Patent Application
20250187864
The present invention relates to a sheet stacking apparatus for stacking sheets, and an image forming system including the sheet stacking apparatus.
Japanese Patent Application Laid-Open No. 2015-63406 discloses a sheet stacking apparatus including a stacking tray that can be lifted and lowered, and an alignment member that aligns sheets discharged onto the stacking tray in a width direction on the stacking tray. In the configuration described in Japanese Patent Application Laid-Open No. 2015-63406, every time a sheet is stacked on the stacking tray, the alignment member is moved in the width direction to align the sheet.
In recent years, there has been a demand for improving the productivity of apparatuses. If productivity is improved, the interval at which sheets are consecutively discharged onto the stacking tray reduced, and if the alignment member is moved in the width direction to align a sheet every time a sheet is stacked on the stacking tray as described in Japanese Patent Application Laid-Open No. 2015-63406, there is a possibility that a second sheet may start to be discharged onto the stacking tray while a first sheet is being aligned, and the second sheet may collide with the alignment member that is performing the alignment.
The present invention provides a sheet stacking apparatus and an image forming system capable of receiving a next sheet while an alignment member is performing alignment.
According to a first aspect of the present invention, a sheet stacking apparatus includes a stacking tray configured to stack sheets, a lowering unit configured to lower the stacking tray as the sheets are stacked, a conveyance unit configured to convey a sheet toward the stacking tray, a first action unit and a second action unit configured to act on both edge ends in a width direction of a sheet bundle stacked on the stacking tray to align the sheet bundle, and, a permitting portion configured to permit a next sheet to be temporarily received above the stacking tray when the first action unit and the second action unit are aligning the sheet bundle.
According to a second aspect of the present invention, an image forming system includes an image forming portion configured to form an image on a sheet, a stacking tray configured to stack sheets on which images are formed by the image forming portion, a lowering unit configured to lower the stacking tray as the sheets are stacked, a conveyance unit configured to convey sheets toward the stacking tray, a first action unit and a second action unit configured to act on both ends in a width direction of a sheet bundle stacked on the stacking tray to align the sheet bundle, and, a permitting portion configured to permit a next sheet to be temporarily received above the stacking tray when the first action unit and the second action unit is aligning the sheet bundle.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
A first embodiment will be described with reference to
In the present embodiment, a copying machine is used as an image forming apparatus, and a sheet processing apparatus is connected to a sheet opening portion of the copier. The image forming system 1000 includes an image forming apparatus A and a sheet processing apparatus B. The sheet processing apparatus B receives a sheet S on which an image is formed by the image forming apparatus A downstream of the image forming apparatus A, and performs predetermined processing such as binding processing as necessary. The processed sheet S is sent to a sender downstream of the sheet processing apparatus B. The image forming apparatus A includes various structures such as a copying machine, a printer, a printing machine, a facsimile machine, and a multifunction machine having a plurality of functions thereof. Hereinafter, the image forming apparatus A and the sheet processing apparatus B will be described in detail. In the following description, regarding the image forming apparatus A and the sheet processing apparatus B, a side on which an operator such as a user operates the apparatus (e.g., a side on which an operation panel, an operation button, and the like are located) will be referred to as a front side (a front side of the paper of
As illustrated in
The feeding portion 2 includes a plurality of cassettes 2a, 2b, and 2c, and sheets S of different standard sizes selected in advance can be stored in the cassettes 2a, 2b, and 2c, respectively. The sheets S are, for example, paper sheets or plastic sheets. Each of the cassettes 2a, 2b, and 2c incorporates a separation mechanism for separating the sheets S therein one by one and a feeding mechanism for feeding out the sheets S. Among the sheets S stored in the feeding portion 2 having such a configuration, a sheet S having a size designated by a control unit 310 (
A large-capacity cassette 2d and a manual feed tray 2e are connected to the feeding path 6. The large-capacity cassette 2d is configured as an optional unit that stores sheets having a size to be consumed in a large amount. The manual feed tray 2e is configured to be able to supply special sheets such as cardboard sheets, coating sheets, and film sheets which are difficult to separate and feed.
The image forming portion 3 is configured to form an image on the sheet S sent from the feeding portion 2, and various image forming mechanisms can be adopted. In the illustrated embodiment, an electrostatic image forming mechanism is shown as the image forming portion 3. However, the image forming portion 3 is not limited to the illustrated electrostatic image forming mechanism, and an inkjet image forming mechanism, an offset image forming mechanism, or the like can also be adopted.
In the image forming portion 3 illustrated in
The image reading unit A2 that optically reads a document image formed by the image forming portion 3 is provided above the image forming unit A1 configured as described above, and the document feeding unit A3 is further mounted above the image reading unit A2.
The image reading unit A2 includes a first platen 17 and a second platen 21 made of transparent glass, a reading carriage 18, a light source mounted on the reading carriage 18, a photoelectric conversion element 19, and a reduction optical system 20 configured by combining a mirror and a lens. Then, the reading carriage 18 is scanned along the first platen 17, an image of a document placed on the first platen 17 is irradiated with light from the light source, and reflected light from the image of the document is guided to the photoelectric conversion element 19 by the reduction optical system 20 to read the image. The photoelectric conversion element 19 converts the image data into an electrical signal and transfers the electrical signal to the image forming portion 3.
The document feeding unit A3 includes a feeding tray 22, a feeding path 23, and a stacking tray 24, and conveys documents placed on the feeding tray 22 one by one along the feeding path 23, causes the documents to pass over the second platen 21, and sends out the documents to the stacking tray 24. At the time of reading a document passing over the second platen 21 after being fed from the document feeding unit A3, the reading carriage 18 is stopped below the second platen 21 in advance, and image data is generated from an image passing over the second platen 21.
Next, an overall configuration of the sheet processing apparatus B that performs processing such as stapling or folding processing on sheets sent from the image forming apparatus A will be described with reference to
In the illustrated apparatus, the sheet sent to the conveyance path and the straight path 28 serving as a first conveyance path is transferred from the processing unit B1, which will be described below, to the first tray 49 and the second tray 71, and from the saddle unit B2, which will be described below, to the saddle stacking unit 131. Each device includes a control unit, a communication unit, etc. such as blocks showing a control configuration in the entire apparatus illustrated in
The processing unit B1 is disposed below a path outlet (delivering portion 35) of the straight path 28, aligns and accumulates a plurality of sheets sequentially delivered from the straight path 28 via the delivering portion 35 to form a sheet bundle, and can execute binding processing, which is an example of predetermined processing, on an end portion of the sheet bundle. The sheet bundle subjected to the binding processing is stacked on the first tray 49 serving as a stacking portion.
The saddle unit B2 is disposed below the delivering portion of the saddle path 32 serving as a second conveyance path branching downward in a vertical direction from the straight path 28, aligns and accumulates a plurality of sheets sequentially delivered from the straight path 28 via the saddle path 32 and the delivering portion to form a sheet bundle. The sheet bundle is sent to the saddle stacking unit 131 after being subjected to saddle binding processing or after being subjected to folding processing rather than saddle binding processing. Hereinafter, each component will be described in detail.
As illustrated in
As illustrated in
The second conveyance roller 202 and the third conveyance roller 203 are shift rollers that can move a sheet in a sheet width direction (front-rear direction) intersecting the sheet conveyance direction. That is, the second conveyance roller 202 and the third conveyance roller 203 are movable in the width direction by a driving unit (not illustrated), and can shift the sheet to the front side or the rear side in a state where the sheet is nipped.
The first discharge path 31 is connected to the delivering portion 35 of the straight path 28, and a pre-processing roller 36 serving as a conveyance unit is disposed at this connection portion. The sheet delivered from the straight path 28 to the first discharge path 31 and sent out from the first discharge path 31 is sent out to the first tray 49 or guided to the processing unit B1. Each of the above-described conveyance rollers may be another member capable of conveying a sheet, such as a conveyor belt.
As illustrated in
A buffer path 39, which is a branch path branching downward in the vertical direction from the straight path 28, is connected between the second conveyance roller 202 and the third conveyance roller 203. The buffer path 39 serving as a buffer portion is a path where a sheet can be temporarily placed on standby. In the case where the sheet is buffered in the buffer path 39, the sheet conveyed downstream of the portion where the buffer path 39 branches from the straight path 28 in the first direction is conveyed in the direction opposite to the first direction by reversely rotating the third conveyance roller 203 or the like, and guided to the buffer path 39 by a switching member (not illustrated).
Then, the sheet is conveyed to the buffer path 39 by a conveyance roller 208, and the rotation of the conveyance roller 208 is stopped at a position where a trailing edge of the sheet has passed out of the straight path 28. In this state, a next sheet can be conveyed downstream of the portion where the buffer path 39 branches from the straight path 28 in the first direction. Further, in the present embodiment, by reversely rotating the conveyance roller 208, the sheet in the buffer path 39 can be conveyed toward the straight path 28, and this sheet and a next sheet can be joined together at the branch portion. Further, these two sheets can be overlapped and conveyed by the third conveyance roller 203 and the pre-processing roller 36 serving as a buffer conveyance unit.
The upper conveyance path switching member 34 includes a switching member guide that is movable to change the conveyance path to convey the sheet received from the receiving portion 26 to either the first discharge path 31 or the upper conveyance path 30, and is connected to a driving unit (not illustrated) such as an electromagnetic solenoid or a mini-motor.
The upper conveyance path 30 (print-out discharge path) for conveying a sheet other than the sheet to be discharged to the first discharge path 31 is connected to the straight path 28, and the upper conveyance path switching member 34 for guiding the sheet to the upper conveyance path 30 is provided at a path branch portion. A fourth conveyance roller 204, a fifth conveyance roller 205, a sixth conveyance roller 206 serving as conveyance rollers that guide a sheet to the second tray 71, and a second sheet discharge roller pair 207 serving as a discharging unit are provided in the upper conveyance path 30. As a result, the sheet guided to the upper conveyance path 30 is sent out from an upper conveyance path opening portion 40 to the second tray 71 (overflow tray) serving as a stacking tray (stacking portion) by the second sheet discharge roller pair 207.
The processing unit B1 includes a processing tray 37 serving as a placing portion disposed downstream of the straight path 28 to place a sheet sent from the first discharge path 31, and align and accumulate a plurality of sheets placed thereon, and a binding processing mechanism (stapler) 47 serving as a processor that performs binding processing on the accumulated sheet bundle. Then, the processing unit B1 performs binding processing on the sheet bundle placed on the processing tray 37. The binding processing mechanism 47 is disposed below the straight path 28 in the vertical direction. The binding processing mechanism 47 is movable in the width direction, and can perform binding processing at a desired position in the width direction with respect to the sheet bundle placed on the processing tray 37. As illustrated in
Specifically, an upper conveyance roller 41 and a lower conveyance roller 48 that nip and convey a sheet are provided in the first discharge path 31. The upper conveyance roller 41 and the lower conveyance roller 48 constitute a sheet discharge roller pair 42 serving as a discharging unit. The upper conveyance roller 41 can abut on and be separated from the lower conveyance roller 48, and convey a sheet in a direction toward the first tray 49 (discharge direction) and in a direction opposite to this direction in a state where the sheet is nipped between the upper conveyance roller 41 and the lower conveyance roller 48. Then, the sheet can be conveyed toward the processing tray 37 via the first switchback path by the upper conveyance roller 41 and the lower conveyance roller 48. In addition, the upper conveyance roller 41 and the lower conveyance roller 48 (that is, the sheet discharge roller pair 42) sends out the sheet or the sheet bundle on the processing tray 37 from the opening portion 31a to the first tray 49 serving as a stacking tray (stacking portion). The opening portion 31a is a portion opened above the lower conveyance roller 48 in the apparatus housing 27. Further, the sheet discharge roller pair 42 sends out the sheet conveyed to the first discharge path 31 without passing through the processing tray 37 from the opening portion 31a to the first tray 49.
The processing unit B1 includes a trailing edge regulating portion 47a serving as an abutment portion that abuts on an end portion (trailing edge) of the sheet to position the sheet. A reversing portion 38 is disposed on the processing tray 37 to convey the sheet conveyed onto the processing tray 37 by the upper conveyance roller 41 and the lower conveyance roller 48 toward the trailing edge regulating portion 47a. Then, the binding processing mechanism 47 is placed on the processing tray 37, and performs binding processing on an end portion of a sheet bundle including a plurality of sheets of which the positions of the end portions are regulated by the trailing edge regulating portion 47a. In addition, the binding processing mechanism 47 includes a sheet bundle carrying-out mechanism that carries out the sheet bundle to the first tray 49 after performing the binding processing on the end portion of the sheet bundle.
In addition, the processing unit B1 includes a pair of aligning plates 270 serving as shift members, a trailing edge dropping member 44 serving as a sheet dropping unit, and a bundle discharging member 45. The pair of aligning plates 270 moves in the width direction (shift direction) of the sheet intersecting the first direction while abutting edge ends along the conveyance direction (first direction) of the sheet placed on the processing tray 37, thereby moving the sheet conveyed by the pre-processing roller 36 in the width direction. The pair of aligning plates 270 is disposed to face each other in the width direction. Further, the pair of aligning plates 270 moves in the width direction and abuts on the edge ends of the sheet in the width direction, thereby performing an alignment of the sheet in the width direction. The front-side aligning plate 270 of the pair of aligning plates 270 is moved in the width direction by driving an aligning plate 1 moving motor M13, and the rear-side aligning plate 270 is moved in the width direction by driving an aligning plate 2 moving motor MT14.
The trailing edge dropping member 44 is disposed above the processing tray 37 and moves in an up-down direction to abut on an upper surface of a sheet on an upstream side in the conveyance direction and operate to drop an upstream edge portion (trailing edge portion) of the sheet toward the processing tray 37. The bundle discharging member 45 pushes a trailing edge of a sheet bundle placed on the processing tray 37 to discharge the sheet bundle onto the first tray 49.
Note that the binding processing unit B1 illustrated in
A saddle path 32 for conveying a sheet to the above-described saddle unit B2 is connected to the straight path 28, and a saddle path switching member 33 for guiding the sheet to the saddle path 32 is provided at a path branch portion. The sheet guided to the saddle unit B2 by the saddle path 32 is sent to the saddle stacking unit 131 via an after-folding path guide 114, an after-second roller path guide 116, and a saddle discharge guide 124 arranged in the substantially horizontal direction after being subjected to half-folding processing and folding processing. In the present embodiment, the saddle discharge guide 124 is used as an auxiliary guide for appropriately stack sheets on the saddle stacking unit 131.
An outline of a control configuration of the image forming system 1000 will be described with reference to
The operation unit 302 is connected to the control unit 310, and is, for example, an operation panel provided in the image forming apparatus A to allow an operator to operate the apparatus and perform various settings. The conveyance control unit 303 controls various conveyance rollers that convey a sheet and a switching member that switches a conveyance path in the image forming apparatus A. The image processing unit 304 controls the image forming portion 3. The driving unit 305 controls various motors and power sources. The communication unit 306 communicably connects the control unit 310 to an external device 301 such as a personal computer and a communication unit 321 of the sheet processing apparatus B.
The sheet processing apparatus B includes a stacker control unit 330, a conveyance control unit 322, an end binding control unit 323, a discharge processing control unit 324, and a communication unit 321. Similarly to the control unit 310, the stacker control unit 330 includes a CPU 331, a ROM 332, and a RAM 333. The conveyance control unit 322 controls various conveyance rollers that convey a sheet and a switching member that switches a conveyance path in a portion other than the saddle unit B2 of the sheet processing apparatus B. The end binding control unit 323 controls the processing unit B1. The discharge processing control unit 324 controls the discharge of sheets and various stacking trays on which the discharged sheets are stacked. The communication unit 321 communicably connects the stacker control unit 330 to the communication unit 306 of the image forming apparatus A and a communication unit 341 of the saddle unit B2. Note that the communication unit 306 and the communication unit 321 may communicate with each other in a wired manner or in a wireless manner.
Note that the communication unit 321 functions as a notification unit. As will be described below, when it is detected that there is a sheet on a stacking tray such as the first tray 49 or the second tray 71, the communication unit 321 notifies that there is a sheet. Specifically, the communication unit 321 transmits information indicating that there is a sheet to the communication unit 306 of the image forming apparatus A, so that the information indicating that there is a sheet is displayed, for example, on a display unit of the operation unit 302.
The saddle unit B2 includes a saddle control unit 350, a conveyance control unit 342, a saddle binding control unit 343, a half-folding control unit 344, and a communication unit 341. Similarly to the control unit 310, the saddle control unit 350 includes a CPU 351, a ROM 352, and a RAM 353. The conveyance control unit 342 controls various conveyance rollers that convey a sheet and a switching member that switches a conveyance path in the saddle unit B2. The saddle binding control unit 343 controls a saddle binding processing unit 104. The half-folding control unit 344 controls a half-folding processing mechanism C1. The communication unit 341 communicably connects the saddle control unit 350 to the communication unit 321 of the sheet processing apparatus B.
As illustrated in
A sheet stacking apparatus 400 included in the sheet processing apparatus B of the present embodiment will be described in detail with reference to
The tray lifting and lowering motor MT18 (
Here, relationships between drive motors of some components of the sheet processing apparatus B on the periphery of the sheet stacking apparatus 400 and various sensors will be described with reference to a block diagram of
First, an inlet conveyance motor MT1, a conveyance motor MT2, a shift 1 conveyance motor MT3, a shift 2 conveyance motor MT4, and a pre-processing conveyance motor MT5 are motors capable of rotatably driving the inlet roller 29, the first conveyance roller 201, the second conveyance roller (shift roller) 202, the third conveyance roller (shift roller) 203, and the pre-processing roller 36, respectively, in both forward and reverse directions. A discharge roller 1 motor MT6 is a motor capable of rotatably driving the upper conveyance roller 41 in both forward and reverse directions. A discharge roller 1 motor MT6 also rotationally drives a paddle 275, which will be described below. A discharge roller 2 motor MT7 is a motor capable of rotatably driving the lower conveyance roller 48 in both forward and reverse directions. A buffer conveyance motor MT8 is a motor capable of rotationally driving the conveyance roller 208 that conveys a sheet in the above-described buffer path 39 in both forward and reverse directions.
A shift 1 motor MT9 and a shift 2 motor MT10 are motors that move the second conveyance roller 202 and the third conveyance roller 203, respectively, in the width direction. As described above, a discharge roller swing motor MT11 is a motor that swings the upper conveyance roller 41 in the up-down direction to abut on and be separated from the lower conveyance roller 48. A trailing edge dropping drive motor MT12 is a motor that moves the trailing edge dropping member 44 in the up-down direction. As described above, an aligning plate 1 moving motor M13 and an aligning plate 2 moving motor MT14 are motors that move the pair of aligning plates 270 that align a sheet in the processing tray 37 in the width direction.
Further, a stapler moving motor MT15 is capable of moving the binding processing mechanism 47 in the width direction. A stapler motor MT16 is a motor that drives the binding processing mechanism 47 to perform binding processing. A bundle discharging motor MT17 is a motor that drives the bundle discharging member 45. A tray lifting and lowering motor MT18 is a motor that lifts and lowers the first tray 49. A jogger lifting and lowering motor MT19 is a motor that lifts and lowers the pair of aligning plates (joggers) 401 and 402 as will be described below. In the present embodiment, the aligning plates 401 and 402 are lifted and lowered by one motor, but the aligning plates 401 and 402 may be lifted and lowered by separate motors. As described above, the jogger 1 moving motor MT20 and the jogger 2 moving motor MT21 move the pair of aligning plates 401 and 402, respectively, in the width direction. A paddle lifting and lowering motor MT22 is a motor that lifts and lowers the paddle 275, which will be described below.
Next, various sensors will be described. As illustrated in
A shift roller 1HP detection sensor SN4 detects a home position (HP) of the second conveyance roller 202 in the width direction. A shift roller 2HP detection sensor SN5 detects a home position (HP) of the third conveyance roller 203 in the width direction. A jogger lifting and lowering HP detection sensor SN6 detects a home position (HP) of the pair of aligning plates 401 and 402 in the lifting and lowering direction. A jogger 1HP detection sensor SN7 detects a home position (HP) of the front-side aligning plate 401 in the width direction. A jogger 2HP detection sensor SN8 detects a home position (HP) of the rear-side aligning plate 402 in the width direction. Each of the pair of aligning plates 401 and 402 is movable in the width direction as will be described below. The home positions in the lifting and lowering direction and in the width direction of the pair of aligning plates 401 and 402 are positions illustrated in
A paddle lifting and lowering HP detection sensor SN9 detects a home position (HP) of the paddle 275 in the lifting and lowering direction. The home position of the paddle 275 is a position illustrated in
Next, components from the first conveyance roller 201 to the first tray 49 of the sheet processing apparatus B will be described with reference to
The first tray 49 stacks sheets discharged from the opening portion 31a of the first discharge path 31. An abutment member 271 against which a trailing edge (an upstream edge portion in the discharge direction) of a discharged sheet abuts is provided between the first tray 49 and the processing unit B1 below the opening portion 31a on an outer surface of the apparatus housing 27. The abutment member 271 has a role of aligning the conveyance direction of the sheet discharged and stacked on the first tray 49. A stacking surface 49a, which is an upper surface of the first tray 49, is gently inclined downward toward the abutment member 271. That is, the stacking surface 49a of the first tray 49 on which the sheets are stacked is inclined at a first angle with respect to the horizontal direction to be upward toward the downstream side in the discharge direction. The sheet discharged from the opening portion 31a to the stacking surface 49a slides down along the inclination of the stacking surface 49a after falling onto the first tray 49, and the trailing edge of the sheet eventually reaches the abutment member 271 and stops.
The first tray 49 is lifted and lowered in the up-down direction by the tray lifting and lowering motor MT18 via a lifting and lowering mechanism (not illustrated). That is, when a sheet is discharged onto the first tray 49 or the second tray 71, it is necessary to lift and lower the first tray 49 or the second tray 71 in order to keep the position of the stacking surface 49a or the uppermost sheet on the stacking surface 49a constant so that the alignment of the stacked sheet is not degraded. For this reason, in the present embodiment, the first tray 49 or the second tray 71 is lowered as sheets are stacked by the tray lifting and lowering motor MT18 serving as a lowering unit so that the height of the uppermost sheet among the sheets discharged by the sheet discharge roller pair 42 or the second sheet discharge roller pair 207 and stacked on the first tray 49 or the second tray 71 falls within a predetermined range, and the first tray 49 or the second tray 71 is lifted when the sheets stacked on the first tray 49 or the second tray 71 are removed.
In addition, the pair of aligning plates 401 and 402 that perform alignment in the sheet width direction intersecting the sheet discharge direction and the paddle 275 that performs alignment in the sheet discharge direction are disposed above the first tray 49. The pair of aligning plates 401 and 402 are movable in the up-down direction and movable in the width direction. That is, the pair of aligning plates 401 and 402 can be lifted and lowered to a first position where the uppermost sheet on the first tray 49 can be aligned and a second position that is higher than the first position and does not interfere with a sheet discharged from the sheet discharge roller pair 42 by the jogger lifting and lowering motor MT19 serving as an alignment member lifting and lowering unit. At least one of the pair of aligning plates 401 and 402 is movable to an alignment position where the sheet bundle is aligned in the width direction and to a position farther away from the edge end of the sheet bundle in the width direction than the alignment position. Specifically, the pair of aligning plates 401 and 402 can be moved by the jogger 1 moving motor MT20 and the jogger 2 moving motor MT21 serving as alignment member moving units to an alignment position where the uppermost sheet is aligned in the width direction and to a position farther away from the uppermost sheet in the width direction than the alignment position. Note that the position farther away from the uppermost sheet in the width direction than the alignment position is, for example, a sheet reception position, which will be described below.
A recess 49b, into which the pair of aligning plates 401 and 402 can enter when lowered, is formed on the stacking surface 49a of the first tray 49.
On the other hand, the paddle 275 is movable in the up-down direction, and is rotatable to convey a sheet on the first tray 49 in a direction opposite to the discharge direction. That is, the paddle 275 is movable to a conveyance position where the paddle 275 contacts a sheet on the first tray 49 and conveys the sheet upstream in the sheet discharge direction and an upper position where the paddle 275 is retracted upward from the conveyance position.
Next, configurations of the pair of aligning plates 401 and 402 will be described with reference to
Each of the pair of aligning plates 401 and 402 has an alignment surface 4001 serving as an alignment portion, a guide surface 4002 as a permitting portion (guide portion), and a sheet receiving surface 4003 as an inclination portion (upstream guide portion). Note that the aligning plates 401 and 402 have the same basic configuration except that the alignment surfaces 4001 for aligning a sheet are arranged to face each other, and thus the aligning plates denoted by representative reference numeral 401 will be described below
The alignment surfaces 4001 are surfaces that abuts against both edge ends in the width direction of a sheet bundle when the sheet bundle is aligned, and may be flat surfaces or surfaces having some irregularities. Each of the aligning plates 401 and 402 has a first portion 4001a located on the downstream side and a second portion 4001b located upstream of the first portion 4001a in a direction in which a sheet is discharged by the sheet discharge roller pair 42. A width in the up-down direction (a length in the vertical direction) of the first portion 4001a is larger than a width in the up-down direction of the second portion 4001b. An upper edge portion of the first portion 4001a and an upper edge portion of the second portion 4001b are positioned on the same straight line and are continuous with the guide surface 4002, which will be described below.
On the other hand, a lower edge of the first portion 4001a is inclined such that some part on the downstream side in the discharge direction is directed upward toward the downstream side, and the other part on the upstream side in the discharge direction is directed upward toward the upstream side. A lower edge of the second portion 4001b is continuous with the lower edge of the upstream part of the first portion 4001a, and is further inclined upward toward the upstream side in the discharge direction at an inclination angle larger than that of the upstream part of the first portion 4001a. As a result, the width in the up-down direction of the first portion 4001a of the alignment surface 4001 is larger than the width in the up-down direction of the second portion 4001b of the alignment surface 4001. Then, the first portion 4001a of the alignment surface 4001 can abut on or face an edge end in the width direction of a sheet on the first tray 49 in a wide range in the up-down direction. Note that the recess 49b of the first tray 49 described above has a shape corresponding to the shape of the lower edge portions of the aligning plates 401 and 402 so that the lower edge portions can enter the recess 49b.
The guide surface 4002 permits a next sheet to be temporarily received thereon above the first tray 49 when the pair of aligning plates 401 and 402 align a sheet bundle. Here, the expression “when the sheet bundle is aligned” means a series of operations in which the pair of aligning plates 401 and 402 moves from the reception position to the alignment position and returns to the reception position. In addition, the expression “temporary reception of a next sheet” means temporarily guiding a next sheet in the same job as the sheet bundle aligned on the first tray 49 or a next sheet following a current sheet bundle in a job consecutive to a job for the current sheet bundle above the first tray 49 until the alignment of the sheet bundle is completed. In a case where the “next sheet” is a next sheet in the same job as the sheet bundle aligned on the first tray 49, for example, in a job in which 10 sheets are set as one sheet bundle, the “next sheet” refers to any of the second to tenth sheets. Further, in a case where the “next sheet” is a next sheet following the current sheet bundle in a job consecutive to the job for the sheet bundle aligned on the first tray 49, for example, when two jobs each including 10 sheets as one sheet bundle are consecutive, the “next sheet” refers to the first sheet of the second sheet bundle (the eleventh sheet when counted from the job for the first sheet bundle). Then, the pair of aligning plates 401 and 402 aligns the next sheet temporarily received by the guide surface 4002 together with the sheet bundle aligned when the next sheet is temporarily received.
Specifically, the guide surface 4002 is a surface that guides a next sheet upward from the alignment surface 4001 on which the uppermost sheet is aligned when the next sheet is discharged from the sheet discharge roller pair 42 in a state where the next sheet is shifted in the width direction with respect to the uppermost sheet while the pair of aligning plates 401 and 402 align the uppermost sheet at the alignment position. The guide surface 4002 is formed on each of the upper surfaces of the pair of aligning plates 401 and 402. As described above, the stacking surface 49a of the first tray 49 is inclined at the first angle with respect to the horizontal direction to be upward toward the downstream side in the discharge direction. On the other hand, at the alignment position, the guide surface 4002 is inclined upward at the second angle larger than the first angle with respect to the horizontal direction toward the downstream side in the discharge direction.
In addition, as illustrated in
As described above, in the present embodiment, the angle of the guide surface 4002 with respect to the horizontal direction is larger than the angle of the stacking surface 49a with respect to the horizontal direction. Therefore, the width in the vertical direction of the first portion 4001a of the alignment surface 4001 can be secured, and the position of the upstream edge portion of the guide surface 4002 can be easily positioned below the nip line N2, more preferably below the nip point N1. As a result, a sheet can be aligned in a wide range of the alignment surface 4001, and the discharged sheet can be hardly caught by the upstream edge portion of the guide surface 4002. If the sheet can be aligned in a wide range of the alignment surface 4001, the number of sheets stacked on the first tray 49 that can be aligned by the aligning plates 401 and 402 can be increased.
The sheet receiving surface 4003 serving as an inclination portion is a surface provided at the upstream edge portion of the guide surface 4002 in the discharge direction in a state where the pair of aligning plates 401 and 402 are at the alignment position, and inclined to be directed inward in the width direction, where the uppermost sheet is positioned, toward the downstream side in the discharge direction to guide a next sheet discharged from the sheet discharge roller pair 42 to the guide surface 4002. That is, the sheet receiving surface 4003 has a role of receiving a leading edge of a sheet discharged from the sheet discharge roller pair 42 on the guide surface 4002 so as to be scooped up in a state where the pair of aligning plates 401 and 402 are at the alignment position.
In a state where the pair of aligning plates 401 and 402 are at the alignment position, such a sheet receiving surface 4003 is inclined to be directed downward toward the inside in the width direction. As a result, for example, even when a sheet having weak stiffness is discharged in a drooping state from the sheet discharge roller pair 42, a leading edge of the sheet is easily scooped up by the sheet receiving surface 4003. Note that the sheet receiving surface 4003 may be omitted, for example, in a case where the upstream edge portion of the guide surface 4002 is positioned to be close to the sheet discharge roller pair 42 and the upstream edge portion of the guide surface 4002 is positioned to be sufficiently lower than the nip point N1, so that a sheet discharged from the sheet discharge roller pair 42 easily passes on the guide surface 4002.
In the present embodiment, since the guide surfaces 4002 are provided in the pair of aligning plates 401 and 402 as described above, even though a next sheet is discharged in a state where the pair of aligning plates 401 and 402 align the sheets, the next sheet can be guided by the guide surfaces 4002 as will be described below. If such a guide surface 4002 is not provided, when a next sheet is discharged in a state where the aligning plates 401 and 402 are at the alignment position, the next sheet may collide with any of the aligning plates, causing the sheet to lose its posture or become bent. In particular, as will be described below, in a case where the interval at which sheets are discharged consecutively is reduced in order to increase productivity, the sheets are discharged in a state where the aligning plates 401 and 402 are at the alignment position. In the present embodiment, since the guide surface 4002 is provided to guide a sheet discharged from the sheet discharge roller pair 42 in a state where the aligning plates 401 and 402 are at the alignment position as described above, it is possible to reduce the collision of the sheet with any of the aligning plates. The operation of the aligning plates 401 and 402 at the time of discharging a sheet will be described below.
Next, a configuration for driving the pair of aligning plates 401 and 402 and the paddle 275 will be described with reference to
The front-side aligning plate 401 (the upper right side in
The swing shaft 405 is disposed above the sheet discharge roller pair 42 across the width direction. The position of the swing shaft 405 in the discharge direction is as close as possible to the sheet discharge roller pair 42, and in the present embodiment, the swing shaft is positioned further upstream than an upstream edge of the recess 49b of the first tray 49 in the discharge direction. Since the pair of swing arms 403 and 404 are driven by the jogger lifting and lowering motor MT19 serving as an alignment member lifting and lowering unit, the swing arms 403 and 404 can swing in the up-down direction about the swing shaft 405 disposed above the sheet discharge roller pair 42. Specifically, the drive of the jogger lifting and lowering motor MT19 is transmitted to the pair of swing arms 403 and 407 via the aligning plate lifting and lowering mechanism 430, so that the pair of swing arms 403 and 407 swing in the up-down direction about the swing shaft 405. The pair of aligning plates 401 and 402 are disposed inside the pair of swing arms 403 and 404 on the side where the uppermost sheet is positioned in the width direction, and is pivotably connected to the pair of swing arms 403 and 404.
The pair of swing arms 403 and 404 are supported to be rotatable with respect to the swing shaft 405 and to be relatively movable along an axial direction. Therefore, the swing arms 403 and 404 do not swing when only the swing shaft 405 rotates. Therefore, the sheet stacking apparatus 400 includes an aligning plate lifting and lowering mechanism 430 serving as a drive transmission unit. The aligning plate lifting and lowering mechanism 430 transmits the drive of the jogger lifting and lowering motor MT19 to the swing arms 403 and 404 to swing the swing arms 403 and 404 about the swing shaft 405, and includes a transmission mechanism 431, a parallel shaft 432, a connecting portion 433, and an engagement hole 434 serving as an engaging portion.
The transmission mechanism 431 includes a gear 431a to which drive is transmitted from a drive gear of the jogger lifting and lowering motor MT19, a pulley (not illustrated) that rotates integrally with the gear 431a, a pulley 431b fixed to the swing shaft 405, and a belt 431c stretched between the pulley on the gear 431a side and the pulley 431b. The driving force of the jogger lifting and lowering motor MT19 is transmitted to the swing shaft 405 via the gear 431a, the pulley (not illustrated), the belt 431c, and the pulley 432b.
The parallel shaft 432 is provided in parallel with the swing shaft 405, and is connected to the swing shaft 405 by the connecting portion 433. In the present embodiment, parallel shafts 432 are arranged in front of and behind the paddle 275, and each of the parallel shafts 432 is connected to the swing shaft 405 by the connecting portion 433. Therefore, the pair of parallel shafts 432 pivot about the swing shaft 405. The engagement holes 434 are provided in the pair of swing arms 403 and 404, respectively, and engaged with the parallel shafts 432 to pivot the pair of swing arms 403 and 404 together with the parallel shafts 432 when the parallel shafts 432 pivot about the swing shaft 405. As a result, the pair of aligning plates 401 and 402 supported by the pair of swing arms 403 and 404, respectively, move in the up-down direction.
Such engagement holes 434 are through holes through which the parallel shafts 432 can be inserted, and through which the parallel shafts 432 and the swing arms 403 and 404 can relatively move within a predetermined range in a rotation direction about the swing shaft 405. That is, the engagement hole 434 is a through hole having a shape curved in a direction along an arc centered on the swing shaft 405, and the inserted parallel shaft 432 is relatively movable within the predetermined range in a direction along the arc. The parallel shafts 432 inserted through the engagement holes 434 are engaged with upstream edge portions in the discharge direction of the engagement holes 434 by the weight of the swing arms 403 and 404 at the home position (second position) illustrated in
However, for example, when the pair of aligning plates 401 and 402 comes into contact with a sheet or a sheet bundle on the first tray 49 before reaching the first position while being lowered from the second position to the first position, the pair of aligning plates 401 and 402 and the pair of swing arms 403 and 404 are lifted higher than when they are at the first position. At this time, if the parallel shafts 432 and the pair of swing arms 403 and 404 are connected in such a manner as not to be movable relative to each other in a pivoting direction, the jogger lifting and lowering motor MT19 is driven as much as the amount of movement until the pair of aligning plates 401 and 402 reach the first position, and thus, there is a possibility that the sheet on the first tray 49 may be damaged by the pair of aligning plates 401 and 402. In contrast, by making the parallel shaft 432 and the engagement hole 434 relatively movable within the predetermined range in the pivoting direction as described above, even if the pair of aligning plates 401 and 402 abut on the sheet, the parallel shaft 432 moves in the engagement hole 434, so that the amount of movement of the pair of aligning plates 401 and 402 as described above can be absorbed. As a result, it is possible to suppress damage to the sheet on the first tray 49.
The paddle 275 is rotatably supported at a leading edge portion of the paddle arm 276. The paddle arm 276 is rotatably supported with respect to the swing shaft 405. Therefore, the paddle arm 276 does not swing when only the swing shaft 405 rotates. Therefore, the sheet stacking apparatus 400 includes a paddle lifting and lowering mechanism 440. The paddle lifting and lowering mechanism 440 transmits the drive of the paddle lifting and lowering motor MT22 to swing the paddle arm 276 about the swing shaft 405, and includes a gear 442 to which drive is transmitted from a drive gear 441 of the paddle lifting and lowering motor MT22, a pulley 443 that rotates integrally with the gear 442, a pulley 444 rotatably supported by the swing shaft 405 and fixed to the paddle arm 276, and a belt 445 stretched between the pulley 443 and the pulley 444. The driving force of the paddle lifting and lowering motor MT22 is transmitted to the paddle arm 276 via the drive gear 441, the gear 442, the pulley 443, the belt 445, and the pulley 444. When the paddle arm 276 swings about the swing shaft 405, the paddle 275 supported at the leading edge portion of the paddle arm 276 moves in the up-down direction between the conveyance position and the upper position described above.
The paddle 275 is rotationally driven by the discharge roller 1 motor MT6 (not illustrated in
The first transmission unit 451, the second transmission unit 453, and the third transmission unit 454 are constituted by various power transmission members such as a gear, a pulley, and a belt. The first transmission unit 451 is disposed on the rear side of the swing shaft 405 in the width direction, and the second transmission unit 453 and the third transmission unit 454 are disposed between the pair of aligning plates 401 and 402 in the width direction. The transmission shaft 452 is disposed above the swing shaft 405 in parallel with the swing shaft 405, and connects the first transmission unit 451 and the second transmission unit 453 to transmit the drive. An output pulley 453a for outputting the drive input to the second transmission unit 453 and an input pulley 454a for inputting the drive to the third transmission unit 454 are integrated, and a belt 454c is stretched between the input pulley 454a of the third transmission unit 454 and a pulley 454b fixed to a rotation shaft of the paddle 275. The output pulley 453a and the input pulley 454a are supported to be relatively rotatable with respect to the swing shaft 405. With this configuration, the driving force of the discharge roller 1 motor MT6 input from the rear side to the first transmission unit 451 is transmitted to the paddle 275 via the transmission shaft 452, the second transmission unit 453, and the third transmission unit 454, and the paddle 275 rotates.
As described above, the front-side aligning plate 401 is moved in the width direction by the front-side moving mechanism 410, and the rear-side aligning plate 402 is moved in the width direction by the rear-side moving mechanism 420. In addition, the pair of aligning plates 401 and 402 are supported to be movable in the width direction with respect to the swing shaft 405 via the pair of swing arms 403 and 404. The front-side moving mechanism 410 and the rear-side moving mechanism 420 have the same configuration. The front-side moving mechanism 410 includes a gear 412 to which the drive is transmitted from a drive gear 411 of the jogger 1 moving motor MT20, a pulley 413 that rotates integrally with the gear 412, a pair of pulleys 414 disposed outside the movable range in the width direction of the aligning plate 401 in a direction parallel to the swing shaft 405, a belt 415 stretched between the pulley 413 and the pair of pulleys 414, and a tension pulley 416 that applies tension to the belt 415. A portion of the belt 415 stretched between the pair of pulleys 414 is parallel to the swing shaft 405, and a slide member 435 is fixed to a part of the portion of the belt 415 parallel to the swing shaft 405. The slide member 435 is movable in the width direction together with the swing arm 403, but is connected to be relatively rotatable with respect to the swing arm 403 so as not to pivot even when the swing arm 403 pivots about the swing shaft 405. Therefore, the portion of the belt 415 parallel to the swing shaft 405 is moved in parallel to the swing shaft 405 by rotationally driving the jogger 1 moving motor MT20, and the swing arm 403 fixed to this portion moves in the width direction along the swing shaft 405. Since the aligning plate 401 is supported by the swing arm 403, the aligning plate 401 moves in the width direction together with the swing arm 403.
Similarly, the rear-side moving mechanism 420 includes a gear 422 to which the drive is transmitted from a drive gear 421 of the jogger 2 moving motor MT21, a pulley 423 that rotates integrally with the gear 422, a pair of pulleys 424 disposed outside the movable range in the width direction of the aligning plate 402 in a direction parallel to the swing shaft 405, a belt 425 stretched between the pulley 423 and the pair of pulleys 424, and a tension pulley 426 that applies tension to the belt 425. A portion of the belt 425 stretched between the pair of pulleys 424 is parallel to the swing shaft 405, and a slide member 435 is fixed to a part of the portion of the belt 425 parallel to the swing shaft 405. The slide member 435 is movable in the width direction together with the swing arm 404, but is connected to be relatively rotatable with respect to the swing arm 404 so as not to pivot even when the swing arm 404 pivots about the swing shaft 405. Therefore, the portion of the belt 425 parallel to the swing shaft 405 is moved in parallel to the swing shaft 405 by rotationally driving the jogger 2 moving motor MT21, and the swing arm 404 fixed to this portion moves in the width direction along the swing shaft 405. Since the aligning plate 402 is supported by the swing arm 404, the aligning plate 402 moves in the width direction together with the swing arm 404.
With such a configuration, the pair of aligning plates 401 and 402 are independently movable in the width direction by driving the jogger 1 moving motor MT20 and the jogger 2 moving motor MT21, respectively. Note that the pair of aligning plates 401 and 402 may be moved in the width direction in synchronization by one motor. The parallel shafts 432 for moving the pair of aligning plates 401 and 402 in the up-down direction are disposed in parallel with the swing shaft 405, and the engagement holes 434 provided in the swing arms 403 and 404 are through holes through which the parallel shafts 432 are inserted. Therefore, when the pair of aligning plates 401 and 402 moves, the pair of aligning plates 401 and 402 are allowed to move in the width direction with the engagement holes 434 engaged with the parallel shafts 432. In addition, since the engagement holes 434 and the parallel shafts 432 are engaged with each other regardless of the positions of the pair of aligning plates 401 and 402 in the width direction, the pair of aligning plates 401 and 402 can move in the up-down direction at any positions in the width direction.
Next, the jogger lifting and lowering HP detection sensor SN6, the jogger 1HP detection sensor SN7, the jogger 2HP detection sensor SN8, and the paddle lifting and lowering HP detection sensor SN9 for detecting positions of the aligning plates 401 and 402 in the width direction and in the lifting and lowering direction and a position of the paddle 275 in the lifting and lowering direction will be described with reference to
First, a flag 406 is fixed to the swing shaft 405 or the pulley 431b. The jogger lifting and lowering HP detection sensor SN6 is provided at a position where the flag 406 passes. When the jogger lifting and lowering motor MT19 is rotationally driven to lift and lower the pair of aligning plates 401 and 402, this driving force is transmitted to the swing shaft 405 via the aligning plate lifting and lowering mechanism 430, and the flag 406 also rotates together with the swing shaft 405. In
When the pair of aligning plates 401 and 402 starts to be lowered from the second position, the flag 406 enters the jogger lifting and lowering HP detection sensor SN6, and the sensor becomes turned on. Further, even when the pair of aligning plates 401 and 402 are lowered to reach the first position illustrated in
Next, a flag 417 is fixed to the slide member 435 fixed to the portion stretched between the pair of pulleys 414 of the belt 415 for moving the front-side aligning plate 401 in the width direction, and a flag 427 is fixed to the slide member 435 fixed to the portion stretched between the pair of pulleys 424 of the belt 425 for moving the rear-side aligning plate 402 in the width direction. The jogger 1HP detection sensor SN7 and the jogger 2HP detection sensor SN8 are provided at positions where the flags 417 and 427 pass, respectively. When the jogger 1 moving motor MT20 is rotationally driven to move the front-side aligning plate 401 in the width direction, this driving force is transmitted to the swing arm 403 via the front-side moving mechanism 410. At this time, since the portion stretched between the pair of pulleys 414 of the belt 415 of the front-side moving mechanism 410 moves in the width direction, the flag 417 fixed to this portion moves in the width direction together with the swing arm 403 and the aligning plate 401 on the front side. Similarly, the rear-side flag 427 moves in the width direction together with the swing arm 404 and the aligning plate 402 on the rear side.
Next, a flag 277 is provided at a portion of the paddle arm 276 rotatably supported by the swing shaft 405. The paddle lifting and lowering HP detection sensor SN9 is provided at a position where the flag 277 passes. When the paddle lifting and lowering motor MT22 is rotationally driven to lift and lower the paddle 275, this driving force is transmitted to the paddle arm 276 via the paddle lifting and lowering mechanism 440, and the flag 277 swings about the swing shaft 405 together with the paddle arm 276. In
When the paddle 275 starts to be lowered from the upper position, the flag 277 is removed from the paddle lifting and lowering HP detection sensor SN9, and the sensor becomes turned off. Further, the paddle 275 is lowered in a state where the sensor remains turned off, and reaches the conveyance position illustrated in
Next, interlocking mechanisms 460 that change the angle of the pair of aligning plates 401 and 402 in conjunction with the swinging of the pair of swing arms 403 and 404 when the pair of swing arms 403 and 404 swing will be described with reference to
As described above, the swing arms 403 and 404 are swung in the up-down direction about the swing shaft 405 by the jogger lifting and lowering motor MT19 via the aligning plate lifting and lowering mechanism 430. The interlocking mechanisms 460 change the angle θ formed by the first virtual line α1 and the second virtual line α2 in conjunction with the swing operation of the swing arms 403 and 404 about the swing shaft 405. The interlocking mechanisms 460 will be described in detail. The interlocking mechanisms 460 are disposed inside the swing arms 403 and 404, respectively, to cause the aligning plates 401 and 402 to pivot with respect to the leading edge portions of the swing arms 403 and 404 in conjunction with the swing operation of the swing arms 403 and 404, respectively. Since the interlocking mechanisms 460 for pivoting the aligning plates 401 and 402 have the same configuration, the interlocking mechanism 460 for pivoting the aligning plate 402 in conjunction with the swing operation of the swing arm 404 will be described as a representative with reference to
The interlocking mechanism 460 includes a toothed pulley 461 serving as a first toothed pulley, a toothed pulley 462 serving as a second toothed pulley, and a toothed belt 463. The toothed pulley 461 is supported to be rotatable with respect to the swing shaft 405, and its phase in the rotation direction around the swing shaft 405 does not change regardless of the swing operation of the swing arm 404. In the present embodiment, the toothed pulley 461 is fixed to the slide member 435. The toothed pulley 462 is fixed to the aligning plate 402, and is rotatable together with the aligning plate 402 about the pivot shaft 465. The toothed belt 463 is stretched between the toothed pulley 461 and the toothed pulley 462. Each of the toothed pulleys 461 and 462 has a plurality of teeth formed on an outer circumferential surface thereof. The toothed belt 463 has a plurality of teeth formed on an inner circumferential surface thereof to mesh with a plurality of teeth formed on the toothed pulleys 461 and 462.
In the present embodiment, a spring 464 is provided as a tension applying portion that applies tension to the toothed belt 463. The spring 464 connects a first portion 463a and a second portion 463b of the toothed belt 463 in a state where a portion between the first portion 463a and the second portion 463b is bent. That is, in a state where the toothed belt 463 between the first portion 463a and the second portion 463b is bent, one edge portion of the spring 464 is fixed to the first portion 463a by a fixing portion 464a, and the other edge portion of the spring 464 is fixed to the second portion 463b by a fixing portion 464b. As a result, a tensile force of the spring 464 acts between the first portion 463a and the second portion 463b, and tension can be applied to the toothed belt 463.
If tension is not applied to the toothed belt 463, the toothed belt 463 may be excessively tightened or loosened due to tolerance between the toothed pulleys 461 and 462 and the toothed belt 463. If the toothed belt 463 is too tight, this causes a swing load on the swing arm 404. On the other hand, if the toothed belt 463 is loose, the rotation position of the aligning plate 402 about the pivot shaft 465 cannot be appropriately determined. In other words, the aligning plate 402 cannot be brought into an appropriate posture. In particular, the posture of the aligning plate 402 is determined in a state where the lower portion of the toothed belt 463 stretched by the toothed pulleys 461 and 462 is tensioned. Therefore, if the lower portion of the toothed belt 463 is bent, the aligning plate 402 takes a posture in which the upstream edge is lowered with respect to the desired posture. In order to apply tension to the toothed belt 463, for example, a tensioner that biases a part of the toothed belt 463 outward or inward may be provided, but in this case, the apparatus becomes large. For this reason, in the present embodiment, as described above, tension is applied to the toothed belt 463 by providing the spring 464 in a state where a part of the toothed belt 463 is bent.
As described above, since the toothed pulley 462 is fixed to the aligning plate 402, the aligning plate 402 also rotates about the pivot shaft 465 together with the toothed pulley 462 as the swing arm 404 swings downward. That is, the position where the plurality of teeth on the inner circumferential surface of the toothed belt 463 mesh with the plurality of teeth on the outer circumferential surface of the toothed pulley 461 changes, and the toothed belt 463 rotates in a direction indicated by an arrow 463c in
The toothed pulleys 461 and 462 have the same number of teeth, but may have different numbers of teeth. As a result, the ratio of the angle between the aligning plate 402 and the swing arm 404 (the angle θ formed by the first virtual line α1 and the second virtual line α2) to the swing amount of the swing arm 404 can be changed. For example, the variation amount of the angle θ with respect to the swing amount of the swing arm 404 increases by reducing the number of teeth of the toothed pulley 462 with respect to the number of teeth of the toothed pulley 461, and the variation amount of the angle θ with respect to the swing amount of the swing arm 404 decreases by increasing the number of teeth of the toothed pulley 462 with respect to the number of teeth of the toothed pulley 461.
In the present embodiment, the aligning plate 402 is movable between the first position and the second position while the posture of the aligning plate 402 is substantially maintained by the interlocking mechanism 460 as described above. Therefore, as will be described in detail below, the angle θ formed by the first virtual line α1 and the second virtual line α2 is smaller at the second position illustrated in
For example, if the pair of aligning plates 401 and 402 extend downstream of the pivot shaft 465 in the discharge direction, and the angle of the pair of aligning plates 401 and 402 with respect to the pair of swing arms 403 and 404 at the first position is the same as that at the second position, when the pair of aligning plates 401 and 402 are lifted to the second position, the aligning plates 401 and 402 are in a posture protruding to a position above the swing arms 403 and 404. In this case, a large space is required above the first tray 49 in order to secure a space for the aligning plates 401 and 402 at the second position. Therefore, the second tray 71 located above the first tray 49 cannot be lowered sufficiently, and the number of sheets stacked on the second tray 71 decreases.
In contrast, in the present embodiment, the pair of aligning plates 401 and 402 are movable between the first position and the second position while substantially maintaining the posture extending upstream of the pivot shaft 465 in the discharge direction with respect to the pair of swing arms 403 and 404. Therefore, even when the aligning plates 401 and 402 move to the second position, the aligning plates 401 and 402 do not protrude into a space above the swing arms 403 and 404, or even if the aligning plates 401 and 402 protrude, the amount of protrusion is small. Therefore, it is possible to easily secure the amount in which the second tray 71 located above the first tray 49 can be lowered, and it is possible to secure the number of sheets to be stacked on the second tray 71.
In the above-described example, the interlocking mechanism 460 includes toothed pulleys and a toothed belt, but they may be constituted by a plurality of gears. That is, the interlocking mechanism 460 may have any configuration as long as the aligning plates 401 and 402 can be pivoted about the pivot shaft 465 in conjunction with the swing operation of the swing arms 403 and 404, such that the postures of the aligning plates 401 and 402 are maintained even though the swing arms 403 and 404 swing in the up-down direction. If an interlocking mechanism is constituted by toothless pulleys and a toothless belt, the pulleys and the belt slip, which makes it difficult to move the aligning plates 401 and 402 in the up-down direction while maintaining their postures. Therefore, as in the present embodiment, the interlocking mechanism 460 is preferably constituted by toothed pulleys and a belt, or constituted by a plurality of gears meshing with each other.
Here, in the present embodiment, the sheet stacking apparatus 400 can execute a job of forming a sheet bundle at the same position in the sheet width direction on the first tray 49 by repeating aligning sheets one by one using the pair of aligning plates 401 and 402 multiple times. As such a job, there is a shift discharge mode or a straight discharge mode, which will be described below. First, the shift discharge mode will be described in which sheets are moved (shifted) in the width direction and discharged onto the first tray 49 without being subjected to binding processing, forming a sheet bundle made up of a plurality of unbound sheets. In the shift discharge mode, for example, as illustrated in
The stacker control unit 330 can execute the shift discharge mode, and operates the pair of aligning plates 401 and 402 as follows when the shift discharge mode is executed. First, a case will be described in which a job of stacking a second sheet bundle on the first tray 49 with a shift to one side in the width direction with respect to a first sheet bundle made up of a plurality of sheets stacked on the first tray 49 is executed. In this case, after aligning the first sheet bundle stacked on the first tray 49 at the first position, the pair of aligning plates 401 and 402 are lifted from the first position to the second position. Next, after a leading edge of a first sheet of the second sheet bundle subsequent to the first sheet bundle is discharged from the sheet discharge roller pair 42, the pair of aligning plates 401 and 402 are lowered from the second position to the first position in a state where the pair of aligning plates 401 and 402 are shifted to one side from the position where the first sheet bundle is aligned, and align sheets included in the second sheet bundle.
Hereinafter, discharge operations will be described in order, starting from an operation of discharging a first sheet S11 of the first sheet bundle. Here, a case will be described in which the first sheet bundle is stacked on the first tray 49 while being shifted to the front side, and the subsequent second sheet bundle is stacked on the first sheet bundle while being shifted to the rear side. As illustrated in
At this time, the pair of aligning plates 270 serving as shift members that align or shift a sheet on the processing tray 37 are also shifted to the front side from the center reference position in the width direction. That is, when the pair of aligning plates 401 and 402 are positioned at a first reception position for receiving a sheet at a predetermined position of the first tray 49, the pair of aligning plates 270 are positioned at a first width-direction position. In addition, when the pair of aligning plates 401 and 402 are positioned at a second reception position for receiving a sheet at a position shifted to one side (here, the front side) in the width direction from the predetermined position of the first tray 49, the pair of aligning plates 270 are positioned at a second width-direction position shifted to one side (here, the front side) in the width direction from the first width-direction position.
Here, the pair of aligning plates 270 have guide surfaces serving as a shift member-side guide portion that guide a sheet conveyed toward the sheet discharge roller pair 42 rather than being placed on the processing tray 37. The guide surfaces 270a are formed downstream of the pre-processing roller 36 in the conveyance direction on the upper surfaces of the pair of aligning plates 270, and guide a sheet having passed through the pre-processing roller 36 to the sheet discharge roller pair 42. In the state illustrated in
Note that the front side is the lower side in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
During the alignment of the sheet S11, the paddle 275 is lifted to the upper position. The timing at which the paddle 275 is lifted is before the aligning plate 401 reaches the alignment position. In the present embodiment, the aligning plate 401 reaches the alignment position after the paddle 275 moves away from the upper surface of the sheet. The timing at which the paddle 275 starts to be lifted from the conveyance position and the timing at which either or both of the aligning plates 401 and 402 start to move from the reception position to the alignment position are after a predetermined time has elapsed since the trailing edge of the sheet passes through the sheet edge detection sensor SN3.
During the alignment of the first sheet S11 by the pair of aligning plates 401 and 402, the second sheet S12 starts to be discharged from the sheet discharge roller pair 42. At this time, the second sheet S12 may be discharged with a shift in the width direction with respect to the sheet S11 that is being aligned. For example, in
In the apparatus of the present embodiment, the tolerance of the amount of shift by the second conveyance roller 202 and the third conveyance roller 203 is 5 mm. The front-side aligning plate 401 that is performing alignment is moved by 10 mm toward the rear side from the reception position for the sheet S1, and the aligning plate 401 located at the reception position is at a position that 5 mm away toward the front side from the edge portion of the sheet in the width direction at the reference position. Therefore, the position of the front-side aligning plate 401 located at the alignment position is a position shifted by 5 mm on the rear side from the edge portion of the sheet in the width direction at the reference position. Therefore, in a case where a sheet is shifted to the front side by 5 mm, which is the maximum amount of tolerance, from the edge portion of the sheet in the width direction at the reference position by the second conveyance roller 202 and the third conveyance roller 203, and the sheet is discharged from the sheet discharge roller pair 42 in this state, the sheet may be discharged with a shift to the front side by a maximum of 10 mm with respect to the alignment surface 4001 of the front-side aligning plate 401.
Therefore, in the present embodiment, the thickness of the guide surface 4002 in the width direction is set to 10 mm or more, for example, 11 mm. As a result, even if the second sheet S12 is discharged from the sheet discharge roller pair 42 with a shift of 5 mm, which is a tolerance of the amount of shift by the second conveyance roller 202 and the third conveyance roller 203, the sheet S12 can be guided by the guide surface 4002.
Next, as illustrated in
The above-described operations are performed on succeeding sheets included in the first sheet bundle, and the first sheet bundle is stacked on the first tray 49 as illustrated in
Since the interval between the last sheet of the first sheet bundle and the first sheet S21 of the second sheet bundle is the same as the interval between the plurality of sheets of the first sheet bundle, even if the pair of aligning plates 401 and 402 are stared to be lifted within the interval between the last sheet of the first sheet bundle and the first sheet S21 of the second sheet bundle, the operation of lifting the pair of aligning plates 401 and 402 may not complete before the operation of discharging the first sheet S21 is started and the sheet S21 may come into contact with the aligning plates 401 and 402. Therefore, in the present embodiment, as illustrated in
That is, in a case where the second sheet bundle including the first sheet S21 (first sheet) and the second sheet S22 (second sheet) is stacked on the first tray 49 while being shifted to one side (here, the rear side) in the width direction with respect to the first sheet bundle stacked on the first tray 49, the stacker control unit 330 causes the sheet S21 to temporarily stand on the buffer path 39. Then, the sheet S22 is conveyed, together with the sheet S21, toward the sheet discharge roller pair 42 by the third conveyance roller 203 serving as a buffer conveyance unit and the pre-processing roller 36. Specifically, the sheet S21 that stands by on the buffer path 39 is conveyed toward the straight path 28 by the conveyance roller 208 and joined with the next sheet S22 conveyed in the straight path 28. Then, the sheet S21 and the sheet S22 are conveyed toward the sheet discharge roller pair 42 in an overlapping state by the third conveyance roller 203 and the pre-processing roller 36.
In the present embodiment, the conveyance roller 208 is also a shift roller capable of moving a sheet in the width direction. Therefore, the sheet S21 can be shifted to the front side or to the rear side in a state where the first sheet S21 is nipped by the third conveyance roller 203 and the conveyance roller 208. Therefore, in a state where the third conveyance roller 203 nips the sheets S21 and S22, the conveyance roller 208 nips the sheet S21, and the second conveyance roller 202 nips the sheet S22, the second conveyance roller 202, the third conveyance roller 203, and the conveyance roller 208 are moved in the same direction, so that the sheet S21 and the sheet S22 can be shifted in an overlapping state. In
As illustrated in
Here, in a case where the angle θ formed by the first virtual line α1 and the second virtual line α2 at the first position is the same as that at the second position, unless the amount by which the swing arms 403 and 404 swing is large, the aligning plates 401 and 402 are not sufficiently away from the first position, and thus it takes time for the aligning plates 401 and 402 to reach the second position. In contrast, in the present embodiment, since the angle θ formed by the first virtual line α1 and the second virtual line α2 is smaller at the second position than at the first position, even if the amount by which the swing arms 403 and 404 swing upward is small, the aligning plates 401 and 402 can be moved to a position sufficiently away from the first position. Therefore, the amount by the swing arms 403 and 404 swing until the aligning plates 401 and 402 are moved from the first position to the second position can be reduced, and the time for lifting the aligning plates 401 and 402 to the second position can be shortened.
In the present embodiment, as described above, the angle θ formed by the first virtual line α1 and the second virtual line α2 at the first position is an acute angle. Therefore, the amount of change in the angle θ for movement from the first position to the second position can be reduced. That is, the amount of swing of the swing arms 403 and 404 to the second position can be reduced. As a result, the time required for lifting the aligning plates 401 and 402 to the second position can be further shortened. In order to make the angle θ an acute angle, it is preferable to make the swing arms 403 and 404 sufficiently long, that is, to increase the distance between the swing shaft 405 and the pivot shaft 465. To this end, it is preferable to make the position of the swing shaft 405 in the discharge direction as close as possible to the sheet discharge roller pair 42. As a result, the aligning plates 401 and 402 can be positioned at the first position even if the angle θ is small.
If the aligning plates 401 and 402 can be lifted from the first position to the second position in a short time in this manner, the aligning plates 401 and 402 can be lifted to the second position in time until the operation of discharging the first sheet S21 of the second sheet bundle only by causing the first sheet S21 to temporarily stand by. That is, if the aligning plates 401 and 402 cannot be lifted from the first position to the second position in a short time, for example, the conveyance of the first sheet S21 of the second sheet bundle may need to be stopped, and the conveyance of the sheet S21 may need to be started after waiting until the aligning plates 401 and 402 are lifted to the second position. In this case, productivity decreases in the shift discharge mode. In contrast, in the present embodiment, since the aligning plates 401 and 402 can be lifted from the first position to the second position in a short time, productivity can be improved.
In the present embodiment, as illustrated in
Next, as illustrated in
Next, as illustrated in
During the alignment of the first and second sheets S21 and S22 by the pair of aligning plates 401 and 402, the third sheet S23 starts to be discharged from the sheet discharge roller pair 42. In this case as well, similarly to the case described with reference to
Next, the straight discharge mode will be described in which sheets are discharged onto the first tray 49 without being shifted and without being subjected to binding processing, forming a sheet bundle made up of a plurality of unbound sheets. In the straight discharge mode, for example, as illustrated in
The stacker control unit 330 can execute the straight discharge mode, and operates the pair of aligning plates 401 and 402 as follows when the straight discharge mode is executed. First, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
When the second sheet S2 is discharged while being shifted in the width direction, a leading edge of the sheet S2 comes into contact with the guide surface 4002 at one of the following timings.
In either case, the sheet S2 is guided to a position above the alignment surface 4001 by any of the guide surfaces 4002 of the aligning plates 401 and 402. That is, when the sheet S2 is shifted to the front side, the sheet S2 is guided by the guide surface 4002 of the front-side aligning plate 401, and when the sheet S2 is shifted to the rear side, the sheet S2 is guided by the guide surface 4002 of the rear-side aligning plate 402.
That is, the guide surface 4002 permits a leading edge of a next sheet to be received in a state where the aligning plates 401 and 402 are at the alignment position or in a state where the aligning plates 401 and 402 are moving from the alignment position to the reception position. In other words, the next sheet is guided by the guide surfaces 4002 when the aligning plates 401 and 402 are at either position (1) or (2) described above and the leading edge of the next sheet reaches a position downstream of the upstream edge portions of the alignment surfaces 4001 of the aligning plates 401 and 402 in the discharge direction (the direction along the nip line N2).
In addition, the leading edge of the next sheet does not reach the upstream edge portions of the alignment surfaces 4001 of the aligning plates 401 and 402 until the aligning plates 401 and 402 move from the reception position to the alignment position to align the first sheet. This is because, if the leading edge of the next sheet reaches an alignment surface area β (
Next, as illustrated in
Similarly to the sheet S2, the sheet S3 is also guided by any of the guide surfaces 4002 of the aligning plates 401 and 402, and is aligned in the width direction by the aligning plates 401 and 402. Such operations are performed up to the last sheet of the sheet bundle. The aligning plates 401 and 402 are returned to the reception position while the last sheet is being discharged. When a trailing edge of the last sheet passes out of the sheet discharge roller pair 42, the last sheet is aligned by moving the aligning plates 401 and 402 to the alignment position, and the job ends. At the end of the job, the pair of aligning plates 401 and 402 are returned to the home position. The positions of the aligning plates 401 and 402 at the end of the job will be described below.
As described above, in the present embodiment, in either the shift discharge mode or the straight discharge mode, even when a plurality of consecutive sheets are discharged onto the first tray 49 at short intervals, the sheets can be aligned by the aligning plates 401 and 402. Therefore, the productivity of the apparatus can be improved.
In the straight discharge mode of the present embodiment, both the aligning plates 401 and 402 are moved from the reception position to the alignment position at the time of aligning a sheet. However, at the time of aligning a sheet, even if the sheet is discharged with a shift toward the aligning plate 401, the aligning plate 401 may be fixed at a position where the sheet is not in contact with the aligning plate 401, only the aligning plate 402 may be moved from the reception position toward the aligning plate 401, so that the discharged sheet is aligned to abut on the aligning plate 401, and the aligning plate 402 may be moved to the reception position. In this case, since a next sheet may hit the aligning plate 402 during an alignment operation, the guide surface 4002 may be provided only on the aligning plate 402.
Next, the positions of the aligning plates 401 and 402 at the end of the job will be described with reference to
Therefore, in the present embodiment, one aligning plate (e.g., the front-side aligning plate 401) of the pair of aligning plates 401 and 402 moves to the other side (e.g., the rear side) in the width direction, rather than toward an edge portion on one side (e.g., an edge portion on the front side) in the width direction, of a sheet S stacked on the first tray 49 after the job of stacking sheets on the first tray 49 ends and the aligning plate is lifted from the first position to the second position. In the present embodiment, the other aligning plate (e.g., the rear-side aligning plate 402) of the pair of aligning plates 401 and 402 also moves to one side (e.g., the front side) in the width direction, rather than an edge portion on the other side (e.g., an edge portion on the rear side) in the width direction, of the sheet S stacked on the first tray 49 after the job ends and the aligning plate is lifted from the first position to the second position. That is, as illustrated in
Note that the positions of the aligning plates 401 and 402 in the width direction at the home position are preferably inside both edge portions in the width direction of a sheet having the minimum size that can be processed by the apparatus. However, in consideration of frequency of use, the positions of the aligning plates 401 and 402 in the width direction at the home position may be determined inside both edge portions in the width direction of a sheet (e.g., an A4-size sheet) larger than the sheet having the minimum size. Further, it is preferable that the positions of the aligning plates 401 and 402 in the width direction at the home position are set to predetermined positions regardless of the size of sheets to be stacked on the first tray 49. In addition, the position at which a sheet serving as a reference is stacked at this time is a position when the sheet is discharged with the center in the width direction as a reference.
Further, in consideration of the case where a sheet is discharged in the shift discharge mode, the positions of the aligning plates 401 and 402 in the width direction at the home position may be set to positions inside both edge portions of the sheet in the width direction even if the sheet is shifted in any direction. That is, in any case, the pair of aligning plates 402 and 401 are positioned inside both edge portions in the width direction of a sheet, such that the position of the rear-side aligning plate 402 is inside an edge portion on the rear side of the sheet when the sheet is stacked on the first tray 49 while being shifted to the front side, and the position of the front-side aligning plate 401 is inside an edge portion on the front side of the sheet when the sheet stacked on the first tray 49 while being shifted to the rear side.
By defining the positions of the aligning plates 401 and 402 in the width direction at the home position in this manner, the aligning plates 401 and 402 are less likely to be an obstacle when the operator takes out the sheet or the sheet bundle stacked on the first tray 49, making it possible to improve easiness in taking out a sheet or a sheet bundle from the first tray 49. In particular, since the aligning plates 401 and 402 on both sides are positioned inside edge portions in the width direction of sheets, when the number of sheets in the sheet bundle is large, it is easy to take out the sheets by gripping the sheets from the front side and the rear side with both hands.
As illustrated in
Also, during a job standby period, the positions of the aligning plates 401 and 402 in the width direction may be set to the positions at the end of the job described above. That is, it is preferable to position the aligning plates 401 and 402 at the home position during the job standby period. The job standby period refers to a standby state in which the apparatus is powered on but the job is not executed. In addition, the job standby period may include a sleep state in which power consumption is lower than that in the standby state.
The pair of aligning plates 401 and 402 described above are connected to the swing arms 403 and 404 via the pivot shaft 465 at the edge portions in the longitudinal direction (a direction extending upstream in the discharge direction from the pivot shaft 465) of the aligning plates 401 and 402. However, the position where the aligning plate is connected to the swing arm is not limited to the edge portion in the longitudinal direction. For example, as illustrated in
The aligning plate 402A (401A) illustrated in
A second embodiment will be described with reference to
As illustrated in
The support member 4020 is driven by a drive source (not illustrated) such as a motor, and is movable in a sliding manner between the permitting position and the retraction position described above. Therefore, the abutment member 271 has an opening portion through which the support member 4020 can pass. The support member 4020 moves between the retraction position inside the apparatus housing 27 (
In the present embodiment, a pair of support members 4020 are provided to correspond to the pair of aligning plates 401 and 402. That is, the pair of support members 4020 are arranged to be spaced apart from each other in the width direction. The positions and lengths of the pair of support members 4020 in the width direction are set to cover the respective movable ranges of the pair of aligning plates 401 and 402. That is, the support member 4020 corresponding to the front-side aligning plate 401 is positioned above the upstream edge portion of the aligning plate 401 in the discharge direction, at the permitting position, and is configured to guide a sheet discharged from the sheet discharge roller pair 42 to a position above the alignment surface 4001 regardless of the position of the aligning plate 401 within the movable range. Similarly, the support member 4020 corresponding to the rear-side aligning plate 402 is positioned above the upstream edge portion of the aligning plate 402 in the discharge direction, at the permitting position, and is configured to guide a sheet discharged from the sheet discharge roller pair 42 to a position above the alignment surface 4001 regardless of the position of the aligning plate 402 within the movable range. Note that one support member 4020 may be used instead of the pair of support members 4020. In this case, one support member 4020 covers the movable ranges of the pair of aligning plates 401 and 402.
Next, the operation of the support member 4020 will be described. The operation of the support member 4020 is the same in both the shift discharge mode and the straight discharge mode. First, as illustrated in
Next, as illustrated in
When the second sheet S2 is discharged in a state whether the second sheet S2 is shifted in the width direction with respect to the sheet S1 that is being aligned, a leading edge of the sheet S2 is guided to upper surfaces 4021 of the support members 4020 as illustrated in
Next, as illustrated in
In the present embodiment as well, similarly to the first embodiment, in either the shift discharge mode or the straight discharge mode, even when a plurality of consecutive sheets are discharged onto the first tray 49 at short intervals, the sheets can be aligned by the aligning plates 401 and 402. Therefore, the productivity of the apparatus can be improved. However, since the guide surfaces 4002 serving as a permitting portion are integrally formed with the pair of aligning plates 401 and 402 in the first embodiment, the first embodiment can achieve lower costs than the present embodiment.
In the above-described embodiments, binding processing is performed as predetermined processing performed by the processing unit. However, the predetermined processing is not limited to the binding processing, and may be folding processing, shifting processing, punching processing, creasing, laminating processing, or the like. In the above-described embodiments, the periphery of the first tray 49 of the sheet processing apparatus B is controlled by the stacker control unit 330 (CPU 331). However, this control may be performed by the control unit 310 (CPU 311) of the image forming apparatus A.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2023-206469, filed on Dec. 6, 2023, Japanese Patent Application No. 2023-206470, filed on Dec. 6, 2023, Japanese Patent Application No. 2023-206471, filed on Dec. 6, 2023, and Japanese Patent Application No. 2024-156720, filed on Sep. 10, 2024, which are hereby incorporated by reference herein in their entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-206469 | Dec 2023 | JP | national |
| 2023-206470 | Dec 2023 | JP | national |
| 2023-206471 | Dec 2023 | JP | national |
| 2024-156720 | Sep 2024 | JP | national |
