JP2016050091A - Sheet accumulation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet accumulation apparatus which guides sheets to an accumulation tray along a moving path according to the types of the sheets to load the sheets with good arrangement.SOLUTION: A sheet accumulation apparatus includes: an accumulation tray 23 on which sheets P are accumulated; a discharge roller pair 32 which discharges each sheet P to the accumulation tray 23; a gripper 33 which grips a tip Pa of the sheet P discharged by the discharge roller pair 32; moving means having a timing belt 38 which causes the gripper 33 to move toward the accumulation tray 23; and a stopper 35 configured to come in contact with the tip Pa of the sheet P, which is gripped by the gripper 33 and moves in conjunction with movement of the moving means, and release the sheet P from the gripper 33. The moving means includes path change means formed by a tension roller 41 which changes a moving path of the gripper 33 in a vertical direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a sheet stacking apparatus that sequentially stacks sheets on which images are formed by an image forming apparatus such as a copying machine or an image scanner.

  Conventionally, sheets that have been processed in an image forming apparatus or the like are stacked on a stacking tray for each predetermined sheet type or each predetermined number of sheets by a sheet stacking apparatus. As the sheet stacking device, there is known a structure in which the leading ends of sheets sequentially discharged from the image forming apparatus are guided and stored on a stacking tray while being gripped by a gripper member or the like (Patent Document 1).

  In the sheet stacking apparatus using the gripper member, after the sheet discharged from the image forming apparatus is received by the pair of rollers on the entrance side, the leading end of the sheet is directed toward the end on the stacking tray while being gripped by the gripper member. Then, it is guided to be pulled out and brought into contact with a stopper member waiting at a predetermined position. The sheet in contact with the stopper member is released from gripping of the gripper member and is stacked on the stacking tray as it is. Thus, when the sensor detects that a predetermined number of sheets are stacked on the stacking tray, the stacking tray is lowered by a predetermined amount to secure a new stacking space.

JP 2006-124051 A

  In the sheet stacking apparatus provided with the gripper member, when the gripper member holding the leading end of the sheet passes through the stopper member to release the sheet, the trailing end of the sheet is first stacked on the stacking tray. The top surface of the sheet comes into contact with the sheet, and thereafter, the leading edge of the sheet falls onto the top sheet and is accommodated. For this reason, there are cases where the trailing edge of the sheet guided by the gripper member is stacked in a state where it does not reach the trailing edge reference position of the stacking tray. On the other hand, since the leading edge of the sheet is regulated by the leading edge regulating portion of the stacking tray, there is a possibility that the sheets are sequentially stacked on the stacking tray while the leading edge side of the sheet remains largely curved.

  In the sheet stacking device disclosed in Patent Document 1 described above, if the stacked sheets have a standard thickness and are relatively strong, the sheet stacking apparatus is curved when stored in the stacking tray. Even if it is, it will be resolved naturally in the process of being loaded sequentially. However, in the case of thin sheets with weak stiffness, if the sheet remains curved when stored, the state is not canceled and is stored in the stacking tray, and the next sheet is stacked thereon. become. For this reason, there is a problem that wrinkles, creases, and the like occur in the sheets stacked on the stacking tray, and the alignment is impaired.

  Accordingly, an object of the present invention is to provide a sheet stacking apparatus capable of stacking a plurality of sheets with good alignment by guiding them to a stacking tray along a moving track corresponding to the type of sheet.

  In order to solve the above-described problems, a sheet stacking apparatus according to the present invention includes a stacking unit having a stacking tray for stacking sheets, a discharging unit that discharges sheets toward the stacking unit, and a sheet discharged by the discharging unit. A gripping means that grips the leading edge of the sheet, a moving means that moves the gripping means toward the stacking tray, and a leading edge of the sheet gripped by the gripping means that moves along with the moving means abuts, and the gripping means In the sheet stacking apparatus provided with the contact means for releasing the sheet, the moving means includes a trajectory changing means for changing the moving trajectory of the gripping means up and down.

  According to the sheet stacking apparatus of the present invention, since the movement trajectory of the sheet toward the stacking tray can be changed up and down according to the thickness of the sheet, the leading edge and the trailing edge of the sheet when stacked on the stacking tray The landing positions can be made uniform. As a result, even thin sheets that are weak can be stacked on the stacking tray with good alignment without being displaced.

1 is a configuration diagram of an image forming processing system including a sheet stacking apparatus according to the present invention. It is sectional drawing which shows the internal structure of a sheet stacking apparatus. It is a top view which shows the internal structure of a sheet stacking apparatus. It is sectional drawing which shows the state (a) in which a sheet | seat is conveyed by parallel track mode, and the state (b) in which a sheet | seat is conveyed by inclination track mode. It is a block diagram of a sheet stacking apparatus. It is a flowchart of the initial operation of the sheet stacking apparatus. FIG. 6 is a flowchart illustrating an operation of a tension roller of the sheet stacking apparatus. It is principal part sectional drawing of the sheet | seat stacking apparatus provided with the 1st tension assistance mechanism (a) and the 2nd tension assistance mechanism (b).

  Hereinafter, embodiments of the sheet stacking apparatus according to the present invention will be described in detail. FIG. 1 shows a configuration example of an image forming processing system 10 corresponding to a large amount of sheet processing. This image forming processing system 10 has a configuration in which a sheet feeding device 12 and a sheet stacking device 13 of the present invention are combined with an image forming device 11 as a center. The image forming apparatus 11 includes a reading unit 16 including a platen glass 14 and an ADF 15, a conveying unit 19 that feeds and conveys a sheet from the image forming unit 17 and the built-in cassette 18. The sheet supply device 12 is for continuously supplying a large amount of sheets to the image forming apparatus 11 from the outside. The sheet supply device 12 includes a paper feed tray 21 on which a large capacity of sheets can be stacked, and an image forming process is performed by connecting a supply path 22 of the paper feed tray 21 to a conveying unit 19 of the image forming apparatus 11. Is called.

  The sheet stacking apparatus 13 stacks the sheets on which the image is formed by the image forming apparatus 11 on the stacking tray 23 in a aligned state. As shown in FIG. 2, the sheet stacking apparatus 13 includes a stacking unit 31 having a stacking tray 23 for stacking sheets P, and a discharging unit (a pair of discharge rollers) that discharges the sheet P toward the stacking unit 31. ) 32, gripping means (gripper) 33 for gripping the leading edge (sheet leading edge) Pa of the sheet P, moving means 34 for moving the gripper 33 onto the stacking tray 23, and the sheet gripped by the gripper 33 A contact means (stopper) 35 for releasing the front end Pa of the sheet P by contacting the front end Pa of the P is provided. Further, the moving means 34 is provided with a trajectory changing means 36 for changing the moving trajectory of the gripper 33 up and down according to the paper quality such as the type and thickness of the sheets P to be accumulated.

  The stacking tray 23 provided in the stacking means 31 is attached to the lifting mechanism 24 and moves up and down according to the stacking amount of the sheets P. The elevating mechanism 24 engages with a slide groove (not shown) provided on the inner wall surface 25 of the sheet stacking apparatus 13, and moves up and down by an elevating drive motor M3. The inner wall surface 25 is a regulating surface for aligning the rear ends Pb of the sheets P sequentially stacked on the stacking tray 23. Further, when the stacked sheets P reach a predetermined height of the stacking tray 23, the elevating mechanism 24 is controlled to descend by a predetermined amount in order to secure a new stacking space above.

  One of the discharge roller pair 32 is constituted by a drive roller and the other is a drive roller. The discharge roller pair 32 feeds the sheet P toward the stacking tray 23 in conjunction with the discharge roller pair 27 provided on the discharge path 26 side. .

  As shown in FIG. 2, the leading edge Pa of the sheet P discharged by the discharge roller pair 32 is gripped by the gripper 33 that circulates by the moving means 34 and guided onto the stacking tray 23. When the leading edge Pa of the sheet P comes into contact with the stopper 35, the gripping from the gripper 33 is released, and the trailing edge Pb of the sheet P is also released from the nip state of the discharge roller pair 32. As a result, the sheet P is completely released (free), and is landed and stacked on the stacking tray 23 as it is.

  As shown in FIG. 2 and FIG. 3, the moving means 34 is spanned between a pair of belt rollers 37 that are disposed to face each other across the stacking tray 23, and the pair of belt rollers 37. And a loop-shaped timing belt 38. As shown in FIG. 3, the pair of belt rollers 37 are arranged in parallel along a direction perpendicular to the sheet P discharge direction, and a timing belt 38 is stretched around each belt roller 37. Yes. One of the belt rollers 37 is composed of a driving roller and the other is a driven roller, and the timing belt 38 rotates in a direction toward the sheet P discharging direction. The belt roller 37 is driven in conjunction with the driving of the discharge roller pair 32.

  The grippers 33 are respectively provided at positions that equally divide the entire length of the timing belts 38, and both grippers 33 circulate so as to alternately pass above the stacking tray 23. This rotation is started by detecting the sheet P that has passed through the inlet sensor S1 disposed on the downstream side of the discharge roller pair 32. At this time, the gripper 33 stands by at a position for gripping the leading edge Pa of the sheet P. By continuously performing this operation, the sheets P can be sequentially stacked on the stacking tray 23.

  One end of the stopper 35 is rotatably supported by a third shaft 46 provided on the plate 47, and the other end serves as a contact surface protruding toward the stacking tray 23. The contact surface is disposed so as to be orthogonal to the moving direction of the timing belt 38 and regulates the leading edge Pa of the sheet P. When the leading edge Pa of the sheet P gripped by the gripper 33 comes into contact with the stopper 35, the sheet P stops, but the gripper 33 rotates around the timing belt 38 as it is. The gripping of the sheet P by the gripper 33 is released by the impact when the sheet P stops, and the sheet P is loaded on the stacking tray 23 as it is.

  The trajectory changing means 36 is for changing the moving trajectory of the gripper 33 that moves along the circular motion of the timing belt 38, and a tension member (tension roller) 41 that abuts against the inner surface of the timing belt 38. It has. The tension roller 41 is provided on the downstream side of the stopper 35, and the contact position of the sheet P with the stopper 35 can be changed.

  The tension roller 41 applies a predetermined urging force from the inside to the outside of the timing belt 38 to give tension to the outside, thereby changing the orbit of the timing belt 38. As shown in FIG. 3, the tension roller 41 is provided between the belt roller on the downstream side of each of the belt rollers 37 and the stopper 35, and rotatably supports the three tension rollers 41. The first shaft 42, a movable arm 43 having one end connected to the first shaft 42, a second shaft 44 that supports the other end of the movable arm 43 so as to be slidable, and the rotation of the second shaft 44 is restricted. And a tension motor M4 for applying a rotational force to the second shaft via the gear group 45.

  The tension motor M4 can swing the first shaft 42 and the tension roller 41 attached via the movable arm 43 up and down by driving the second shaft 44 forward or backward. As a result, as shown in FIG. 4A, the tension roller 41 is not energized, and the parallel orbit mode A by parallel driving between two points by the pair of belt rollers 37, and FIG. As shown in the drawing, it is possible to select any one of the inclined orbit mode B by triangular driving between three points including the urging point of the tension roller 41. The parallel trajectory mode A is suitable for sheets such as plain paper and photo paper having a certain thickness and stiffness, such as copy paper, and the inclined trajectory mode B is thinner and relatively weaker than the plain paper. Suitable for sheets.

  Next, the control of the sheet stacking apparatus 13 having the above configuration will be described with reference to FIGS. FIG. 5 shows a control block for controlling the sheet stacking apparatus 13. An interface unit for exchanging information with the image forming apparatus 11, an input unit including a plurality of sensors, and an output unit including a plurality of motors are provided with a control unit including a CPU and a memory as a center. The interface unit transmits information such as the sheet type and size to the image forming apparatus 11. The input unit includes an inlet sensor S <b> 1 that detects discharge of a sheet from the image forming apparatus 11 and a home position (HP) sensor S <b> 2 that detects an initial position of the tension roller 41. The output unit includes a roller drive motor M1 that drives the discharge roller pair 32, a belt drive motor M2 that drives the timing belt 38, a lift drive motor M3 that raises and lowers the stacking tray 23, and a tension motor M4 that drives the tension roller 41. I have.

  FIG. 6 shows a flow of an initial operation when the sheet stacking apparatus 13 is activated. In this flow, the state of the HP sensor S2 is first detected. If the HP sensor S2 is ON, the tension motor M4 is driven to apply a predetermined urging force to the tension roller 41. When the HP sensor S2 is turned off from this state, the locked state where the driving of the tension motor M4 is stopped is obtained. In this initial operation setting, as shown in FIG. 4A, the leading edge Pa of the sheet P is slightly lowered from the nip position of the discharge roller pair 32. The tension roller 41 is urged downward so as to contact the stopper 35 at the first contact position P1 slightly lowered by about one sheet. Then, based on the acquired sheet information, when the stacked sheets P are plain papers having a predetermined thickness and stiffness, they contact the stopper 35 along the parallel trajectory mode A in the initially set state. Let As a result, the rear end Pb of the sheet P first lands on the stacking tray 23. However, since the sheet P is stiff, the front end Pa is not greatly bent or bent, so that the sheet P maintains a substantially flat state. In this state, it can land on the stacking tray 23.

  In the initial operation, if the HP sensor S2 is not in the OFF state, it is determined that the inclined track mode B is formed by the tension roller 41, and the tension motor M4 is driven to rotate backward. Then, the tension motor M4 is stopped when the HP sensor S2 is turned on. As a result, the tension roller 41 is positioned at the home position (HP) as shown in FIG. As described above, when the sheet discharging operation toward the sheet stacking device 13 is executed, the tension roller 41 is surely positioned at the HP, so that the sheet P stacking operation can be quickly handled.

  FIG. 7 shows an operation flow of the tension roller 41. Here, control is performed based on the sheet information acquired from the image forming apparatus 11. If it is recognized from this sheet information that the stacked sheets P are thin paper, the tension motor M4 is driven. Then, as shown in FIG. 4B, the tension roller 41 is driven until the urging force of the timing belt 38 reaches a predetermined amount, and when the predetermined amount is reached, the tension motor M4 is stopped and the urging force is reduced. Hold. If it is recognized that the sheet information is not thin paper, the tension motor M4 is not driven and no urging force is applied to the tension roller 41.

  When the tension motor M4 is driven, the timing belt 38 circulates along the inclined orbit mode B. By changing to the inclined track mode B, the moving track of the gripper 33 toward the stopper 35 is inclined downward, and the contact position of the sheet P with respect to the stopper 35 is changed from the first contact position P1 to the sheet stacking tray. The second contact position P2 close to the uppermost sheet surface stacked on the sheet 23 can be set. As a result, the drop between the leading edge Pa of the sheet P and the trailing edge Pb that is first released from the nip of the discharge roller pair 32 can be eliminated. It is possible to sequentially load the stacking tray 23 with the leading end Pa and the rear end Pb of the P aligned.

  As shown in FIG. 3, the trajectory changing means 36 is provided with a HP detecting means for detecting the home position (HP) of the tension roller 41 on a plate 47 arranged in the trajectory of the timing belt 38. . This HP detection means can be constituted by, for example, an HP sensor S2 made of a photo interrupter arranged on the rotation path of the second shaft 44, and a flag FG attached to the second shaft 44.

  In the sheet stacking apparatus 13 of the present invention, the tension roller 41 is employed to make the trajectory of the sheet P guided to the stacking tray 23 variable. However, the tension applied to the timing belt 38 by driving the tension roller 41. May not be constant and may cause problems in sheet conveyance and durability. A configuration example for improving this is shown in FIG.

  FIG. 8A shows the first tension assist mechanism 51. The tension assist mechanism 51 can alternately switch the urging direction of the tension roller 41 between the lower side and the upper side of the timing belt 38. According to this mechanism, as shown in FIG. 4B, when the sheet guided on the stacking tray 23 is conveyed along the inclined track mode B, the tension roller 41 is urged downward. As shown in FIG. 4A, when the sheet stacking apparatus 13 is initially started or when the sheet is conveyed along the parallel track mode A, as shown in FIG. 41 is biased upward. Accordingly, the tension applied to the timing belt 38 can be made constant regardless of which of the parallel orbital mode A and the inclined orbital mode B is selected.

  FIG. 8B shows the second tension assist mechanism 52. The tension assist mechanism 52 is configured to axially support any one of the belt rollers 37 so as to be slidable. For example, a shaft hole 54 provided in the belt roller 37 is formed in a long hole shape, and a buffer member 55 such as a spring is disposed between a roller shaft 53 that rotatably supports the belt roller 37 and one end of the shaft hole 54. Accordingly, even when the urging force by the tension roller 41 is applied to the timing belt 38, the urging force can be absorbed by the buffer member 55, so that FIGS. 4A and 4B are used. In any case of the parallel orbit mode A and the inclined orbit mode B as shown, the tension applied to the timing belt 38 can be kept constant.

  In the sheet stacking apparatus 13 of the present invention, in order to improve the alignment when the sheets P guided on the stacking tray 23 are sequentially landed by their own weight, the moving path of the sheet P is changed by the tension roller 41, The landing width from the front end Pa of the sheet P was shortened. On the other hand, as described above, the stacking tray 23 is controlled so as to descend when a certain amount of sheets P are stacked and to secure a new sheet stacking space. However, when the raising / lowering control of the stacking tray 23 is increased, the control is complicated accordingly, and the effect of reducing the power consumption cannot be achieved.

  As means for improving such a problem, the following control method can be applied to the configuration in the above embodiment. For example, in the initial state, the contact position of the sheet P with respect to the stopper 35 is set as short as possible from the surface of the uppermost sheet P stacked on the stacking tray 23. Then, the tension roller 41 is raised by a predetermined amount from this state. As the tension roller 41 is lifted, the track of the gripper 33 is changed, and the contact position of the sheet P with the stopper 35 is moved upward by the lift of the tension roller 41. Thereby, a predetermined number of storage spaces can be secured.

  The above operation is repeated a plurality of times until the initial position (parallel orbit mode A) where the urging force by the tension roller 41 does not reach is reached. When the tension roller 41 reaches the initial position, the stacking tray 23 is lowered, and the upper surface position of the stacked sheets is returned to the state when the first sheet stacking apparatus 13 is activated. As described above, by repeating the operation by the cooperation of the tension roller 41 and the stacking tray 23 according to the discharge amount and stacking amount of sheets, it is possible to simultaneously improve the stacking efficiency of sheets and to reduce the power consumption.

A parallel track mode B inclined track mode P sheet Pa leading edge Pb trailing edge P1 first contact position P2 second contact position M1 roller drive motor M2 belt drive motor M3 lift drive motor M4 tension motor S1 inlet sensor S2 home position sensor 10 Image forming processing system 11 Image forming apparatus 12 Sheet feeding apparatus 13 Sheet stacking apparatus 14 Platen glass 15 ADF
DESCRIPTION OF SYMBOLS 16 Reading means 17 Image forming means 18 Built-in cassette 19 Conveying means 21 Paper feed tray 22 Supply path 23 Stacking tray 24 Lifting mechanism 25 Inner wall surface 26 Paper discharge path 27 Paper discharge roller pair 31 Stacking means 32 Paper discharge pair (discharge means)
33 Gripper (gripping means)
34 Moving means 35 Stopper (contact means)
36 Trajectory Change Means 37 Belt Roller 38 Timing Belt 41 Tension Roller 42 First Shaft 43 Movable Arm 44 Second Shaft 45 Gear Group 46 Third Shaft 47 Mounting Plate 51 First Tension Auxiliary Mechanism 52 Second Tension Auxiliary Mechanism 53 Roller Shaft 54 Shaft hole 55 Buffer member

Claims (7)

An accumulating means having an accumulating tray for accumulating sheets, an ejecting means for ejecting sheets toward the accumulating means, a grasping means for grasping a leading end of a sheet ejected by the ejecting means, and the grasping means for the accumulating tray A sheet accumulating apparatus comprising: a moving unit that moves the sheet toward the sheet; and a contact unit that abuts the leading end of the sheet held by the holding unit that moves with the moving unit and releases the sheet from the holding unit. ,
The sheet accumulating apparatus according to claim 1, wherein the moving unit includes a trajectory changing unit that changes a moving trajectory of the gripping unit up and down. The trajectory changing means includes a parallel trajectory mode in which the contact position of the sheet in the contact means is set to a first contact position;
The sheet stacking apparatus according to claim 1, wherein the sheet stacking apparatus can be switched to an inclined track mode in which the second contact position is set lower than the first contact position.   The sheet stacking apparatus according to claim 2, wherein the first contact position is set at a position substantially parallel to a discharge unit that discharges the sheet.   3. The sheet stacking apparatus according to claim 2, wherein the trajectory changing unit selects the parallel trajectory mode when the thickness of the sheet is greater than a predetermined thickness, and selects the inclined trajectory mode when the thickness is smaller than the predetermined thickness. The moving means includes a pair of belt rollers facing each other across the stacking tray, and a timing belt for rotating the gripping means between the pair of belt rollers.
The trajectory changing means abuts the inner surface of the timing belt and causes the timing belt to project outward by a predetermined pressing force, thereby changing the trajectory of the gripping means from the parallel trajectory mode to the inclined trajectory mode. The sheet stacking apparatus according to claim 1, further comprising a tension member.   6. The sheet stacking apparatus according to claim 5, wherein the track changing unit includes a tension assist mechanism that adjusts a tension applied to the timing belt in the parallel track mode and the inclined track mode.   The sheet stacking apparatus according to claim 1, wherein a moving track of the gripping unit in the track changing unit is changed in accordance with a stacking amount of sheets stacked on the stacking tray.

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