JP2005170578A - Post-treatment device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time required for elevating a paper discharge tray to the waiting position after removing a large amount of paper sheets from the paper sheets in a stacked condition in the elevating operation of the paper discharge tray of a post-treatment device, to maintain the productivity of an image forming device thereby, and to correctly maintain the stop position of the paper discharge tray at the waiting position. <P>SOLUTION: A post-treatment device FS in which a paper sheet S discharged from an image forming device A is post-treated, and stacked on an elevating/lowering paper discharge tray 62 comprises a tray elevating position detection sensor PS2 to detect the paper discharge waiting position of the paper discharge tray 62, a tray speed determination sensor PS3 which detects the upper face position of the paper sheet stacked in the paper discharge tray 62 and selects the operational speed changing position of the paper discharge tray 62, a driving means to elevate/lower the paper discharge tray 62 in a speed-changing manner, and a post-treatment control means 200 to control the driving means in a speed-changing manner. The post-treatment control means 200 controls the elevating/lowering speed of the paper discharge tray 62 by the driving means based on the result of detection of the tray speed determination sensor PS3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as an electrophotographic copying machine and a printer, and a post-processing apparatus that stores sheets discharged from a post-processing apparatus that performs folding processing, binding processing, and the like in a discharge tray that can be moved up and down. .

  A paper discharge tray that accommodates a large amount of paper discharged from a discharge port of an image forming apparatus or a post-processing apparatus is generally driven to be able to move up and down, and descends in accordance with the paper stacking amount. If the discharge height from the discharge port to the paper stacking surface of the paper output tray (or the top surface of the paper when paper is loaded) becomes too high, the landing angle of the paper leading edge will increase and the leading edge will curl. There is a problem of loading. In order to prevent this, conventionally, a sheet surface detecting means is provided to make the discharge height substantially constant.

  In addition, as known from Patent Document 1 or the like, the conventional post-processing apparatus stacks sheets discharged from the image forming apparatus on a discharge tray and stacks all or a part of the discharge tray. When the sheet is removed, the sheet discharge tray is raised from the lowered position. Further, some conventional post-processing devices are configured so that the operation of the image forming apparatus is not started unless the paper discharge tray is in a predetermined position.

  The sheet post-processing apparatus described in Patent Document 2 includes a first means for moving the discharge tray up and down in accordance with the stack amount of sheets, and a predetermined time before the completion of the lifting operation of the discharge tray. And a second means for enabling the operation of the forming apparatus. The second means is a time when the sheet discharge tray rises and a sheet from the image forming apparatus reaches the discharge tray from the start of the operation of the image forming apparatus. It is a time corresponding to the time until.

In the paper stacking device described in Patent Document 3, the first paper discharge tray is provided so as to be able to pass through the discharge port in the vertical direction. When paper is extracted from the second paper discharge tray, the paper stacking device is provided on the first paper discharge tray. The change in the upper surface position of the sheet is detected by the distance measuring sensor, and the control unit calculates the estimated time for the discharge tray to finish rising from the change in the upper surface position, and notifies the image forming apparatus of this. In the image forming apparatus, a time obtained by subtracting the paper conveyance time in the image forming apparatus from the estimated time is calculated, and this is set as a delay time for delaying paper output.
JP-A-4-125246 JP-A-11-231753 JP 2003-26366 A

  In the sheet post-processing apparatus of Patent Document 1, when the sheet on the sheet discharge tray is removed, the sheet discharge tray is raised to a predetermined position. Therefore, when the sheet on the sheet discharge tray is removed and the operation of the image forming apparatus is started. The sheet is discharged to the sheet discharge tray before the sheet discharge tray reaches the predetermined position, and there is a problem that the distance between the discharge port and the sheet discharge tray is large and the sheet stackability of the sheet discharge tray is deteriorated.

  Further, in the sheet post-processing apparatus in which the operation of the image forming apparatus is not started unless the paper discharge tray is in a predetermined position, the above problem can be solved, but the waiting time of the image forming apparatus becomes long, Productivity of the image forming apparatus decreases.

  In the sheet post-processing apparatus of Patent Document 2, the sheet stackability of the discharge tray and the productivity of the image forming apparatus, which are the above problems, are improved, but a large number of sheets are stacked and accommodated on the discharge tray that can be raised and lowered. After that, if a large number of sheets stored in the paper discharge tray are removed at once, it takes time for the paper output tray to rise to the specified paper output standby position. Will get worse.

  For this reason, it is desirable to increase the time for raising the discharge tray. However, if the raising / lowering operation of the discharge tray is performed at a high speed, there will be a time delay difference in the stop operation when it is raised depending on the sheet stacking amount. Dispersion of the output tray is large, which deteriorates the stackability of sheets.

  As in the paper stacking device disclosed in Patent Document 3, in order to prioritize the stackability of the paper, the paper ejection on the image forming apparatus side is calculated until the paper ejection tray rises or the time during which the paper ejection tray rises. However, it is possible to take a temporary stop until the paper can be discharged, but the productivity of the image forming apparatus decreases.

  According to the present invention, in the ascending operation of the discharge tray of the post-processing apparatus, after removing a large amount of sheets from the stacked sheets, the time for raising the discharge tray to the standby position is shortened. It is an object of the present invention to provide a post-processing device and an image forming apparatus having the post-processing device that improve the stackability of paper by maintaining the operability and accurately maintaining the stop position of the paper discharge tray in the standby position. To do.

  The post-processing apparatus of the present invention is particularly applicable when sheets discharged from an image forming apparatus capable of high-speed processing are stacked on a discharge tray that can be lifted and lowered after post-processing.

  The above object is solved by the post-processing apparatus and the image forming apparatus of the present invention.

  (1) a first detection unit that detects a paper discharge standby position of the paper discharge tray in a post-processing device that post-processes the paper discharged from the image forming apparatus and then stacks the paper on a vertically movable paper discharge tray; Second detecting means for detecting an upper surface position of the paper stacked on the paper discharge tray and selecting an operation speed switching position of the paper discharge tray; drive means for driving the paper discharge tray up and down at a variable speed; Post-processing control means for controlling the driving means to be variable in speed, and the post-processing control means controls the raising / lowering speed of the paper discharge tray by the driving means based on the detection result of the second detection means. A post-processing device.

(2) First detecting the discharge standby position of the discharge tray in the post-processing apparatus that receives and discharges the paper discharged from the image forming apparatus and stacks it on a liftable discharge tray. Detection means; second detection means for detecting an upper surface position of the paper stacked on the paper discharge tray and selecting an operation speed switching position of the paper discharge tray; and drive for driving the paper discharge tray up and down at a variable speed. Means, and post-processing control means for controlling the drive means to be variable in speed,
The post-processing control means switches the raising / lowering speed of the discharge tray by the driving means between a low speed operation and a high speed operation based on a detection result of the second detection means, and the second processing control means After detecting that the paper discharge tray reaches the low speed operation area from the high speed operation area, the detection means switches the speed of the paper discharge tray to the low speed operation, and raises and lowers the speed of the discharge tray in the low speed operation area, The post-processing apparatus is controlled to a speed at which the sheet can be stacked at a predetermined position where the sheet loading performance can be secured.

  (3) An image forming apparatus main body including an image writing unit, an image forming unit, a sheet conveying unit, an input unit, and a main control unit, and the post-processing apparatus described in (1) or (2). An image forming apparatus.

  As is clear from the above description, the following effects can be obtained by the post-processing apparatus and the image forming apparatus of the present invention.

  (1) Based on the detection result of the second detection means for detecting the upper surface position of the paper stacked on the paper discharge tray, the drive means controls the raising / lowering speed of the paper discharge tray to discharge the paper from the post-processing device and stack it. When a part or all of a large amount of paper is removed, the time for raising the upper surface of the paper discharge tray or the paper stacked on the paper discharge tray to the vicinity of the paper discharge port is shortened, and the paper is discharged from the post-processing device. It is possible to securely store the sheets and minimize the deterioration of the stackability of the sheets. In particular, the post-processing device of the present invention is effective when a large amount of paper is taken out from a paper discharge tray on which a large amount of paper is stacked.

  (2) Based on the detection result of the second detection means, the raising / lowering speed of the discharge tray by the driving means is switched between the low speed operation and the high speed operation, and the second detection means operates the discharge tray at a high speed during the upward stroke of the discharge tray. After detecting that the low speed operation area is reached from the area, the speed of the paper discharge tray is switched to low speed operation, and the position where the paper discharge tray does not rise too much is determined by the third detection means. By controlling the ascending / descending speed in the operation area to a speed that can be stopped at a predetermined position that can secure the paper stacking performance, some or all of the large amount of paper ejected from the post-processing device and loaded is removed. The time required to raise the upper surface of the paper stacked on the paper discharge tray or the paper discharge tray to the vicinity of the paper discharge opening is shortened, the paper discharged from the post-processing device is quickly stored, and the paper stacking property is improved. Damaged Things can be kept to a minimum. In particular, the post-processing device of the present invention is effective when a large amount of paper is taken out from a paper discharge tray on which a large amount of paper is stacked.

  (3) In an image forming apparatus comprising an image forming apparatus main body and a post-processing apparatus that are placed on a paper discharge tray that can be moved up and down after receiving paper discharged from the image forming apparatus, the post-processing apparatus When a part or all of a large amount of sheets discharged and stacked is removed, the time required to raise the upper surface of the discharge tray or the sheets stacked on the discharge tray to the vicinity of the discharge outlet is shortened, and the image forming apparatus Thus, it is possible to minimize the deterioration of the stackability of the paper without reducing the productivity of the paper. In particular, the present invention has an excellent effect when applied to an image forming apparatus on which a large amount of sheets discharged from a post-processing apparatus connected to an image forming apparatus main body that performs high-speed processing is stacked.

  Next, a post-processing apparatus and an image forming apparatus according to the present invention will be described with reference to the drawings.

[Image forming apparatus]
FIG. 1 is an overall configuration diagram of an image forming apparatus including an image forming apparatus main body A and a post-processing apparatus FS.

  In the image forming apparatus main body A, a charging unit 2, an image exposure unit (writing unit) 3, a developing unit 4, a transfer unit 5A, a charge eliminating unit 5B, and a cleaning unit 6 are arranged around the rotating image carrier 1. It has an image forming unit, and after the surface of the image carrier 1 is uniformly charged by the charging unit 2, exposure scanning based on image data read from the document is performed by the laser beam of the image exposure unit 3, and the latent image is formed. And the latent image is reversely developed by the developing means 4 to form a toner image on the surface of the image carrier 1.

  On the other hand, the paper S stored in the paper storage means 7A is fed by the paper feed means 7B and sent to the transfer position. The toner image is transferred onto the paper S by the transfer means 5A at the transfer position. Thereafter, the charge on the back surface of the sheet S is erased by the charge eliminating unit 5B, separated from the image carrier 1, conveyed by the intermediate conveying unit 7C, subsequently heated and fixed by the fixing unit 8, and discharged from the sheet discharging unit 7D. .

  When image formation is performed on both sides of the sheet S, the sheet S heated and fixed by the fixing unit 8 is branched from the normal sheet discharge path by the conveyance path switching plate 7E, and is switched back by the reverse conveyance unit 7F. After being reversed, the paper is discharged out of the apparatus by the paper discharge means 7D. The paper S discharged from the paper discharge means 7D is sent to the post-processing device FS.

  On the other hand, the developer remaining on the surface of the image carrier 1 after image processing is removed by the cleaning unit 6 to prepare for the next image formation.

  The paper S discharged from the image forming apparatus main body A is subjected to punching processing by the punching means 40, shift processing by the shift means 50, and binding means (stapling means) disposed in the stacking unit (intermediate stacker) 70 in the post-processing device FS. After post-processing such as binding processing by 70A and folding processing by the folding processing unit 80, the fixed paper discharge tray 33 of the direct paper discharge means 30, a discharge tray (hereinafter referred to as tray) 62 that can be raised and lowered, It is sent to one of the paper boards 85.

  The communication unit 101 of the main control unit 100 of the image forming apparatus main body A and the communication unit 201 of the post-processing control unit 200 of the post-processing device FS are electrically connected, and control signals are exchanged.

  By the selection means of the operation unit 9, paper feeding by the first paper feeding means 20 </ b> A and the second paper feeding means 20 </ b> B of the post-processing device FS, punching processing by the punching means 40, shift processing by the shift means 50, and end binding by the stacking unit 70. Each of the saddle stitching processes and the middle folding process by the folding processing unit 80 are set.

  With this setting, the main control unit 100 sends a control signal to the post-processing device FS via the communication unit 101. The control signal is transmitted to the post-processing control unit 200 via the communication unit 201. The post-processing control means 200 drives each set processing means.

[Post-processing equipment]
FIG. 2 is a cross-sectional view of the post-processing device FS.

<Feeding paper for insertion and cover>
The receiving unit 11 of the post-processing device FS includes a sheet S that has undergone image formation processing from the image forming apparatus main body A, an insertion sheet KA that partitions a bundle of sheets supplied from the first sheet feeding unit 20A, and a second sheet feed. The cover sheet KB supplied from the means 20B is introduced.

  The insertion sheet KA accommodated in the sheet feeding tray of the first sheet feeding means 20A is separated and fed by the sheet feeding unit 21, is sandwiched between the conveying rollers 22, 23, 24, and is introduced into the receiving unit 11. . Further, the cover sheet KB accommodated in the sheet feeding tray of the second sheet feeding unit 20B is separated and fed by the sheet feeding unit 25, is sandwiched between the transport rollers 23 and 24, and is introduced into the receiving unit 11. .

<Perforation processing>
The punching means 40 disposed on the downstream side of the receiving unit 11 in the paper transport direction includes the paper S sent from the image forming apparatus main body A, the insertion paper KA transported from the first paper feed means 20A, and the second paper feed means. A perforation process is performed on the cover sheet KB conveyed from 20B.

<Paper branch>
On the downstream side of the punching means 40 in the paper transport direction, a paper branching means comprising switching means G1, G2 is provided. The switching means G1 and G2 are selectively branched into any one of the first conveyance path r1, the middle second conveyance path r2, and the lower third conveyance path r3.

<Simple paper discharge>
When this sheet conveyance is set, the switching unit G1 blocks the second conveyance path r2 and the third conveyance path r3 and opens only the first conveyance path r1.

  The sheet S or the like passing through the first conveyance path r1 is sandwiched and raised by the conveyance roller 31, is discharged by the discharge roller 32, is placed on the fixed sheet discharge table 33, and is sequentially stacked. Up to about 200 sheets S or the like can be stacked on the fixed sheet discharge tray 33.

<Shift processing>
When this conveyance mode is set, the switching means G1 retracts upward, and the switching means G2 blocks the third conveyance path r3 and opens the second conveyance path r2 to allow the paper S to pass. The sheet S passes through a sheet passing path formed between the switching units G1 and G2.

  The image-formed paper S discharged from the image forming apparatus main body A, the insertion paper KA fed from the first paper feed unit 20A, or the cover paper KB fed from the second paper feed unit 20B is used. Then, after passing through the intermediate sheet passing path of the switching means G1 and G2, the shift means 50 performs a shift process in a direction orthogonal to the sheet conveying direction.

  The shift means 50 performs a shift process for changing the paper discharge position in the transport width direction every predetermined number of sheets. The shifted paper is nipped by a pair of paper discharge rollers 61 of the paper discharge means 60, discharged from the discharge port 60A to the tray 62 outside the apparatus, and sequentially placed. The tray 62 is configured to descend sequentially when a large number of sheets S are discharged.

<Side stitch processing>
When the side stitching process is set in the operation unit 9 (see FIG. 2), the image-formed sheet S that has been subjected to the image forming process in the image forming apparatus main body A and has been sent to the receiving unit 11 of the post-processing apparatus FS. Then, it passes through the punching means 40, is sent to the third transport path r3 below the switching means G2, and is sandwiched by the transport rollers 12 and transported downward.

  In the third conveyance path r3, the sheet S passes through the sheet passage path 13, is sandwiched by the conveyance roller 14, is nipped by the downstream inlet conveyance roller pair 15, and is sent out. The sheet is discharged into the space above the table 71 and is in contact with the upper surface of the sheet mounting table 71 or the sheet S stacked on the sheet mounting table 71 and is conveyed obliquely upward. After the trailing end of the sheet S in the advancing direction is discharged from the holding position of the conveying roller 14, the sheet S turns down due to its own weight, is conveyed on the inclined surface of the sheet placing table 71, and is flat near the binding means 70A. The trailing edge of the sheet S comes into contact with the sheet abutting surface of the first abutting member 72 for binding and stops.

  Reference numeral 73 denotes a pair of upstream width alignment members that are movably provided on both side surfaces of the sheet placing table 71. The width alignment member 73 performs the width alignment (width alignment) of the paper S by tapping the side edge in the width direction of the paper S. When a predetermined number of sheets S are stacked and aligned on the sheet placing table 71 at this stop position, the side binding process is performed by the binding unit 70A, and the sheets S are bound.

<Saddle stitching>
When the saddle stitching process is set, the first abutting member 72 in the vicinity of the stapling position of the binding needle of the binding means 70 </ b> A is retracted from the conveyance path, and the second abutting member 78 also used for the saddle stitching and middle folding downstream is passed. The sheet passing path 77 is blocked by moving a predetermined distance in the direction of the extended surface of the path 77.

  After the paper S is positioned and placed on the paper placement table 71, the saddle stitching process by the binding means 70A is performed on the paper S.

  The bound sheet S is held on the trailing edge of the sheet S by the discharge claw 76 of the rotating discharge belt 75, is placed on the discharge belt 75, and slides on the loading surface of the sheet loading table 71. Then, it is pushed upward obliquely and proceeds to the position where the paper discharge roller pair 61 of the paper discharge means 60 is nipped. The paper S sandwiched between the pair of rotating paper discharge rollers 61 is discharged and stacked on the tray 62 from the discharge port 60A.

<Folding process>
A folding processing unit 80 is disposed obliquely below the stacking unit 70. After the saddle stitching process, the second abutting member 78 linearly moves in the downstream direction of conveyance of the paper S. The movable second abutting member 78 restricts the stop position of the sheet S during the saddle stitching process at the upper position and restricts the stop position of the sheet S during the middle folding process at the lower position.

  The folding processing unit 80 includes a folding plate 82, folding rollers 83 and 84, and the like, and performs folding processing on the sheet S in two. The folded paper S is discharged out of the apparatus by a paper discharge means (not shown) and is stored in the lower paper discharge tray 85.

<Driving drive for loading and unloading tray>
FIG. 3 is a cross-sectional view showing the tray lifting / lowering means of the paper discharge means 60 of the post-processing device FS.

  The motor M with variable rotation speed drives and rotates the drive pulley 63A via the reduction gear train Z, and rotates the wire 64 that winds the drive pulley 63A and the upper driven pulley 63B. A base portion of the tray 62 is fixed to a part of the wire 64 by a locking member 65. In the tray 62, a roller 66 rotatably supported at a base portion of the tray 62 slides on the paper rear end reference member 67. As the wire 64 rotates, the tray 62 moves up and down along the paper trailing edge reference member 67.

  Above the paper trailing edge reference member 67, there are a tray upper limit position sensor PS1 for detecting the upper limit position of the tray 62, and a tray lift position sensor (first detection means) for detecting the lift position of the sheets S stacked on the tray 62. ) PS2, a tray speed determination sensor (second detection means) PS3 for determining the lifting speed of the tray 62, and a lifting speed detection member 69 that contacts the upper surface of the paper S stacked on the tray 62 are disposed. . Note that an ultrasonic sensor may be disposed in place of the tray speed determination sensor PS3 and the elevation speed detection member 69 so that the upper surface position of the paper S stacked on the tray 62 is detected without contact.

  Due to the detection signal of the tray upper limit position sensor PS1, the tray 62 is stopped from being lifted by the motor M at the upper limit position. A motor so that the uppermost surface of the paper S stacked on the tray 62 and the outer peripheral surface of the paper discharge roller pair 61 are held at a constant distance when the paper S is discharged by the detection signal of the tray lift position sensor PS2. Driven by M.

  A broken line shown in FIG. 3 indicates the lowest limit position of the tray 62. A tray lower limit detecting sensor PS4 for detecting the lower limit of the tray 62 is disposed below the sheet rear end reference member 67.

  As a large amount of sheets S are stacked on the tray 62, the tray 62 gradually descends along the sheet trailing edge reference member 67. When the tray 62 is lowered and the detected portion of the tray 62 blocks the optical path of the tray lower limit detection sensor PS4, the post-processing control means 200 stops driving the motor M that drives the tray 62 to move up and down. Stop at a predetermined minimum position. At the lowest position, a maximum of about 3000 sheets S can be stacked on the tray 62.

[Traft control of paper output tray]
4A is a sectional view showing the upper limit position of the tray 62, and FIG. 4B is a sectional view showing the raised position of the tray 62. As shown in FIG.

  In FIG. 4A, in the vicinity of the upper part of the paper trailing edge reference member 67, a paper upper limit detecting means comprising a photo interrupter type tray raising position sensor PS2 and a swingable paper upper limit detecting member (actuator) 68 is installed. Has been. When the tray 62 is driven up and the leading end 68A of the sheet upper limit detection member 68 contacts the upper surface of the tray 62 or the upper surface of the sheet S placed on the tray 62, the rear end of the sheet upper limit detection member 68 68B opens the light detection part of the tray lift position sensor PS2 to switch it off, and stops driving the tray 62.

  In the stop state of the tray 62, the sheet S sandwiched and discharged by the pair of discharge rollers 61 including the rotating lower roller 61A and the upper roller 61B and placed on the tray 62 is always predetermined by the lower roller 61A. And are fed into the paper trailing edge reference member 67 and aligned at the trailing edge. As the number of sheets S stacked on the tray 62 increases, the tray 62 is driven downward, and the uppermost surface of the sheets S stacked on the tray 62 comes into contact with the leading end 68A of the sheet upper limit detection member 68, It is detected and controlled by the tray lift position sensor PS2, always kept at a constant upper surface height, and press-contacts the lower roller 61A with a predetermined pressure.

  In FIG. 4B, when the tray 62 is driven up and the leading end 68 </ b> A of the sheet upper limit detection member 68 contacts the upper surface of the sheet S placed on the tray 62, the rear of the sheet upper limit detection member 68. The end portion 68B opens the light detection portion of the tray lift position sensor PS2 that detects the lift position of the tray 62 to switch off, and the drive of the tray 62 is temporarily stopped. Subsequently, the post-processing control unit 200 and the driving unit lower the tray 62 and stop it at a predetermined position. The stop position of the tray 62 is a position where the sheet S placed on the tray 62 holds a gap g where it does not contact the lower roller 61A.

  With this gap g held, the paper S discharged from the paper discharge roller pair 61 is placed on the tray 62, and the trailing edge of the paper S is disposed on the rotating shaft of the lower roller 61A and rotates. It enters below 61C and comes into contact with the paper trailing edge reference member 67 and stops.

  As the number of sheets S stacked on the tray 62 increases, the tray 62 is driven downward, and the uppermost surface of the sheets S stacked on the tray 62 is a tray lift position sensor that detects the sheet lift position of the tray 62. It is detected and controlled by PS2, and is always held at a constant gap g from the uppermost surface of the paper S stacked on the tray 62.

  The gap g is controlled to be different depending on whether the single sheet S is discharged or if a booklet formed by binding a plurality of sheets is discharged.

  FIG. 5 is a perspective view showing the paper discharge means 60 of the post-processing device FS.

  Above the pair of paper discharge rollers 61, a tray speed determination sensor PS3 for detecting the raising / lowering speed of the tray 62 is disposed.

  FIG. 6 is a front view of the paper discharge means 60 showing the paper S stacked on the tray 62 and the operation of the tray speed determination sensor PS3. FIG. 7 is a block diagram of the raising / lowering control of the tray 62.

  FIG. 6A shows a state where a large number of sheets S have been extracted from the sheets S stacked on the tray 62.

  The ascending / descending speed detecting member 69 supported so as to be swingable is self-weighted or spring-biased so that the front end portion 69A contacts the uppermost layer of the remaining paper S stacked on the tray 62, and the rear end portion 69B is the tray. The detection optical path of the speed determination sensor PS3 is turned off.

  The post-processing control means 200 drives the tray M driving motor M with variable rotation speed based on the OFF signal of the tray speed determination sensor PS3 to raise the tray 62 at high speed.

  FIG. 6B shows the process of raising the tray 62.

  The upper surface of the paper S stacked on the tray 62 that is raised by the high speed operation at the high speed V1 swings the elevation speed detecting member 69 and raises the leading end 69A. When the leading end 69A reaches the tray lifting speed switching position H1, the tray speed determination sensor PS3 is turned on, and the post-processing control means 200 switches the motor M to a low speed and lowers the tray 62 by the detection signal. Increase by low speed operation of speed V2.

  When the tray lift position sensor PS2 detects that the upper surface of the paper S stacked on the tray 62 that is lifted by the low speed operation has reached the tray lift detection position H2, the drive of the motor M is stopped and the tray 62 is lifted. Stopped and kept in standby state. At the tray rise detection position H2, the paper S discharged from the paper discharge means 60 of the post-processing device FS is discharged onto the preceding paper S stacked on the tray 62, and the rear end of the paper S in the discharge direction is The sheet abuts against the sheet trailing edge reference member 67 and stops.

  Thereafter, when the tray 62 is raised by the low-speed driving of the motor M and the upper surface of the sheet S stacked on the tray 62 has reached the tray upper limit detection position H3, the motor M is detected. Is stopped, and the raising of the tray 62 is stopped. At the tray upper limit detection position H3, the upper surface of the paper S stacked on the tray 62 comes into pressure contact with the peripheral surface of the lower roller 61A of the discharge roller pair 61.

  FIG. 8 is a flowchart of a process for controlling the raising and lowering of the tray 62.

  S (Step) 101 The power of the post-processing device FS is turned on.

  S102 The upper limit position of the tray 62 is confirmed by the tray upper limit position sensor PS1.

  S103 If the upper limit position of the tray 62 by the tray upper limit position sensor PS1 is ON, the process proceeds to the tray lowering drive in S104. If the upper limit position is OFF, the tray 62 is already in the lowered position, and the process proceeds to the tray raising position confirmation in S105.

  S104 The tray 62 is driven downward. The descending speed is set to high speed or low speed by the tray speed subroutine of S111.

  S105 The raising position of the tray 62 is confirmed by the tray raising position sensor PS2.

  S106 If the raising position of the tray 62 by the tray raising position sensor PS2 is ON, the process proceeds to S107.

  S107 The tray 62 is driven upward. The rising speed is set to high speed or low speed by the tray speed subroutine of S111.

  S108 If the tray 62 is lifted off in S106, the tray 62 is not lifted and stopped, and the process proceeds to S109.

  S109 When the tray 62 is stopped in S108, the power of the post-processing device FS is turned off.

  S110 When the power is turned off, the control of the raising and lowering of the tray 62 is completed.

  S111 to S115 show a subroutine for controlling the operation speed of the tray 62 in S104 and S107.

  S111 A subroutine for setting the operation speed control of the tray 62 is started.

  S112 The start of the operation speed control of the tray 62 is confirmed by the tray speed determination sensor PS3.

  S113 If the operation speed of the tray 62 is the high speed V1 region, the process proceeds to S114.

  S114 If the operation speed of the tray 62 is the high speed V1, the post-processing control means 200 sets the tray lifting drive motor M to the high speed V1 to raise the tray 62 at a high speed, and proceeds to S107.

  S115 If the operation speed of the tray 62 is the low speed V2, the post-processing control means 200 sets the tray lifting drive motor M to the low speed V2, raises the tray 62 at a low speed, and proceeds to S104.

  FIG. 9 is a timing chart showing the steps of the normal standby position operation of the tray 62.

  (T1) While the tray upper limit position sensor PS1 and the tray lift position sensor PS2 are both off, the tray 62 stops at the upper limit position and stands by.

  (T2) In response to the drive start signal from the post-processing control means 200, the drive of the tray lifting / lowering drive motor M is started, the tray 62 is lowered, and the tray upper limit position sensor PS1 is turned on. The tray 62 is driven downward until the tray lift position sensor PS2 is turned on (S104). The speed of the descending operation is the low speed V2. The low speed V2 is, for example, a rotational speed of the motor M for driving the raising / lowering of the tray to 1200 rpm and a descending linear speed of the tray 62 of 16 mm / sec.

  (T3) When the tray 62 is lowered and the tray lift position sensor PS2 is turned on, the rotation direction of the motor M for raising and lowering the tray is reversely rotated to drive the tray 62 up (S107). The speed of the ascending operation is the low speed V2 because the tray speed determination sensor PS3 is on. The low speed V2 is, for example, a rotational speed of the motor M for driving the raising / lowering of the tray of 1200 rpm, and a rising linear speed of the tray 62 of 16 mm / sec. At the position where the tray 62 is raised and the raising position sensor PS2 of the tray 62 is turned off, the raising drive of the tray 62 is stopped and held in a standby state (S108).

  FIG. 10 is a timing chart showing the steps of raising and lowering the tray 62 when some of the sheets are removed from the sheets stacked on the tray 62.

  (T4) While the tray upper limit position sensor PS1 and the tray lift position sensor PS2 are both turned off, the tray 62 stops at the upper limit position and stands by.

  (T5) In response to the drive start signal from the post-processing control means 200, the drive of the tray lifting drive motor M is started, the tray 62 is raised, and the tray lift position sensor PS2 is turned on. The tray 62 is driven up until the tray lift position sensor PS2 is turned on (S105). The speed of the ascending operation is the high speed V1 because the tray speed determination sensor PS3 is off. The high speed V1 is about twice the normal standby position operation shown in FIG. 9, for example, the rotational speed of the motor M for raising and lowering the tray is 2400 rpm, and the rising linear speed of the tray 62 is 32 mm / sec.

  (T6) When the tray 62 is raised and the tray speed determination sensor PS3 is turned on, the drive of the tray lifting motor M is switched from the high speed V1 to the low speed V2, and the tray 62 is raised at a low speed. Let The low speed V2 is, for example, a rotational speed of the motor M for driving the raising / lowering of the tray to 1200 rpm and a descending linear speed of the tray 62 of 16 mm / sec. The tray 62 is raised at a low speed, and the tray 62 is stopped at a position where the tray raising position sensor PS2 is turned off, held in a standby state, and waiting for the start of the loading of the paper S.

  In the embodiment of the present invention, the post-processing apparatus connected to the copying machine is shown. However, the present invention can also be applied to a post-processing apparatus used by connecting to an image forming apparatus such as a printer or a light printing machine. is there.

  Further, the present invention is not limited to the above-described post-processing apparatus that performs folding processing and binding processing, but is applied to a paper discharge unit of a post-processing apparatus such as a gluing bookbinding processing apparatus, a trimming apparatus that performs edge alignment, and a large capacity paper stacking apparatus. Is also applicable.

1 is an overall configuration diagram of an image forming apparatus including an image forming apparatus main body and a post-processing apparatus. Sectional drawing of a post-processing apparatus. Sectional drawing which shows the tray raising / lowering means of the paper discharge means of a post-processing apparatus. Sectional drawing which shows the upper limit position and raising position of a tray. The perspective view which shows the paper discharge means of a post-processing apparatus. The front view of the paper discharge means which shows the paper loaded on a tray, and the action | operation of the sensor for tray speed judgment. The block diagram of raising / lowering control of a tray. The flowchart of the process which controls the raising / lowering of a tray. The timing chart which shows the process of the normal standby position operation | movement of a tray. 6 is a timing chart showing a process of raising and lowering the tray when some sheets are removed from the sheets stacked on the tray.

Explanation of symbols

60 Paper discharge means 61 Paper discharge roller pair 61A Lower roller 62 Paper discharge tray (tray)
68 Paper upper limit detection member (actuator)
69 Lifting speed detection member 100 Main control means 200 Post-processing control means A Image forming apparatus main body FS Post-processing apparatus H1 Tray raising speed switching position H2 Tray raising detection position H3 Tray upper limit detection position M Motor PS1 Tray upper limit position sensor PS2 Tray raising position Sensor (first detection means)
PS3 Tray speed sensor (second detection means)
PS4 Tray lower limit detection sensor S Paper

Claims (3)

In a post-processing device that, after post-processing the paper discharged from the image forming apparatus, is stacked on a liftable discharge tray,
First detection means for detecting a discharge standby position of the discharge tray;
Second detection means for detecting an upper surface position of the paper stacked on the paper discharge tray and selecting an operation speed switching position of the paper discharge tray;
Drive means for raising and lowering the discharge tray at a variable speed;
Post-processing control means for controlling the drive means to be variable in speed,
The post-processing apparatus is characterized in that the post-processing control unit controls the raising / lowering speed of the paper discharge tray by the driving unit based on the detection result of the second detection unit. In a post-processing apparatus that receives paper discharged from the image forming apparatus, performs post-processing, and then stacks it on a liftable discharge tray.
First detection means for detecting a discharge standby position of the discharge tray;
Second detection means for detecting an upper surface position of the paper stacked on the paper discharge tray and selecting an operation speed switching position of the paper discharge tray;
Drive means for raising and lowering the discharge tray at a variable speed;
Post-processing control means for controlling the drive means to be variable in speed,
The post-processing control means switches the raising / lowering speed of the discharge tray by the driving means between a low speed operation and a high speed operation based on the detection result of the second detection means,
During the upward stroke of the paper discharge tray, after the second detection means detects that the paper discharge tray reaches the low speed operation area from the high speed operation area, the speed of the paper discharge tray is switched to the low speed operation,
A post-processing apparatus that controls a lifting speed in a low-speed operation region of the discharge tray to a speed that can be stopped at a predetermined position where the sheet stacking performance can be secured. An image comprising: an image forming apparatus main body comprising an image writing means, an image forming means, a paper conveying means, an input means, and a main control means; and the post-processing device according to claim 1 or 2. Forming equipment.

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