JP2007119150A - Sheet aligning device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet aligning device capable of delivering a sheet P to a stacking tray 18 at a shorter interval by enhancing the rotating speed of a paddle 17, without damaging aligning performance of the sheet P by the paddle 17. <P>SOLUTION: The paddle 17 contacts the sheet P within a predetermined range of one rotation of the paddle 17 and makes the sheet P abut on a stacking wall part 20. The paddle 17 is driven by a step motor having variable rotating speed. During a period when the paddle 17 contacts with the sheet P, the rotating speed of the paddle 17 is kept slow, and only during a period when the paddle 17 does not contact with the sheet P, the rotating speed is enhanced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet aligning apparatus that stacks sheets discharged from an image forming apparatus such as a copying machine, a printer, and a multifunction machine while aligning them, and an image forming apparatus equipped with the sheet aligning apparatus.

  When the processed sheets discharged one by one from the image forming apparatus such as a copying machine or a printer are sequentially stacked on the stacking surface, the vertical and horizontal end surfaces are positioned and stacked, that is, aligned, and thereafter. 2. Description of the Related Art Sheet aligning devices designed for convenience such as packing, organizing, and stapler (binding) processing have been put into practical use.

  The sheet aligning apparatus includes a sheet stacking unit that stacks the image-formed sheets, and rotates a flexible member called a paddle to contact the sheet surface on the sheet stacking unit (see Patent Document 1). Here, the sheet moves along with the rotation of the flexible member and abuts against a wall surface arranged on one end side of the stacking surface.

  Patent Document 2 discloses a sheet stacking apparatus in which a sheet stacking unit is supported to be movable up and down with respect to a housing structure. Here, the sheet stacking means is lowered as the sheets are stacked.

JP 2001-130817 A JP 2002-68561 A

  By the way, the applicant of the present application arranges an alignment mechanism having a flexible member as shown in Patent Document 1 at a position above the sheet stacking means that can move up and down as shown in Patent Document 2, An attempt is being made to propose a sheet aligning apparatus that performs alignment at the same time. Here, the rotating shaft of the flexible member is fixed to the upper part of the housing structure, and the sheet stacking means is raised and lowered so that the positional relationship between the uppermost stacked sheet and the alignment mechanism is constant. The flexible member stands by at a home position that does not prevent the sheet from being discharged, and starts rotating once and rotates once each time the sheet is discharged. The flexible member is moved in contact with the sheet as it rotates, and is stopped when the flexible member is separated from the sheet and returns to the home position in the subsequent rotation.

  In such a sheet aligning apparatus, the next sheet cannot be received unless the flexible member returns to the home position. If one cycle of contact-moving-returning in the flexible member becomes longer than the sheet processing time of the image forming apparatus, the image forming apparatus must wait for the flexible member to return, and cannot fully exhibit its processing capability. .

  Therefore, it is desirable to set the rotation speed of the flexible member high to shorten one cycle of contact-movement-return. However, if the rotation speed of the flexible member is set high, the discharged sheet can be discharged. Colliding with the flexible member or separating the flexible member from the sheet while alignment is incomplete, resulting in disordered and uneven sheet alignment.

  An object of the present invention is to provide a sheet aligning apparatus that does not disturb the aligned state of aligned sheets even if one cycle of contact-movement-return in a flexible member is shortened.

  The sheet aligning apparatus of the present invention comprises: a sheet stacking unit on which received sheets are stacked; and an aligning unit that contacts the sheet discharged to the sheet stacking unit and moves it to a predetermined position on the sheet stacking unit. In the provided sheet aligning apparatus, the aligning means is a means that contacts the sheet within a predetermined range of the periodic operation and does not contact the sheet outside the predetermined range, and is outside the predetermined range. The operation speed of the matching means is set higher than the operation speed in the predetermined range.

  In the sheet aligning apparatus of the present invention, the aligning means contacts the sheet only during one period of the periodic operation and is involved in sheet alignment. Does not affect alignment results. Therefore, for at least a part of the period in which the aligning means is not in contact with the sheet, the operation speed of the aligning means is increased more than in at least a part of the period in which the aligning means is in contact with the sheet, and the total required one cycle of the cyclic operation Time has been shortened. As a result, the time interval until the next sheet can be received is reduced, and the number of sheet alignment processes per unit time can be increased without impairing the alignment result.

  FIG. 1 is an explanatory diagram of a copying machine as an example of an embodiment of the present invention, FIG. 2 is an explanatory diagram of a mechanism of a sheet aligning device, FIG. 3 is an explanatory diagram of an alignment mechanism in the sheet width direction in the sheet aligning device, and FIG. FIG. 5 is a flowchart of paddle rotation speed control, FIG. 6 is an illustration of the paddle home position, FIG. 7 is an illustration of the paddle high-speed rotation period, and FIG. 8 is a paddle low-speed control diagram. It is explanatory drawing of a rotation period.

  A copying machine 501 according to an embodiment of the present invention includes, for example, a sheet aligning device 400 that is a sheet aligning device of the present invention. The sheet aligning device 400 includes, for example, the paddle 17 that is the aligning unit of the present invention, the stacking tray 18 that is the sheet stacking unit of the present invention, the paddle motor 16 that is the motor unit of the present invention, and the control unit of the present invention. For example, the control unit 510 is provided, and the rotation speed during the period when the paddle 17 contacts the sheet P is set smaller than the rotation speed until the paddle 17 contacts the sheet P.

  As shown in FIG. 1, a copying machine 501 as an example of an embodiment of the present invention has a sheet aligning device 400 disposed downstream of the apparatus main body 501A of the copying machine 501, and a sheet P discharged from the apparatus main body 501A. Loading / aligning. The apparatus main body 501A includes a reader unit 100 that reads an original and converts it into image data, and a printer unit 200 that forms an image based on the image data. The apparatus main body 501A has an original on the platen glass 102 one by one. An automatic document feeder (ADF) 300 is provided. The automatic document feeder 300 is not necessarily provided, and the user may place the document directly on the platen glass 102.

  The printer unit 200 includes a plurality of types of sheet cassettes 204 and 205 on which a plurality of sheets are stacked, and forms image data on the sheet P as a visible image by a print command. The reader unit 100 collects an image of a document surface through the scanner unit 104 stopped at the reading position while the automatic document feeder 300 conveys the document to a predetermined reading position on the platen glass 102 and passes it. If the user opens the automatic document feeder 300 rearward and places the document on the platen glass 102, the scanner unit 104 can be moved in the left-right direction to collect an image of the document surface.

  In any case, when the light of the lamp 103 of the scanner unit 104 is irradiated onto the original surface, the reflected light from the original is imaged on the CCD image sensor unit 109 from the mirrors 105, 106 and 107 through the lens 108. . The original image formed on the CCD image sensor unit 109 is subjected to electrical processing such as photoelectric conversion in the CCD image sensor unit 109, and is subjected to normal digital processing. Thereafter, these image signals are input to the printer unit 200.

  The image signal input to the printer unit 200 is modulated by the exposure control unit 201 and converted into an optical signal, and irradiates, for example, a photoconductor 202 that is an image forming unit. The latent image formed on the photosensitive member 202 by the irradiation light is developed with toner by the developing unit 203 to become a toner image. Then, the sheet P is conveyed from one of the sheet cassettes 204 and 205 in synchronization with the leading edge of the toner image, and the toner image is transferred to the sheet P by the transfer unit 206. The transferred toner image is fixed on the sheet P by the fixing unit 207. The sheet P on which the toner image is fixed is discharged from the sheet discharge unit 208 to the outside of the apparatus main body 501A through a pass 214. Thereafter, the sheet P is aligned at the side edges by the sheet aligning device 400.

  The sheet aligning device 400 is provided on the side of the apparatus main body 501A, and is, for example, an upper stack tray 18 that is a sheet stacking unit, an upper transport conveyance path 62, and a lower stack tray that is a sheet stacking unit. 37, a lower-stage transport discharge path 63, and the like.

  The upper and lower stacking trays 18 and 37 are configured as follows. As shown in FIG. 2, the stacking tray 18 is supported so as to be movable up and down with respect to the housing structure 410, and is driven up and down by a lifting device 66. That is, the base portion of the stacking tray 18 is fixed on the tray table 44, and guide rollers 46 and 47 are rotatably attached to the tray table 44. The guide rollers 46 and 47 are engaged with the vertically long guide rail 60 of the housing structure 410. A timing belt 54 is connected to the tray base 44. The timing belt 54 is driven to circulate by receiving the rotational force of the tray motor 56 via the timing belt 58, the worm gear 50, and the worm wheel 51. Therefore, when the tray motor 56 rotates and the timing belt 54 circulates, the stacking tray 18 moves up and down together with the guide rail 60 and the tray base 44 guided by the guide rollers 46 and 47.

  The lifting device 67 that lifts and lowers the lower stacking tray 37 is also configured in the same manner as the lifting device 66 of the upper stacking tray 18. That is, the base portion of the stacking tray 37 is fixed on the tray table 45, and guide rollers 48 and 49 are rotatably attached to the tray table 45. The guide rollers 48 and 49 are engaged with the vertically long guide rail 61 of the housing structure 410. A timing belt 55 is connected to the tray base 45. The timing belt 55 is driven to circulate by receiving the rotational force of the tray motor 57 via the timing belt 59, the worm gear 52, and the worm wheel 53. Therefore, when the tray motor 57 rotates and the timing belt 55 circulates, the stacking tray 37 moves up and down together with the guide rail 61 and the tray base 45 guided by the guide rollers 48 and 49.

  The conveyance / discharge path 62 for guiding the sheet P to the upper stack tray 18 is configured as follows. As shown in FIG. 2, a timing belt 5 is stretched between the rotation shaft of the conveyance drive motor 6 that is started by the operation of the inlet sensor S <b> 1 and the connection gear 4. A timing belt 3 is stretched between the connecting gear 4 and the upper entrance roller 1. A driven roller 2 is in pressure contact with the inlet roller 1. A timing belt 8 is stretched between the discharge drive motor 7 and the connecting gear 9. A timing belt 10 is wound around the connecting gear 9, the paper discharge roller 11, and the idler pulley 64. A timing belt 29 is stretched between the upper discharge roller 11 and the lower discharge roller 30. A driven roller 12 is in pressure contact with the paper discharge roller 11.

  The sheet P conveyed on the upper conveyance conveyance path 62 is composed of an entrance roller 1 and a driven roller 2 that are rotated by driving of the conveyance drive motor 6, and a discharge roller 11 and a driven roller that are rotated by driving of the discharge drive motor 7. 12 and discharged to the sky above the stacking tray 18.

  An inlet sensor S1 is disposed on the upstream side of the inlet roller 1. The entrance sensor S1 detects the leading edge and the trailing edge of the sheet P sent from the apparatus main body 501A of the copying machine 501 to the sheet aligning apparatus 400. A flapper 13 is disposed near the downstream side of the inlet sensor S1. The flapper 13 can change the conveying direction of the sheet P to either the upper stacking tray 18 or the lower stacking tray 37 by a driving solenoid 14.

  A paper discharge sensor S <b> 2 is provided on the upstream side of the paper discharge roller 11. The paper discharge sensor S2 detects the leading edge and the trailing edge of the conveyed sheet P. The upper stacking tray 18 is provided with a sheet detection sensor S7 that detects whether or not the sheets P are stacked on the stacking tray 18.

  When the sheet P is discharged from the paper discharge roller 11, the paper discharge sensor S2 detects the trailing edge of the sheet P. Based on the sheet detection operation of the paper discharge sensor S2, the paddle motor 16 is started and the paddle 17 starts to rotate. At this time, the rear end of the sheet P has already passed through the paper discharge roller 11. The paddle 17 contacts the sheet P in a predetermined angle range during one rotation, and feeds the sheet P dropped on the stacking tray 18 between the plurality of knurled belts 19 and the stacking tray 18. The knurled belt 19 that is regulated as an alignment reference for sheet shifting has already been rotated in conjunction with the sheet discharge roller 11 by the timing belt 10, and the sheet P is abutted against the stacking wall portion 20 and the rear end of the sheet P is moved. Align. Since the sheet P is in the vicinity of the knurled belt 19, the sheet P is reliably pulled in and the rear end portion is aligned.

  Here, as shown in FIGS. 6, 7, and 8, the paddle 17 is a flexible and elastic rod-like member that is disposed with the rotation shaft fixed to the housing structure 410 in the upper position of the stacking tray 18. It is a member. The paddle 17 has its standby position detected by the home position sensor S11, and returns to the standby position by one rotation each time one sheet P is stacked with the standby position as a base point. The paddle motor 16 is composed of a step motor that outputs a rotation speed corresponding to the frequency of the supply pulse, and the rotation speed is set to two stages by switching the supply pulse frequency to two stages.

  The conveyance / discharge path 63 for guiding the sheet P to the lower stacking tray 37 is configured as follows. As shown in FIG. 2, a timing belt 5 is stretched between the rotation shaft of the conveyance drive motor 6 that is started by the operation of the inlet sensor S <b> 1 and the connection gear 4. By the rotation of the connection gear 4, the plurality of lower entrance rollers 21 and the driven rollers 22 driven by the entrance rollers 21 are rotated. A timing belt 23 is wound around the entrance roller 21 and the plurality of vertical path first rollers 24. A driven roller 25 that is driven and rotated is in pressure contact with the vertical path first roller 24. A timing belt 26 is stretched between the vertical path first roller 24 and the vertical path second roller 27. A driven roller 28 that is driven and rotated is in pressure contact with the vertical path second roller 27. A timing belt 29 is stretched between the upper discharge roller 11 and the lower discharge roller 30. A plurality of driven rollers 31 that are driven to rotate are pressed against the plurality of paper discharge rollers 30.

  The sheet P conveyed on the lower conveyance conveyance path 63 is brought into pressure contact with the entrance roller 21, the vertical path first roller 24, the vertical path second roller 27, and each of these rollers which are rotated by driving of the conveyance drive motor 6. It is conveyed by the driven rollers 22, 25, 28, the discharge roller 30 and the driven roller 31 rotated by the discharge drive motor 7, and discharged to the lower stacking tray 37.

  Between the entrance roller 21 and the vertical path first roller 24, a vertical path first sensor S3 is disposed. Between the vertical path first roller 24 and the vertical path second roller 27, a vertical path second sensor S4 is disposed. A paper discharge sensor S5 is disposed between the vertical path second roller 27 and the paper discharge roller 30. These sensors S3, S4, and S5 detect the leading edge and the trailing edge of the sheet P. The stacking tray 37 is also provided with a sheet detection sensor S8 that detects whether or not the sheets P are stacked on the stacking tray 37.

  When the paper discharge sensor S5 detects the trailing edge of the sheet P, the lower paddle motor 33 is started and the paddle 34 starts to rotate. At this time, the trailing edge of the sheet P has already passed through the paper discharge roller 30. The paddle 34 feeds the sheet P dropped on the stacking tray 37 between the plurality of knurled belts 36 and the lower stacking tray 37. The knurled belt 36 that is regulated as an alignment reference for sheet shifting has already been rotated in conjunction with the sheet discharge roller 30 by the timing belt 35 that is stretched between the sheet discharge roller 30 and the idler pulley 65, and the sheet P is loaded on the stacking wall. The rear end of the sheet P is aligned with the portion 38. Since the sheet P is in the vicinity of the knurled belt 36, the sheet P is reliably pulled in and the rear end portion is aligned.

  Here, the paddle 34 is formed in the same material and the same shape as the upper paddle 17, and is arranged with the rotation shaft fixed to the housing structure 410 in the upper position of the stacking tray 37. The paddle 34 is detected in its standby position by the home position sensor S12, and returns to the standby position by one rotation each time one sheet P is stacked with the standby position as a base point. The paddle motor 33 is composed of a step motor that outputs a rotation speed corresponding to the frequency of the supply pulse, and the rotation speed is set to two stages by switching the supply pulse frequency to two stages.

  By the way, when the sheet aligning device 400 discharges the sheet P to the upper stacking tray 18, the sheet aligning device 400 can execute the discharge process in the offset mode in addition to the normal discharge mode. In the offset mode, the sheet P is moved by moving the sheet discharge roller 11 in a direction intersecting the sheet conveyance direction (sheet width direction) with the sheet discharge roller 11 and the driven roller 12 sandwiching the sheet P. Is an operation mode in which the sheet is discharged while being shifted in the width direction. At this time, the driven roller 12 moves through the sheet P as the paper discharge roller 11 moves. Similarly, for the lower stacking tray 37, the discharge roller 30 can be moved to execute the offset mode discharge processing, but detailed description is omitted to avoid duplication.

  A mechanism for moving the upper discharge roller 11 in the sheet width direction is configured as follows. As shown in FIG. 3, the paper discharge roller 11 is provided integrally with the rotation shaft 71. The rotation shaft 71 is disposed in a direction orthogonal to the conveyance direction of the sheet P, and is rotatable so as to be movable in a thrust direction (arrows A and B directions = width direction of the sheet P) by a bearing (not shown). It is supported. The rotation shaft 71 passes through a pulley 72, and the pulley 72 is supported by a support member (not shown) so that the movement in the thrust direction is restricted and is rotatable. A driving timing belt 10 shown in FIG. 2 is hung on the pulley 72, and the pulley 72 is driven to rotate by the circulation of the timing belt 10 to drive the rotating shaft 71.

  For this reason, a spline groove (not shown) is formed in the inner diameter of the pulley 72, while a spline shaft (not shown) is formed in a part of the rotating shaft 71, and the pulley 72 and the rotating shaft 71 are moved in the axial direction. They are connected by a movable spline mechanism. As a result, even if the rotary shaft 71 is offset in the thrust direction, the pulley 72 can rotate at the same position.

  In addition, a plurality of grooves 73 along the rotation direction are formed along a thrust direction in a part of the outer periphery of the rotation shaft 71. A worm gear 74 is engaged with the groove 73, and the worm gear 74 is rotationally driven by a discharge roller moving motor 76 via a timing belt 75.

  Accordingly, the sheet discharge roller 11 is offset by the rotation of the sheet discharge roller moving motor 76 in the thrust direction while rotating by the rotation of the pulley 72 while the conveyed sheet P is nipped. It can be discharged near the left alignment plate 40 or the right alignment plate 39 described later. The discharge roller moving motor 76, the timing belt 75, the worm gear 74, the rotating shaft 71 and the like constitute a discharge roller moving device 77.

  The offset device 80 of the left alignment plate 40 and the offset device 70 of the right alignment plate 39 are configured as follows. As shown in FIG. 3, the left alignment plate 40 moves in the direction of arrow B to align the left end of the sheet P. A timing belt 93 is hung on the left alignment plate driving motor 42 and the pulley 92, and a pinion 91 integrated with the pulley 92 is engaged with a rack 94 integrated with the left alignment plate 40. The position of the left alignment plate 40 shown in FIG. 3 is a home position, and the detection plate 1b provided on the left alignment plate 40 shields the detection portion of the home position sensor S6b provided on the main body. Is detected. These left alignment plate driving motor 42, timing belt 93, pulley 92, pinion 91, rack 94, and the like constitute an offset device 80 for the left alignment plate 40. Therefore, when the left alignment plate driving motor 42 rotates, the pinion 91 rotates via the timing belt 93 and the pulley 92, and the left alignment plate 40 moves in the direction of the arrow B together with the rack 94. Align the left edge.

  Further, the right alignment plate 39 moves in the direction of arrow A to align the right end of the sheet P. A timing belt 83 is hung on the right alignment plate driving motor 41 and a pulley 82 integral with the pinion 81, and the pinion 81 meshes with a rack 84 integral with the right alignment plate 39. The position of the right alignment plate 39 shown in FIG. 3 is the home position, and the position is that the detection plate 1a provided on the right alignment plate 39 shields the detection unit of the home position sensor S6a provided on the main body. Detected by. The right alignment plate driving motor 41, the timing belt 83, the pulley 82, the pinion 81, the rack 84, and the like constitute an offset device 70 for the right alignment plate 39. Therefore, when the right alignment plate driving motor 41 rotates, the pinion 81 rotates via the timing belt 83 and the pulley 82, and the right alignment plate 39 moves in the direction of arrow A together with the rack 84. Align the right edge.

  As shown in FIG. 1, the control unit 520 in the apparatus main body 501A of the copier 501 transmits a command related to sheet alignment after image formation to the control unit 510 of the sheet alignment apparatus 400. From the control unit 510 of the sheet aligning apparatus 400, status information including permission to accept sheets is returned to the control unit 520 in the apparatus main body 501A.

  As shown in FIG. 4, communication between the control unit 520 in the apparatus main body 501 </ b> A and the control unit 510 of the sheet aligning apparatus 400 is performed via an interface controller 511. The ROM 512 stores a control program for the sheet aligning apparatus 400 and various necessary data, and stores a sheet conveyance distance, a paddle rotation position, and the like. The RAM 514 stores information necessary for executing the operation sequence, and is used as a work memory. The EEPROM 515 is a non-volatile memory that stores device-specific parameters or information used continuously.

  The CPU 519 receives information from the control unit 420 of the apparatus main body 501A, sheet alignment operation order information stored in the ROM 512, information necessary for operation execution stored in the RAM 514 and the EEPROM 515, and almost real time via the input port 516. The calculation is executed based on the detection signal of each sensor (S1 to S8) that can be read out and the calculation result is output to the output port 517, whereby the conveyance drive motor 6 is connected via the drive unit (driver circuit) 518. The discharge driving motor 7, the right alignment plate driving motor 41, the left alignment plate driving motor 42, the discharge roller moving motor 76, the other motors, the solenoid 14, and the other solenoids are controlled.

  In this embodiment, the control unit 520 in the apparatus main body 501A and the control unit 510 of the sheet aligning apparatus 400 are separate, but are provided integrally in either the apparatus main body 501 or the sheet aligning apparatus 400. It may be done.

  Now, the CPU 519 controls the home position return and the rotation start timing of the paddles 17 and 34 by driving the paddle motors 16 and 33 with reference to the outputs of the home position sensors S11 and S12. Further, the CPU 519 switches the frequency of the supply pulse to the paddle motors 16 and 33 to adjust the rotation speed during rotation in two stages.

  In the state where paddle 17 is detected by home position sensor S11 for the first time (or when the previous sheet discharge and alignment have been completed), control unit 510 of sheet alignment apparatus 400 transfers to control unit 520 in apparatus main body 501A. A sheet discharge permission signal is transmitted. Then, a discharge notice signal and sheet information are transmitted from the control unit 520 in the apparatus main body 501A to the control unit 510 of the sheet aligning apparatus 400. Then, as shown in FIG. 5, in step S151, the sheet size is determined based on the sheet information.

  Then, when the sheet P is actually discharged from the apparatus main body 501A and conveyed through the upper conveyance discharge path 62, and when the discharge sensor S2 is turned on in step S152, the discharge drive motor 7 shown in FIG. to start. As a result, in step S <b> 153, the sheet P is conveyed by the paper discharge roller 11 and the driven roller 12 and is discharged to the upper position of the stacking tray 18. At this time, the offset movement control described above is also executed.

  Then, in step S154, the paddle motor 16 is immediately activated, and the paddle motor 16 is driven at a high speed until it is detected in step S155 that the paddle 17 has reached the number of steps rotated 120 degrees. Thereafter, in step S156, the paddle motor 16 is continuously driven until the paddle motor 16 reaches the number of steps at which the paddle 17 further rotates 120 degrees by switching from high speed to low speed. Thereafter, in step S157, the paddle motor 16 is continuously driven until the home position sensor 11 detects the paddle 16 while maintaining a low speed.

  In the sheet aligning device 400 configured as described above, the control unit 510 controls the number of clocks of the discharge drive motor 7 from the time when the sheet discharge sensor S2 detects the sheet P, thereby determining the conveyance amount of the sheet P. Location management is performed. Similarly, the rotational speed of the paddle is controlled by the control unit 510 by controlling the number of clocks of the paddle motor 16 with respect to the rotational operation of the paddle.

  After the sheet P is discharged from the paper discharge roller 11, the paddle 17 starts rotating when the paddle motor 16 starts and stops at the home position standby position shown in FIG. At this time, as shown in FIG. 7, the rotating operation is performed at a high speed up to a position where the discharged sheet P can be sufficiently contacted.

  Thereafter, the paddle 17 turns and rotates at a low speed, and as shown in FIG. 8, the sheet P dropped on the stacking tray 18 is slowly swept away, and a plurality of knurls that regulate the sheet P as an alignment reference for sheet gathering. The sheet is fed between the belt 19 and the stacking tray 18 and abutted against the stacking wall portion 20. That is, the paddle rotation operation at a low speed is performed until the paddle 17 is pulled into the knurled belt 19 from the position where the paddle 17 can sufficiently contact the sheet P.

  Thereafter, the alignment operation of the side end along the conveyance direction of the sheet P is performed. Then, after the pull-in operation of the sheet P is completed by the rotation operation of the paddle 17, in preparation for the next sheet discharge, the home position shown in FIG. 6 is moved to the standby position while maintaining the low speed.

  The lower paddle 34 is controlled in the same manner as the upper paddle 17, but the illustration and description of the lower paddle 34 are omitted to avoid duplication and complication.

  As described above, in the sheet aligning device 400 according to the embodiment of the present invention, when the sheet P is retracted by the paddle 17 (34), the paddle 17 (34) is in contact with the sheet P. The knurling belt 19 (which regulates the end surface of the sheet P by stabilizing the behavior of the sheet P to be pulled back is performed by performing the operation from the contact to the knurling belt 19 (36) at a high speed. 36), the sheet P is guided in a stable state, and the alignment can be maintained without causing the sheet P to be pulled in or out of alignment.

  Further, it has a paddle 17 that contacts the sheet P on the stacking tray 18 and moves the sheet P to a predetermined position on the stacking tray 18 at a period of the periodic operation, and the paddle 17 contacts the sheet P. Since the operation speed at the time when the sheet is in operation is set lower than the operation speed at the time when the sheet P is not in contact with the sheet P, the total time required for one cycle of the periodic operation is shortened and the time interval at which the sheet can be received And the number of sheet alignment processes per unit time is increased.

  Further, since the paddle 17 is disposed at the upper position of the stacking tray 18 and is driven to rotate, the rotation axis is set at a high position that does not affect the discharge of the sheet P, the paddle 17 is relatively long, and the home position is also the sheet P. Therefore, the rotation angle from the home position to the sheet P contact position becomes large, and the rotation speed in this angle range greatly affects the required time for one round. However, since it is involved in alignment by contacting the sheet P only at one time of the rotational operation, no matter how much the operation speed is increased, the result of aligning the sheet will not be affected, and compared with other types of paddles. Thus, the time required for one round can be greatly reduced without impairing the function at the time involved in the alignment.

  Further, since the stacking tray 18 has a stacking surface and is supported so as to be able to move up and down, and the paddle 17 has a rotating shaft fixed at an empty position on the stacking surface, a drive mechanism for the paddle 17 and a discharge mechanism for the sheet P are provided. Therefore, the mechanism and drive system are simpler and more accurate than when the paddle is raised and lowered with respect to the fixed stacking tray, and the drive mechanism of the paddle 17 is compactly configured. A plurality of stacking trays 18 and 37 can be arranged at a limited apparatus height.

  Further, the control unit 510 of the sheet aligning apparatus 400 that identifies the paddle motor 16 that drives the paddle 17 and the periodic phase timing of the paddle 17 and electrically changes the rotational speed of the paddle motor 16 according to the identification result. Therefore, the phase position for switching the rotational speed, the angle range for maintaining the same rotational speed, and the rotational speed level can be arbitrarily and freely set as compared with the case where the speed is mechanically switched.

  Further, since the sheet aligning apparatus 400 having such a high alignment processing speed is mounted, the time for the apparatus main body 501A to wait for the paddles 17 and 34 of the sheet aligning apparatus 400 is reduced, and the number of sheets processed per time of the copying machine 501 is increased. did.

  In the sheet aligning apparatus 400, one rotation of the paddle 17 is divided into two periods, a period A from the home position to the sheet contact and a period B from the sheet contact to the return to the home position. However, the B period is further divided into the B1 period from the sheet contact to the sheet separation and the B2 period from the sheet separation to the return to the home position, and the low speed is set for the B1 period and the high speed is set for the B2 period. It may be assigned.

  Further, according to the combination of the step motor and the pulse control circuit, it is easy to set the low speed allocated to the B1 period in a plurality of stages. Therefore, in step S151 shown in FIG. 5, the sheet thickness and the sheet surface are matched to the sheet size. The properties and the like may also be determined, and the rotational speed of the paddle 17 in the B1 period may be set to a rotational speed corresponding to the sheet. That is, the control unit 510 of the sheet aligning apparatus 400 may also identify information about the sheet, and set the operation speed when the paddle 17 is in contact with the sheet P according to the identification result. For example, in the case of a large sheet size, a thin sheet, a sheet with a small friction on the upper surface, or a sheet with a large friction on the lower surface, the sheet is slowly swept up by setting a lower rotation speed than usual, or gradually from the stopped state throughout the B1 period. The rotational speed of the paddle 17 can be avoided by sudden acceleration of the seat. Even in such a case, by applying a high speed for the period A and the period B2, it is possible to maintain the number of sheet alignment processes per unit time without increasing the time required for one rotation of the paddle 17.

  Further, the control unit 510 of the sheet aligning apparatus 400 confirms that the type and curl state of the sheet P and the speed of the knurled belt 19 that always regulates the end face of the stacked sheet P as the alignment reference are synchronized with the sheet drawing speed. The alignment difficulty level may be determined based on the determination of whether or not, and if the alignment difficulty level is high, the rotation speed of the period B may be set smaller. Further, the rotational speed of the paddle 17 in the period A may be set according to the conveyance and discharge positions of the sheet P. In any case, by changing the rotational speed of the paddle 17 and recovering the delay in the period in which the paddle 17 is in contact with the period in which the sheet P is not in contact with the sheet P, the pulling in of the sheet P is stabilized, without causing a defect due to the pulling in or alignment. The sheet can be stacked with a high number of processed sheets per time while maintaining sheet consistency.

  Examples of the image forming apparatus include a copying machine, a facsimile, a printer, and a complex machine of these. Therefore, the sheet aligning apparatus of the present invention can be connected / mounted on an image forming apparatus other than a copying machine. Further, the sheet aligning device is not limited to the one that is installed / connected outside the image forming apparatus main body, and may be integrated into the image forming apparatus main body.

  The present invention can also be applied to various sheet aligning apparatuses that perform alignment when stacking processed or inspected sheets on the sheet stacking means.

1 is an explanatory diagram of a copying machine as an example of an embodiment of the present invention. It is explanatory drawing of the mechanism of a sheet alignment apparatus. It is explanatory drawing of the alignment mechanism of the sheet width direction in a sheet alignment apparatus. It is a block diagram of a control system of the sheet alignment apparatus. It is a flowchart of paddle rotation speed control. It is explanatory drawing of the home position of a paddle. It is explanatory drawing of the high-speed rotation period of a paddle. It is explanatory drawing of the low-speed rotation period of a paddle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Entrance roller 6 Conveyance drive motor 7 Discharge drive motor 11, 30 Paper discharge roller 16, 33 Paddle motor 17, 34 Paddle (alignment means)
18, 37 Loading tray (sheet stacking means)
19, 36 Knurled belts 20, 38 Stacking wall portions 62, 63 Transport discharge paths 66, 67 Lifting device 100 Reader portion 200 Printer portion 202 Photosensitive member (image forming means)
300 Automatic Document Feeder 400 Sheet Aligner 501 Copying Machine (Image Forming Apparatus)
501A Apparatus main body 510 Control section 520 Control section (for apparatus main body of copying machine)
S1 Entrance sensor S2, S5 Discharge sensor S7, S8 Sheet detection sensor P1 Sheet SW1, SW2 Home position sensor

Claims (6)

Sheet stacking means on which received sheets are stacked;
A sheet aligning device comprising: an aligning unit that contacts the sheet discharged to the sheet stacking unit and moves the sheet to a predetermined position on the sheet stacking unit;
The alignment means is means for contacting the sheet within a predetermined range of the periodic operation and not contacting the sheet outside the predetermined range,
The sheet aligning apparatus, wherein an operation speed of the aligning unit outside the predetermined range is set to be higher than an operation speed in the predetermined range.   2. The sheet aligning apparatus according to claim 1, wherein the aligning unit is disposed above the sheet stacking unit and is rotationally driven, and is a unit that contacts the sheet within a predetermined angular range during one rotation. . The sheet stacking means is supported to be movable up and down with respect to the housing structure,
3. A sheet aligning apparatus according to claim 2, wherein the aligning means has a rotating shaft fixed to the housing structure above the sheet stacking means. Motor means for driving the alignment means;
4. Control means for identifying a phase time in a periodic operation of the matching means and changing a rotation speed of the motor means in accordance with the identified phase time. The sheet aligning apparatus described.   The control means is means for identifying information relating to the alignment difficulty level of the sheet, and changing the operation speed of the phase timing when the alignment means is in contact with the sheet in correspondence with the identified alignment difficulty level. The sheet aligning apparatus according to claim 4. 6. An image forming apparatus comprising an image forming unit for forming an image on a sheet, comprising the sheet aligning device according to claim 1.

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