JP2006213492A - Sheet loading device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet loading device which prevents a driving mechanism of a loading tray 18, a mechanism in a sheet delivery cover 59, or a bundle of sheet from being damaged by prohibiting the lifting of the loading tray 18 when an operator's property or the like exists between the loading tray 18 and an upper sheet delivery cover 59. <P>SOLUTION: The sheet loading device is provided with the sheet delivery cover 59 which contacts an object on a loaded surface and moves upward, and a micro switch SW1 operating by detecting the movement of the sheet delivery cover 59. When the sheet delivery cover 59 contacts to the object in the lifting process of the loading tray 18, the control part 63 forcibly stops the lifting of the loading tray 18 based on the output of the micro switch SW1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet stacking apparatus that stacks and aligns sheets discharged from an image forming apparatus such as a copying machine or a printer, and an image forming apparatus including the sheet stacking apparatus.

  When sequentially stacking processed sheets that are discharged one by one from an image forming apparatus such as a copying machine or printer, the vertical and horizontal end faces are positioned and stacked, that is, aligned, and then packed and organized. A sheet stacking apparatus designed for convenience such as binding processing has been put into practical use.

  Such a sheet stacking apparatus includes a sheet stacking unit that stacks received sheets, and an alignment unit that is rotationally driven with flexibility and moves to a predetermined position in contact with the sheet during the rotation process. (See Patent Document 1).

  Here, an abutting surface is disposed on one end side in the sheet receiving direction, and each time a sheet is received, a flexible alignment means called a paddle is rotated once toward the abutting surface. The paddle is pressed against the sheet surface and rubs against the sheet surface while bending and deforming.

  Another sheet stacking apparatus includes a housing structure that supports the sheet stacking unit so that the sheet stacking unit can be moved up and down, and a plurality of switches are arranged in the housing structure along the lifting path of the sheet stacking unit, Is detected. (See Patent Document 2).

JP 2001-130817 A JP 2002-68561 A

  By the way, the applicant of the present application has proposed a sheet stacking apparatus in which an aligning unit that is rotationally driven to come into contact with a sheet is disposed above a sheet stacking unit that can be moved up and down to perform alignment simultaneously with stacking. The sheet stacking apparatus includes a housing structure that supports the sheet stacking unit so that the sheet stacking unit can be moved up and down, and a part of the sheet stacking unit is positioned above the sheet stacking unit. The rotating shaft of the aligning means is fixed. The sheet stacking height is detected by a sensor fixed to the housing structure, and the sheet stacking unit is moved up and down so that the positional relationship between the uppermost sheet and the aligning unit is constant.

  In such a sheet stacking apparatus, if the height of the entire apparatus is to be kept low, the distance between the sheet stacking means and the upper casing structure becomes narrow, and when the sheet stacking means is raised, the object is moved to this distance. The possibility of pinching is increased. If the sheet stacking means continues to rise while the object is sandwiched, the aligning means and the housing structure may be damaged.

  In particular, after the stacking is completed and the operator takes out the sheet bundle, when the sheet stacking means is automatically raised to return to the origin, the operator fails to take out the sheet bundle and the sheet bundle collides with the alignment mechanism. There is a possibility that the operator may pinch his belongings or clothes between the casing cover and the sheet bundle.

  Therefore, it has been considered to provide a switch (see Patent Document 2) that operates when the sheet stacking means itself reaches a predetermined height, and stops the rise of the sheet stacking means simultaneously with the switch operation. However, in this case, since the sheet stacking means continues to rise until the predetermined height is reached, any object on the sheet stacking means is caught. That is, the height of the sheet stacking unit itself is not a problem, but the problem is whether there is an abnormal object in the interval between the sheet stacking unit and the upper casing structure.

  In the present invention, when there is a sheet bundle or an operator's clothes between the sheet stacking means and the upper casing structure, the sheet stacking means is stopped from rising, and the alignment means and the sheet bundle are separated. It is an object of the present invention to provide a sheet stacking apparatus that can avoid damage.

  A sheet stacking apparatus according to the present invention includes: a sheet stacking unit that stacks received sheets; and a housing structure that supports the sheet stacking unit so that the sheet stacking unit can be moved up and down, and a portion thereof is positioned above the sheet stacking unit. A sheet stacking device that raises and stops the sheet stacking unit to a predetermined height, a detection unit capable of detecting an object on the sheet stacking unit in a rising process before reaching the predetermined height, and an output of the detection unit And a control means for stopping the ascending process based on the above.

  According to the sheet stacking apparatus of the present invention, when the detection unit detects an object on the sheet stacking unit in the ascending process, the control unit forcibly stops the ascending process of the sheet stacking unit. It rises more than that, and it is difficult for the object to damage the housing structure in the sky or to be sandwiched between the object and the housing structure. Therefore, the possibility that the sheet stacking means, the mechanism of the housing structure, and the stacked sheet bundle are damaged by the object is reduced.

  1 is an explanatory view of the entire mechanism of a sheet stacking apparatus according to an embodiment of the present invention, FIG. 2 is a flowchart of control in the sheet stacking apparatus, FIG. 3 is an explanatory view of a mechanism that performs alignment in the sheet width direction, and FIG. 5 is an explanatory diagram of the angle between the stacking tray and the stacking wall, FIG. 5 is an explanatory diagram of the relationship between the stacking tray and the safety space, FIG. 6 is an explanatory diagram of the switch arrangement and the discharge cover, and FIG. FIG. 8 is a flowchart for returning the origin of the stacking tray, FIG. 9 is an explanatory view of the operation of the discharge cover, and FIG. 10 is an explanatory view of a sheet stacking apparatus according to another embodiment (comparative example) of the present invention.

  A sheet stacking apparatus 100 that is one of the embodiments that can implement the present invention includes a stacking tray 18 that is a sheet stacking unit, and a casing structure 100A (including paper discharge covers 59 and 60) that is a casing structure. For example, the sheet pull-back paddle 17 serving as the aligning unit, the micro switch SW1 and the sheet discharge cover 59 serving as the detecting unit, and the control unit 63 serving as the control unit are provided. When the discharge cover 59 hits an object during the raising process of the stacking tray 18, the control unit 63 stops the raising of the stacking tray 18 based on the output of the micro switch SW1.

  As shown in FIG. 1, a sheet stacking apparatus 100 called a stacker is provided on a side portion of an image forming apparatus 110. The control unit 63 communicates with the image forming apparatus 110 and controls the operation of each part of the sheet stacking apparatus 100 based on the outputs of a large number of sensors arranged inside the sheet stacking apparatus 100, thereby The sheets output one by one from the feeding roller pair 111 can be sorted and stacked on the upper stacking tray 18 and the lower stacking tray 37. A housing structure 100A of the sheet stacking apparatus 100 includes stacking trays 18 and 37 that can be moved up and down and includes sheet discharge covers 59 and 60.

  The base of the upper stack tray 18 is fixed on the tray base 44. Guide rollers 46 and 47 are rotatably attached to the tray base 44, and can engage with the guide rail 64 and move in the vertical direction. The tray base 44 is fixed to the timing belt 54, and the tray motor 56 drives the timing belt 54 via the timing belt 58 and the coupling gears 50 and 51. The upper surface detection sensor S7 detects the height of the uppermost sheet stacked on the stacking tray 18 by detecting the stacking surface of the stacking tray 18 fixed to the casing structure 100A (see FIG. 6). If the tray motor 56 is driven until the upper surface detection sensor S7 detects the uppermost sheet, the stacking tray 18 can be moved to a position where the height of the uppermost sheet is always the same.

  A base portion of the lower stacking tray 37 is fixed on the tray base 45. Guide rollers 48 and 49 are rotatably attached to the tray base 45, and can engage with the guide rail 65 and move up and down. The tray base 45 is fixed to the timing belt 55, and the tray motor 57 drives the timing belt 55 via the timing belt 59 and the coupling gears 52 and 53. The upper surface detection sensor S8 that is fixed to the housing structure 100A and detects the stacking surface of the stacking tray 37 detects the height of the uppermost sheet stacked on the stacking tray 37. If the tray motor 57 is driven until the upper surface detection sensor S8 detects the uppermost sheet, the stacking tray 37 can be moved to a position where the uppermost sheet height is always the same.

  The upper sheet conveyance path PU conveys the sheet output from the feeding roller pair 111 from the entrance roller 1 to the sheet discharge roller 11 and discharges it to the space above the stacking tray 18. Here, when the timing belt 5 connected to the rotation shaft of the conveyance drive motor 6 drives the coupling gear 4 and rotates the entrance roller 1 via the timing belt 3, the driven roller 2 follows the entrance roller 1. . When the timing belt 8 connected to the rotation shaft of the drive motor 7 drives the connecting gear 9 and rotates the paper discharge roller 11 via the timing belt 10, the driven roller 12 follows the paper discharge roller 11.

  An inlet sensor S1 is provided on the upstream side of the inlet roller 1, and the inlet sensor S1 detects the leading edge and the trailing edge of the conveyed sheet. A flapper 13 is disposed on the downstream side of the inlet sensor S1, and the flapper 13 is driven by a solenoid 14 to change the sheet conveyance direction to either the upper side or the lower side.

  A paper discharge sensor S2 is provided on the upstream side of the upper paper discharge roller 11, and the paper discharge sensor S2 detects the leading edge and the trailing edge of the conveyed sheet. When the trailing edge of the sheet discharged from between the discharge roller 11 and the driven roller 12 is detected by the discharge sensor S2, the paddle motor 16 is activated and the sheet pull-back paddle 17 driven by the paddle motor 16 starts to rotate. To do.

  On the other hand, a plurality of knurled belts 19 are provided below the paper discharge rollers 11 so as to partially protrude from the stacking wall portion 20 and regulate the trailing edge of the sheet as an alignment reference for paper feeding. The knurled belt 19 is driven from the paper discharge roller 11 via the timing belt 10. The sheet pull-back paddle 17 sends the sheet dropped on the stacking tray 18 toward the knurled belt 19 and causes the trailing edge of the sheet to abut against the knurled belt 19. The knurled belt 19 pulls in the sheets and aligns the sheet end surfaces with the stacking wall portion 20.

  The lower-stage sheet conveyance / discharge path PD passes the sheet output from the feeding roller pair 111 from the entrance roller 21 to the discharge roller 30 via the vertical path first roller 24 and the vertical path second roller 27. It is conveyed and discharged to the space above the stacking tray 37. Here, when the entrance roller 21 is driven by the connecting gear 4 driven from the drive motor 6 via the timing belt 5, the driven roller 22 follows the entrance roller 21 in the same manner as the sheet conveyance / discharge path PU in the upper stage direction. Rotate. Further, a driven roller 25 is driven and rotated by a first vertical roller 24 driven from the entrance roller 21 via a timing belt 23, and a driven roller is driven by a second roller 27 driven by a timing belt 26. 28 is driven to rotate. On the other hand, the lower discharge roller 30 is driven by the upper discharge roller 11 via the timing belt 29, and the driven roller 31 is driven to rotate by the discharge roller 30.

  A vertical path first sensor S3 is upstream of the vertical path first roller 24, a vertical path second sensor S4 is upstream of the vertical path second roller 27, and a paper discharge sensor S5 is upstream of the paper discharge roller 30. They are arranged to detect the leading edge and trailing edge of the conveyed sheet. When the sheet discharge sensor S5 detects the trailing edge of the sheet, the paddle motor 33 is activated, and the sheet pull-back paddle 34 driven by the paddle motor 33 starts to rotate.

  A plurality of knurled belts 36 are provided below the paper discharge rollers 30 so as to partially protrude from the stacking wall portion 38 and regulate the trailing edge of the sheet as an alignment reference for paper feeding. The knurled belt 36 is driven from the paper discharge roller 30 via the timing belt 40. The sheet pull-back paddle 34 sends the sheet dropped on the stacking tray 37 toward the knurling belt 36 and causes the trailing edge of the sheet to abut against the knurling belt 36. The knurled belt 36 pulls in the sheets and aligns the sheet end surfaces with the stacking wall portion 38.

  By the way, when discharging the sheets onto the stacking tray 18 (37), the sheet stacking apparatus 100 can select the discharge processing in the offset mode in addition to the non-sort discharge that is the normal discharge mode. In the offset mode, when the sheets are discharged, the sheet discharge roller 11 (30) sandwiching the sheets is moved in the sheet width direction, whereby the sheet width direction on the stacking tray 18 (37) (the sheet conveyance direction) This is an operation mode in which sheets are stacked at a position shifted by a predetermined amount in the (perpendicular direction).

  Here, since the basic operation is the same on both the lower side and the upper side, the sheet conveyance / discharge path on the upper side will be described. In the offset mode, the control unit 63 discharges on the upstream side of the discharge roller 11. When the paper sensor S2 detects the front edge of the sheet, as shown in FIG. 3, the sheet discharge roller 11 is moved in the left-right direction by driving the offset drive motor 42, and after the sheets are moved in the left-right direction, the stacking tray 18 is moved. Drop the sheet on top.

  The alignment in the sheet width direction is performed by the right alignment plate 39 and the left alignment plate 40. The right alignment plate 39 and the left alignment plate 40 have independent drive systems, and the right alignment plate 39 and the left alignment plate 40 have a function of aligning sheets one by one for each discharge.

  The right alignment plate 39 is moved by the right alignment plate driving motor 41A and the timing belt, and the left alignment plate 40 is similarly reciprocated independently by the left alignment plate driving motor 41B and the timing belt in the left-right direction. ing.

  The right alignment plate 39 is provided with a detection plate 1a, and the detection plate 1a shields the detection portion of the home position sensor S6a provided on the main body side, thereby home position (HP) of the right alignment plate 39. Is to be detected. Similarly, the left alignment plate 40 is provided with a detection plate 1b, and the detection plate 1b shields the detection portion of the home position sensor S6b provided on the main body side, whereby the home position of the left alignment plate 40 is provided. (HP) is detected.

  As shown in FIG. 2, in step 201, when sheet post-processing is first started, whether or not there is a sheet on the stacking tray 18 is detected by a tray paper detection sensor S9 (see FIG. 1) described later. If a sheet is detected on the stacking tray 18, the process proceeds to step 202 to acquire sheet information to be discharged, step 203 acquires sheet information on the stacking tray, and step 204 acquires both sheets based on the acquired sheet information. Compare sizes.

  In the next step 205, the sheet discharge roller 11 is moved to offset the sheet on the stacking tray 18 so that one end of the sheet to be discharged next is aligned with the designated one side. The alignment plate 40 on the side to be aligned is moved to the position.

  In the next step 206, the size of the sheet on the stacking tray 18 is compared with the next sheet to be discharged. If the size of the sheet on the stacking tray 18 is smaller than the next sheet to be discharged, the process proceeds to step 207. Thus, the sheet size data on the stacking tray 18 is updated for one side whose size exceeds the size. Thereafter, in step 208, the alignment plate 39 on the opposite side is moved in accordance with the updated size while fixing the alignment plate 40 on one end side to be aligned. If the size of the sheet on the stacking tray 18 is larger than the next sheet to be discharged, steps 207 and 208 are not executed.

  On the other hand, if no sheet can be detected on the stacking tray 18 in step 201, the process proceeds to step 209 to acquire sheet information to be discharged next. In step 210, the sheet size and the offset amount are obtained based on the sheet information. Is calculated as the maximum tray data, and this data is stored as tray information. In the following step 211, the aligning plate 40 at one end to be aligned based on the tray information is moved and fixed. When the offset is performed, the movement amount of the alignment plate 40 is calculated in consideration of the offset direction and the movement amount in addition to the sheet size. By performing this operation, even with sheets of different sizes, it is possible to align any left and right sides by aligning the alignment plate 40 or the alignment plate 39.

  On the other hand, in the alignment of the sheet conveying direction, that is, the trailing edge of the sheet, it is necessary to align the sheet by dropping it into the stacking tray 18 (37) and then pressing the sheet toward the stacking wall portion 20 (38). When the paper discharge sensor S2 (S5) detects the rear end, the sheet pull-back paddle 17 (34) driven by the timing belt 15 (32) and the paddle motor 16 (33) is rotated by the paper discharge roller 11 (30). At this time, the leading edge of the sheet has already passed through the paper discharge roller 11 (30). Since the rear end of the sheet is in the vicinity of the knurled belt 19 (36), the sheet pull-back paddle 17 (34) reliably pulls the sheet into the knurled belt 19 (36), and rear end alignment is realized. The stack tray 18 (37) is provided with a tray paper detection sensor S9 (S10). The tray paper detection sensor S9 (S10) detects the presence or absence of sheets on the stacking tray 18 (37).

  In the sheet stacking apparatus 100 of the embodiment configured as described above, the sheet is pulled back to the stacking wall portion 20 (38) side that is opposite to the transport direction by the sheet pull-back paddle 17 (34), and the trailing end of the sheet is Since the knurled belt 19 (36) in contact with the upper surface of the sheet is brought into contact with and aligned with the stacking wall portion 20 (38), the rear ends of the sheets having different lengths in the conveying direction can be aligned.

  Further, the stacking tray 18 (37) is lifted and lowered so that the uppermost surface of the stacked sheets is in contact with the knurled belt 19 (36). Regardless, a large number of sheets can be aligned on the stacking tray 18 (37).

  Further, as shown in FIG. 6, a flag type upper surface detection sensor S7 (S8) for detecting the uppermost surface of the sheets stacked on the stacking tray 18 (37) is provided at a position corresponding to the contact surface with the sheet. As a result, the rear end of the sheet on the side of the stacking wall 20 (38) is brought into contact with the stacking wall 20 (38) after coming into contact with the knurled belt 19, so that even a sheet with a sheet hook is more reliably aligned. It can be loaded.

  In other words, the uppermost surface can be detected by the upper surface detection sensor S7 (S8) on the contact surface of the knurled belt 19 with the sheet regardless of the presence or absence of the sheet curl and the number of stacked sheets and even when the stacked sheets are aligned. The stacking tray 18 (37) is appropriately raised and lowered based on a signal from the upper surface detection sensor S7 (S8) so that the uppermost surface of the sheet is accurately brought into contact with the knurled belt 19, and the alignment plates 39 and 40 are It is possible to reliably align and stack a large number of sheets by bringing the sheets into contact with each other under the same conditions.

  Further, since the sheet stacking apparatus 100 includes the alignment plates 39 and 40 that align the width direction orthogonal to the discharge direction of the discharged sheets, the sheet discharge direction and the width direction can be set regardless of the presence or absence of the sheet flaw and the number of stacked sheets. It is possible to ensure alignment.

  As shown in FIG. 4, the actual stacking wall portion 20 (38) in the sheet stacking apparatus 100 is disposed at an angle of 5 degrees to the rear side of the stacking tray 18 (37). It is assembled perpendicular to the wall 20 (38). This is because the sheet stacked with the back side of the stacking tray 18 (37) lowered is pressed against the stacking wall 20 (38) by its own weight, thereby increasing the stability of the stacked sheets. is there.

  Further, as shown in FIG. 5, the actual stacking tray 18 (37) in the sheet stacking apparatus 100 has a stacking origin point set immediately below the sheet discharge cover 59 (60), and during operation, the stacking of sheets is performed. Moves downward by the amount. This is a result of reducing the overall height of the apparatus by reducing the height of the entire apparatus while securing the same amount of sheet stacking as the sheet stacking apparatus 100J of the comparative example. As a result, the idle space Z1 (Z2) existing between the discharge cover 59J (60J) and the stacking tray 18J (37J) of the sheet stacking apparatus 100J of the comparative example disappears, and the stacking tray 18 (37 from the origin position) disappears. ) Is less likely to rise.

  Therefore, as shown in FIG. 6, a discharge cover 59 (60) is pivotally supported with respect to the housing structure 100A of the apparatus so that it can be opened rearward, and a switch actuator is provided on the discharge cover 59 (60). The micro switch SW1 (SW2) is placed in contact with the sheet tray, and control is performed so as not to allow the stack tray 18 (37) to rise while the paper discharge cover 59 (60) is open and the micro switch SW1 (SW2) is OFF. is doing. Although not shown in FIG. 6, the sheet pull-back paddle 17 (34) and its driving mechanism are housed inside the paper discharge cover 59 (60). Further, an upper surface detection sensor S7 (S8) is arranged so that the front end of the switch flag is brought into contact with the sheet bundle (stacked sheets) ST, and the uppermost surface of the sheets of the sheet bundle ST stacked on the stacking trays 18 and 37 is disposed. Is detected.

  As a result, as shown in FIG. 7, an abnormality detection area Z3 is secured below the paper discharge cover 59 (60), and an object or operator's limbs and head that have entered the abnormality detection area Z3 are covered by the paper discharge cover 59 (60). ) Is automatically stopped ascending the stacking tray 18 (37).

  Further, for example, as shown in FIG. 8, a control procedure for returning the origin of the stacking tray 18 after taking out the sheet bundle is shown, and the stacking tray 18 is controlled according to the control procedure. In step 221, it is determined whether or not loading is completed. Until loading is completed, loading and alignment are repeated in step 222 as described above. If the stacking is completed, the process proceeds to step 223, waits for the operator to take out the sheet bundle ST for a predetermined time, and if the sheet bundle ST is not taken out for a predetermined time, the process ends.

  However, when the sheet bundle ST is taken out, for example, after elapse of 5 seconds in step 224, the process proceeds to step 225. If the upper surface detection sensor S7 detects the stacking tray 18 in step 225 (origin position), the process ends with YES in step 225. If the upper surface detection sensor S7 does not detect the stacking tray 18 in step 225, the process proceeds to step 226. If the switch SW1 is ON, the process proceeds to step 227 and the stacking tray 18 starts to rise. Then, the process returns to step 225, the stacking tray 18 is raised until the upper surface detection sensor S7 detects (origin position), and the process ends in YES at step 225.

  That is, when the sheet bundle is removed in step 223, the process proceeds to steps 224, 225, 226, and 227. In step 225, the stacking tray 18 is raised until the stacking tray 18 is detected by the upper surface detection sensor S7 (origin position). However, at this time, if the micro switch SW1 is OFF in step 226, the stacking tray 18 does not start to rise. In the embodiment, as described above, while the micro switch SW1 (SW2) is OFF, control is performed so as not to allow the stacking tray 18 (37) to be lifted. ) Is turned off, the raising of the stacking tray 18 is stopped until it is turned on again.

  The control procedure shown in FIG. 8 is the same for the origin return of the stacking tray 37 after the sheet bundle is taken out. In step 225, the stacking tray 37 is moved until the upper surface detection sensor S8 detects the stacking tray 37 (origin position). It is rising. In step 226, the operation is described with SW1 replaced by SW2.

  As a result, as shown in FIG. 9, even if the stack tray 18 is accidentally raised due to the operator taking out and leaving the sheet bundle ST halfway, the sheet bundle ST contacts the paper discharge cover 59 and lifts it up. At the beginning, the raising of the stacking tray 18 is interrupted, and the sheet bundle ST collapses and is folded, or the sheet pull-back paddle 17 (34) in the sheet discharge cover 59 and its drive mechanism collide with the sheet bundle ST. The situation of being damaged is avoided.

  In the sheet stacking apparatus according to the embodiment configured as described above, after the alignment operation is completed, the operator removes the sheet bundle ST of the stacking tray 18 (37), and then detects the uppermost sheet after a predetermined time has elapsed. The stacking tray 18 (37) moves up to a height at which the upper surface detection sensor S7 (S8) is turned on. At that time, when the operator tries to take out the sheet bundle ST, if the raising operation of the stacking tray 18 (37) malfunctions, the operator's belongings may be sandwiched between the sheet bundle ST and the apparatus, There is no risk of causing damage.

  Further, as in the embodiment shown in FIG. 10, the discharge cover 59 (60), which is the exterior cover of the apparatus, is rotated up and down as shown in FIG. When it is movable and moved upward, the microswitch SW1 (SW2), which is a safety switch provided inside, operates to cut off the current of the tray motor 56 (57) that drives the stacking tray 18 (37). The lifting operation of the stacking tray 18 (37) is immediately stopped to prevent the stacking tray 18 (37) from buckling, damage to the apparatus, or the operator's hand pinching.

  In addition, since the micro switch SW1 (SW2) capable of detecting the object on the sheet stacking means in the ascending process before reaching the predetermined height is provided and the ascending process is stopped when the object is detected, the upper surface is adopted. The stacking tray 18 (37) can be stopped before the detection sensor S7 (S8) detects the predetermined height, and the catastrophic rise from the object detection to the predetermined height and the damage due to the rise can be prevented. In other words, the detection means constituted by the micro switch SW1 (SW2) and the paper discharge cover 59 (60) detects “an object exceeding the stacking height” that cannot be supplemented by the upper surface detection sensor S7 (S8). The unit 63 commonly recognizes the sheet bundle ST that is out of the upper surface detection sensor S7 (S8) as shown in FIG. 9 and the object on the normally stacked sheet bundle ST as shown in FIG. Thus, the raising of the stacking tray 18 (37) can be stopped immediately.

  Therefore, specifically, the stacking tray 18 (37) is raised further, and it is difficult for these objects to collide with the mechanism including the sheet pull-back paddle 17 (34) or to pinch the object. The possibility that the housing mechanism including the paddle 17 (34) is damaged by the collision and the stacked sheet bundle ST is damaged by the object and the housing mechanism is reduced.

  Further, the micro switch SW1 (SW2) operates when the paper discharge cover 59 (60) comes into contact with an object on the stacking surface. It is possible to reliably capture objects that may interfere. In other words, it is possible to detect the sheet bundle ST that may be damaged and the belongings and clothes of an operator that may be pinched, and stop the stacking tray 18 (37) immediately before the damage occurs.

  Further, since the actuator of the micro switch SW1 (SW2) is configured by the paper discharge cover 59 (60) that covers the mechanism including the sheet pull-back paddle 17 (34) from above, a dedicated member as in the embodiment shown in FIG. Compared to the case where the micro switch SW1 (SW2) is operated by providing the actuator 62, the number of parts is reduced, and the linear region along the front edge of the paper discharge cover 59 (60) is removed from the dedicated actuator 62. In addition, the space for providing the actuator 62 can be saved, and the layout design and size reduction of the mechanism including the sheet pull-back paddle 17 (34) can be facilitated.

  Further, since the discharge cover 59 (60) is a cover that can be opened and closed by rotating upwardly of the sheet stacking apparatus 100, maintenance and inspection of the mechanism including the sheet pull-back paddle 17 (34), the discharge roller 11 ( 30) Convenient for clearing paper jams. Further, since the micro switch SW1 (SW2) can also be used as a cover sensor that is originally necessary to prevent the operation from being resumed unless the discharge cover 59 (60) is closed, as compared with the embodiment shown in FIG. The number of sensors required for the entire system can be reduced by two.

  When the paper discharge cover 59 (60) comes into contact with an object on the stacking surface, it escapes upward, so that it touches the object on the stacking surface like the fixed paper discharge cover 59B of the embodiment shown in FIG. There is no risk of damage or overloading of the drive mechanism of the stacking tray 18 (37).

  Further, since the image forming apparatus 110 includes the sheet stacking apparatus 100 configured as described above, the possibility that the image forming apparatus 110 cannot be used due to an object on the stacking surface is reduced, and from the occurrence of an accident to the return. The operation efficiency of the image forming apparatus 110 is improved, for example, the time is significantly reduced.

  The sheet stacking apparatus 100 in the embodiment described above is configured as a component independent of the image forming apparatus 110. However, the sheet stacking apparatus is integrated and integrated in the housing of the image forming apparatus. An image forming apparatus controlled by the control unit may be configured.

  Further, as the control means, for example, the control unit 63 that executes a special program corresponding to the control procedure shown in FIG. 8 is shown, but one of the wirings of the tray motor 56 (57) is connected to the micro switch SW1 (SW2). Thus, a simple electronic circuit control means for direct ON / OFF may be provided.

  In addition, the microswitches SW1 and SW2 can detect objects on the loading tray in the ascending process before reaching a predetermined height regardless of contact type, non-contact type, mechanical type, electric type, fluid type, or optical type. As long as it is replaced with various types of sensors.

  FIG. 10 shows a sheet stacking apparatus 100B according to another embodiment of the present invention. As described above, the sheet discharge cover 59B is fixed to the apparatus main body and is placed inside the sheet discharge cover 59B. A fixed micro switch (not shown) actuator 62 is disposed above the stacking tray 18. The configuration other than the paper discharge cover 59B, the micro switch, and the actuator 62 is the same as that described with reference to FIGS.

  The present invention is not limited to a sheet stacking apparatus that is used in combination with an image forming apparatus such as a copying machine, a printer, or a facsimile, or is incorporated in the image forming apparatus, and has been processed or inspected on a sheet stacking unit. The present invention can be applied to various sheet stacking apparatuses configured to stack sheets.

It is explanatory drawing of the whole mechanism of the sheet | seat stacking apparatus which is embodiment of this invention. 5 is a flowchart of control in the sheet stacking apparatus. It is explanatory drawing of the mechanism which performs alignment of a sheet | seat width direction. It is explanatory drawing of the angle of a loading tray and a loading wall. It is explanatory drawing of the relationship between a loading tray and safety space. It is explanatory drawing of switch arrangement | positioning and a paper discharge cover. FIG. 4 is a perspective view around a sheet discharge cover in the sheet stacking apparatus. It is a flowchart of the origin return of a stacking tray. FIG. 10 is an explanatory diagram of the operation of the paper discharge cover. It is explanatory drawing of the sheet stacking apparatus of another embodiment of this invention.

Explanation of symbols

1, 21 Entrance roller 6 Conveyance drive motor 7 Drive motor 11, 30 Paper discharge roller 13 Flapper 14 Solenoid 16, 33 Paddle motor 17, 34 Sheet pull-up paddle (alignment means)
18, 37 Stacking tray (sheet stacking means)
19, 36 Knurled belt 20, 38 Stacking wall 39, 40 Alignment plate 41A, 41B, 42 Alignment plate drive motor 56, 57 Tray motor 59, 60 Paper discharge cover (detection means)
63 Control unit (control means)
64, 65 Guide rail 100A Housing structure S2, S5 Paper discharge sensor S7, S8 Upper surface detection sensor SW1, SW2 Micro switch (detection means)

Claims (7)

Sheet stacking means for stacking received sheets;
A housing structure that supports the sheet stacking means so as to be movable up and down, and a part of the sheet stacking means is positioned above the sheet stacking means,
In the sheet stacking apparatus that raises and stops the sheet stacking means to a predetermined height,
Detecting means capable of detecting an object on the sheet stacking means in the ascending process before reaching the predetermined height;
And a control unit that stops the ascending process based on an output of the detection unit. In the process of being rotationally driven, it comprises an aligning means that contacts the sheet on the sheet stacking means and moves to a predetermined position
2. The sheet stacking apparatus according to claim 1, wherein a rotation shaft of the aligning unit is fixed to the casing structure in a portion located above the sheet stacking unit.   3. The sheet stacking apparatus according to claim 1, wherein the detecting unit is a switch unit that operates in contact with an object on the sheet stacking unit that exceeds the stacking height of the sheet. An actuator member that moves in contact with an object on the sheet stacking means that exceeds the stacking height of the sheet;
4. A switch element configured to detect the movement of the actuator member and to be disposed in the casing structure in a portion located above the sheet stacking means, to constitute the switch means. The sheet stacking apparatus described.   5. The sheet stacking apparatus according to claim 4, wherein the actuator member is a cover member that can be opened and closed by rotating to the rear side of the housing structure.   An image forming apparatus comprising an image forming unit for forming an image on the sheet, comprising the sheet stacking device according to claim 1, wherein the sheet on which an image is formed by the image forming unit is stacked. Image forming apparatus. Image forming means for forming an image on a sheet, sheet stacking means for stacking the sheets,
A housing structure that supports the sheet stacking means so as to be movable up and down, and a part of which is positioned above the sheet stacking means;
A control unit that raises and stops the sheet stacking unit to a predetermined height, and a detection unit that can detect an object on the sheet stacking unit in a rising process before reaching the predetermined height,
The image forming apparatus, wherein the control unit stops the ascending process based on an output of the detection unit.

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