyance center; The paper stacking device according to claim 1 .

4. the control device fine-adjusts the position of the fence in a state in which the fence is moved to a position along an edge of the paper stack while aligning the center of the paper stack with the conveyance center. The paper stacking device according to claim 1 .

5. the control device fine-adjusts the position of the bottom plate in a state in which the fence is moved to a position along an edge of the paper stack so as to align the center of the paper stack with the conveyance center. The paper stacking device according to claim 1 .

6. the control device moves the bottom plate toward the front in the tray opening direction when the tray sensor detects that the tray is open. The paper stacking device according to claim 1 .

7. the fences include side fences that are movable laterally to positions along the side edges of the paper stack, and end fences that are movable back and forth to positions along the rear edge of the paper stack. The paper stacking device according to claim 1 .

8. An image forming apparatus comprising the paper stacking device according to any one of claims 1 to 7.

Images