JP5326835B2 - Stacker and image forming system including the stacker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stacker stacking sheets without interference of the sheets already stacked on a stack tray and a stopper even if the front end position of the sheets is changed toward the direction opposite to the sheet discharging direction in the stacker provided with a front end alignment mechanism aligning the front end of the sheets by pressingly move the sheets by the stopper. <P>SOLUTION: The front end alignment mechanism 51 is constituted to include the stopper 58, a vertical movement part 57 supporting the stopper 58 so as to move vertically, and a horizontal movement part 59 supporting the vertical movement part 57 so as to advance and retract to the sheet discharging direction and its opposite direction. Also, a control unit is provided which makes the vertical movement part 57 and the horizontal movement part 59 act so as to align the front end of the sheets discharged to the stack tray by making the stopper 58 pressingly move the sheets toward the opposite direction of the sheet discharging direction and so as to raise the stopper and to align the front end of the sheets already stacked on the stack tray on the opposite direction side of the sheet discharging direction with respect to the front end of the sheets. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to an image forming system including a stacker that aligns an image-formed sheet discharged to a stack tray at a predetermined position on the stack tray.

There is a stacker that receives sheets formed with an image by an image forming apparatus and stacks the sheets with their leading ends aligned at predetermined positions on a vertically movable stack tray provided inside the apparatus.
Further, this stacker includes a stopper that restricts the position of the leading end portion on the discharge direction side of the sheet on the stack tray, and moves and adjusts the position of the stopper according to the size of the sheet (for example, see Patent Document 1). ).

However, the stacker described above is configured so that the stopper position is simply laterally moved in accordance with the sheet size to align the leading edge of the sheet, so that the sheet is moved in the direction opposite to the sheet discharge direction while the sheets are being stacked. When it is necessary to change the leading end position of the sheets and stack the sheets, the sheets already stacked on the stack tray interfere with the stopper, and cannot be dealt with.
However, since this stacker can move up and down, the stack tray can be simply lowered to avoid interference between the sheets already stacked on the stack tray and the stopper. It is extremely difficult to lower the stack tray with a mechanism using gears and to ensure that the leading edge of the newly loaded sheet is aligned with the stopper.
The present invention has been made in view of such a situation. Even when it is necessary to change the leading end position of the sheet in the direction opposite to the sheet discharge direction during the stacking of the sheets, the stack tray It is an object of the present invention to provide an image forming system including a stacker that can easily avoid interference between a sheet already stacked thereon and a stopper and can stack a new sheet having a different tip position.

In order to solve the above problems, the present invention has taken the following technical means. The invention according to claim 1 is a stack tray on which sheets are stacked, a tip alignment mechanism that is provided above the stack tray and aligns the tips of the sheets discharged to the stack tray, and a control that controls the tip alignment mechanism. The tip aligning mechanism includes a plate-like stopper, a vertically moving portion that supports the stopper so as to move up and down, and the vertically moving portion as a discharge direction of the sheet and A lateral movement unit supported so as to be capable of moving back and forth in a direction opposite to the discharge direction, and the control unit causes the stopper to move the sheet discharged to the stack tray with the stopper. It is possible to align the leading edge of the sheet by pushing it in the reverse direction, and the stopper is raised to discharge the sheet from the leading edge of the sheet already stacked on the stack tray. And capable aligns the leading edge of the sheet in the reverse direction, the vertical direction moving unit and is configured to enable the said lateral mobile unit, the standby position of the tip justification near the home position in the lateral direction of the stopper The stopper is moved to a position where the standby position becomes a base point for pushing the sheet, and the stopper is raised to a predetermined height at the standby position, and the stopper is moved from the raised position to a position near the new leading edge alignment position. The stopper is moved to a second standby position where the lower end is lowered to just before contacting the uppermost surface of the already placed sheet, and the second standby position is used as a base point for pushing the sheet. A rolling roller is provided at a lower end of the stopper, and the vertical movement unit includes a proportional solenoid actuator as a drive source for operating the stopper, and the proportional solenoid actuator. Formed with increasing configured to allow the stopper in pulling back operation of the rod constituting the Chueta a stacker comprising and a spring for resiliently urging said stopper downward, a desired image on the sheet And an image forming apparatus configured to be capable of delivering an image-formed sheet from the image forming apparatus to the stacker .

  According to the present invention, since the stopper can be moved horizontally and vertically, even if it is necessary to change the leading end position of the sheet in the direction opposite to the sheet discharge direction during the stacking of the sheets, the stack tray It is possible to easily avoid the interference between the sheet already stacked on the top and the stopper and stack a new sheet having a different tip position.

It is the front view which showed the outline of the stacker concerning this Embodiment. It is a top view of a sheet alignment unit It is a perspective view of a tip alignment mechanism. It is a longitudinal cross-sectional view of an up-down direction moving part. It is a cross-sectional top view of an up-down direction moving part. It is a longitudinal cross-sectional view of the up-down direction moving part at the time of a raise of a stopper. It is a perspective view around an abutting wall part. FIG. 10 is an operation explanatory diagram illustrating a sheet alignment operation. FIG. 10 is an operation explanatory diagram illustrating a sheet alignment operation. It is the elements on larger scale of the stopper of another aspect.

Embodiments of a stacker included in an image forming system according to the present invention will be described with reference to the drawings.
The stacker according to the present embodiment is capable of delivering a sheet by combining a sheet discharge port of an image forming apparatus (not shown) that forms an image on a sheet and a first conveyance path unit 3 described later. As shown in FIG. 1, the apparatus is provided with the apparatus main body 1, a sheet alignment unit 28, a stack tray 60, and a control unit. The image forming apparatus is a known image forming apparatus of an electrophotographic system or an ink jet system, and detailed description thereof is omitted.
The apparatus main body 1 includes a sheet conveying mechanism, an abutting wall portion 65, and a tray lifting / lowering mechanism.
As shown in FIG. 1, the sheet conveying mechanism receives the image-formed sheet output from the image forming apparatus and discharges it to the proof tray 2 provided on the upper surface of the apparatus, and the sheet. Immediately after receiving, the second conveyance path section 4 branched from the first conveyance path section 3 and discharged toward the stack tray 60, and the intermediate section of the first conveyance path section 3 branched from the first conveyance path section 3. A sheet that has been conveyed while being swingably provided at a branching portion between the third conveyance path portion 5 that can be discharged from the other side surface, and the first conveyance path portion 3 and the second conveyance path portion 4 is transferred to the first conveyance path. A first switching claw unit 6 for switching the conveyance path so that the conveyance path can be conveyed to either the conveyance path unit 3 or the second conveyance path unit 4, the first conveyance path unit 3, and the third conveyance path unit 5 A sheet that is provided so as to be swingable at the branch portion of the sheet and that has been conveyed is fed to the first conveyance path unit 3 or the third conveyance path 5 and a second switching claw portion 7 for switching the transportable convey path Kano either.

The first conveyance path unit 3, the second conveyance path unit 4, and the third conveyance path unit 5 are a plurality of rotatable roller pairs 8 that convey a sheet and a guide plate (not shown) that guides the sheet. With. In addition, sheet passage detection sensors S1 and S2 made of optical sensors are provided in the transport path upstream of the first switching claw section 6 and the second transport path section 4.
In addition, the sheet conveying mechanism includes a rotatable driving roller 912 having a driving motor (not shown) as a driving source at the end of the second conveying path portion 4 and a driving roller that is elastically biased toward the driving roller 912. A cross that is driven by hitting the rear end portion of the sheet discharged to the stack tray 60 downward using the above-described drive motor (not shown) as a drive source and a driven roller 914 that can be driven to rotate by rotation of 912. Paddle 916.
As shown in FIG. 7, the abutting wall portion 65 is a substantially L-shaped strip-shaped member in which a slit 65 b for escaping the paddle and the driving roller 912 is formed in a vertical wall 65 a as an abutting wall against which the rear end of the sheet abuts. It is attached to the machine frame.
As shown in FIG. 1, the tray lifting mechanism includes a support shaft 10, a timing pulley 12, a timing belt 13, a stack tray support portion, a connecting portion, and a driving portion.

The support shaft 10 can be rotated in the apparatus frame toward the depth direction in FIG. 1 below a sheet aligning unit 28 (to be described later) and in the vicinity of a receiving portion that receives an image-formed sheet discharged from the image forming apparatus. And a pair that is pivotably mounted on the machine frame at a predetermined interval downward from the installation position, and is parallel to the pair of support shafts 10 on the downstream side of the sheet alignment unit 28 in the conveying direction. It consists of four with a pair erected on.
The timing pulley 12 has teeth that mesh with the timing belt 13 on the outer peripheral surface. The timing pulley 12 is a predetermined inner side of the depth width of the stack tray 60 in each of the four support shafts 10 and in the depth direction in FIG. A total of eight are attached at intervals of.
The timing belt 13 is hung between timing pulleys 12 composed of four pairs of upper and lower pairs in plan view.
The stack tray support portion supports the bottom surface of the corner portion of the stack tray 60 in plan view, and supports arms 14 attached to each of the four timing belts 13 so as to be moved up and down by the rotation of the timing belt 13, and extends vertically. And a guide rod 15 that is supported by the apparatus frame and inserted through the support arm 14.

  The connecting portion is synchronized with a pair of synchronization upper timing pulleys 16 attached to the left and right upper support shafts 10 so as to be adjacent to the inside of the depth side upper timing pulley 12 and below the synchronization upper timing pulley 16. Hang between a pair of lower synchronization timing pulleys 17 that are pivotally supported on the apparatus frame at a predetermined distance narrower than the upper timing pulley 16 for synchronization, and the upper timing pulley 16 for synchronization and the lower timing pulley 17 for synchronization. And a synchronized synchronization timing belt 18.

  The drive section is supported by the first gear shaft 19 fitted on the upper one support shaft 10 so as to be adjacent to the inner side of the one upper timing pulley 16 for synchronization, and is pivotally supported by the apparatus frame, and the inner side of the timing belt 18 for synchronization. The second gear 20 meshed with the first gear 19, the third gear 21 pivotally supported by the apparatus frame and meshed with the second gear 20 inside the synchronization timing belt 18, and the third gear A worm wheel 22 attached to the pivot of 21; a worm 23 (screw gear) provided on the upper part of the pivot extending in the vertical direction and meshed with the worm wheel 22; A timing pulley 24, a drive motor 25 supported by the device frame and operating in synchronization with the pulse power, a drive timing pulley 26 attached to a rotating shaft of the drive motor 25, Of and a driving timing belt 27 which is hung on a driving timing pulley 26 and the driven timing pulley 24.

In this drive unit, the worm 23 rotates via the drive timing pulley 26, the driven timing pulley 24, and the drive timing belt 27 when the rotation shaft of the drive motor 25 rotates. The worm wheel 22 engaged with the worm wheel 22 rotates, the third gear 21 coaxial with the worm wheel 22 rotates, the second gear 20 engaged with the third gear 21, and the second gear 20 engaged with the second gear 20. The upper support shaft 10 is rotated via the first gear 19, and the upper support shaft 10 is rotated synchronously via the connecting portion. As a result, the four timing belts 13 are rotated in synchronization, the support arms 14 attached to the four timing belts 13 are moved up and down, and the stack tray 60 supported by the support arms 14 is moved up and down. Move. Further, by using the worm 23 and the worm wheel 22, the stack tray 60 can be maintained in a state of being held at an arbitrary height position.
Further, as shown in FIG. 1, by preparing a carriage 64 directly under the stack tray 60, the stack tray 60 is automatically placed on the carriage 64 when the support arm 14 is lowered to the lowest position. The sheets placed and stacked on the stack tray 60 can be carried out by the carriage 64.

Further, a filler (not shown) is provided in the vicinity of the paddle 916 so as to be swingable in the vertical direction, and the sheet is pushed up by the stacked sheet each time the sheet is stacked on the stack tray 60. It has become. The height position of the filler is detected by a stack height detection sensor S3 (FIG. 1) that is an optical sensor, and the stack height of the sheets on the stack tray 60 is detected. When the stack height detection sensor S3 is ON, the stack tray 60 is lowered by the drive motor 25, and the drive motor 25 is stopped after the stack height detection sensor S3 is turned OFF. Therefore, every time the stack height detection sensor S3 is turned on by the sheets stacked on the stack tray 60, the stack tray 60 is lowered by a predetermined distance. Further, the stack tray 60 can be lowered by a predetermined distance according to the number of discharged sheets after the number of sheets is counted by the sheet passage detection sensor S2.
As shown in FIG. 2, the sheet aligning unit 28 includes a support frame 29, a first width direction aligning mechanism 32, a second width aligning mechanism 42, and a tip aligning mechanism 51.
The support frame 29 is a member that supports the first width direction aligning mechanism 32, the second width aligning mechanism 42, and the tip aligning mechanism 51, and is formed in a rectangular shape in plan view with a bottom wall and a side wall. Each of the upper edges of the opposing long side walls is provided with a total of four inverted L-shaped hooking claws 30 projecting at two predetermined intervals. The directions of the four latching claws 30 are all in the same direction. The support frame 29 is suspended in the apparatus main body by being hooked with the latching claw 30 in the latch hole 11 provided in the apparatus machine frame, and is detachable from the apparatus main body.

  The first width direction aligning mechanism 32 is timingd by a plurality of timing pulleys 33 and a timing pulley 34 attached to the rotation shaft of the drive motor 36 so as to extend in the side wall direction (sheet width direction) on the long side. A pair of belt drive units on which a belt 35 is suspended and each member is disposed opposite to each other across a horizontal center line in plan view of the support frame 29, and a guide shaft installed along the pair of timing belts 35 37, a rotatable spline shaft 39 linked to the rotation shaft of the drive motor 38 and installed along the guide shaft 37, and fixedly attached to each timing belt 35 and slidably inserted into the guide shaft 37. And a pair of U-shaped moving blocks 40 in plan view that are loosely inserted so that the spline shaft 39 is exposed in the middle of the plan view, and a U-shaped portion in plan view of the moving block 40 A pair of scissors in which the base is slidably engaged with the spline shaft 39, the tip is suspended from the opening provided in the bottom wall of the support frame 29, and the midway is convexly curved outward. Main jogger 41 (FIG. 1), a filler (not shown) fastened to one end (drive motor 38 side) of the spline shaft 39, and a jogger rotation comprising an optical sensor engageable with the filler The position detection sensor S7 can be engaged with a shielding plate (not shown) attached to each of the moving blocks 40, and the main joggers 41 are positioned at a maximum distance from each other on the support frame 29. A main jogger width direction position detection sensor S8 including a pair of attached optical sensors, and is disposed on one short side wall side of the bottom wall of the support frame 29 that serves as the above-described sheet receiving portion side. That.

In the first width direction aligning mechanism 32, the timing belt 35 is rotated by rotating the rotation shaft of the drive motor 36, and the moving block 40 fixed to the timing belt 35 moves along the guide shaft 37. As a result, the main jogger 41 engaged with the moving block 40 and the spline shaft 39 moves. In this way, the main joggers 41 are brought close to each other, and the sheet discharged to the stack tray 60 is dropped to a predetermined position and pushed to correct the position in the width direction. When the main jogger width direction position detection sensor S8 detects the shielding plate attached to each moving block 40, that is, the position where the main joggers 41 are separated from each other approximately at the maximum is set as the origin position.
In addition, the rotation axis of the drive motor 38 linked to the spline shaft 39 rotates, so that the main jogger 41 engaged with the spline shaft 39 rotates from the suspended state to the horizontal state by an arbitrary angle, When necessary, interference with the sheets stacked on the stack tray 60 is avoided. When the jogger rotation position detection sensor S7 detects the filler, the main jogger 41 is in the suspended state and the state is the origin position of the main jogger 41.

In the second width aligning mechanism 42, a timing belt 45 is hung on a plurality of timing pulleys 43 and a timing pulley 44 attached to a rotating shaft of a drive motor 46 so as to extend in the direction of the long side wall. The belt drive unit, a pair of guide shafts 47 laid in parallel along the timing belt 44, and fixed to one running side of the timing belt 44 and slidably engaged with the pair of guide shafts 47 The first moving block 48, the second moving block 49 fixed to the other running side of the timing belt 44 and slidably engaged with the pair of guide shafts 47, the first moving block 48 and the first moving block 48 A pair of scissors-shaped sub joggers 50 (FIG. 1) suspended from the two moving blocks 49, and a shielding plate (not shown) attached to the first moving block 48; and A sub-jogger width direction position detection sensor S9 composed of an optical sensor mounted on the support frame 29 so that the bujogers 50 are positioned at a maximum distance, and a midway portion between the short side walls of the support frame 29 It is arranged.
The second width aligning section 42 includes a first moving block 48 and a second moving block 49 that are fixed to the timing belt 44 by rotating the timing belt 44 when the rotation shaft of the drive motor 46 rotates. However, it moves along a pair of guide shafts. In this way, the sub-joggers 50 are brought close to each other, and the sheet discharged to the stack tray 60 is dropped to a predetermined position and pushed to correct the position in the width direction. When the sub jogger width direction position detection sensor S9 detects the shielding plate attached to the first moving block 48, that is, the position where the sub joggers 50 are separated from each other by the maximum is set as the origin position.

As shown in FIGS. 2 and 3, the tip aligning mechanism 51 includes a stopper 58, a vertical movement unit 57, and a horizontal movement unit 59.
The stopper 58 is made of a plate-like member having a lower portion formed in a bifurcated shape and an upper portion formed in a narrow shape. The stopper 58 is an execution unit that horizontally moves along the stack tray 60 or the sheet by a lateral movement unit 59 described later, and aligns the leading edge of the sheet. FIGS. 10 (1) and 10 (2). As shown in FIG. 5, it is preferable to provide a rolling roller 58a at the lower end of each of the fork-shaped lower portions so as to reduce friction as much as possible when it comes into contact with the already stacked sheets.
As shown in FIGS. 4 and 5, the vertically moving portion 57 includes a rectangular case 57 a in which an internal space is formed and a slit-like communication hole 57 b is formed on one end of the bottom surface, and the communication hole side. Guide rail 57c laid vertically on the inner surface of the case, a rectangular bearing 57d slidably engaged with the guide rail 57c, and fixed to the bearing 57d and connected to the communication hole 57b. A mounting plate 57e to which the upper portion of the loosely inserted stopper 58 is fixed, a support portion 57f erected in the middle of the bottom surface in the case, and a pin 57g whose one end projects from the middle of both side surfaces of the mounting plate 57e. And a rocking link 57h having a substantially L-shaped side view when the ridge portion is pivotally attached to the support portion 57f, and a main body base portion pivotally supported on the inner surface of the case facing the guide rail 57c. One end of the proportional solenoid actuator 57m with the tip of the rod 57k pivotally supported on the other end of the shaft and one end of the swing link 57h on the other end and the other end on the bottom of the case A tension spring 57n that biases the moving link 57h downward. The proportional solenoid actuator 57m described above can arbitrarily control the position of the rod 57k according to the magnitude of the current flowing through the coil.

The vertically moving unit 57 configured as described above is configured such that the swing link 57h and the support unit 57f are moved by the rod 57k being pulled into the main body of the proportional solenoid actuator 57m by a control signal (energization) from a control unit described later. The swinging link 57h swings so that one end side of the swinging link 57h floats around the shaft support portion of the shaft. By this swinging, the mounting plate 57e attached to the bearing body 57d and engaged with the pin 57g moves upward along the guide rail 57c, so that the stopper 58 attached to the mounting plate 57e rises ( FIG. 6).
By the control signal (non-energized) from the control unit, the suction of the rod 57k into the main body is released, and the stopper 58 is lowered by the pulling force of the pulling spring 57n. In the present embodiment, as shown in FIG. 4, when the stopper 58 is located at the lower end, the origin position in the vertical direction of the stopper 58 is set.
By using the proportional solenoid actuator 57m and the tension spring 57n as a drive source for the vertical movement of the stopper 58, the cost can be reduced as compared with the motor, and the response speed of the vertical movement of the stopper 58 can be increased.

As shown in FIGS. 2 and 3, the lateral direction moving part 59 is disposed in the middle part between the long side walls of the support frame 29, and a plurality of the lateral direction moving parts 59 extend in the direction of the short side wall. A belt drive unit in which a timing belt 54 is hung on a timing pulley 52 and a timing pulley 53 attached to a rotation shaft of a drive motor 55, and a pair of guide shafts 56 laid in parallel along the timing belt 54. The case 57a of the vertical movement part 57 is fixed to one running side of the timing belt 54, and the case 57a of the vertical movement part 57 is slidably engaged with the pair of guide shafts 56. The case 57a of the vertical movement unit 57 is supported so as to be able to move forward and backward in the sheet discharging direction and in the opposite direction.
In addition, the support frame at a position where the stopper 58 can be engaged with a shielding plate (not shown) attached to the case 57a of the up-down direction moving portion 57 and the stopper 58 is separated from the first width direction alignment mechanism 32 substantially at the maximum. 29 is provided with a stopper pushing position detection sensor S6 composed of an optical sensor, and the state where the stopper pushing position detection sensor S6 detects the above-described shielding plate is the origin position for pushing the sheet of the stopper 58. It is said.

The lateral movement unit 59 configured in this manner has the timing belt 54 rotated by the rotation of the rotation shaft of the drive motor 55, and the case 57 a of the vertical movement unit 57 that is fixed to the timing belt 54. By moving along the pair of guide shafts 56, the stopper 58 suspended from the case 57a of the vertically moving portion 57 pushes the sheet discharged to the stack tray 60 so as to be positioned at a predetermined position. Then correct the leading edge position of the sheet. In the present embodiment, as shown in FIG. 7, the stopper 58 pushes the sheet until the rear end of the sheet P abuts against the vertical wall 65a as the abutting wall.
The stack tray 60 is movable independently of the stacker and is formed in a rectangular shape that can be placed on the support arm 14. As shown in FIG. 1, a pair of main joggers 41 is placed on the tray surface on which the sheets are stacked. A recess 60a into which the lower end of the stopper enters and a recess 60b into which the lower end of the stopper 58 enters are formed. Of these, the width of the recess 60b is such that the inner wall of the recess 60b and the stopper 58 do not interfere when the stopper 58 is shifted in the sheet width direction.
The control unit controls operation parts such as the sheet conveying mechanism, the tray lifting / lowering mechanism, the first width direction aligning mechanism 32, the second width aligning mechanism 42, and the tip aligning mechanism 51, and performs a series of operations as a stacker. The details will be replaced with the following operation description.

Next, a series of operations of the stacker will be described with reference to FIGS. 1 and 8 to 9.
First, a proof discharge mode in which a sheet is discharged to the proof tray 2 via the first conveyance path unit 3 by the user, and the sheet is discharged to the stack tray 60 via the second conveyance path unit 4. Either the shift discharge mode or the straight discharge mode in which the sheet is discharged from the side surface so as to pass through the apparatus via the third conveyance path unit 5 is selected.
In the case of the proof discharge mode and the straight discharge mode, the sheet aligning unit 28 provided with the leading edge aligning mechanism 51, which is the main part of the present invention, does not operate. Therefore, the align operation (job) in the shift discharge mode will be described below.
When the user selects the shift discharge mode, the first switching claw portion 6 is switched so that the sheet moves to the second conveyance path portion 4, and the stack tray 60 moves to the initial position on which the sheet is placed (raised). ) The image-formed sheet starts to move from the image forming apparatus attached to the apparatus toward the stack tray 60 via the second conveyance path unit 4 (FIG. 8 (1)).
The pair of driving rollers 912 and the pair of driven rollers 914 sandwich the sheet therebetween and discharge them to the stack tray 60. Immediately before discharge of the sheet to the stack tray 60, the stopper 58 is separated from the leading edge of the sheet to be placed based on the sheet size signal (sheet length) sent from the image forming apparatus. Move to standby.

At the same time or substantially simultaneously with the movement of the stopper 58 to the standby position, a pair of distances from the both edges of the sheet to be placed to a certain distance based on the sheet size signal (sheet width) sent from the image forming apparatus. The main jogger 41 and the sub jogger 50 are moved and waited (FIG. 8 (2)).
When a sheet is discharged to the stack tray 60 by the pair of driving rollers 912 and the pair of driven rollers 914, the pair of main joggers 41 and the sub joggers 50 are moved from the standby position based on the sheet size signal (sheet width). The sheet is placed at a predetermined position by starting to move so as to gradually narrow toward the sheet and dropping and pushing the sheet while guiding both edges of the sheet.
Next, the sheet on the stack tray 60 is pushed by the stopper 58 until the trailing edge of the sheet comes into contact with the vertical wall 65a, and the sheet is placed at a predetermined position (FIG. 8 (3)). Then, the pair of main jogger 41, sub jogger 50, and stopper 58 are returned to their respective standby positions, and the shift discharge of the first sheet is completed.
The pair of main joggers 41, sub joggers 50, and stoppers 58 align the sheets by repeating the above-described operation a predetermined number of times, with the respective standby positions as the starting points of the pushing.

When the above-described alignment of the sheets is completed and a new sheet having a different size is aligned and mounted on the sheet, the following control is performed. Since a new sheet is placed on a sheet that has already been placed in alignment, either the sheet width, the sheet length, or both are shortened.
When the new sheet is shorter than the already placed sheet and the sheet width is the same, the stopper 58 is raised from the above-described standby position by the vertical movement unit 57 (FIG. 9 (1)), Based on the size signal (sheet length), the top surface of the already placed sheet is moved to a position that is a certain distance away from the leading edge of the newly placed sheet (FIG. 9 (2)). Then, it is lowered to a position just before the lower end of the stopper 58 comes into contact with the stopper 58 (FIG. 9 (3)). This new standby position is set as the second standby position, and is set as a base point for pushing the stopper 58. In this way, by performing control to raise the stopper 58 from the standby position described above and move it to the second standby position, there is no waste in the movement procedure of the stopper 58, so that the productivity for stacking sheets can be improved.

Then, during the movement of the stopper 58 to the second standby position, the pair of main joggers 41 and the sub jogger 50 are caused to wait at the respective standby positions.
When a new sheet having a different size is discharged to the stack tray 60 by the pair of driving rollers 912 and the pair of driven rollers 914, the pair of main joggers 41 and the sub joggers 50 are set to the respective standby positions and stoppers 58. The second standby position is used as the starting point for pushing, and the same operation as described above is repeated to align a predetermined number of new sheets on the already placed sheets (FIG. 9 (4)).
When the new sheet is shorter or the same as the already placed sheet and the width of the sheet is narrow, the sub jogger 50 is returned to the origin position, and the pair of main joggers 41 is moved from the suspended state to the horizontal state. The width aligning operation described above is performed after rotating by an arbitrary angle to avoid interference with the sheets already stacked on the stack tray 60.

When a stack of sheets of different sizes is stacked on the stack tray 60 in this way (job end), or when the user inputs an instruction to take out a sheet or the forced end of shift discharge (job stop), the tray lifts and lowers. The stack tray 60 is lowered by the moving mechanism, and the pair of main joggers 41, the sub joggers 50, and the stoppers 58 are returned to their original positions by operations reverse to those described above.
As the stack tray 60 is lowered, the stack tray 60 is automatically placed on a cart 64 prepared in advance immediately below the stack tray 60 and is ready for unloading (see FIG. 1).
Further, the pair of main jogger 41, sub jogger 50, and stopper 58 return to their respective origin positions when energization of the device is started and when the reset button is pushed (initial operation). .
As described above, according to the present embodiment, the stopper 58 can be moved laterally and vertically, so that it is necessary to change the leading end position of the sheet in the direction opposite to the sheet discharge direction during the stacking of the sheets. Even in such a case, it is possible to easily avoid the interference between the sheet already stacked on the stack tray and the stopper 58 and stack a new sheet having a different tip position.

As mentioned above, although the stacker concerning this embodiment was explained, the embodiment mentioned above shows an example of the suitable embodiment of the present invention, and the present invention is not limited to it, and the summary Various modifications can be made without departing from the scope of the invention.
In addition, the stacker according to the present embodiment has been illustrated as being attached to an electrophotographic or inkjet image forming apparatus, but the image forming apparatus may be an image forming system in addition to the configuration. In this case, as described above, the stacker may be provided in the image forming apparatus, and the stacker and the image forming apparatus may be independent components. However, the stacker according to the present invention is provided in the image forming apparatus. There is no particular limitation on the appearance of one structural body, or each of the machine frames can be engaged with each other to form a single structural body.

  51 ... Tip alignment mechanism 57 ... Vertical movement part 57a ... Case 57b ... Communication hole 57c ... Guide rail 57d ... Bearing body 57e ... Mounting plate 57f ... Support part 57g ... Pin 57h ... Swing link 57k ... Rod 57m ... Proportional solenoid actuator 57n ... tension spring 58 ... stopper 59 ... lateral movement part 60 ... stack tray 58a ... rolling roller

Patent No. 4091789

Claims (1)

A stacker comprising: a stack tray for stacking sheets; a tip alignment mechanism that is provided above the stack tray and aligns the leading ends of the sheets discharged to the stack tray; and a control unit that controls the tip alignment mechanism. And
The tip alignment mechanism is
A plate-shaped stopper;
A vertically moving portion that supports the stopper so as to be vertically movable;
A horizontal movement unit that supports the vertical movement unit so as to be capable of moving forward and backward in the discharge direction of the sheet and in a direction opposite to the discharge direction;
The control unit is configured to push the sheet discharged to the stack tray in the direction opposite to the sheet discharging direction by the stopper to align the leading end of the sheet, and to raise the stopper, The vertical movement unit and the horizontal movement unit are configured to be operable so that the leading edge of the sheet can be aligned on the side opposite to the discharge direction of the sheet from the leading edge of the sheet already stacked on the stack tray . The stopper is moved from the lateral origin position of the stopper to a standby position in the vicinity of the leading edge alignment position, and the standby position is used as a base point for pushing the sheet, and the stopper is raised to a predetermined height at the standby position. A second standby position in which the lower end of the stopper is lowered from the raised position to a position just before the lower end of the stopper comes into contact with the top surface of the already placed sheet. In moving the stopper is configured to wait the second position so as to the origin of the pressing of the sheet,
A rolling roller is provided at the lower end of the stopper,
The vertical movement unit is configured to be able to raise the stopper by a proportional solenoid actuator as a driving source for operating the stopper, and a return operation of a rod constituting the proportional solenoid actuator, and the stopper is moved downward. and a stacker comprising a spring to resiliently biased toward,
An image forming apparatus configured to form a desired image on the sheet,
An image forming system configured to be able to deliver an image-formed sheet from the image forming apparatus to the stacker.

Images