JP2014134596A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus including a plurality of post-processing functions which are arranged in a space-saving manner to perform processing on a longitudinal end face parallel to a conveyance direction.SOLUTION: At the start of shifting a sheet P received in a sheet post-processing device 200, rotation of an orthogonal roller pair 205 is started. When a tip of the sheet P reaches a punching position, rotation of a conveyance roller pair 203 is stopped, while continuing shifting operation, and the sheet P is shifted to the orthogonal roller pair 205, to transfer the sheet P from the conveyance roller pair 203 to the orthogonal roller pair 205. The sheet P is conveyed by shifting operation of the conveyance roller pair 203 and rotation of the orthogonal roller pair 205. When a side end of the sheet P reaches the punching position, the shifting operation of the conveyance roller pair 203 and rotation of the orthogonal roller pair 205 are stopped. Alignment to the punching position is completed in both right-angled conveyance directions d1, d2.

Description

The present invention relates to an image forming apparatus having a paper post-processing function of receiving paper (recording paper) after image formation, performing processing such as punching and stapling, and discharging the paper to a stack tray.
About.

  In an image forming apparatus such as a laser printer or a color image copying machine using an electrophotographic method, generally, image data input from a personal computer or an image input apparatus is exposed by a laser or the like to an image carrier such as a photosensitive drum. On the other hand, an electrostatic latent image is formed, and after developing the toner by the developing device, the image is transferred to the paper, and then the image is fixed and discharged by melting the toner on the paper by the heating roller type fixing device. It has been.

  There is also provided an apparatus in which such an image forming apparatus is connected to a device for performing post-processing such as stapling, punching, sorting (collating), bookbinding, folding, etc., and the operation is automated. A sheet post-processing apparatus that performs post-processing of a sheet on which an image is recorded by such an image forming apparatus is known. Paper post-processing by the paper post-processing device includes stack processing for stacking paper on a sheet-by-copy basis and stacking on a paper discharge tray, and stapling processing for binding a predetermined number of sheets and stacking them on a stack tray.

As this type of technology, for example, the inventions disclosed in Patent Documents 1 and 2 are known.
In Patent Document 1, a document reading unit is arranged at the upper part of the apparatus main body, a paper feeding unit is arranged at the lower part of the apparatus main body, a printing unit is arranged between the document reading unit and the paper feeding unit, and is placed in the space of the apparatus main body. Proposed is an image forming apparatus in which a sheet post-processing section capable of performing a plurality of sheet post-processing and a discharge section for discharging sheets are arranged on a sheet conveyed from the apparatus main body after printing by the printing section. Has been.
In Patent Document 2, in a paper post-processing device provided in a space between the document reading unit and the image forming unit, the paper post-processing device and the discharge roller of the main body of the image forming device can be separated, and other post-processing is performed. A configuration has been proposed in which an apparatus (punch unit) can be selectively mounted.

  However, in the invention of Patent Document 1, when a sheet on which an image is recorded is conveyed from the apparatus main body by SEF (Short Edge Feed), post-processing is performed on the long end surface side parallel to the sheet conveying direction. If the punch function, stapling function, and paper stacking function after processing are disposed on the longitudinal end surface side parallel to the transport direction, the function is not less than the same length as the paper length in each function. There is a problem that an arrangement space is required.

  In the invention of Patent Document 2, since another post-processing device (punch unit) is mounted between the discharge roller of the main body of the image forming apparatus and the paper post-processing device, the transport path of the mounted post-processing device is long. Therefore, there is a problem that the paper processing time including the conveyance time becomes long regardless of the presence or absence of the punching process.

  The present invention has been made in view of the above-described problems. In the case where a plurality of post-processing functions that can be processed are arranged in a space-saving manner on the side of the longitudinal end surface parallel to the transport direction, and when post-processing is not performed. The object is to improve productivity by shortening the paper conveyance time and the required inter-paper time.

  An image forming apparatus according to the present invention includes an image reading unit that reads image information, a sheet feeding unit that feeds a sheet, and an image forming unit that performs an image forming process on the sheet conveyed from the sheet feeding unit. A post-processing unit that is disposed in a space formed between the image reading unit and the image forming unit and performs post-processing in parallel with a paper conveyance direction in which an image is formed in the image forming unit A cross transport unit that transports the paper post-processed by the post-processing unit in a direction orthogonal to the transport direction of the paper transported from the image forming unit, and the paper ejected by the cross transport unit A shift unit that slides in a direction orthogonal to the sheet conveyance direction on which the image is formed by the image forming unit, and the shift unit when the post-processing unit performs post-processing on the sheet. Slide in the direction of the post-processing section If you do not want to post-processing and having a shift control means for sliding the shift means in the stacking section direction.

  According to the present invention, the shortest transport path that does not pass through the post-processing unit can be selected, the time required for transporting the paper is shortened, and the next paper can be received at an earlier timing, thereby improving productivity. it can.

1 is a diagram illustrating an outline of a system configuration of an image forming system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of a sheet post-processing apparatus illustrated in the system of FIG. 1, in which (A) is a plan view and (B) is a side view. FIG. 3 is a plan view showing a moving direction of a sheet conveyed to the sheet post-processing apparatus of FIG. The block diagram which shows the control structure of the system in Embodiment 1 of this invention. 6 is a flowchart illustrating control of the sheet post-processing apparatus according to the first exemplary embodiment of the present invention. The figure which shows operation | movement in case the paper post-processing apparatus in Embodiment 1 of this invention performs a punching process. The figure which shows operation | movement when the paper post-processing apparatus in Embodiment 1 of this invention does not perform a punching process. The figure which shows operation | movement of the paper post-processing apparatus about the shift amount by the difference in paper width, and shift operation speed control. Flow chart showing control of the sheet post-processing apparatus Flow chart of control of paper post-processing device showing shift operation stop control when paper is released Flow chart of control of paper post-processing device showing shift amount and shift operation timing control due to difference in paper width FIG. 3 is a diagram illustrating an outline of a system configuration of an image forming system according to a second embodiment of the invention. FIG. 12 is a schematic configuration diagram of a sheet post-processing apparatus 200 according to the second embodiment shown along line II-II in FIG. The figure which shows the positional relationship of a punch unit and a stapler (A), and the figure which shows the relationship with the shift direction of a shift roller (B) The figure which shows the example which provided the registration detection sensor which detects the registration position of a paper, and the front-end | tip detection sensor which detects the stop position of the front end of a paper from a shift roller pair. When the registration detection sensor does not turn off even if the paper position is shifted by a predetermined range, the shift operation is stopped (A), and when the paper cannot be moved to the punch position, the shift operation is stopped (B). Figure showing

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the image forming apparatus according to the present invention is not limited to the illustrated embodiments.

  In short, the image forming apparatus according to the embodiment of the present invention shortens the paper conveyance time and the required inter-paper time when no post-processing is performed, thereby improving productivity. Therefore, when post-processing is performed on the paper in the post-processing unit, the shift unit is slid in the direction of the post-processing unit to convey the paper to the post-processing unit. When the post-processing is not performed on the paper, the shift unit is set in the stacking unit direction. The paper is directly conveyed toward the paper discharge means. As a result, the shortest conveyance path that does not pass through the post-processing unit can be selected, the time required for sheet conveyance is reduced, and the next sheet can be received at an earlier timing, so that productivity can be improved.

  Note that in this application, the image forming apparatus is not limited to an apparatus generally recognized as an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multi-function machine thereof, but also has a post-processing function as described above. As a matter of course, it includes a combination of separate devices having a post-processing function as described above.

  FIG. 1 is a diagram showing an outline of the system configuration of an image forming system according to an embodiment of the present invention. As illustrated, the image forming system according to the present embodiment includes an image forming apparatus main body 100, a sheet post-processing apparatus 200, and an image reading apparatus 300.

  The image forming apparatus main body 100 is an indirect transfer tandem color image forming apparatus. In the figure, an image forming unit 110 having a four-color image forming station 111 disposed substantially at the center is provided as an image forming unit that performs image forming processing. An optical writing unit (not shown) is provided adjacent to the lower side of the image forming unit 110. Below the image forming unit 110, a paper feeding unit 120 is provided as a paper feeding unit. Then, the paper picked up by the paper feeding unit 120 is fed to the intermediate transfer unit 140 and the fixing unit 150, and a paper feeding conveyance path (vertical conveyance path) 130, and the paper on which the image is fixed is conveyed to the paper post-processing apparatus 200 side. A paper discharge path 160 is provided with a double-sided conveyance path 170 for reversing a sheet having an image formed on one side and forming an image on the other side.

  The image forming unit 110 includes the photosensitive drums for the colors Y, M, C, and K of the image forming station 111. Along the outer periphery of the photosensitive drum, a charging unit, a developing unit, a primary transfer unit, a cleaning unit, and a charge eliminating unit, and an intermediate transfer belt 112 that intermediately transfers an image formed on the photosensitive drum by the primary transfer unit. I have.

An optical writing unit for writing an image for each color is provided around the photosensitive drum. The optical writing unit is disposed below the image forming station 111, and the intermediate transfer belt 112 is disposed above the image forming station 111.
The intermediate transfer belt 112 is rotatably supported by a plurality of support rollers. One support roller 114 is opposed to the secondary transfer roller 115 via the intermediate transfer belt 112 in the intermediate transfer unit 140, so that the image on the intermediate transfer belt 112 can be secondarily transferred onto a sheet. In the figure, reference numeral 116 denotes a toner container disposed so as to be replaceable. Since the image forming process of the indirect transfer tandem type color image forming apparatus is known, detailed description thereof is omitted.

  The paper feeding unit 120 includes a paper feeding tray 121, a pickup roller 122, and a paper feeding / conveying roller 123, and feeds the paper picked up from the paper feeding tray 121 upward along the vertical conveying path 130. The fed sheet is transferred with an image by the intermediate transfer unit 140 and sent to the fixing unit 150.

  The fixing unit 150 includes a fixing roller and a pressure roller, and heat and pressure are applied in a process in which the paper passes through the nip between the two, and the toner is fixed to the paper.

  A paper discharge path 160 and a double-sided conveyance path 170 are provided downstream of the fixing unit 150, and both are branched in two directions by a branching claw 161. A case where the sheet is conveyed to the sheet post-processing apparatus 200 side and a case where the sheet is conveyed to the duplex conveying path 170 is selected. A branch conveyance roller 162 is provided in the immediate vicinity of the branch claw 161 on the upstream side in the sheet conveyance direction, and applies a conveyance force to the sheet.

  The image reading device 300 is known as an image reading unit that scans an original set on a contact glass to read image information on the original surface. Since the configuration and function of the image reading apparatus 300 itself are known, detailed description thereof is omitted.

  The sheet post-processing apparatus 200 is disposed in a space between the image reading apparatus 300 and the image forming unit 110 inside the image forming apparatus main body 100. Then, the image-formed paper conveyed from the image forming apparatus main body 100 is subjected to a predetermined process and stacked on the paper discharge tray 210 located on the most downstream side. Details will be described later.

  The image forming apparatus main body 100 generally configured as described above generates image data used for writing based on document data read from the image reading apparatus 300 or print data transferred from an external PC or the like. Then, based on the image data, optical writing is performed from the optical writing unit to each photosensitive drum. Images formed for the respective colors at the respective image forming stations are sequentially transferred to the intermediate transfer belt 112, and a color image in which four color images are superimposed on the intermediate transfer belt 112 is formed. On the other hand, paper is fed from the paper feed tray 121 according to the image formation. The sheet is temporarily stopped at a registration roller position (not shown) immediately before the intermediate transfer unit 140, sent in time with the leading edge of the image on the intermediate transfer belt 112, secondarily transferred by the intermediate transfer unit 140, and sent to the fixing unit 150. It is sent.

  In the case of single-sided printing or after double-sided printing of double-sided printing, the paper on which the image is fixed by the fixing unit 150 is transported to the discharge path 160 side by the switching operation of the branching claw 161, and in the case of double-sided printing. It is conveyed to the double-sided conveyance path 170 side.

  The paper conveyed to the double-sided conveyance path 170 is reversed, and finally sent to the intermediate transfer unit 140, an image is formed on the other side, and then returned to the paper discharge path 160 side. The paper transported to the paper discharge path 160 side is transported to the paper post-processing device 200 via the main body discharge roller 169, and is subjected to predetermined paper processing by the paper post-processing device 200 or to the paper output tray 210 without processing. The paper is ejected.

2A and 2B are diagrams illustrating a schematic configuration of the sheet post-processing apparatus 200, where FIG. 2A is a plan view, FIG. 2B is a side view, and FIG. 3 is a diagram illustrating a moving direction of the sheet conveyed to the sheet post-processing apparatus 200. is there.
2 and 3, the sheet post-processing apparatus 200 is provided with an inlet roller pair 201, a sheet discharge conveyance path 202, and a conveyance roller pair 203 that is a shift roller pair from the upstream side in the sheet conveyance direction. The paper P is transported along the paper discharge transport path 202 by rotating the entrance roller pair 201 and the transport roller pair 203 by an unillustrated entrance motor. The transport roller pair 203 functions as a shift means that can be shifted in the transport directions d2 and d3 by a shift motor (not shown) in addition to being rotated in the transport direction d1 by an inlet motor (not shown). In the figure, reference numeral 212 denotes a paper discharge guide plate, 209 denotes a paper discharge roller pair, 221 denotes a tray DC motor, and 222 denotes a driving device for the paper discharge tray 210.

  In this embodiment, the cross conveyance unit includes a shift unit including a conveyance roller pair 202 and a shift motor, and an orthogonal roller capable of conveying the sheet P in the conveyance directions d2 and d3 perpendicular to the conveyance direction d1 of the image forming apparatus main body 100. 205. A punch unit 251 as a post-processing unit that performs post-processing on the paper P is arranged as a punching unit on the edge e2 side of the paper P, and the discharged paper P is placed on the edge e3 side of the opposing paper P. A paper discharge tray 210 as a stacking unit to be stacked is disposed. That is, a punch unit 251 as a post-processing unit is disposed in the vicinity of the conveyance roller pair 202 and the like constituting the cross conveyance unit.

  An entrance sensor 901 is disposed in the paper discharge conveyance path 202. The entrance sensor 901 detects the leading and trailing ends of the paper P in the transport direction (the edge in the direction perpendicular to the paper transport direction after passing through the transport roller pair 203). Then, the detection result of the leading and trailing edges of the paper P in the transport direction, the detection timing of the detected leading edge (e1) of the paper P, and the side edge (e2) perpendicular thereto, and the driving of the inlet motor, which is a stepping motor, are detected. The timing when each paper processing is performed is determined by the number of steps.

  The paper discharge tray 210 includes a fixed tray portion 222a on the downstream side in the transport direction and a movable tray portion 222b on the upstream side, and the movable tray portion 222b moves up and down by a tray DC motor 221a and a cam / link mechanism 221b. The movable tray portion 222b is pivotally supported on the fixed tray portion 222a via the support shaft 221c with the upstream end as a pivot end, and the operating end of the cam / link mechanism 221 is the movable tray portion 222b. It is connected to. As a result, the tray DC motor 221a rotates, and the movable tray portion 222b swings around the support shaft 221c according to this rotation. When the number of discharged sheets reaches a certain number, the movable tray section 222b rotates the tray DC motor 221a according to a command from a control section described later, and lowers the free end on the upstream side in the sheet transport direction.

FIG. 4 is a block diagram showing a control configuration of the system according to the present embodiment.
The control of the sheet post-processing apparatus 200 is executed by a post-processing apparatus control unit 400 having a built-in CPU 401, ROM 402, RAM 403, serial I / F 404, timer 405, and the like. The post-processing device control unit includes a function as shift control means.

  Program code for control is stored in the ROM 402, and the CPU 401 expands the program code in the RAM 403 and stores data necessary for control in the RAM 403. Then, the control defined by the program code is executed while using the RAM as a work area, and various DC loads 420 are controlled.

  The image forming apparatus main body 100 and the sheet post-processing apparatus 200 exchange commands necessary for sheet conveyance control via the serial I / Fs 415 and 404. The sheet post-processing apparatus 200 performs sheet conveyance control and post-processing based on the command and sheet position information obtained from the various sensors 430. Further, the post-processing apparatus control unit 400 includes a sheet abnormality detecting unit that detects an abnormality of the sheet P being conveyed, and a load abnormality detecting unit that detects an abnormality of a load that drives the post-processing unit, the stacking unit, and the cross conveying unit. ing.

FIG. 5 is a flowchart showing the control of the sheet post-processing apparatus 200 of this embodiment.
The sheet post-processing apparatus 200 conveys the sheet P by SEF (short end surface conveyance) downstream from the conveyance roller pair 203, and performs post-processing such as punching and stapling in parallel with the conveyance direction d1 of the image forming apparatus main body 100. It is applied to the end face (see FIG. 3) of the paper P. Downstream of the pair of conveyance rollers 203, it is determined whether or not post-processing is executed (step S100 in FIG. 5), and the conveyance direction d2 or d3 of the sheet P is perpendicular to the conveyance direction d1 of the image forming apparatus main body 100. Switch to.

FIGS. 6A to 6G are diagrams illustrating operations when the paper post-processing apparatus 200 performs the punching process.
When the paper P is passed from the image forming apparatus main body 100, the entrance roller pair 201 and the transport roller pair 203 start rotating operations (step S101 in FIG. 5). The paper P received by the paper post-processing apparatus 200 from the image forming apparatus main body 100 via the main body discharge roller 169 is transported in the transport direction d1 through the inlet roller pair 201 and the transport roller pair 203 (FIG. 6A). )). In synchronization with the timing when the sheet P passes through the entrance roller pair 201 (step S102 in FIG. 5), the transport roller pair 203 starts a shift operation in the transport direction d2 (step S103 in FIG. 5). Since the sheet P is shifted while being conveyed, the sheet P is conveyed in an oblique direction d12 toward the punch unit 251 (FIG. 4B).

  Simultaneously with the start of the shift operation, the orthogonal roller pair 205 starts to rotate in the d2 direction and prepares for paper delivery (step S104 in FIG. 5). When the position of the paper leading edge (e1) reaches the punching position in the transport direction d1 (step S105 in FIG. 5), the rotation operation of the transport roller pair 203 is stopped (step S106 in FIG. 5), and only the shift operation is continued. Then, the paper P is shifted to the orthogonal roller pair 205 (FIG. 4C), and the delivery of the paper P from the conveying roller pair 203 to the orthogonal roller pair 205 is completed.

  The sheet P nipped by the orthogonal roller pair 205 is conveyed by the shift operation of the conveyance roller pair 203 and the rotation operation of the orthogonal roller pair 205. When the paper side end (e2) reaches the punching position in the transport direction d2 (step S107 in FIG. 5), the shift operation of the transport roller pair 203 and the rotation operation of the orthogonal roller pair 205 are stopped (steps S108 and S109 in FIG. 5). Then, the alignment is completed (FIG. 6D). The alignment in the transport direction d1 (paper front end e1) has already been completed in the state of FIG. Therefore, at this time, the alignment to the punching position is completed in both the transport directions d1 and d2, and punching is performed by the punch unit 251 (step S110 in FIG. 5). The paper P at the time of punching is in a state of being nipped between the conveying roller pair 203 and the orthogonal roller pair 205. After punching, while rotating the orthogonal roller pair 205 in the transport direction d3, the transport roller pair 203 is shifted in the transport direction d3 at the same speed as that rotation speed (FIG. 6E: steps S111 and S112 in FIG. 5). . In addition, since the above-described operation is performed, the punching position can be adjusted by the transport amount from the transport roller pair 203 and the movement amount of the transport roller pair 203.

  The paper P is transported in the oblique direction d13 by rotating the transport roller pair 203 in the transport direction d1 while shifting the paper P in the transport direction d3. When the sheet P passes through the conveyance roller pair 203 (FIG. 6F: Step S113 in FIG. 5), the shift operation and the rotation operation of the conveyance roller pair 203 are stopped (Steps S114 and S115 in FIG. 5), and the paper discharge guide. The plate 212 is lowered and nipped by the discharge roller pair 209 (step S116 in FIG. 5). When the paper P is transported in the transport direction d3 by the rotation operation of the paper discharge roller pair 209 (step S117 in FIG. 5), the paper P is discharged to the paper discharge tray 210 (FIG. 6G).

  When the paper P passes through the paper discharge roller pair 209 (step S118 in FIG. 5) and is discharged to the paper discharge tray 210, the paper discharge guide plate 212 is raised and the rotation operation of the paper discharge roller pair 209 is stopped (FIG. 5). Steps S119 and S120), and the discharge of the paper P is completed.

FIG. 7 is a diagram illustrating an operation when the paper post-processing apparatus 200 does not perform the punching process.
When the paper P is passed from the image forming apparatus main body 100, the entrance roller pair 201 and the transport roller pair 203 start rotating operations (step S201 in FIG. 5). The paper P received by the paper post-processing apparatus 200 from the image forming apparatus main body 100 via the main body discharge roller 169 is transported in the transport direction d1 through the inlet roller pair 201 and the transport roller pair 203 (FIG. 7A). )). In synchronization with the timing at which the trailing edge (e4) of the sheet passes through the entrance roller pair 201 (step S202 in FIG. 5), the transport roller pair 203 starts the shift operation in the transport direction d3 (step S203 in FIG. 5). Since the paper P shifts while being conveyed, it is conveyed in an oblique direction d13 toward the paper discharge tray 210 (FIG. 7B).

  When the trailing edge (e4) of the sheet passes through the conveying roller pair 203 (FIG. 7C: Step S204 in FIG. 5), the shift operation and the rotation operation of the conveying roller pair 203 are stopped (Steps S205 and S206 in FIG. 5). Then, the discharge guide plate 212 is lowered and nipped by the discharge roller pair 209 (step S207 in FIG. 5). By transporting the paper P in the transport direction d3 by the rotation operation of the paper discharge roller pair 209 (step S208 in FIG. 5), the paper P is discharged to the paper discharge tray 210 (FIG. 7D).

  When the paper side end (e2) passes through the paper discharge roller pair 209 (step S209 in FIG. 5) and is discharged to the paper discharge tray 210, the paper discharge guide plate 212 is raised and the rotation operation of the paper discharge roller pair 209 is stopped. (Steps S210 and S211 in FIG. 5), and the discharge of the paper P is completed.

  Next, the shift amount and shift operation speed control depending on the sheet width will be described. FIG. 8 is a diagram illustrating the operation of the sheet post-processing apparatus 200, and FIG. 9 is a flowchart illustrating the control of the sheet post-processing apparatus 200. 8A to 8C show the receipt and discharge of the paper PA having a large paper width (paper length in the d2 and d3 directions), and FIGS. 8D to 8F show the paper PB having a small paper width. It is a figure which shows operation | movement.

  When the paper P not subjected to post-processing by the punch unit 251 is passed from the image forming apparatus main body 100, the paper post-processing apparatus 200 shifts and shifts according to the paper width size notified from the image forming apparatus main body 100 in advance. The speed is determined (step S301 in FIG. 9). When the sheet P is passed from the image forming apparatus main body 100, the entrance roller pair 201 and the transport roller pair 203 start rotating operations (step S302 in FIG. 9). The sheet P received by the sheet post-processing apparatus 200 from the image forming apparatus main body 100 via the main body discharge roller 169 is transported in the transport direction d1 through the inlet roller pair 201 and the transport roller pair 203 (FIG. 8A ), (D)). The conveyance roller pair 203 starts a shift operation in the conveyance direction d3 (step S304 in FIG. 9) in synchronization with the timing at which the rear end (e4) of the sheet exits the entrance roller pair 201 (step S303 in FIG. 9).

  A distance L2 from the sheet conveyance center to the sheet side end (e3) is calculated based on sheet size information notified from the image forming apparatus main body 100. The paper PA is L2a and the paper PB is L2b. At this time, the amount of shift required until the trailing edge (e4) of the sheet passes from the pair of entrance rollers 201 to the pair of transport rollers 203 is arranged on the discharge tray 210 side when the pair of transport rollers 203 is removed. Nipping is possible by a pair of discharge rollers 209 attached to the discharge guide plate 212. When the distance from the sheet conveyance center to the nip position of the discharge roller pair 209 is L1, the movement amount of L3a is necessary for the paper PA and L3b is necessary for the paper PB. Since the length L2a from the conveyance center of the paper PA to the paper side end (e3) is longer than the length L2b from the conveyance center of the paper PB to the paper side end (e3), the shift amount L3a of the paper PA is equal to the paper PB. Is set to be smaller than the shift amount L3b. The shift operation speed is determined by a shift amount necessary until the trailing edge (e4) of the sheet passes the distance L4 from the entrance roller pair 201 to the conveyance roller pair 203.

  For example, if the shift amount L3a of the paper PA is a movement amount that is ½ of the shift amount L3b of the paper PB, the shift operation speed of the paper PA is operated at ½ of the shift operation speed of the paper PB. Since the paper P shifts while being transported, it is transported toward the paper discharge tray 210 in oblique directions d13A and d13B, respectively (FIGS. 8B and 8E). When the trailing edge (e4) of the sheet has passed through the conveying roller pair 203 (FIGS. 8C and 8F), the shift amount d3B of the sheet PB is controlled to be larger than the shift amount d3A of the sheet PA. . When the trailing edge (e4) of the sheet passes through the transport roller pair 203 (step S305 in FIG. 9), the shift operation and the rotation operation of the transport roller pair 203 are stopped (steps S306 and S307 in FIG. 9). Then, the paper discharge guide plate 212 is lowered and nipped by the paper discharge roller pair 209 (step S308 in FIG. 9). By transporting the paper P in the transport direction d3 by the rotation operation of the paper discharge roller pair 209 (step S309 in FIG. 9), the paper P is discharged to the paper discharge tray 210. Then, when the paper side end (e2) passes through the paper discharge roller pair 209 (step S310 in FIG. 9) and is discharged to the paper discharge tray 210, the paper discharge guide plate 212 is raised. At the same time, the rotation operation of the discharge roller pair 209 is stopped (steps S311 and S312 in FIG. 9), and the discharge of the paper P is completed.

Next, shift operation stop control at the time of paper release will be described with reference to a control flowchart of the paper post-processing apparatus 200 shown in FIG.
When the paper P not subjected to post-processing by the punch unit 251 is passed from the image forming apparatus main body 100, the paper post-processing apparatus 200 shifts and shifts according to the paper width size notified from the image forming apparatus main body 100 in advance. The speed is determined (step S401 in FIG. 10). When the sheet P is passed from the image forming apparatus main body 100, the inlet roller pair 201 and the conveying roller pair 203 start operation (step S402 in FIG. 10). The paper P received by the paper post-processing device 200 from the image forming apparatus main body 100 via the main body discharge roller 169 is transported in the transport direction d1 through the inlet roller pair 201 and the transport roller pair 203. In synchronization with the timing at which the rear end (e4) of the sheet exits the entrance roller pair 201 (step S403 in FIG. 10), the transport roller pair 203 starts a shift operation in the transport direction d3 (step S404 in FIG. 10). Since the sheet P is shifted while being conveyed, the sheet P is conveyed in an oblique direction d13 toward the punch unit 251 as a post-processing unit. After a predetermined T1 msec has elapsed since the trailing edge (e4) of the sheet has passed the entrance roller pair 201 (step S405 in FIG. 10), the operation of the shift motor is stopped (step S406 in FIG. 10). When the time for the trailing edge (e4) of the sheet to pass the distance from the entrance roller pair 201 to the discharge roller pair 203 is T2 milliseconds, the shift operation stop time T1 is set to a value smaller than the time T2.

  When the trailing edge (e4) of the sheet passes through the conveyance roller pair 203 (step S407 in FIG. 10), the rotation operation of the conveyance roller pair 203 is stopped (step S408 in FIG. 10), and the paper discharge guide plate 212 is lowered and discharged. Nipping is performed by the paper roller pair 209 (step S409 in FIG. 10). By transporting the paper P in the transport direction d3 by the rotation operation of the paper discharge roller pair 209 (step S410 in FIG. 10), the paper P is discharged to the paper discharge tray 210. When the paper side end (e2) passes through the paper discharge roller pair 209 (step S411 in FIG. 10) and is discharged to the paper discharge tray 210, the paper discharge guide plate 212 is raised and the rotation operation of the paper discharge roller pair 209 is stopped ( The discharge of the paper P is completed in steps S412 and S413 in FIG.

Further, the shift amount and shift operation timing control due to the difference in sheet width will be described with reference to the control flowchart of the sheet post-processing apparatus 200 shown in FIG.
When the paper P not subjected to post-processing by the punch unit 251 is passed from the image forming apparatus main body 100, the paper post-processing apparatus 200 shifts and shifts according to the paper width size notified from the image forming apparatus main body 100 in advance. The start timing is determined (step S501 in FIG. 11). When the paper P is passed from the image forming apparatus main body 100, the entrance roller pair 201 and the transport roller pair 203 start rotating operations (step S502 in FIG. 11).

  The paper P received by the paper post-processing device 200 from the image forming apparatus main body 100 via the main body discharge roller 169 is transported in the transport direction d1 through the inlet roller pair 201 and the transport roller pair 203. When the trailing edge (e4) of the sheet passes through the entrance roller pair 201 and the shift operation start timing T13 is reached (step S503 in FIG. 11), the transport roller pair 203 starts a shift operation in the transport direction d3 (step in FIG. 11). S504). The shift operation start timing is determined by the amount of shift required until the trailing edge (e4) of the sheet passes the distance L4 from the entrance roller pair 201 to the transport roller pair 203. Since the method for determining the shift amount has been described above, a description thereof will be omitted.

  When the time for the trailing edge (e4) of the sheet to pass the distance from the inlet roller pair 201 to the paper discharge roller pair 203 is T11 milliseconds, and the shift operation time is T12 milliseconds, the shift operation start timing T13 is until T11 elapses. (T11-T12) milliseconds are set so that the shift operation can be completed. For example, if the shift amount L3a of the paper PA having the large paper width is a movement amount ½ of the shift amount L3b of the paper PB having the small paper width, the shift operation times of the paper PA and the paper PB are T12a and T12b, respectively. In addition, T12a is half the time of T12b. The shift operation start timing T13a of the paper PA is (T11- (T12b / 2)), and the shift operation start timing T13b of the paper PB is (T11-T12b). Therefore, the operation start timing of the paper P is delayed as the paper P has a larger paper width.

  Since the paper P is shifted while being conveyed, the paper P is conveyed in an oblique direction d13 toward the paper discharge tray 210. When the trailing edge (e4) of the sheet passes through the conveying roller pair 203, the shift amount d3B of the sheet PB is controlled to be larger than the shift amount d3A of the sheet PA. When the trailing edge (e4) of the sheet passes through the transport roller pair 203 (step S505 in FIG. 11), the shift operation and the rotation operation of the transport roller pair 203 are stopped (steps S506 and S507 in FIG. 11). Then, the paper discharge guide plate 212 is lowered and nipped by the paper discharge roller pair 209 (step S508 in FIG. 11). By transporting the paper P in the transport direction d3 by the rotation operation of the paper discharge roller pair 209 (step S509 in FIG. 11), the paper P is discharged to the paper discharge tray 210.

  When the paper side end (e2) passes through the paper discharge roller pair 209 (step S510 in FIG. 11) and is discharged to the paper discharge tray 210, the paper discharge guide plate 212 is raised and the rotation operation of the paper discharge roller pair 209 is stopped ( In step S511 and S512 in FIG. 11, the discharge of the paper P is completed.

<Embodiment 2>
FIG. 12 is a diagram showing an outline of the system configuration of an image forming system according to Embodiment 2 of the present invention. As shown in the figure, the configuration is almost the same as that of the image forming system according to the first embodiment shown in FIG. Therefore, only the common reference numerals are given to the common parts, and redundant description is omitted.

FIG. 13 is a schematic configuration diagram of the paper post-processing apparatus 200 according to the second embodiment shown along line II-II in FIG. 12, and FIG. 14 is a diagram (A) showing the positional relationship between the punch unit and the stapler and the shift roller. It is a figure (B) which shows the relationship with the shift direction.
In the drawing, a sheet post-processing apparatus 200 includes an inlet roller 201 pair, a sheet discharge conveyance path 202, a sheet discharge roller pair 203, a hitting roller 204, a staple tray 206, a trailing edge reference fence 207, a staple, from the upstream side in the sheet conveyance direction. A pull jogger fence 208 (alignment plate), a discharge roller pair 209, and a discharge tray 210 are mainly configured.

  The paper receiving unit of the paper post-processing apparatus 200 transports the received paper P from the paper discharge transport path 202 of the image forming apparatus main body 100 to a site where the received paper P and the punch unit 251 described later are provided. A paper discharge conveyance path 202 and a pair of paper discharge rollers 203 are provided. Then, the paper P is transported along the paper discharge transport path 202 by rotating the pair of inlet rollers 201 and the pair of paper discharge rollers 203 by an inlet motor (not shown) which is a stepping motor.

  In addition, an entrance sensor 901 is disposed in the paper discharge conveyance path 202 (not shown) as in the previous embodiment, detects the leading edge and trailing edge of the paper P, and detects the leading edge and trailing edge of the detected paper P. The timing at which each paper processing is performed is determined based on the detection timing and the number of steps of driving the inlet motor. The inlet roller pair 201 and the discharge roller pair 203 provided along the paper discharge conveyance path 202 function as a conveyance unit.

  In order to make the apparatus itself compact, the image forming apparatus main body 100 according to the present embodiment transports the paper P by SEF (short end surface transport) as shown in FIG. For this reason, as a configuration arrangement of the sheet post-processing apparatus downstream from the paper discharge roller pair 203, post-processing such as the punch unit 251 and the stapler 252 needs to be performed on the end face parallel to the transport direction as shown in FIG. Therefore, downstream of the paper discharge roller pair 203 in the paper conveyance direction, the conveyance direction of the paper P is switched to a direction perpendicular to the conveyance direction from the image forming apparatus main body 100 to process the paper P. In the figure, reference numeral 231 denotes a punch jogger, and 251a denotes a punch base.

  The paper P conveyed from the pair of paper discharge rollers 203 enters the punch stage with the back end face of the paper supported by the punch unit 251 and the front end face supported by the staple tray 206, and then punched by the paper discharge roller pair 203. The paper P is moved in the direction of the unit 251 and punched by the punch unit 251. After punch holes are punched, the paper discharge roller pair 203 is moved, and the end face on the back side of the paper is dropped from the punch unit 251 onto the staple stage constituting the binding unit.

  Here, in the mode in which punch punching is not performed, the punching operation by the punch unit 251 is not performed during the punch hole punching operation described above, and the sheet end surface is dropped onto the staple stage.

  After the end face of the paper has dropped from the punch stage, the shift mode in which the paper P is shifted and discharged is different from the shift mode in which a plurality of papers P are bound and discharged. To do.

First, the shift mode will be described.
The shift mode is a mode in which the sheets P are sorted by a predetermined number of right and left as viewed from the front (FIG. 12) of the image forming apparatus main body 100 on the sheet discharge tray 210 without performing the binding process on the sheets P. . The staple tray 206 is provided with a staple jogger fence 208 and is inserted into a guide shaft (not shown) fixed to the staple tray 206. Further, the staple jogger fence 208 is connected to a stepping motor via a timing belt (not shown). A linear reciprocating movement is performed by forward / reverse rotation driving of the stepping motor, and each of the staple jogger fences 208 can be driven independently.

  After the sheet P falls to the staple stage, the sheet rear side end surface is abutted against the rear end reference fence 207 by the hitting roller 204. Thus, alignment in the transport direction in the sheet post-processing apparatus is performed, and alignment in the direction perpendicular to the transport direction in the sheet post-processing apparatus is performed by the staple jogger fence 208.

  A paper discharge guide plate 212 and a paper discharge roller pair 209 are disposed downstream of the hitting roller 204 in the paper conveyance direction. The paper discharge guide plate 212 can be moved up and down by a stepping motor (not shown), and the paper P is conveyed by a pair of paper discharge rollers 209 and a driven roller 213 attached to the paper discharge guide plate 212, and the paper P is discharged from the paper discharge tray. The paper is discharged to 210 and stacked on the paper discharge tray 210.

  When sorting the paper P every predetermined number of sheets, the paper is discharged onto the paper discharge tray 210 by shifting the alignment position (position of the staple jogger fence 208) perpendicular to the transport direction in the paper post-processing device by the amount moved. To do. As a result, when the sheets are stacked on the paper discharge tray 210, the paper discharge positions are alternately shifted every predetermined number of sheets, and the paper P is sorted.

  At a portion where the paper discharge tray 210 is attached to the main body of the paper post-processing apparatus 200, a pair of paper discharge rollers 209 is also disposed as a paper presser for pressing the paper P stacked on the paper discharge tray 210. By this discharge roller pair 209, the paper press release operation and the paper press operation are performed by turning on / off the solenoid 218. That is, the solenoid 218 is turned on in accordance with the conveyance of the paper P to release the pressing operation of the paper discharge roller pair 209, and when the paper P passes through the paper discharge roller pair 209, the solenoid 218 is turned off to press the paper.

  Further, a tray paper surface sensor (not shown) is disposed on the paper discharge roller pair 209. If the tray paper surface sensor is OFF while the paper discharge roller pair 209 is pressing the paper, the paper discharge tray 210 is raised until the paper surface sensor is turned ON. If the paper surface sensor is ON, the paper discharge tray 210 is lowered until the paper surface sensor is turned OFF, and then raised until it is turned ON again. Thus, the height of the paper discharge tray on which the paper P is stacked is kept constant.

  In this manner, the free end of the movable tray portion 222b is moved up and down according to the paper stacking state of the paper discharge tray 210, and the distance from the nip portion of the paper discharge roller pair 209 to the paper stacking portion of the movable tray portion 222b is kept constant. . Thus, the contact angle between the paper P discharged from the paper discharge roller pair 209 and the movable tray portion 222b is made constant. In addition, the alignment quality of the sheets P stacked on the sheet discharge tray 210 can be stabilized, and a large number of sheets can be stacked.

  By repeating the above operation, the sorted paper P is stacked on the paper discharge tray 210.

Next, the stipple mode will be described.
In the stipple mode, when the paper P is discharged, the paper is bound by the stapler 252 every predetermined number and discharged. A hitting roller 204 that is driven in the vertical direction by a stepping motor (not shown) is disposed upstream of the paper discharge guide plate 212 in the paper conveyance direction. The hitting roller 204 includes a lever portion that moves up and down and a roller portion. The roller portion is rotated by a paper discharge motor 217 in the direction opposite to the paper transport direction in the paper post-processing device.

  In the staple mode, the tapping roller 204 is lowered at the timing when the rear end surface of the sheet is pushed out of the punch unit, and the sheet P is pressed against the staple tray 206 as a stacking unit at the roller portion. Further, the roller portion is rotated to switch back until the trailing edge of the sheet comes into contact with the trailing edge reference fence 207, and the conveying direction in the sheet finishing apparatus is adjusted. This alignment is performed based on the rear end reference fence 207 by abutting against the rear end reference fence 207.

  When the switchback of the sheet P is completed, the sheet alignment in the direction perpendicular to the sheet conveyance direction in the sheet post-processing apparatus is performed by the staple jogger fence 208 arranged on the staple tray 206 described above in the description of the shift mode. .

  As illustrated, the staple tray 206 is provided with a staple jogger fence 208, and the staple jogger fence 208 is inserted into a guide shaft (not shown) fixed to the staple tray 206. The staple jogger fence 208 is also connected to a stepping motor (not shown) via a timing belt (not shown), and linearly reciprocates by the forward / reverse rotation driving of the stepping motor. Therefore, each of the staple jogger fences 208 can be driven independently.

  Next, a home sensor for detecting the standby position of the staple jogger fence 208 is provided on the staple tray 206 (not shown). In addition, the staple tray 206 is provided with a reference fence (not shown) via a slider on a guide shaft (not shown), and can move in the same direction as the staple jogger fence 208. Since the rack holds the rack and is connected to a gear disposed substantially at the center of the staple tray 206, the reference fence moves symmetrically with respect to the gear.

  Further, a guide portion is provided at an end portion of a reference fence (not shown), and a base (not shown) of the stapler 252 follows the reference fence by hooking the inside of the guide portion as the stapler 252 moves. Will do. When the stapler 252 moves in the end direction of the staple tray 206, the interval between the reference fences is increased. When the stapler 252 moves to the center of the staple tray 206, the reference fence is urged toward the center of the staple tray 206 by a spring (not shown), so the interval between the reference fences is narrowed.

  After the binding process, the paper discharge guide plate 212 is lowered, the paper bundle is held between the paper discharge roller pair 209 and the driven roller attached to the paper discharge guide plate 212, and the paper bundle is discharged onto the paper discharge tray 210. While the paper P is being discharged onto the paper discharge tray 210, the solenoid 218 is turned on to release the paper discharge roller pair 209, and the paper discharge tray 210 is further lowered by a certain amount. Next, the paper discharge guide plate 212 is raised at the timing when the rear end of the bundle of paper discharged onto the paper discharge tray 210 passes the position of the paper discharge sensor 224 (not shown) to prepare for receiving the next paper. Further, at the same timing, the solenoid 218 is turned off to perform sheet pressing.

  As shown in FIG. 15A, an entrance sensor 250 is installed in front of the paper discharge roller pair 203, and the distance at which the leading edge of the conveyed paper P is conveyed from the nip of the paper discharge roller pair 203 is indicated by this entrance sensor 250. Measure with The entrance sensor 250 confirms that the trailing edge of the paper P has passed through the pair of rollers upstream of the paper discharge roller pair 203 in the paper transport direction, and the paper P is shifted to the punch unit 251 by the paper discharge roller pair 203. Normally, when the transport distance from the paper discharge roller pair 203 is X mm and the shift movement amount is Y mm, the punch position is set to x mm in the transport direction and the y mm punch position is adjusted to the front of the transport perpendicular direction. Control is performed so that the transport distance is (X−x) mm and the shift movement amount is (Y−y) mm. The adjustment amounts x and ymm are preferably input from an operation panel provided in the image forming apparatus, for example.

  15B, a registration detection sensor 253A that detects the registration position of the paper P in front of the paper discharge roller pair 203 and a front end detection that detects the stop position of the paper front from the paper discharge roller pair 203. A sensor 253B may be provided. When the leading edge of the paper P is detected by the registration detection sensor 253A, the paper P has been transported closer to the front (lower side in the paper surface of FIG. 15), so that the paper is discharged with a shift movement amount of (Y + α) mm. The pair of rollers 203 is moved to correct the registration position deviation. When a CIS (line sensor) is used as the registration detection sensor 253A, the shift movement amount is changed in accordance with the measured value for each sheet of paper to be transferred from the aim of the end face position of the paper P. By using the CIS for the sensor, the movement amount of the paper discharge roller pair 203 can be accurately changed, and the punch position accuracy can be further improved. Note that the conveyance direction of the paper P is controlled so as to stop the rotation of the paper discharge roller pair 203 when it is detected by the leading edge detection sensor 253B.

  That is, by adjusting the movement amount of the paper discharge roller pair 203 and the conveyance amount of the paper P, the punch position can be adjusted simultaneously in both the paper conveyance direction and the right-angle direction. This improves user convenience. By providing a sensor for detecting the position of the paper P, the paper P can be accurately fed to the punching device for each paper P being conveyed, so that the punch position accuracy is improved. Further, when the paper discharge roller pair 203 is moved, it is detected that the end of the paper P is not accurately fed to the punching device, and in this case, the operation is stopped to prevent the paper P from being damaged. Can do.

  For example, as shown in FIG. 16, if the registration detection sensor 253A is not turned off even if the position of the sheet P is shifted by Fmm which is the detection range of the registration detection sensor 253A which is CIS, the shift operation is stopped (FIG. 16). 16 (A) state). The shift operation is also stopped when the paper P cannot move to the punch position due to the curl of the paper P (state of FIG. 16B).

  The present invention is not limited to the embodiments described above, and many variations are possible by those having ordinary knowledge in the art within the technical idea of the present invention.

100: Image forming apparatus main body 110: Image forming unit 111: Image forming station 112: Intermediate transfer belt 114: Support roller 115: Secondary transfer roller 120: Paper feed unit 121: Paper feed tray 122: Pickup roller 123: Paper feed conveyance Roller 130: Vertical conveyance path 140: Intermediate transfer section 150: Fixing section 160: Paper discharge path 161: Branch claw 162: Branch conveyance roller 169: Main body discharge roller 170: Double-side conveyance path 200: Paper post-processing device 201: Entrance roller 202 : Discharge conveyance path 203: conveyance roller pair 204: roller 205: orthogonal roller 206: staple tray 207: rear end reference fence 208: staple jogger fence 210: discharge tray 212: discharge guide plate 213: driven roller 217 : Paper discharge motor 218: Solenoid 221: Link mechanism 2 1a: tray DC motor 221b: link mechanism 221c: support shaft 222a: fixed tray portion 222b: movable tray portion 224: paper discharge sensor 250: inlet sensor 251: punch unit 252: stapler 253A: registration detection sensor 253B: tip detection sensor 300 : Image reading device 400: Post-processing device control unit 401: CPU
402: ROM
403: RAM
404: Serial I / F
405: Timer 415: Serial I / F
420: DC load 430: Sensor 901: Entrance sensor P: Paper

JP 2006-240759 A JP 2009-063832 A

Claims (7)

An image reading unit for reading image information;
A paper feeder that feeds paper,
An image forming unit that performs an image forming process on paper conveyed from the paper feeding unit;
In an image forming apparatus having
A post-processing unit that is disposed in a space formed between the image reading unit and the image forming unit, and performs post-processing in parallel with a paper conveyance direction in which an image is formed in the image forming unit;
A cross transport unit that transports the paper post-processed by the post-processing unit in a direction orthogonal to the transport direction of the paper transported from the image forming unit;
A stacking unit for stacking sheets ejected by the cross conveyance unit;
Shift means for sliding in a direction orthogonal to the paper conveyance direction on which the image is formed in the image forming unit;
A shift control unit that slides the shift unit toward the post-processing unit when the post-processing unit performs post-processing on the paper; and a slide control unit that slides the shift unit toward the stacking unit when the post-processing is not performed.
An image forming apparatus comprising: The image forming apparatus according to claim 1.
When the post-processing is not performed on the paper, the shift movement amount of the shift unit is determined by the paper length in a direction orthogonal to the transport direction of the paper transported from the image forming unit.
An image forming apparatus. The image forming apparatus according to claim 1, wherein
The post-processing unit includes a punching unit that punches paper, and a binding unit that performs binding processing,
The perforating unit is disposed on the binding unit;
The cross conveyance unit is composed of a shift roller pair arranged in the vicinity of the post-processing unit and movable in the direction perpendicular to the conveyance,
An image forming apparatus characterized in that a punching position by the punching unit can be adjusted by a conveyance amount from the shift roller pair and a movement amount of the shift roller pair. The image forming apparatus according to claim 3.
A sensor that detects the leading edge of the paper transport direction and the edge perpendicular to the paper transport direction;
An image forming apparatus, wherein a conveyance amount of a sheet from the shift roller pair and a movement amount of the shift roller are changed according to a detection result of the sensor. The image forming apparatus according to claim 4.
Even if the shift roller moves the paper toward the perforation unit by a certain amount, if the sensor detects an edge perpendicular to the transport direction of the paper, the shift operation of the paper by the shift roller is stopped. An image forming apparatus. The image forming apparatus according to claim 4 or 5,
An image forming apparatus characterized in that a sensor for detecting an edge in a direction perpendicular to the sheet conveying direction is a line sensor. The image forming apparatus according to claim 6.
An image forming apparatus, wherein the line sensor is a CIS.