Patent Application
20230264920
The present invention relates to a sheet processing device for processing a sheet and an image forming system for forming an image on the sheet.
As an option of an image forming apparatus which is, for example, an electrophotographic multi-function machine, a sheet processing device in which the sheet on which the image is formed in an image forming apparatus main assembly is subjected to processing such as binding processing or sort processing is used. For example, in Japanese Laid-Open Patent Application (JP-A) 2021-095291, a post-processing device in which sheets fed to a processing tray of a sheet processing device are subjected to the binding processing and then are stacked on a discharge tray is disclosed. In this post-processing device, a discharge guide is slid and moved to push out the sheets from the processing tray and the pushed-out sheets are received by a feeding roller pair, and then the sheets are stacked on the discharge tray by rotationally driving a discharging roller pair.
As in the case of the feeding roller pair in a conventional technique, as regards sheet feeding by rollers, there is a possibility that the sheet is obliquely moved by a slip thereof or the like. When the sheets are stacked in a state in which the sheets are obliquely moved, this has the influence on an alignment state of the sheets on the discharge tray. For this reason, it is required that the alignment state of the sheets stacked on the discharge tray is improved by reducing a degree of the oblique movement of the fed sheets.
The present invention has been accomplished in view of these circumstances. A principal object of the present invention is to provide a sheet processing device and an image forming system which are capable of improving an alignment state of recording materials stacked on a discharge tray by reducing a degree of oblique movement of the recording materials fed to the discharge tray.
According to an aspect of the present invention, there is provided a sheet processing device comprising: a stacking member configured to stack a sheet; a discharging member configured to discharge the sheet stacked on the stacking member; a discharging tray on which the sheet discharged by the discharging member is stacked; a pushing-out member configured to push out the sheet from the stacking member toward the discharging member by being moved in a pushing-out direction; and a controller configured to select, on the basis of information of the sheet stacked on the stacking member, whether to move the pushing-out member to which position of a first position and a second position positioned on a side downstream of the first position with respect to the pushing-out direction.
According to another aspect of the present invention, there is provided an image forming system comprising: an image forming apparatus configured to form an image on a sheet; and a sheet processing device according to claim 1, wherein the sheet processing device receives the sheet from the image forming apparatus and subjects the received sheet to predetermined processing.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Parts (a) and (b) of
Parts (a) to (d) of
Parts (a) to (d) of
Parts (a) to (d) of
Parts (a) to (c) of
In the following, embodiments for carrying out the present invention will be described with reference to the drawings.
The original feeding device 3 feeds an original placed on an original tray 18, to image reading portions 16 and 19. Each of the image reading portions 16 and 19 is an image sensor for reading image information from an original surface, and reading of double (both) sheets of the original is made by original feeding once. The original from which the image information is read is discharged to an original discharging portion 20. Further, the image reading device 2 is capable of reading image information from a static original set on an original platen glass by reciprocating the image reading portion 16 by a driving device 17. The static original includes an original such as a booklet original which cannot be used by the original feeding device 3.
The image forming apparatus 1 is an electrophotographic apparatus including an image forming portion 1B of a direct transfer type. The image forming portion 1B includes a cartridge 8 provided with a photosensitive drum 9 and includes a laser scanner unit 15 provided above the cartridge 8. In the case where an image forming operation is performed, the surface of a rotating photosensitive drum 9 is electrically charged, and the laser scanner unit 15 writes an electrostatic latent image on the surface of the photosensitive drum 9 (hereinafter, also referred to as a “drum surface”) on the basis of the image information. The electrostatic latent image carried on the photosensitive drum 9 is developed into a toner image by charged toner particles, and the toner image is conveyed to a transfer portion where the photosensitive drum 9 and a transfer roller 10 oppose each other. A controller (printer controller 100) of the image forming apparatus 1 causes an image forming portion 1B to carry out an image forming operation on the basis of the image information read by the image reading portions 16 and 19 or the image information received from an external computer via a network.
The image forming apparatus 1 is provided with a plurality of feeding devices 6 each for feeding sheets one by one. The sheet fed from the feeding device 6 is subjected to correction of oblique movement thereof by a registration roller pair 7 and is sent to the transfer portion, where the toner image carried on the photosensitive drum 9 is transferred onto the sheet. On a sheet downstream of the transfer portion with respect to a sheet feeding direction, a fixing unit 11 is disposed. The fixing until 11 includes a rotatable member pair for nipping and conveying the sheet and a heat generating member such as a halogen lamp for heating the toner image, and fixing an image on the sheet by heating and pressing the toner image on the sheet.
In the case where the sheet on which the image is formed is discharged to an outside of the image forming apparatus 1, the sheet passed through the fixing unit 11 is conveyed to a post-processing device 4 via a horizontal feeding (conveying) portion 14. In the case of a sheet for which the image is formed on a first sheet in double sheet printing, the sheet passed through the fixing until 11 is delivered to a reversing roller 12 and is fed in a switch-back manner by the reversing roller 12 and then is fed again to the registration roller pair 7 via a re-feeding portion 13. Then, the sheet passes again through the transfer portion and the fixing unit 11, so that the image on a second sheet of the sheet and is thereafter fed to the post-processing device 4 via the horizontal feeding portion 14.
The image forming portion 1B is an example of an image forming means, and an electrophotographic unit of an intermediary transfer type in which the toner image formed on a photosensitive member (photosensitive drum) is transferred onto the sheet through an intermediary transfer member may be used.
Further, a printing unit of an ink jet type or an offset type may be used as an image forming means.
The post-processing device 4 receives the sheet from the image forming apparatus 1 and subjects the sheet to predetermined processing. The predetermined processing includes at least one of longitudinal (vertical) alignment processing, lateral (horizontal) alignment processing, binding processing, and discharge processing. The longitudinal alignment processing is processing for aligning end portions of a plurality sheets with respect to the sheet feeding direction in a first feeding (conveying) mechanism described later. The lateral alignment processing for aligning end portions of the plurality of sheets with respect to a direction perpendicular to the sheet feeding direction in the first feeding mechanism. The binding processing is processing for binding the plurality of sheets. The post-processing device 4 includes a binding processing portion 4A for subjecting the sheets to the binding processing, and subjects the sheets, received from the image forming apparatus 1, to the binding processing and then discharges the sheets as a sheet bundle. Further, the post-processing device 4 is also capable of simply discharging (discharge processing) the sheets without subjecting the sheets, received from the image forming apparatus 1, to the binding processing.
The post-processing device 4 includes a receiving path 81, an inner discharge path 82, a first discharge path 83, and a second discharge path 84 which are provided as feeding passages along which the sheets are fed, and is provided with an upper discharging tray 25 and a lower discharging tray 37 as discharging designations to which the sheets are discharged. The receiving path 81 is the feeding passage along which the sheets are received and fed from the image forming apparatus 1, and the inner discharge path 82 is the passage along which the sheets are fed toward the binding processing portion 4A. The first discharge path 83 is the feeding passage along which the sheets are discharged to the upper discharging tray 25, and the second discharge path 84 is the feeding passage along which the sheets are discharged to the lower discharging tray 37.
Along the receiving path 81, an entrance roller pair 21, a pre-buffer roller pair 22, and an entrance sensor 27 are provided. Along the first discharge path 83, a reversing roller pair 24 as a reversing means is provided. Along the inner discharge path 82, an inner discharging roller pair 26, an intermediary between roller pair 28, a kicking roller pair 29, and a pre-intermediary stacking sensor 38 are provided. Along the second discharge path 84, a bundle discharging roller pair 36 is provided. Each of the entrance sensor 27 and the pre-intermediary stacking sensor 38 detects passing of the sheet at a predetermined position in the associated feeding passage in the post-processing device 4 (hereinafter, this position is also referred to as a detecting position). As the entrance sensor 27 and the pre-intermediary stacking sensor 38, for example, an optical sensor for detecting presence or absence of the sheet in the detecting position with use of light can be used.
In the following, a sheet feeding passage in the post-processing device 4 will be described. The sheet discharged from the horizontal feeding portion 14 of the image forming apparatus 1 is received by the entrance roller pair 21 and passes through the receiving path 81, and is fed toward the pre-buffer roller pair 22. The entrance sensor 27 detects the sheet in the detecting position between the entrance roller pair 21 and the pre-buffer roller pair 22. The pre-buffer roller pair 22 feeds the sheet, received from the entrance roller pair 21, toward the first discharge path 83. In the case of the upper discharge tray 25 which is the destination of the sheet, the reversing roller pair 24 discharges the sheet, to the upper discharging tray 25, received from the pre-buffer roller pair 22.
In the case where the destination of the sheet is the lower discharging tray 37, the reversing roller pair 24 subjects the sheet, received from the pre-buffer roller pair 22, to the switch-back feeding and feeds the sheet to the inner discharge path 82. In a branch portion where the receiving path 81 and the inner discharge path 82 are branched from the first discriminate path 83 on a side upstream of the reversing roller pair 24 with respect to the feeding direction in the discharging direction of the sheet by the reversing roller pair 24, a back-flow preventing valve 23 is provided. The back-flow preventing valve 23 has a function of restricting that the sheet subjected to the switch-back processing by the reversing roller pair 24 is fed back to the receiving path 81.
The inner discharging roller pair 26, the intermediary feeding roller pair 28, and the kicking roller pair 29 which are disposed along the inner discharge path 82 feeds the sheets, received from the reversing roller pair 24, to the binding processing portion 4A while successively delivering the sheets. The pre-intermediary stacking sensor 38 detects the sheet between the intermediary feeding roller pair 28 and the kicking roller pair 29.
The binding processing portion 4A includes stapler 51 which is an example of a binding means and binds a sheet bundle at a predetermined position by the stapler 51 after the plurality of sheets received from the inner discharge path 82 are aligned with each other. Detailed constitution and operation of the binding processing portion 4A will be described later. The sheet bundle (set) bound by the binding processing portion 4A is delivered to a bundle discharging roller pair 36 via the second discharge path 84 by slide movement of a bundle discharging guide 34 which is a pushing-out member of the binding processing portion 4A. Then, the sheet bundle is discharged to the lower discharging tray 37 by the bundle discharging roller pair 36 which is a second feeding mechanism of the binding processing portion 4A.
Each of the upper discharging tray 25 and the lower discharging tray 37 is movable vertically relative to a casing of the post-processing device 4. The post-processing device 4 is provided with sheet surface sensors (not shown) for detecting upper surface positions (sheet stacking heights) of the sheets on the upper discharging tray 25 and the lower discharging tray 37, respectively, and when either one of the sensors detects the sheet, the post-processing device 4 lowers a corresponding tray in an associated one of an arrow A2 direction and an arrow B2 direction. By this, the upper discharging tray 25 or the lower discharging tray 37 is moved to an associated position indicated by a broken line in
Next, the binding processing portion 4A will be described. Part (a) of
The upper intermediary guide 31 and the lower intermediary guide 32 constitute the intermediary stacking portion on which the sheets which are objects to be processed are stacked. In the following, the upper intermediary guide 31 and the lower intermediary guide 32 are also referred to as the intermediary stacking portion. The lower intermediary guide 32 is a stacking portion of the sheet(s) discharged from the kicking roller pair 29 which is a most downstream roller pair in the inner discharge path 82.
On a sheet downstream of the kicking roller pair 29, a bundle pressing flag 30 is rotatably provided. A lower surface of the bundle pressing flag 30 presses a trailing end of the sheet discharged early on the intermediary stacking portion (hereinafter, this sheet is referred to as a current sheet). By this, a leading end of a sheet discharged later by the kicking roller pair 29 (hereinafter, this sheet is referred to as a subsequent sheet) passes through over the trailing end of the current sheet. That is, the bundle pressing flag 30 function as a means for preventing collision between the sheets by moving a trailing end portion of the sheet discharged from the kicking roller pair 29. The lower surface of the bundle pressing flag 30 is disposed in a range with respect to a sheet widthwise direction in which the bundle pressing flag 30 can press opposite end portions of the sheet with respect to the sheet widthwise direction. The sheet widthwise direction is a direction perpendicular to the sheet feeding direction.
The longitudinal alignment roller 33 is disposed above the lower intermediary guide 32. The longitudinal alignment roller 33 is formed of an elastic material such as a synthetic rubber or an elastomer resin and includes a roller portion 33a adjusted so that an outer peripheral surface thereof has a predetermined friction coefficient. The roller portion 33a is supported by a shaft portion 33b rotatably supported by the upper intermediary guide 31, and is driven so as to be intermittently rotated every one rotation by a drive transmitting device including a gear portion 33c. The roller portion 33a which is an outer peripheral potion of the longitudinal alignment roller 33 has a non-circular shape as viewed in an axial direction of the shaft portion 33b. In a waiting (stand-by) state before the sheet is discharged on the intermediary stacking portion, the longitudinal alignment roller 33 is kept at an angle of rotation such that the roller portion 33a is not exposed form the upper intermediary guide 31. Further, during one full rotation of the longitudinal alignment roller 33, the roller portion 33a is temporarily exposed through an opening 31a provided in the upper intermediary guide 31, and contacts the upper surface of an uppermost sheet of the sheets stacked on the lower intermediary guide 32 and thus imparts a feeding force to the uppermost sheet. A contact pressure of the longitudinal alignment roller 33 to the sheet(s) is adjusted so that the longitudinal alignment roller 33 slips with the sheet after the sheet abuts against the longitudinal alignment reference plate 39.
The intermediary stacking portion is provided with a pressing guide 56 which is a flexible sheet member. The pressing guide 56 is disposed so as to contact the lower intermediary guide 32 and presses the upper surface of the sheets stacked on the intermediary stacking portion with a predetermined pressure. The longitudinal alignment reference plate 39 is provided downstream of the longitudinal alignment roller 33 with respect to a sheet discharging direction by the kicking roller pair 29. The longitudinal alignment reference plate 39 includes a reference wall 39a projects, as a restricting portion contactable to end portions of the sheets, upward from the upper surface of the lower intermediary guide 32. Further, the longitudinal alignment reference plate 39 is provided in, for example, two positions on opposite sheets of a direction (sheet widthwise direction) perpendicular to the sheet discharging direction.
In the following, in the binding processing portion 4A, a direction of movement of the sheet, toward the longitudinal alignment reference plate 39, discharged by the kicking roller pair 29 is referred to as a “longitudinal alignment direction X1”. The longitudinal alignment direction X1 is not only a direction along a normal feeding direction in the inner discharge path 82 but also a direction in which the longitudinal alignment roller 33 is moved toward the longitudinal alignment reference plate 39. Further, a direction opposite to the longitudinal alignment direction X1, i.e., a direction in which the sheet bundle is discharged from the binding processing portion 4A is referred to as a “bundle discharge direction X2”.
The stapler 51 is mounted on the intermediary stacking portion and subjects the sheets, aligned with respect to the longitudinal alignment direction X1 and the sheet widthwise direction, to the binding processing in a predetermined position. The stapler 51 is provided on the same sheet as a lateral alignment are reference plate 52 with respect to the sheet widthwise direction and is disposed movable in the longitudinal alignment direction X1 and the bundle discharge direction X2. Further, the lower intermediary guide 32 has a space (area) in which A4-size sheets fed in a long-sheet feeding direction can be stacked. Here, the long-sheet feeding direction refers to a feeding direction such that the longitudinal alignment direction X1 is a long-sheet direction and that the sheet widthwise direction is a short-sheet direction. Accordingly, the stapler 51 is capable of performing not only corner binding such that the sheet bundle stacked on the intermediary stacking portion is bound in a corner but also a long-sheet binding operation in which the stapler 51 binds the sheet bundle in a plurality of positions along the long side of the sheet bundle while moving relative to the sheet bundle. Arrows F and G and a lateral alignment jogger 58 will be described later.
The printer controller 100 includes a central processing unit (CPU) 101 and a memory 102. The CPU 101 reads and executes a program stored in the memory 102 and integrally controls the image forming apparatus 1. For example, the CPU 101 executes processing by causing the image forming portion 1B to execute the image forming operation and executes processing for acquiring the image information by causing the image reading device 2 to execute a reading operation. The memory 102 includes a non-volatile storing medium such as a read-only memory (ROM) and a volatile storing medium such as a random-access memory (RAM), and becomes not only a storage space of programs and data but also a working (operation) space when the CPU 101 executes the programs. The memory 102 is an example of a non-transient storing medium in which the program for controlling the image forming apparatus 1 is stored.
The printer controller 100 is connected to an external device 105 such as a personal computer or a portable information device via an external interface (I/F) 104 and receives an execution instruction or the like of an image forming job to the image forming system 1S. Further, the printer controller 100 is connected to an operating display portion 103 which is a user interface of the image forming system 1S. The operating display portion 103 includes a display device such as a liquid crystal panel for presenting information to a user and an input device, such as a touch panel function portion of physical button and a liquid crystal panel, for receiving an input operation by the user. The printer controller 100 carries out communication with the operating display portion 103, whereby the printer controller 100 controls display contents of the display device and receives information inputted through the input device.
The finisher controller 400 includes a central processing unit (CPU) 401, a memory 402, and an I/O port 403. The CPU 401 reads and executes a program stored in the memory 402 and integrally controls the post-processing device 4. The memory 402 includes a non-volatile storing medium such as a read-only memory (ROM) and a volatile storing medium such as a random-access memory (RAM), and becomes not only a storage space of programs and data but also a working (operation) space when the CPU 401 executes the programs. The memory 402 is an example of a non-transient storing medium in which the program for controlling the image post-processing device 4 is stored.
The CPU 401 and the memory 402 are connected to the I/O port 403 via a bus 404, and the I/O port 404 permits output and input of control signals to various constituent elements of the post-processing device 4.
Incidentally, various functions of the printer controller 100 and the finisher controller 400 may be implemented as independent hardware on a circuit of the controller or may be implemented as a function unit of the program in a software form. Further, a part or all of functions of the finisher controller 400 described below can also be performed by the printer controller 100.
To the I/O port 403, the entrance sensor 27, the pre-intermediary stacking sensor 38, and the stapler 51, and in addition, a plurality of motors (M1 to M12) which are driving sources for feeding the sheets and driving sources for the binding processing portion 4A. An entrance motor M1 rotationally drives an entrance roller 21. A pre-buffer motor M2 rotationally drives a pre-buffer roller pair 22. A reverse motor M3 rotationally drives a reverse roller 24. An inner discharge motor M3 rotationally drives an inner discharge roller 26. A kicking(-out) motor M5 rotationally drives a kicking(-out) roller pair 29.
A longitudinal alignment motor M6 supplies a driving force for intermittently operating a longitudinal alignment roller 33 by one rotation. A jogger driving motor M7 moves a lateral alignment jogger 58 in the sheet widthwise direction. A stapler driving motor M8 moves the stapler 51 in the longitudinal alignment direction X1 and the bundle discharge direction X2. A binding motor M9 causes the stapler 51 to perform a binding operation of the sheet bundle. A guide driving motor M10 drives a guide driving portion 35, and slides and moves a bundle discharging guide 34.
The guide driving motor M10 moves the bundle positioning guide 34 in the longitudinal alignment direction X1 by rotational drive in the clockwise direction (hereinafter, referred to as a CW direction), and moves the bundle discharging guide 34 in the bundle discharging direction X2 by rotational drive in the counterclockwise direction (hereinafter, referred to as a CCW direction). A bundle discharge roller driving motor M11 rotationally drives a bundle discharge roller 36. A bundle discharge contact/separation motor M12 causes a roller pair of the bundle discharge roller 36 to contact each other by the rotational drive in the CW direction, and causes the roller pair of the bundle discharge roller 36 to separate from each other by the rotational drive in the CCW direction.
The sheet feeding controller 410 drives the guide driving motor M10 to slide and move the bundle discharging guide 34 in the bundle discharging direction X2 through the guide driving portion 35, so that the sheets stacked on the lower intermediary guide 32 are fed. Further, the sheet feeding controller 410 drives the bundle discharge roller driving motor M11 to rotate the bundle discharging roller 36, so that the sheets fed by the bundle discharging guide 34 onto the lower discharging tray 37. Further, the sheet feeding controller 410 causes the guide driving motor M10 to slide and move the bundle discharging guide 34 to a waiting position in the longitudinal alignment direction Xl, so that the bundle discharging guide 34 is put in a state in which the bundle discharging guide 34 is capable of receiving a subsequent sheet. In the embodiment 1, each of a moving speed of the bundle discharging guide 34 and a sheet feeding speed of the bundle discharging roller 36 is 200 mm/sec, for example.
The contact/separation controller 412 drives the bundle discharge roller contact/separation motor M12, so that a roller pair (upper roller 36a, lower roller 36b (see
The sheet receiving position selecting portion 411 selects a sheet receiving position of the bundle discharging roller pair 36 on the basis of information of the sheet (hereinafter, referred to as “sheet information”). Here, the sheet information includes, for example, information indicating sheet characteristics, such as a size (A4, B4, sheet length, or the like), a basis weight (g/m2), glossiness, and the like. Selecting processing of the receiving position based on the sheet information of the sheet receiving position selecting portion 411 will be described using a flowchart shown in
In the where the sheet receiving position selecting portion 411 discriminated in S100 that the sheet length is less than the length SL (predetermined length), the processing goes to S101, and in the case where the sheet receiving position selecting portion 411 discriminated in S100 that the sheet length is not less than the length SL (predetermined length), the processing goes to S102. In S101, the sheet receiving position selecting portion 411 selects a receiving position A and ends the processing. For example, the sheet receiving position selecting portion 411 selects the receiving position A in the case where the sheet length is a longitudinal feeding length (279.4 mm) of a sheet with a letter size. In S102, the sheet receiving position selecting portion 411 selects a receiving position B and ends the processing. For example, the sheet receiving position selecting portion 411 embodiments the receiving position B in the case where the sheet length is the longitudinal feeding length of the sheet with the legal size.
In the embodiment 1, the receiving position A which is a first position is a position where a leading end of the sheet advances from a nip position of the bundle discharging roller pair 36 in the bundle discharging direction X2 by 10 mm, for example. It can be said that the receiving position A is position where the sheet fed by the guide driving portion 35 is stopped on the basis of the sheet information. The receiving position B which is a second position is a position where the leading end of the sheet advances from the nip position of the bundle discharging roller pair 36 in the bundle discharging direction X2 by 140 mm, for example. It can be said that the receiving position B is a position where the sheet fed by the guide driving portion 35 is stopped and which is downstream of the receiving position A with respect to the sheet feeding direction. The receiving position B is a position where the second feeding mechanism receives the sheet on a side downstream of the receiving position A with respect to the sheet feeding direction. The sheet receiving position selecting portion 411 functions as a selecting means for selecting, on the basis of the sheet information, whether the sheet is received in the receiving position A or the receiving position B. In other words, it can be said that the sheet receiving position selecting portion 411 is a selecting means for selecting whether the sheet is fed by the guide driving portion 35 to which one of the receiving position A and the receiving position B. The receiving position B is set, as a position where the leading end of the sheet further advances from the receiving position A in the bundle discharging direction X2, so as to reduce a sheet feeding distance by the bundle discharging roller pair 36.
Running to
In the following, an operation in which the sheets are aligned in the binding processing portion 4A and are bound into a sheet bundle by the stapler 51 and then in which the sheet bundle is discharged onto the lower discharging tray 37 will be described. Side views of
Parts (a) and (b) of
Parts (c) and (d) of
As shown in parts (a) and (b) of
As shown in parts (c) and (d) of
As shown in parts (a) and (b) of
As shown in parts (c) and (d) of
Further, the sheet bundle SB is guided to the bundle discharging roller pair 36 by an upper discharging guide 85 forming the second discharging path 84 and an upstream portion (portion extending toward a side downstream of the kicking roller pair 29 in the bundle discharging direction X2). At this time, in the case where the sheet bundle SB has, for example, the letter size and the receiving position A is selected by the above-described sheet receiving position selecting portion 411, the following state shown in part (a) of
Each of LA of part (a) of
(Movement distance of bundle discharging guide 34)=(Distance L0)−((Length of sheet bundle SB)−(Distance in which leading end of sheet bundle SB advances from sheet bundle SB) formula (1)
Here, the movement distance of the bundle discharging guide 34 is also a feeding distance of the sheet bundle SB by the bundle discharging guide 34.
The distance L0 from the waiting position of the bundle discharging guide 34 to the nip position of the bundle discharging roller pair 36 is 440 mm, for example. Therefore, from the formula (1), the movement printer LA of the bundle discharging guide 34 in the case where the sheet bundle SB with the letter size length is received at the receiving position A is 170.6 mm (=440 mm−(279.4 mm−10 mm)). Further, the movement distance LB of the bundle discharging guide 34 in the case where the sheet bundle SB with the legal-size length is received at the receiving position B is 224.4 mm (=40 mm−(355.6 mm−140 mm)).
Next, the upper roller 36a moves in a P1 direction, so that the bundle discharging roller pair 36 is in a contact state. When the contact of the bundle discharging roller pair 36 is completed, the bundle discharging roller driving motor M11 is driven, so that rotation of the bundle discharging roller pair 36 is started. The sheet bundle SB is nipped by the bundle discharging roller pair 36 and is subsequently discharged in the bundle discharging direction X2 by the bundle discharging roller pair 36. In addition, the bundle discharging guide 34 starts movement in the longitudinal alignment direction X1 (H2 direction) for receiving a subsequent sheet.
As shown in part (c) of
The feeding distance of the sheet bundle SB by the bundle discharging roller pair 36 is acquired by subtracting the distance (distance RA or RB) in which the leading end of the sheet bundle SB advances from the nip position of the bundle discharging roller pair 36, from the length of the sheet bundle SB.
(Feeding distance of sheet bundle SB by bundle discharging roller pair 36)=(Length of sheet bundle SB)−(Distance in which leading end of sheet B advances from nip position of bundle discharging roller pair 36) formula (2)
From the formula (2), the feeding distance LA of the sheet bundle SB by the bundle discharging roller pair 36 in the case where the sheet bundle SB with the letter size length is received at the receiving position A is 269.4 mm (=279.4 mm−10 mm). Further, the feeding distance LB of the sheet bundle SB by the bundle discharging roller pair 36 in the case where the sheet bundle SB with the legal-size length is received at the receiving position B is 215.6 mm (=355.6 mm−140 mm).
A returning time from a start of the discharge of the sheet bundle SB by the bundle discharging guide 34 to movement to the waiting position for receiving the subsequent sheet, in other words, a reciprocating time of the bundle discharging guide 34 is acquired in the following manner. That is, the returning time (reciprocating time) is acquired from the sum of a time obtained by dividing a distance which doubles the movement distance of the bundle discharging guide 34 by a moving speed of the bundle discharging guide 34 and a time required for a contact operation of the bundle discharging roller pair 36.
(Returning time from start of discharge of sheet bundle SB by bundle discharging guide 34 to movement to waiting position for receiving subsequent sheet)={(movement distance of bundle discharging guide 34)×2/(moving speed of bundle discharging guide 34}+(contact time of bundle discharging roller pair 36) formula (3)
From the formula (3), the reciprocating time of the bundle discharging guide 34 in the case where the sheet bundle SB with the letter size length is received at the receiving position A is 2006 milliseconds (ms) (=170.6 mm×2/0.2 mm/ms+300 ms). Further, the reciprocating time of the bundle discharging guide 34 in the case where the sheet bundle SB with the legal-size length is received at the receiving position B is 2544 ms (=224.4 mm×2/0.2 mm/ms+300 ms).
For comparison, calculation results using the formulas (1), (2) and (3) in the case where the sheet bundle SB with the letter size length is received at the receiving position B and the case where the sheet bundle SB with the legal-size length is received at the receiving position A are shown in a table 1 in combination with the above-described cases.
In the table 1, the sheet length, the receiving position, the sheet bundle SB feeding (movement) distance by the bundle discharging guide 34 according to the formula (1), the sheet bundle SB feeding distance by the bundle discharging roller pair 36 according to the formula (2), and the reciprocating time of the bundle discharging guide 34 according to the formula (3) are shown in first to fifth columns, respectively.
As in the case of the bundle discharging roller pair 36, there is a possibility that the sheet is obliquely moved due to a slip or the like of the sheet in the sheet feeding by the rollers. When the sheets are stacked on the lower discharging tray 37 in an obliquely moved state of the sheets, the sheet feeding has the influence of an alignment state of the sheets on the lower discharging tray 37. In the case where the sheet length of the sheet bundle SB is long, the feeding distance by the bundle discharging roller pair 36 is also long, so that compared with the case where the sheet length is short, a possibility that the sheet is obliquely moved becomes high. Therefore, the sheet receiving position selecting portion 411 selects the receiving position B of the bundle discharging roller pair 36 in the case where the sheet length of the sheet bundle SB is long, so that the sheet feeding distance by the bundle discharging roller pair 36 is decreased. By this, for example, as regards the sheet with the legal-size length, the sheet receiving position selecting portion 411 does not select the receiving position A when the sheet feeding distance by the bundle discharging roller pair 36 is 345.6 mm but selects the receiving position B where the sheet feeding distance is 215.6 mm. Incidentally, as regards the sheet with the letter size length, the receiving position A where the reciprocating time of the bundle discharging guide 34 becomes shorter than the reciprocating time in the case of the receiving position B is selected.
A control sequence of the binding processing and the sheet discharge which realize the above-described operations will be described along a flowchart of
Further, this operation sequence is started in the case where the finisher controller 400 receives notification, from the printer controller 100, indicating a start of execution of an image forming job requiring the binding processing by the binding processing portion 4A.
In S200, on the basis of sheet information (for example, the sheet length) of the image forming job received from the printer controller 100, the CPU 401 causes the sheet receiving position selecting portion 411 to select the receiving position of the bundle discharging roller pair 36. A selecting method is as described above using the flowchart of
In an interval bundle a sheet and a subsequent sheet of the sheet bundle (herein, this interval is also referred to as the sheet interval) requires the sum (total time) of a longitudinal alignment operation time by the longitudinal alignment roller 33 and a lateral alignment operation time by the lateral alignment jogger 58.
(Necessary wait time in sheet interval of sheet bundle)=(longitudinal alignment operation time)+(lateral alignment operation time) formula (4)
In the embodiment 1, as an example, a constitution in which the longitudinal alignment operation time of 200 ms and the lateral alignment operation time of 300 ms are required. From the formula (4), the necessary wait time for the sheet interval of the sheet bundle is 500 ms (=200 ms+300 ms).
Between a final sheet of a sheet bundle and a first sheet of a subsequent sheet bundle, a total time of the following times is required. That is the total time of the longitudinal alignment time, the lateral alignment operation time, a binding operation time by the stapler 51, a sheet bundle feeding time by the bundle discharging guide 34, and a returning time of (movement of) the bundle discharging guide 34 to the waiting position is required. The sheet bundle feeding time by the bundle discharging guide 34 and the returning time of the bundle discharging guide 34 to the waiting position are calculated using the bundle discharging guide reciprocating time in the above-described table 1.
(Necessary wait time between final sheet of sheet bundle and first sheet of subsequent sheet bundle)=(longitudinal alignment operation time)+(lateral alignment operation time)+(binding operation time)+(bundle discharging guide reciprocating time) formula (5)
In the embodiment 1, as an example, a constitution in which the binding operation time of 1000 ms is required is employed. This time is a time in which long-side binding of the sheet bundle described later is not performed and is a time to which a moving time of the stapler moving motor M8 is added in the case where the long-side binding of the sheet bundle is performed. For example, the binding operation time is 3000 ms.
From the formula (5), the necessary wait time between the final sheet of the sheet bundle and the first sheet of the subsequent sheet bundle in the case where the long-side binding is not performed becomes 3506 ms (=500 ms+1000 ms+2006 ms) in the case of the letter size and the receiving position A. On the other hand, in the case of the legal size and the receiving position B, the necessary wait time becomes 4044 ms (=500 ms+1000 ms+2544 ms). As regards the necessary wait time, wait times between all the adjacent sheets contained in the sheet information of the image forming job are calculated.
Returning to description of
In S206, the CPU 401 discriminates whether or not the current sheet is a final sheet (whether or not the current sheet is a sheet, of the sheets constituting the sheet bundle, finally received by the binding processing portion 4A). In the case where the CPU 401 discriminated in S206 that the current sheet is not the final sheet of the sheet bundle, the process is caused to go to S207. In S207, the CPU 401 causes the lateral alignment jogger 58 to move toward the waiting position and then returns the process to S203, and then repeats the processes of S203 to S207.
In the case where the CPU 401 discriminated in S206 that the current sheet is the final sheet of the sheet bundle, the CPU 401 causes the process to go to S208.
In S208, the CPU 401 causes the stapler 51 to perform the binding operation of the sheet bundle. In the case where the long-side binding of the sheet bundle is performed, the sheet bundle is bound at a plurality of positions along the long side by the stapler 51 while moving the stapler 51 in the longitudinal alignment direction X1 or the bundle discharging direction X2 by the stapler moving motor M8. In S209, the CPU 401 returns the lateral alignment jogger 58 to the waiting position. In S210, the CPU 401 causes the bundle discharging guide 34 in the bundle discharging direction X2, so that the feeding of the sheet bundle is started.
In S211, the CPU 401 discriminates whether or not the leading end of the sheet bundle SB with respect to the bundle discharging direction X2 passes through the bundle discharging roller pair 36 put in the separated state and feeding of the sheet bundle SB to a receiving position selected by the sheet receiving position selecting portion 411 is completed. In the case where the CPU 401 discriminated in S211 that the sheet bundle SB is not fed to the receiving position, the CPU 401 returns the process to S211, and in the case where the CPU 401 discriminated in S211 that the sheet bundle SB is fed to the receiving position, the CPU 401 causes the process to go to S212. In S212, the CPU 401 stops the feeding of the sheet bundle SB by the bundle discharging guide 34. In S213, the CPU 401 lowers the upper roller 36a of the bundle discharging roller pair 36 and causes the bundle discharging roller pair 36 to nip the sheet bundle (bundle discharging roller contact). In S214, the CPU 401 starts rotation of the bundle discharging roller pair 36. In S216, the CPU 401 starts movement of the sheet bundle SB by the bundle discharging guide 34.
In S216, the CPU 401 discriminates whether or not the sheet bundle SB is discharged onto the lower discharging tray 37 (whether or not the discharge is completed). In the case where the CPU 401 discriminated in S216 that the discharge of the sheet bundle SB onto the lower discharging tray 37 is not completed, the CPU 401 returns the process to S216, and in the case where the CPU 401 discriminated in S216 that the discharge is completed, the CPU 401 causes the process to go to S217. In S217, the CPU 401 stops rotation of the bundle discharging roller pair 36 and raises the upper roller 36a, so that the bundle discharging roller pair 36 is spaced (separated) again from each other. In S218, the CPU 401 discriminates whether or not feeding of all the sheets is ended. In the case where the CPU 401 discriminated in S218 that the sheets to be fed to the binding processing portion 4A remain, the process is returned to S203, and then the above-described processes are repeated. In the case where the CPU 401 discriminated in S218 that all the sheets to be fed to the binding processing portion 4A are discharged to the lower discharging tray 37, the CPU 401 ends the process.
As described above, depending on the length of the sheet, the receiving position of the bundle discharging roller pair 36 is selected. Thus, by decreasing the sheet feeding distance of the sheet by the rollers, the degree of the oblique movement of the sheet due to the sheet feeding by the rollers can be reduced. Further, by reducing the degree of the oblique movement, an alignment state of the sheets stacked on the discharging tray can be improved.
As described above, according to the embodiment 1, the degree of the oblique movement of the fed sheets is reduced, so that it is possible to improve the alignment state of the recording materials stacked on the discharging tray.
An embodiment 2 will be described principally based on a difference from the embodiment 1. In the embodiment 1, in order to reduce the degree of the oblique movement of the sheet by the bundle discharging roller pair 36 during the sheet feeding, the example in which the sheet feeding distance by the bundle discharging roller pair 36 is decreased depending on the sheet length was described. In the case where the sheet feeding distance by the bundle discharging roller pair 36 is decreased, the sheet feeding distance by the bundle discharging guide 34 is increased. For this reason, the necessary waiting time between adjacent sheets (hereinafter, referred to as a sheet bundle) is increased, so that a time in which all the plurality of sheets are stacked on the discharging tray is increased in some instances. That is, there is a case that productivity lowers. Therefore, in the embodiment 2, an example in which an object thereof is such that a degree of a lowering in productivity in the case where a plurality of sheet bundles are continuously discharged is reduced or such that the degree of the oblique movement of the sheet due to the sheet feeding by the rollers is reduced without lowering the productivity will be described. Also, in the embodiment 2, the constitution described with reference to
The sheet receiving position selecting portion 511 in the embodiment 2 selects a sheet receiving position of the bundle discharging roller pair 36 on the basis of information of the sheet. Selecting processing of the receiving position based on the sheet information of the sheet receiving position selecting portion 511 will be described using a flowchart shown in part (a) of
In S300, the sheet receiving position selecting portion 511 discriminates whether or not the number of sheets of the sheet bundle subjected to processing by the binding processing portion 4A at one time is less than a sheet number SM (less than a predetermined sheet number). In the case where the sheet receiving position selecting portion 511 discriminated in S300 that the sheet number of the sheet bundle is not less than the sheet number SM, the processing is caused to go to S102, and the sheet receiving position selecting portion 511 selects the receiving position B is S102 and then the processing is ended. In the embodiment 2, as an example, the sheet number SM which is the predetermined sheet number is 10 sheets. In the case where the sheet receiving position selecting portion 511 discriminated in S300 that the sheet number of the sheet bundle is less than the sheet number SB, the processing is caused to go to S301.
In S301, the sheet receiving position selecting portion 511 discriminates whether or not the sheet bundle is a final sheet bundle of the image forming job received from the printer controller 100. In the case where the sheet receiving position selecting portion 511 discriminated in S301 that the sheet bundle is the final sheet bundle, the processing is caused to go to S102, and in S102, the sheet receiving position selecting portion 511 selects the receiving position B and then the processing is ended. That is, in the case where there is no sheet to be fed by the first feeding mechanism after the sheets are fed by the first feeding mechanism, it can also be said that the sheet receiving position selecting portion 511 selects the receiving position B. In the case where the sheet receiving position selecting portion 511 discriminated in S301 that the sheet bundle is not the final sheet bundle, the processing is caused to go to S101, and in S101, the sheet receiving position selecting portion 511 selects the receiving position A and then the processing is ended. That is, in the case where the sheet number is less than the predetermined sheet number and there is a sheet to be subsequently fed by the first feeding mechanism, it can also be said that the sheet receiving position selecting portion 511 selects the receiving position A.
As regards the operation in which the sheets are aligned in the binding processing portion 4A and in which the sheet bundle is bound by the stapler 51 and then is discharged onto the lower discharging tray 37, the operation is similar to the operation described with reference to
A control sequence of bind processing (operation) and sheet discharging (operation) will be described using a flowchart of
As described above, in the embodiment 2, the example in which the receiving position is selected on the basis of the number of sheets of the sheet bundle in the binding processing portion 4A and the sheet information on whether or not the sheet bundle is the final sheet bundle was described. As described above using the table 1, when the receiving position B is selected for the sheets with the same size, compared with the case of the receiving position A, the sheet feeding distance by the bundle discharging guide 34 is increased. For that reason, in the case where the plurality of sheet bundles are continuously discharged, a necessary wait time between adjacent sheet bundles is increased, so that a time in which all the plurality of sheet bundles are stacked on the lower discharging tray 37 is increased. Then, the sheet receiving position selecting portion 511 selects the sheet receiving position on the basis of the number of the sheets of the sheet bundles. In an example of the embodiment 2, only in the case where the sheet number of the sheet bundles is not less than the set sheet number SM, the sheet feeding distance by the bundle discharging roller pair 36 is decreased in order to reduce a degree of the slip or the like.
In the case where the sheet number of the sheet bundles is large, compared with the case where the sheet number of the sheet bundles is small, the influence of an increasing time per(one) sheet relative to the increase in necessary wait time between adjacent sheet bundles becomes small. Therefore, an increase in time until all the sheet bundles in various sheet numbers in the image forming job are stacked on the lower discharging tray 37 can be reduced. Further, in the case where the sheet bundle is the final sheet bundle, in order to receive the subsequent sheet, there is no need to move the bundle discharging guide 34 to the waiting position. Therefore, the sheet receiving position is selected depending on the information on whether or not the sheet bundle is the final sheet bundle. Therefore, the sheet feeding distance by the bundle discharging roller pair 36 is decreased with no increase in time in which the sheet bundles are stacked on the lower discharging tray 37, the degree of the oblique movement of the sheet due to the sheet feeding by the rollers can be reduced. Further, by reducing the degree of the oblique movement, an alignment state of the sheets stacked on the lower discharging tray 37 can be improved.
As described above, according to the embodiment 2, the degree of the oblique movement of the fed sheets is reduced, so that it is possible to improve the alignment state of the recording materials stacked on the discharging tray.
Incidentally, as the operation of the binding processing portion 4A in the above-described embodiments, i.e., as an operation including the aligning operation by the aligning portion and the binding operation by the stapler, control in which the sheet receiving position is selected by the bundle discharging roller pair 36 was carried out. However, the present invention is not limited to these constitutions and control. For example, as a constitution in which there is no longitudinal alignment roller, a constitution in which the sheet is fed to the longitudinal alignment reference plate 39 by falling due to a self-weight of the sheet may also be employed. Similarly, the present invention is also applicable to a constitution in which the stapler is not provided or to discharge of the sheet bundle in an image forming job in which the binding operation is not performed. Further, the present invention can be applied to an operation such that a sheet bundle for which the lateral alignment operation is performed and a sheet bundle for which the lateral alignment operation is not performed are alternately discharged onto the discharging tray. In the case of these operation and control, a formula obtained by subtracting the longitudinal alignment operation time, the lateral alignment operation time, and the binding operation time from the above-described formulas (4) and (5) depending on contents of the operation performed by the binding processing portion 4A may be used.
Further, although the operation for feeding the sheet bundle was described, an operation for feeding a single sheet, not the sheet bundle may be performed. The sheet receiving position is selected for single sheet feeding, and the single sheet is fed by the bundle discharging guide 34 and is received by the bundle discharging roller pair 36, so that the above-described effect can also be obtained.
Further, although an operation example in which the sheet receiving position of the bundle discharging roller pair 36 is controlled by controlling the movement distances (LA, LB) of the bundle discharging guide 34 from the waiting position of the bundle discharging guide 34 was described, the present invention is not limited to this operation. For example, an operation in which a sheet sensor for detecting the presence or absence of the sheet is provided in the neighborhood of the bundle discharging roller pair 36 and in which the sheet receiving position of the bundle discharging roller pair 36 is controlled by controlling an elapsed time from detection of the sheet by the sheet sensor, a rotation amount of the guide driving motor M10, and the like may also be performed.
Further, the selecting process of the receiving position based on the sheet information described using the flowcharts of
A process in which the process S100 in the flowchart of
As described above, also, in other embodiments, the degree of the oblique movement of the fed recording materials is reduced, so that the alignment state of the recording materials stacked on the discharging tray can be improved.
According to the present invention, the degree of the oblique movement of the fed recording materials is reduced, and thus it is possible to improve the alignment state of the recording materials stacked on the discharging tray.
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. 2022-024515 filed on Feb. 21, 2022, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-024515 | Feb 2022 | JP | national |
