JP2012140236A - Post-processing device and image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform favorable alignment while preventing the attraction of paper sheets caused by static electricity or the like, and to perform favorable alignment even to a paper sheet having a curl, in a post-processing device having a stacker which causes the paper sheet slid along an inclined paper sheet placing face to abut on a stopper and places it thereon.SOLUTION: This post-processing device comprises an air flow forming means which forms a first air flow which is blown to a paper sheet placing face from a stopper side in a parallel direction, and a second air flow which is blown to a direction progressing toward the paper sheet placing face from the upper part of the paper sheet placing face.

Description

  The present invention relates to a post-processing apparatus that bundles and processes sheets discharged from an image forming apparatus, and more particularly, to a post-processing apparatus that includes an aligning unit that aligns sheets on an end surface without being disturbed.

  2. Description of the Related Art Post-processing apparatuses having binding means (stapler) for binding an image-formed sheet discharged from an image forming apparatus such as a printer or a copying machine using a staple (staple) are widely used. A post-processing apparatus with binding means (hereinafter also referred to as a bookbinding apparatus) sequentially receives sheets discharged from an upstream device such as an image forming apparatus, and sequentially places the sheets on a stacker until a predetermined number of sheets is reached. A booklet is formed by binding a binding needle at a predetermined position of the sheet bundle. The booklet is required to be aligned without any disturbance on the end face. Normally, in the process of forming a paper bundle before hitting the binding needle, the booklet is aligned in the vertical direction to align the end face in the paper transport direction and the transport direction. Lateral alignment is performed to align the end faces in the orthogonal direction.

  For example, by tilting the stacker in the paper transport direction, the paper discharged to the stacker is slid down along the top surface of the stacker or the top surface of the paper already placed on the stacker by its own weight, and is stopped by hitting the stopper. Longitudinal alignment is performed to align the edges of the paper in the sliding direction, that is, the conveyance direction. Further, a member that swings on the side surface perpendicular to the sliding direction of the paper in the stacker, for example, an alignment plate, is provided, and the alignment plate is swung in the process of sliding down the upper surface of the stacker, and orthogonal to the sliding direction of the paper. The horizontal alignment is performed to align the end portions in the direction in which the sheet is conveyed, that is, in the direction orthogonal to the transport direction.

  By the way, a sheet conveyed to the stacker and a sheet already placed on the stacker may be attracted. For example, the sheets may be charged with static electricity in the process of being transported to the stacker or in the process of sliding along the upper surface of the paper placed on the stacker, and the sheets may be adsorbed by the static electricity. When the sheets are attracted to each other, neither vertical alignment nor horizontal alignment is suitably performed, and the end face of the sheet bundle may be disturbed. For this reason, a technique has been proposed in which an air flow is blown from the end face side of a sheet abutted against the stopper so that the sheets do not adhere to each other (see Patent Document 1).

  Further, a sheet having curl may be conveyed to the stacker. The paper is heated and pressed by the fixing device in the image forming process in the image forming apparatus to fix the image. However, in the process of being heated and cooled, there is a difference in shrinkage between the front and back surfaces of the paper, which causes curling. There is. When a sheet having curls is placed on the stacker, an air layer is formed between sheets constituting the sheet bundle, and the end face of the sheet bundle may be disturbed. For this reason, a technique has been proposed in which a sheet placed on the stacker is pressed by a roller to eliminate an air layer between the sheets (see Patent Document 2).

JP 2001-80815 A Japanese Patent Laid-Open No. 2004-292081

  The technique proposed in Japanese Patent Laid-Open No. 2004-228867 prevents the sheets from adsorbing to each other due to static electricity or the like, but does not cope with the unevenness of the sheets having curls.

  The technique proposed in Patent Document 2 cannot cope with the adsorption of sheets due to static electricity or the like. Further, in the technique proposed in Patent Document 2, the sheet stack placed on the stacker is once brought into contact with a roller and then separated before binding, thereby forming an air layer between the sheets. However, a drive mechanism for pressing and separating the roller and a control unit for operating the drive mechanism at an appropriate timing are required, which complicates the structure.

  The present invention provides a post-processing apparatus having a simple configuration that can perform favorable alignment by preventing the sheets from adsorbing due to static electricity and the like, and also performing good alignment on a sheet having curls. The issue is to provide.

  The above problem is solved by the following means.

1. A stacker that includes an inclined paper placement surface and a stopper, and places the paper slid along the paper placement surface in contact with the stopper;
A stapler that binds the paper placed on the stacker with a binding needle;
In an aftertreatment device having
An air flow that forms a first air flow that blows in a direction parallel to the paper placement surface from the stopper side and a second air flow that blows in a direction from above the paper placement surface toward the paper placement surface. A post-processing apparatus having a forming means.

2. The air flow forming means includes
An air flow generating means for generating an air flow;
Air flow direction switching means for changing the direction of the air flow generated by the air flow generation means;
Have
The first air flow and the second air flow are formed by changing a direction of an air flow generated by the air flow generation unit by the air flow direction switching unit. Post-processing device as described.

3. A control unit for controlling the air flow forming means;
The control unit forms the first air flow in a process in which the paper slides down the paper placement surface, and forms the second air flow at a timing when the slipped paper comes into contact with the stopper. 3. The post-processing apparatus according to 2, wherein the flow forming means is controlled.

  4). An image forming system comprising: the image forming apparatus connected to the post-processing apparatus according to any one of the above items 1 to 3.

  According to the present invention, there is provided a post-processing apparatus having a simple configuration capable of performing favorable alignment by preventing the adsorption of sheets due to static electricity or the like and performing good alignment with a sheet having curls. it can.

1 is a configuration diagram of an image forming system formed by connecting an image forming apparatus A and a post-processing apparatus B according to an embodiment of the present invention. It is a figure explaining post-processing apparatus B. FIG. It is a figure explaining the airflow formation part. 2 is a block diagram of a control system in the image forming system of the present embodiment. FIG. 6 is a flowchart for explaining a post-processing operation executed by the post-processing apparatus B.

  Although the present invention will be described based on the embodiments, the present invention is not limited to the embodiments.

  FIG. 1 is a configuration diagram of an image forming system formed by connecting an image forming apparatus A and a post-processing apparatus B according to an embodiment of the present invention.

  The image forming apparatus A shown in FIG. 1 includes an automatic document feeder A1, an image reading unit A2, an image writing unit A3, an image forming unit A4, a fixing device A6, a sheet conveying unit A7, and an operation display unit A8. .

  The paper transport unit A7 has a plurality of transport rollers driven by a drive motor, and sequentially transports the paper S stored in the cassette Ac to the image forming unit A4 and the fixing device A6 by the paper transport unit A7. The paper on which the image has been formed is discharged to the post-processing apparatus B.

  The operation display unit A8 includes a touch panel in which a touch screen is placed on a display unit configured by a liquid crystal panel. Various operation screens can be displayed on the operation display unit A8, and conditions for jobs to be executed by the image forming system, such as paper size, presence / absence of post-processing (binding), the number of copies, and the like can be input.

  The document placed on the document table of the automatic document feeder A1 is scanned on one or both sides of the document by the optical system of the image reading unit A2, and the photoelectrically converted analog signal is converted into AD conversion, shading correction, After undergoing processing such as image compression processing, the image is sent to the image writing unit A3.

  In the image writing unit A3, the output light from the semiconductor laser is applied to the photosensitive drum of the image forming unit A4 to form a latent image. In the image forming unit A4, processes such as charging, exposure, development, transfer, separation, and cleaning are performed.

  The post-processing apparatus B includes a stacker 10, a stapler 50, an air flow forming unit 30, and a paper transport unit 70. In addition, on the left side of the post-processing apparatus B in the figure, a movable movable paper discharge stand 74 is disposed.

  The paper transport unit 70 includes a plurality of transport roller pairs driven by a drive motor, and transports paper along the illustrated entrance transport path 7r1, the paper discharge transport path 7r2, and the bookbinding transport path 7r3.

  A transport path switching unit 75 is disposed at the exit of the entrance transport path 7r1, and the sheet transported along the entrance transport path 7r1 is sent to either the discharge transport path 7r2 or the bookbinding transport path 7r3. Lead.

  Whether the paper transported along the entrance transport path 7r1 is guided to the paper discharge transport path 7r2 or the bookbinding transport path 7r3 depends on the transported paper job. For example, in the case of a job for post-processing, that is, binding, the sheet received from the image forming apparatus A is guided to the bookbinding transport path 7r3, and in the case of a job in which binding is not performed, the received sheet is input to the entrance transport path 7r1. Then, the paper is guided to the paper discharge conveyance path 7r2 and discharged to the movable paper discharge tray 74 via the paper discharge conveyance path 7r2.

  The sheets conveyed through the bookbinding conveyance path 7r3 are stacked (stacked) up to the number of sheets designated for the job by the stacker 10 to form a sheet bundle, and the stapler 50 is bound to a predetermined position of the sheet bundle on the stacker 10 by the stapler 50. To form a booklet.

  The formed booklet is discharged to the moving paper discharge stand 74.

  The post-processing performed by the post-processing apparatus B in the present embodiment is a binding process in which a binding needle is applied to the sheet bundle to form a booklet, but the post-processing apparatus to which the present invention can be applied The present invention is not limited to the binding process using the binding needle as long as post-processing that performs batch processing is performed. For example, a booklet may be formed by gluing, or an additional function such as a shift function may be provided in addition to a post-processing function for collectively processing a bundle of sheets.

  The post-processing apparatus B operates under the control of the post-processing control unit 90 shown in FIG. When the post-processing control unit 90 controls and operates the post-processing apparatus B, information such as whether or not to perform binding by the user and selection of the number of sheets to be bound when performing binding are displayed on the operation display unit of the image forming apparatus A. Based on the input result from A8, it is transmitted as job information from the control unit A9 (see FIG. 4) of the image forming apparatus A.

  The post-processing control unit 90 selects an appropriate transport path for executing post-processing based on job information based on the job information transmitted from the image forming apparatus A, and transports the paper through the selected transport path.

  The sheet discharged from the image forming apparatus A is introduced into the inside through the entrance conveyance path 7r1.

  The entrance conveyance path 7r1 branches to the paper discharge conveyance path 7r2 or the bookbinding conveyance path 7r3 at the exit. The paper discharge conveyance path 7r2 is a paper discharge path for discharging a sheet that is not bound.

  The sheets that are not bound are introduced into the paper discharge conveyance path 7r2 and discharged and placed on the movable paper discharge stand 74.

  The movable paper discharge stand 74 is disposed at the exit position of the paper discharge conveyance path 7r2 at a position protruding outside the post-processing apparatus B.

  The movable sheet discharge table 74 can be moved in the vertical direction by a sheet discharge table moving means (not shown) that operates under the control of the post-processing control unit 90. As it increases, it moves downwards and can load a large amount of paper or booklets.

  The sheets to be bound are introduced into the bookbinding transport path 7r3.

  A stacker 10 and a stapler 50 are disposed at the exit of the bookbinding transport path 7r3, and the sheets transported via the bookbinding transport path 7r3 are sequentially placed on the stacker 10 to form a bundle of sheets. Then, a staple is hit by a stapler 50 at a predetermined position on the end surface of the bundle of sheets to form a booklet. The formed booklet is discharged to the moving paper discharge stand 74.

  FIG. 2 is a diagram illustrating the post-processing device B.

  As shown in the figure, the stacker 10 is disposed with an inclination in which the left side of the sheet placement surface 10P on which the sheets to be bound are placed is higher than the horizontal plane.

  The entrance conveyance path 7r1 has a conveyance path switching unit 75 at the exit. The conveyance path switching unit 75 is operated by a conveyance path switching solenoid 75 operating under the control of the post-processing control unit 90, and introduces the paper received in the entrance conveyance path 7r1 into the paper discharge conveyance path 7r2 or the bookbinding conveyance path 7r3. .

  The post-processing control unit 90 controls the operation of the conveyance path switching solenoid 75, and when the sheet received in the entrance conveyance path 7r1 is not a binding target, causes the sheet to be introduced into the paper discharge conveyance path 7r2. The paper introduced into the paper discharge conveyance path 7r2 is discharged to the movable paper discharge stand 74.

  If the sheet received in the entrance conveyance path 7r1 is a binding target, the sheet is introduced into the bookbinding conveyance path 7r3.

  The binding target sheet conveyed through the bookbinding conveyance path 7r3 is discharged into the space above the stacker 10 by the feed roller 71 of the sheet conveyance unit 70.

  Reference numeral 77 denotes a paper sensor. The paper sensor 77 is disposed immediately upstream of the paper transport direction of the delivery roller 71 and detects that the rear end of the paper transported toward the delivery roller 71 has passed.

  The paper discharged from the delivery roller 71 falls toward the paper placement surface 10P of the stacker 10.

  The paper that has fallen and reaches the paper placement surface 10P slides down to the lower right in the drawing along the inclined paper placement surface 10P or the upper surface of the paper already placed on the paper placement surface 10P. . Then, the tip end portion that slides down is received by the stopper 10 </ b> S disposed at a part of the lower right side of the stacker 10 in the drawing and is stopped and placed on the stacker 10.

  In the process in which the paper slides along the inclination of the paper placement surface 10P, the unevenness in the direction perpendicular to the sliding direction, that is, in the lateral direction is caused by a pair of alignment plates 20a and 20b arranged with the stacker 10 interposed therebetween. Edge irregularities are corrected. In FIG. 2, only the alignment plate 20 b disposed on the back side of the stacker 10 in the drawing is shown, and the alignment plate 20 a disposed on the near side of the stacker 10 in the drawing is not shown.

  The alignment plates 20a and 20b are driven by an alignment plate drive motor 20M (shown in FIG. 4) not shown in FIG. 2, and repeatedly contact with and separate from the end surface in the direction orthogonal to the direction in which the paper slides down. Correct or match the unevenness of the lateral end faces.

  At this time, an air flow in a direction parallel to the paper placement surface 10P is sprayed from the air flow forming unit 30 serving as an air flow forming unit to the sliding paper from the stopper 10S side. Hereinafter, the air flow blown from the stopper 10S side in the direction parallel to the sheet placing surface 10P will be referred to as a first air flow. The first air flow prevents the slipping paper from coming into close contact with the paper already placed on the paper placement surface 10P, so that the unevenness in the lateral direction by the alignment plates 20a and 20b is preferably corrected. At the same time, the end of the slipping paper can be reliably brought into contact with the stopper 10S, and the vertical alignment, which is the direction in which the paper slides, is suitably performed.

  In addition, at the timing when the slipping paper comes into contact with the stopper 10S, an air flow in a substantially vertical direction from above the paper placement surface 10P toward the paper placement surface 10P comes into contact with the stopper 10S. Sprayed on top of stopped paper. Hereinafter, the air flow blown in the direction from the upper side of the paper placement surface 10P toward the paper placement surface 10P will be referred to as a second air flow. By the second air flow, an air layer between the sheets that are in contact with and stopped at the stopper 10S is eliminated, and swelling of the sheets stacked on the sheet placement surface 10P is suppressed.

  The blowing of the first air flow and the second air flow by the air flow forming unit 30 is performed under the control of the post-processing control unit 90 every time the paper is received by the paper placement surface 10P. The post-processing control unit 90 functions as a control unit that controls the operation of the air flow forming unit 30 that is an air flow forming unit. Details will be described later.

  When the final sheet, which is the final sheet of the sheets to be bound, is placed and stacked on the stacker 10 to form a sheet bundle, the stapler 50 is actuated to staple the binding needle into the sheet bundle and perform the binding process. Is done. During this time, the air flow forming unit 30 blows the second air flow onto the sheet bundle to suppress the swell of the sheet, and presses and stabilizes the sheet bundle during the binding process.

  The bound sheet bundle is held at the trailing edge of the sheet by the discharge claw 41 disposed on the discharge belt 40 driven by the discharge belt drive motor 40M (shown in FIG. 4), and the sheet placement surface. 10P is pushed up diagonally upward. Then, the paper is sandwiched between the paper discharge rollers 72 and is discharged and stacked on the movable paper discharge stand 74.

  FIG. 3 is a diagram illustrating the air flow forming unit 30.

  The air flow forming unit 30 includes a duct housing 31 and a blower fan 39.

  The duct housing 31 is a housing having a first air passage 31A1, a second air passage 31A2, and a third air passage 31A3, which are three air passages through which air can flow. The second air passage 31A2 and the third air passage 31A3 are branched from the first air passage 31A1. The first air passage 31A1 is provided with an intake port 31h1, and the second air passage 31A2 and the third air passage 31A3 are provided with a first exhaust port 31h2 and a second exhaust port 31h3, respectively.

  The blower fan 39 functioning as an air flow generating means is disposed in the first air passage 31A1, takes air from the intake port 31h1 into the first air passage 31A1, generates an air flow, and generates the second air passage 31A2 or the third air. It blows off from the 1st exhaust port 31h2 or the 2nd exhaust port 31h3 via path 31A3. The blower fan 39 is normally in a non-operating state and operates under the control of the post-processing control unit 90.

  The inner wall surface of the second air passage 31A2 is configured to change the direction of the introduced air flow into a direction parallel to the paper placement surface 10P, and the air flow blown from the first exhaust port 31h2 is on the stopper 10S side. The first air flow is blown in a direction parallel to the sheet placement surface 10P.

  The inner wall surface of the third air passage 31A3 is configured to change the direction of the introduced air flow into a direction perpendicular to the paper placement surface 10P, and the air flow blown from the second exhaust port 31h3 The second air flow is blown in the direction from the top of the placement surface 10P toward the paper placement surface 10P.

  Reference numeral 32 denotes a direction switching plate, which is disposed at a branch portion of the second air passage 31A2 and the third air passage 31A3 branched from the first air passage 31A1. The direction switching plate 32 and the duct housing 31 function as air flow direction switching means for changing the direction of the air flow generated by the blower fan 39.

One end of the direction switching plate 32 is pivotally attached to the inner wall of the duct housing 31. The biasing spring 33 is a tension spring having one end fixed to the direction switching plate 32 and the other end fixed to the inner wall of the third air passage 31A3 in the duct housing 31, and the direction switching plate 32 is directed in the direction of the third air passage 31A3. Energize to rotate. Due to the urging force of the urging spring 33, the distal end portion of the direction switching plate 32 abuts on the inner wall 31 </ b> _U on the upper side of the first air passage 31 </ b> A <b> 1 in the duct housing 31. The tip portion of the direction switching plate 32, in a state in contact with the inner wall 31W _U of the first air passage 31A1, a third air passage 31A3 is closed by the direction changing board 32, the air flow formed by the air blowing fan 39 second It is sent only to the air passage 31A2.

A solenoid 34 is fixed to the duct housing 31. The solenoid 34 is a type of solenoid in which the movable iron core 34P is drawn into the main body of the solenoid when energized, and the distal end portion of the movable iron core 34P is rotatably connected to the direction switching plate 32. When the solenoid 34 is energized, the movable iron core 34P is drawn into the main body of the solenoid 34 against the urging force of the urging spring 33, and the direction switching plate 32 connected to the movable iron core 34P is moved through the first air. together is separated from the inner wall 31W _U tracts 31A1, direction tip portion of switching plate 32 is brought into contact with the inner wall 31W _L shown below the first air passage 31A1 in the duct housing 31. Tip direction changeover plate 32 is spaced from the inner wall 31W _U, when brought into contact with the inner wall 31W _L, third air passage 31A3 is opened, the air flow is introduced into the third air passage 31A3. The solenoid 34 is normally in a non-energized state and is energized under the control of the post-processing control unit 90.

FIG. 3A is a diagram showing a state where the solenoid 34 is not energized. In a state where the solenoid 34 is not energized, the direction switching plate 32 contacts the inner wall 31 </ b> _U by the biasing force of the biasing spring 33, and the third air passage 31 </ b> A <b> 3 disposed in the duct housing 31 is blocked by the direction switching plate 32. . In a state where the third air passage 31A3 is blocked by the direction switching plate 32, an air flow is introduced into the second air passage 31A2. As described above, the inner wall surface of the second air passage 31A2 is configured to change the direction of the introduced air flow into a direction parallel to the sheet placement surface 10P. Then, the air flow indicated by the arrow _AF formed by the blower fan 39 passes through the first exhaust port 31h2 from the stopper 10S side of the stacker 10 to the _{first one} indicated by the arrow A1 parallel to the paper placement surface 10P. It is blown out as one air stream. The first air flow prevents the slipping paper S from coming into close contact with the paper already placed on the paper placement surface 10P, so that it is preferable to correct the unevenness in the lateral direction by the alignment plates 20a and 20b. In addition, the end of the paper S that slides down can be reliably brought into contact with the stopper 10S, and the vertical alignment, which is the direction in which the paper S slides down, is suitably performed.

FIG. 3B is a diagram showing a state where the solenoid 34 is energized. When the solenoid 34 is energized, the solenoid 34 to rotate the direction changeover plate 32 against the biasing force of the biasing spring 33 in a direction away from the inner wall 31W _U. When the direction switching plate 32 is separated from the inner wall 31W _U , the third air passage 31A3 is opened, and an air flow is introduced into the third air passage 31A3. As described above, the inner wall surface of the third air passage 31A3 is configured to change the direction of the introduced air flow into a direction perpendicular to the sheet placement surface 10P.

Then, the air flow indicated by the arrow _AF formed by the blower fan 39 is redirected in the third air passage 31A3 in a direction perpendicular to the paper placement surface 10P, and is passed through the second exhaust port 31h3. It is blown out as a second air stream indicated from above the sheet stacking surface 10P in the direction of arrow a ₂ towards the sheet stacking surface 10P. By the second air flow, even when the paper S that is in contact with and stopped by the stopper 10S has a curl, the air layer between the papers is eliminated, and the end surfaces of the paper S can be aligned without disturbance. Further, by blowing the second air flow during the binding process, the sheet bundle to be hit is pressed and stabilized.

  FIG. 4 is a block diagram of a control system in the image forming system of the present embodiment. In the figure, the periphery of the part necessary for the description of the operation of the present embodiment is mainly described, and other parts known as an image forming system are omitted.

  The control unit A9, which is a control unit in the image forming apparatus A, is a computer system having a CPU (A91), a ROM (A92), and a RAM (A93). In addition to functioning as a control unit that controls various operations of the image forming apparatus A, the control unit A9 also controls operations of the post-processing apparatus B.

  The CPU (A91) controls the operation of each mechanism of the image forming apparatus A by executing a program stored in the ROM (A92), forms an image on a sheet, and discharges the sheet. Then, as described later, the post-processing control unit 90 of the post-processing apparatus B is controlled so that the post-processing apparatus B is operated in conjunction with the image forming apparatus A.

  The RAM (A93) can store and read a plurality of information, and stores data generated or acquired when the CPU (A91) executes control of the image forming apparatus A and the post-processing apparatus B. .

  The communication unit A98 functions as a communication unit, and is connected to the communication unit 908 of the post-processing apparatus B. Between the image forming apparatus A and the post-processing apparatus B, various information such as information on jobs executed by the image forming system is provided. Send and receive information.

  A99 is a bus, and the automatic document feeder A1, the image reading unit A2, the image writing unit A3, the image forming unit A4, the fixing device A6, the sheet conveying unit A7, and the operation display unit together with the control unit A9. A8 is connected to enable mutual information exchange.

  The control unit A9 controls the operation of each device and mechanism unit connected to the bus A99 based on the job information input from the operation display unit A8, and causes image formation based on the input job information. .

  Further, the communication unit A98 connected to the bus A99 is connected to the communication unit 908 of the post-processing apparatus B, so that signals can be exchanged between the image forming apparatus A and the post-processing apparatus B. The control unit A9 controls the image forming apparatus A so as to perform image formation based on the input job information, and the post-processing control unit 90 connected to the post-processing apparatus B connected via the communication unit A98. To perform post-processing based on the input job information.

  A post-processing control unit 90 that is a control unit in the post-processing apparatus B is a computer system including a CPU 901, a ROM 902, and a RAM 903.

  The CPU 901 controls the operation of each mechanism unit of the post-processing apparatus B by executing a program stored in the ROM 902, performs post-processing on the sheet received from the image forming apparatus A, and discharges it.

  The ROM 902 is a storage unit, and stores a program and constants for operating the post-processing apparatus B.

  The stored program includes a post-processing program for the post-processing apparatus B to perform post-processing.

The constants stored in the ROM 902 include two time constants t _1k and t _2k necessary for executing the post-processing program. The two time constants t _1k and t _2k will be described later.

The RAM 903 can store and read a plurality of information. Job information for each sheet transmitted from the image forming apparatus A and data generated when the CPU 901 executes control of the post-processing apparatus B or acquired. Stores data. Further, RAM 903 is a timer T1 to time the time _{t 1} that requires when executing the post-processing program, and also functions as a timer T2, which measures the time _{t 2.}

  Reference numeral 909 denotes a bus. The bus 909 is connected to the post-processing control unit 90, the paper transport unit 70, and the post-processing unit (B1), and is connected to the image forming apparatus A via the communication unit 908. , Enabling mutual exchange of information.

  The image forming apparatus A forms an image on the sheet based on the job conditions input from the operation display unit A8, for example, the size of the sheet, the presence / absence of post-processing (binding), the number of copies, and the like, and discharges it to the post-processing apparatus B To do.

  Then, job information for each sheet to be discharged is transmitted from the control unit A9 of the image forming apparatus A to the post-processing apparatus B.

  The job information transmitted from the control unit A9 is information regarding whether or not the sheet to be ejected is a binding target, and whether or not the last sheet in the bundle of sheets to be bound (hereinafter also referred to as the last sheet). Information and whether or not the sheet is the last sheet in the job.

  The post-processing control unit 90 controls the operation of each unit connected to the bus 909 based on the transmitted control information, and executes post-processing based on job information.

  In the case of a job for binding sheets, the received sheets are bound, and the bound sheets are discharged to the moving sheet discharge stand 74. In the case of a job that does not perform binding, the received paper is directly discharged to the movable paper discharge stand 74.

  As described above, the post-processing device B prevents the paper sliding down the stacker 10 from coming into close contact with the paper already placed on the paper placement surface 10P due to the first air flow from the air flow forming unit 30. Then, the unevenness in the lateral direction is preferably corrected. In addition, the second air flow eliminates an air layer between the sheets that are in contact with the stopper 10S and stopped, and swell of the sheets stacked on the sheet placement surface 10P is suppressed. In this way, by blowing the first air flow and the second air flow at a predetermined timing, it is possible to form a booklet with no irregularities on the end surfaces. Hereinafter, an operation in which the post-processing apparatus B processes the sheet received from the image forming apparatus A will be described.

  FIG. 5 is a flowchart for explaining a bookbinding operation in which the post-processing apparatus B performs bookbinding on a binding target sheet. This bookbinding operation is performed by the CPU 901 executing a post-processing program stored in the ROM 902.

  In step S1, the CPU 901 waits for the binding target sheet to be discharged from the image forming apparatus A and introduced into the entrance conveyance path 7r1, and when the sheet is introduced (step S1 Yes), the process proceeds to step S2.

  Information on whether or not the paper discharged from the image forming apparatus A is a binding target is transmitted from the image forming apparatus A as job information and stored in the RAM 903. When the sheet introduced into the entrance conveyance path 7r1 is a binding target, the CPU 901 proceeds to step S2 and introduces the sheet into the bookbinding conveyance path 7r3. The sheet is introduced into the bookbinding transport path 7r3 by the CPU 901 controlling the operation of the transport path switching solenoid 75S.

In subsequent step S <b> 3, the CPU 901 waits for the paper sensor 77 to detect the trailing edge of the paper conveyed on the bookbinding conveyance path 7 r <b> 3. Here, the rear end of the paper refers to the rear end in the transport direction of the paper transported through the bookbinding transport path 7r3. When the trailing edge of the sheet is detected in step S3 (step S3 Yes), the process proceeds to step S4, where timers T1 and T1 are started, and time t ₁ and t ₂ are respectively started to be measured. Prior to the start of the timer T1 and the timer T1, the timer T1 and the timer T1 are reset so that t ₁ = 0 and t ₂ = 0.

  In continuing step S5, the ventilation fan 39 is turned ON and it transfers to step S6.

In step S6, waits for the timer T1 becomes time _{t 1} for measuring at least the time constant _{t 1k,} it shifts the time _{t 1} is equal to or greater than the time constant _{t 1k} (step S6 Yes) in step S7. The time constant t _1k is stored in the ROM 902 together with the time constant t _2k .

Here, the time constant t _1k and the time constant t _2k will be described.

  As described above, the binding target paper conveyed through the bookbinding conveyance path 7r3 is discharged to the space above the stacker 10 by the feed roller 71 and falls toward the stacker 10. The paper that has fallen and reaches the paper placement surface 10P of the stacker 10 slides down along the inclined paper placement surface 10P or the upper surface of the paper already placed on the paper placement surface 10P. The tip end in the sliding direction is received by the stopper 10S disposed on the stacker 10 and stops.

The time constant t _1k is described in detail in the conveyance direction from when the trailing edge of the sheet conveyed through the bookbinding conveyance path 7r3 is detected by the sheet sensor 77 until it is discharged to the space above the stacker 10 by the delivery roller 71. This is the time until the rear end passes through the nip portion of the feed roller 71, and a predetermined margin time is set at a predetermined time based on the sheet conveyance speed in the post-processing apparatus B, the arrangement space distance of each mechanism unit, and the like. In addition, it is a preset time value. The paper whose rear end is detected by the paper sensor 77 is discharged from the delivery roller 71 at the time when the time t _1k has elapsed from the time when the paper sensor 77 was detected. It is in a state of sliding down along the upper surface of the paper already placed on the surface 10P.

The time constant t _2k elapses from when the trailing edge of the sheet conveyed through the bookbinding conveyance path 7r3 is detected by the sheet sensor 77 until the leading end of the sliding direction is received by the stopper 10S of the stacker 10 and stopped. This is a time value obtained by adding a predetermined margin time to the time. The time that elapses from when the trailing edge of the sheet is detected by the sheet sensor 77 until the leading end in the sliding direction is received by the stopper 10S of the stacker 10 and stops is the sheet conveying speed in the post-processing apparatus B and the mechanism portion. It is determined in advance based on the arrangement space distance and the like. The paper whose rear end is detected by the paper sensor 77 is discharged into the space above the stacker 10 by the feed roller 71 when the time t _2k has elapsed from the time of detection, and is received by the stopper 10S of the stacker 10. Is in a stopped state.

Returning to FIG. 5, in step S6, the timer T1 is transition time _{t 1} which is equal to or greater than the time constant _{t 1k} timing (step S6 Yes) in step S7.

  In step S7, the solenoid 34 is turned OFF. The solenoid 34 is normally in a non-energized state. In step S7, when the solenoid 34 is in a non-energized (OFF) state, the solenoid 34 is maintained as it is, and when it is energized (ON), it is turned off. The solenoid 34 is in the energized (ON) state when the post-processing apparatus B receives the second and subsequent sheets of the binding target sheets in the same job.

  In subsequent step S8, the operation of the alignment plate driving motor 20M is controlled to operate the alignment plates 20a and 20b. In this state, since the blower fan 39 in the airflow forming unit 30 is ON, that is, in an operating state, and the solenoid 34 is OFF, that is, in a non-energized state, the airflow generated in the blower fan 39 is The first air flow is an air flow in a direction parallel to the sheet placement surface 10P blown out through the first exhaust port 31h2. By operating the alignment plates 20a and 20b while blowing the first air flow, the delivery roller 71 releases the air to the space above the stacker 10, and the paper is placed on the paper placement surface 10P or the paper placement surface 10P. The paper sliding down along the upper surface of the paper that has been reached reaches the stopper 10S disposed in the stacker 10 without being attracted to each other, and suitable alignment is performed.

In step S9, waits for the timer T2 is a time _{t 2} for measuring at least the time constant _{t 2k,} shifts the time _{t 2} is equal to or greater than the time constant _{t 2k} (step S9 Yes) in step S10. When the time t _2k has elapsed from when the trailing edge is detected by the sheet sensor 77, the sheet discharged to the space above the stacker 10 by the feed roller 71 contacts the stopper 10S of the stacker 10 and stops sliding. It is time to do.

  In step S10, the operation of the alignment plate drive motor 20M is controlled to stop the alignment plates 20a and 20b, and the process proceeds to step S11.

  In step S11, the solenoid 34 is turned on, that is, energized. In this state, the blower fan 39 in the air flow forming unit 30 is ON, that is, the operating state, and the solenoid 34 is ON, that is, the energized state. Therefore, the air flow generated in the blower fan 39 is 2 The second air flow is an air flow in a direction toward the paper placement surface 10P blown out through the exhaust port 31h3.

  The second air flow is blown against the paper that is stopped by contacting the stopper 10S, and when the paper has a curl, the air layer between the papers is eliminated and the end surfaces of the paper can be aligned without disturbance.

  When the sheet is placed on the stacker 10 in step S11 and the second air flow is blown, it is confirmed in step S12 whether the sheet is the final sheet in the bundle of sheets to be bound. Information about whether or not the sheet is the last sheet in the bundle is transmitted as job information from the image forming apparatus A and stored in the RAM 903. The CPU 901 refers to the job information stored in the RAM 903, and when the sheet is not the final sheet in the bundle (No in step S12), the CPU 901 returns to step S1 and the subsequent sheet to be bound is introduced into the entrance conveyance path 7r1. Wait for it. When the paper is introduced (Yes in step S1), the processes in steps S2 to S2 are repeated until it is confirmed in step S12 that the paper is the last paper in the bundle. If it is confirmed in step S12 that the sheet is the final sheet of the bundle (Yes in step S12), the process proceeds to step S13.

  In step S <b> 13, the CPU 901 controls the operation of the stapler 50 to execute a binding process on the sheet bundle formed on the stacker 10 to form a booklet. Since the second air flow is blown onto the sheet bundle while the binding process is being performed, the swell of the sheet bundle is suppressed to achieve suitable alignment, and the stapled sheet bundle can be stabilized. Further, since the swell of the sheet bundle is suppressed, the number of sheets of the sheet bundle that can be bound by the stapler 50 can be increased.

  In step S14, the booklet formed in step S14 is discharged onto the moving paper discharge stand 74.

  In the subsequent step S15, it is confirmed whether or not the job is completed by discharging the booklet or paper in step S14. Whether or not the job is completed is determined based on information on whether or not the sheet received in step S12 is the last sheet of the job. Information on whether or not the sheet received in step S12 is the final sheet of the job is transmitted from the image forming apparatus A as job information and stored in the RAM 903. The CPU 901 refers to the job information stored in the RAM 903. If the sheet is not the final sheet of the job, that is, if the job is not completed (No in step S15), the process returns to step S1 and steps S1 to S15 are performed. Are repeated until it is confirmed in step S15 that the job has been completed. When it is confirmed in step S15 that the job has been completed (step S15 Yes), the process proceeds to step S16.

  In step S16, the blower fan 39 and the solenoid 34 are turned off and the bookbinding operation is terminated.

  As described above, the post-processing device B blows the first air flow in the process in which the paper slides down the paper placement surface 10P of the stacker 10, and blows the second air flow at the timing when the slipped paper comes into contact with the stopper 10S. The first air flow prevents the sheets from adsorbing due to static electricity and the like and performs good alignment, and the second air flow can also perform good alignment on the paper having the curl, and the edge surface is not disturbed. Bookbinding can be performed.

  Note that the number of sheets discharged to the space above the stacker 10 by the feed roller 71 of the sheet transport unit 70 is not limited to one, and a plurality of sheets are simultaneously discharged to the space above the stacker 10. It is also possible to do. A plurality of discharged sheets fall on the stacker 10 and the first air flow is blown in the process of sliding down the sheet placement surface 10P, thereby preventing the sheets from being adsorbed and achieving good alignment.

  Further, by arranging the air flow forming unit 30 so as to be movable together with the stopper 10S, it is also possible to perform saddle stitching that forms a booklet by hitting the center of the spread of the sheet bundle. In saddle stitching, after a sheet including the final sheet is placed on the stacker 10 to form a sheet bundle, the position of the stopper 10S is moved to a position where the center of the sheet bundle is located at the staple position of the stapler 50. This is done by hitting the needle. In the process in which the sheet to be saddle stitched is discharged into the space above the stacker 10 and slides along the sheet placing surface 10P or the upper surface of the sheet already placed on the sheet placing surface 10P, the first air flow By repeating the operation of spraying the second air flow at the timing of contacting the stopper 10S, it is possible to suitably align the sheets received by the stopper 10S. When the final sheet to be saddle stitched is received by the stopper 10 </ b> S, the stopper 10 </ b> S is moved to a position where the spread center portion of the sheet bundle becomes the staple position of the stapler 50. At this time, the air flow forming unit 30 blowing the second air flow is moved together with the stopper 10S. By moving the air flow forming unit 30 blowing the second air flow together with the stopper 10S, the alignment of the sheet bundle can be maintained even if the stopper 10S is moved. Then, the stapler 50 performs saddle stitching by hitting the center of the double-sheet spread.

  In the post-processing apparatus B according to the embodiment of the present invention, the direction switching in which the air flow generated by the blower fan 39 as the air flow generating means is arranged in the duct housing 31 in the air flow forming unit 30. Although the 1st air flow and the 2nd air flow are formed by changing the position of the board 32, it is not limited to this structure. For example, the direction switching plate 32 is not provided, and the blower fan has a first position where the direction of the generated air flow is parallel to the paper placement surface, and the direction of the generated air flow is perpendicular to the paper placement surface. The air blowing fan is disposed at the first position in the process where the paper slides down the paper placement surface, and the paper that has slipped contacts the stopper. You may make it the structure which arrange | positions to a 2nd position with timing. The blower fan forms a first air flow whose direction is parallel to the paper placement surface when the blower fan is placed at the first position, and second in the direction toward the paper placement surface when placed at the second position. Create an air flow.

A image forming apparatus A1 automatic document feeder A2 image reading section A3 image writing section A4 image forming section A6 fixing device A7 paper transport section A8 operation display section A9 control section A91 CPU
A92 ROM
A93 RAM
A98 Communication unit B Post-processing device 10 Stacker 10P Paper placement surface 10S Stopper 20a, b Alignment plate 20M Alignment plate drive motor 30 Airflow forming unit 31 Duct housing 31A1 First airway 31A2 Second airway 31A3 Third airway 31h1 Intake port 31h2 First exhaust port 31h3 Second exhaust port 32 Direction switching plate 33 Biasing spring 34 Solenoid 39 Blower fan 40 Discharge belt 40M Discharge belt drive motor 50 Stapler 70 Paper transport unit 71 Sending roller 74 Moving paper tray 75 Conveyance Path switching section 75S transport path switching solenoid 77 paper sensor 7r1 inlet transport path 7r2 paper discharge transport path 7r3 bookbinding transport path 90 post-processing control section 901 CPU
902 ROM
903 RAM
908 Communication unit 909 Bus S Paper

Claims (4)

A stacker that includes an inclined paper placement surface and a stopper, and places the paper slid along the paper placement surface in contact with the stopper;
A stapler that binds the paper placed on the stacker with a binding needle;
In an aftertreatment device having
An air flow that forms a first air flow that blows in a direction parallel to the paper placement surface from the stopper side and a second air flow that blows in a direction from above the paper placement surface toward the paper placement surface. A post-processing apparatus having a forming means. The air flow forming means includes
An air flow generating means for generating an air flow;
Air flow direction switching means for changing the direction of the air flow generated by the air flow generation means;
Have
The said 1st air flow and the said 2nd air flow are formed by changing the direction of the air flow which the said air flow generation means produced | generated by the said air flow direction switching means. The after-treatment device described in A control unit for controlling the air flow forming means;
The control unit forms the first air flow in a process in which the paper slides down the paper placement surface, and forms the second air flow at a timing when the slipped paper comes into contact with the stopper. The post-processing apparatus according to claim 2, wherein the flow forming means is controlled.   An image forming system comprising: the image forming apparatus connected to the post-processing apparatus according to claim 1.

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