JP5740998B2 - Paper stacking apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a large-capacity paper stacking apparatus that sorts and collects sheet members (in the present specification, simply referred to as “paper”) such as paper, recording paper, and sheet-like recording medium, and the like. The present invention relates to an image forming apparatus provided with a sheet stacking device integrally or separately.

  The paper stacking device is connected as a paper post-processing device such as an image forming device, and a shift tray for stacking paper is placed on a movable carriage, the carriage is set at a predetermined position in the paper loading apparatus, and then the paper is loaded. When the front door of the stacking device is closed, only the shift tray set on the carriage is raised to the paper discharge position by the shift tray raising means. When the copied and printed sheets are conveyed from the image forming apparatus or the like to the sheet stacking apparatus, the sheets are stacked on the shift tray in the order of conveyance. At this time, the sheets are stacked while keeping the sheet surface height on the shift tray constant in order to ensure the sheet alignment accuracy. While the paper is being loaded, the paper height of the loaded paper is detected, and if the loaded paper is detected to have reached the predetermined height, the shift tray is lowered to always keep the paper discharge position and paper height constant. Perform such control. This ensures sheet alignment accuracy.

  As a paper stacking device that performs such control, for example, Patent Document 1 (Japanese Patent No. 4328865) is known. The present invention detects a thickness of a sheet bundle to be processed for the purpose of performing a bundle process such as an optimal bookbinding process based on the sheet thickness, and a sheet that can be bundled based on the detected thickness of the sheet bundle Change the upper limit of the number of sheets or sheet thickness, eliminate wrinkles and bookbinding mistakes in the finish, etc., and make it possible to bundling up to the upper limit as much as possible, so that optimal bookbinding processing etc. according to the thickness of the sheet used The bundle processing is possible.

  In the conventional paper stacking apparatus including the known example, when it is detected that the paper is stacked to a predetermined height, the shift tray is lowered, and control is performed so that the paper discharge position and the paper surface height are always substantially constant. By doing so, control is performed so as not to cause sheet misalignment in the conveyance direction. Therefore, if the detection sensitivity of the paper surface filler and the paper surface detection sensor for detecting the paper surface is made sensitive, the paper surface detection sensor is turned on only when the paper collides with the paper surface filler, and it is detected earlier than the target paper height to be detected. Resulting in. As a result, the lowering of the shift tray is accelerated and a sheet alignment failure occurs. Therefore, it is necessary to make the sensitivity of the paper surface filler and the paper surface detection sensor insensitive to some extent. Therefore, the paper surface filler and the paper surface detection sensor are configured by using an elastic body such as a spring so that the paper surface filler does not operate with a force that causes the paper to collide with the paper surface filler. Also, when the paper is loaded and the paper surface height gradually rises, the elastic body such as a spring is pushed in and the elastic body contracts, so the force pushing the paper surface filler gradually increases, and as a result, the paper is It becomes difficult to dive under. Therefore, it was not possible to make the paper surface detection insensitive to necessity.

  Therefore, the problem to be solved by the present invention is to ensure high accuracy of sheet alignment regardless of the thickness of the sheet being conveyed.

In order to solve the above-described problems, the present invention provides a stacking unit on which a sheet to be conveyed is stacked, an elevating unit for moving the stacking unit up and down, and an uppermost layer of the sheets stacked on the stacking unit or the mounting unit. Including a detection end for detecting the position of the paper surface and a closed end that moves according to the detected position, and controls the paper level detection means that is turned on or off according to the position of the shielding end ; and a control means for lowering said stacking means to said sheet detection means 38 is turned on from an off state, and counting means for counting the number of sheets received in said loading means, a calculating means for calculating a sheet thickness of the sheet The counting means counts the number of sheets received by the stacking means in a state where the paper surface detecting means is turned on and the stacking means is stopped at the lowered position until the paper surface detecting means is turned off, and the calculating means The paper thickness is calculated from the counted number of paper sheets and the operating distance that the detection end of the paper surface detection means has moved from when the paper surface detection means is turned on to when the paper surface detection means is turned on. The lowering operation of the loading means is controlled according to the thickness .

In the embodiment described later, the stacking means is the shift tray 102, and the lifting means is the tray lifting motor 107, elevator 103, pulley 107a, timing belt 107b, worm gear 106, gear 109, gear 112, gear 105, and timing belt 104. , the sheet surface detection means to the sheet detecting sensor S3 and sheet detection filler 115, counting means, calculation means and the control hand stage to CPU 501, the the paper stacking apparatus to the stacker 100 or the sheet post-processing apparatus B1, B2, their respective Correspond.

  According to the present invention, it is possible to ensure a high accuracy of sheet alignment even when a sheet having any thickness is conveyed.

1 is a diagram showing a configuration of an image forming system in which an image forming apparatus according to an embodiment of the present invention and two first and second sheet post-processing apparatuses are connected together. FIG. It is a figure which removes the front door E of 1st paper post-processing apparatus B1, and shows the internal structure of the said apparatus. FIG. 5 is an enlarged view showing a paper discharge unit to a shift tray, and shows a state where sheets are not stacked. FIG. 5 is an enlarged view of a paper discharge unit to a shift tray, showing a state where sheets are stacked. It is a timing chart which shows the output state of the paper surface detection sensor in paper surface position fixed control. 1 is a block diagram illustrating an electrical configuration of a system including an image forming apparatus and a sheet post-processing apparatus (stacker). It is a perspective view which shows a shift conveyance mechanism. It is a perspective view which shows a front-end | tip alignment mechanism. FIG. 6 is a front view of a main jogger mechanism viewed from the sheet discharge direction. It is a perspective view of the main jogger mechanism seen from the apparatus back side. It is a perspective view of a main jogger. It is a perspective view which shows a sub jogger mechanism. It is a flowchart which shows the process sequence of the example (the 1) which changes a descent | fall timing according to a paper thickness calculation result. It is a flowchart which shows the process sequence of the example (the 2) which changes a descent | fall timing according to a paper thickness calculation result. FIG. 10 is a diagram illustrating a change state of a gap between a paper surface detection sensor and a paper surface in the case of thick paper and thin paper in an example (part 3) in which the descending timing is changed according to a paper thickness calculation result. It is a flowchart which shows the control procedure of the example which changes descent distance. It is a figure which shows the relationship between the frequency | count of a shift tray descent | fall and paper detection thickness.

  In the present invention, the paper thickness is calculated from the number of sheets while the paper surface detection sensor output is reversed after the paper is discharged to the shift tray, and the paper surface filler operating distance determined from the layout of the paper surface detection sensor and the paper surface filler. According to the calculated sheet thickness, the shift tray lowering timing, the lowering distance, the nipping pressure of the rollers of the paper discharge unit, and the like are changed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1. Overall Configuration FIG. 1 is a diagram showing a configuration of an image forming system in which an image forming apparatus according to the present embodiment and two first and second sheet post-processing apparatuses are connected. In FIG. 1, an image forming apparatus A is an apparatus that copies or prints an image or the like to be copied on a sheet and outputs the sheet to the outside of the image forming apparatus A. In the system shown in FIG. 1, a sheet copied and printed from the image forming apparatus A is discharged to a first sheet post-processing apparatus B1. The first and second paper post-processing devices B1 and B2 are paper stacking devices, so-called stackers, and have a function of collecting a large number of sheets after copying or printing and discharging them outside the apparatus. The image forming apparatus A may be any known image forming apparatus such as a known copying machine such as an electrophotographic method or a droplet discharge method, a printer, a plotter copying machine, or a digital multifunction peripheral, and is limited to a specific image forming apparatus. It is not something.

  In this system, a paper discharge destination is set in advance from an operation unit (not shown) on the image forming apparatus A side. The paper discharge destination is the proof tray F, the tray in the first paper post-processing apparatus B1, or the tray in the second paper post-processing apparatus B2. In this embodiment, the proof tray F is a proof tray of the first paper post-processing apparatus B1, and the second paper post-processing apparatus B2 is provided with a similar tray.

  The operation unit C includes an input unit for performing a jam processing operation for performing processing at the time of paper jam when the tray in the paper post-processing device B1 is lowered, when the paper transport is in a normal operation, or the paper post-processing device. The operating state of the sheet post-processing apparatus B1 is displayed when B1 has an error, and further, a predetermined input operation is possible.

  The upper door D is a door that opens and closes in order to remove the jammed paper when a paper jam occurs in the paper post-processing apparatus B1 during paper conveyance. The front door E is a door that opens and closes in order to set a carriage on which a tray is placed in the paper post-processing apparatus B1. This front door E is used for stacking sheets on the tray after loading the sheets, lowering the tray on which the stacked sheets are placed to the carriage, and moving the carriage on which the tray is placed to the outside of the sheet post-processing apparatus B1. Opened and closed. The second paper post-processing device B2 is a device that stacks the transported paper via the first paper post-processing device B1. When the front door E is closed after the carriage is set at a predetermined position in the paper post-processing apparatus B1, the shift tray on the carriage rises to the paper discharge position by the elevator. If the front door E is opened while the shift tray is being lifted, the shift tray is urgently stopped to ensure safety. The sheets are stacked one by one on the shift trays of the sheet post-processing apparatuses B1 and B2, and when the stacking job is completed, the user operates the operation unit C to lower the shift tray on which the sheets are stacked onto the carriage. After that, by opening the front door E, the carriage on which the shift tray on which the paper is loaded can be moved to the outside of the paper post-processing devices B1 and B2.

  The first and second paper post-processing devices B1 and B2 are provided with a paper discharge port G for transporting the paper to the downstream paper post-processing device. In FIG. 1, the sheet post-processing apparatus connected to the downstream side after the second sheet post-processing apparatus B2 is not shown, but a sheet folding apparatus, a sheet binding apparatus, a bookbinding apparatus, and the like are connected as necessary. One system is configured.

2. Configuration of Paper Post-Processing Device FIG. 2 is a diagram showing the internal structure of the first paper post-processing device B1 with the front door E removed. Hereinafter, the sheet post-processing apparatus according to the present embodiment is a sheet stacking apparatus, and therefore the description will be made as the stacker 100. FIG. 2 shows a state where the carriage 108 is set at a predetermined position and the tray 102 is raised to the paper discharge position.

  In the stacker 100, when the sheets are stacked, when the carriage 108 is set at a predetermined position of the stacker 100 with the front door E opened, and the front door is closed, the tray 102 on the carriage 108 is moved by the elevator 103. To rise. The drive source of the elevator 103 is a tray lifting / lowering motor 107, and the tray lifting / lowering motor 107 is rotated by a control signal from the CPU 501 shown in FIG.

  A pulley 107a is press-fitted to the rotation shaft of the tray lifting / lowering motor 107, and the work generated by the rotation of the tray lifting / lowering motor 107 is transmitted via the timing belt 107b. A gear group such as a worm gear 106, a gear 109, a gear 112, and a gear 105 is connected to the tip of the timing belt 107 b, and the gear 105 is connected to the timing belt 104. For example, when the tray lifting / lowering motor 107 rotates forward, the force is transmitted to the timing belt 104 by the connected gear, and the elevator 103 that lifts and lowers the tray 102 connected to the timing belt 104 is raised. On the other hand, when the tray lifting / lowering motor 107 rotates in the reverse direction, the elevator 103 is lowered.

  The stacker 100 includes a transport mechanism in addition to a tray mechanism for loading and discharging the sheets. The transport mechanism discharges the sheet transported from the image forming apparatus A side to the tray 102 or transports it to the subsequent sheet processing apparatus. The transport mechanism includes first to third transport paths L1, L2, and L3, and an entrance. A roller 114, a lower branch claw 120 that switches to either the second transport path L2 or the third transport path L3, and an upper branch claw 121 that switches to either the first transport path L1 or the second transport path L2. ing. The first conveyance path L1 is a conveyance path for discharging a sheet to the proof tray 101, and is a conveyance path from the upper branching claw 121 to the proof tray 101. The second conveyance path L2 is a conveyance path for conveying the sheet to the subsequent sheet processing apparatus, and is a conveyance path from the entrance portion to the paper discharge portion. The third conveyance path L3 is a conveyance path for discharging a sheet to the tray 102, and is a conveyance path from the lower branching claw 120 to the tray 102.

  Note that a conveyance roller (sheet discharge) 111 for discharging a sheet to the tray 102 is disposed at the most downstream portion in the sheet conveyance direction of the third conveyance path L3, and the sheet discharge roller 111 is urged by a spring to be pressed. Then, a driven roller 113 that is driven is provided, and a sheet is nipped between these rollers 111 and 113. An entrance sensor S1 and a sheet transport path sensor S2 are provided along the sheet transport path, and a paper surface sensor S3 is disposed in the vicinity of the paper discharge portion of the paper discharge roller 111. Each of the sheet conveying paths L1, L2, and L3 includes a plurality of conveying rollers that are driven by a driving mechanism (not shown) to convey the sheet to a predetermined position. In FIG. 2, a jogger 210 and a sub jogger 310 for aligning sheets that are discharged and stacked on the shift tray 102 are provided at the upper part of the lifting drive mechanism. The stopper 71 which controls is suspended from the upper part.

  In the stacker 100 generally configured as described above, the sheet discharged from the image forming apparatus A such as a copier installed adjacent thereto is introduced from the guide plate 117 at the entrance from the direction of the arrow A1. In the present embodiment, the stacker 100 can select an operation mode of a proof paper discharge mode, a straight paper discharge mode, and a shift paper discharge mode as described later.

  3 and 4 are enlarged views of the paper discharge portion R1 to the shift tray indicated by the dotted line in FIG. 2, FIG. 3 shows a state in which sheets are not stacked, and FIG. 4 shows a state in which sheets are stacked. .

  As shown in FIG. 3, the home position of the shift tray 102 is set on the paper discharge port side, and a paper surface detection filler 115 and an optical paper surface sensor S3 are provided at the paper discharge port. In the figure, reference numeral 99 denotes an end fence, which regulates the upstream position of the paper on the shift tray 102 in the paper transport direction.

  The paper surface detection filler 115 is swingably supported by the swing support shaft 115a. In the drawing, the end portion protruding from the end fence 99 is a detection end 115b, and the end portion on the paper surface detection sensor S3 side is a light transmission type. This is a shielding end 115c that shields the optical path of the paper surface detection sensor S2 made up of the above sensors. When the shift tray 102 is not at the home position, the detection end 115b of the paper surface detection filler 115 is slightly lower than the position in FIG. 3, and the shielding end 115c is out of the optical path of the paper surface detection sensor S3. The light between the light detection units is not blocked, and the output of the paper surface detection sensor S3 is turned on. On the other hand, when positioned at the home position, the detection end 115b rises, and the shielding end 115c blocks the optical path. As a result, the output of the paper surface detection sensor S3 is turned off. Further, the paper surface detection filler 115 does not operate with a weak force such that the paper collides with the detection end 115b of the paper surface detection filler 115 by the spring 115d attached to the support shaft 115a of the paper surface detection filler 115, and the paper surface detection sensor S3. Output is not reversed from on to off.

When the shift tray 102 is raised by the elevator 103, the detection end 115b of the paper surface detection filler 115 is pushed upward by the shift tray 102 , the paper surface detection filler 115 rotates around the support shaft 115a, and the shielding end 115c is It moves downward and blocks the optical path between the light detection parts of the paper surface detection sensor S3. As a result, the output of the paper surface detection sensor S3 is turned off. When the output of the paper surface detection sensor S3 is turned off, the rotation operation of the tray lifting / lowering motor 107 is stopped and the lifting operation of the shift tray 102 is also stopped. Next, the tray lifting / lowering motor 107 is reversely rotated to lower the shift tray 102 until the output of the paper surface detection sensor S3 is turned on, and the tray lifting / lowering motor is stopped. This position becomes the home position of the shift tray 102.

FIG. 4 shows a state in which sheets copied or printed from the image forming apparatus A side are discharged onto the shift tray 102 in the home position state shown in FIG. As shown in FIG. 4, the paper P is discharged to the shift tray 102 by the paper discharge roller 111 and the driven roller 113 (in the direction of arrow D). When fully sheet P is discharged, by the stopper 71 in the conveying direction leading end side, it moves in the arrow H Direction, moves the sheet P to the end fence 2 side (refer to FIG. 8 described later). In the end fence 99, a paddle 118 formed of an elastic body such as rubber that rotates in conjunction with the motor 55 shown in FIG. 7 abuts on the upper surface of the paper P, and the paper P is pulled toward the end fence 99 by a frictional force. It is possible to align sheets in the transport direction.

  When the above operation is repeated for each sheet P discharged, a plurality of sheets P are stacked on the shift tray 102 as shown in FIG. When a plurality of sheets of paper P are stacked, the detection end 115b of the paper surface detection filler 115 rises upward (rotates in the direction of arrow E in FIG. 4), and the shielding end 115c side of the paper surface detection filler 115 falls downward. The optical path of the paper surface detection sensor S3 is blocked, and the paper surface detection sensor S3 is turned off. When the paper surface detection sensor S3 is turned off, the tray lifting / lowering motor 107 rotates in the reverse direction, and the elevator 103 is lowered until the paper surface detection sensor S3 is turned on. As a result, the position of the paper surface on which the paper P is stacked is controlled so as to be always constant, and the paper P is stacked on the shift tray 102 while repeating this minute lifting operation.

  FIG. 5 is a timing chart showing the output state of the paper surface detection sensor S3 in the paper surface position constant control. Referring to FIG. 5, the output of the paper surface detection sensor S <b> 3 is repeatedly turned off and on in section C repeatedly. This is because the position of the paper surface detection filler 115 is at the last position of the paper surface of the paper P, and as a result of the paper surface being shaken by the rotation of the paddle 111, the output of the paper surface detection sensor S3 is repeatedly turned off and on. Therefore, the lowering control of the shift tray 102 is a control for lowering the tray lifting / lowering motor 107 after waiting for the section I after the output of the paper surface detection sensor S3 is completely turned on.

  Here, when the ultra-thick paper P is transported from the image forming apparatus A and stacked on the shift tray 102, the paper surface detection filler vertical movement movable distance ΔG (= H1-H2) in FIG. Suppose that it was at the time of section I. In the case of thin paper or plain paper, even if the paper surface detection filler vertical movement movable distance is almost zero, the paper P is pressed against the shift tray 102 side by the paddle 118, and the paddle 118 is rotated so that the paper P is pulled toward the end fence 99 side. Therefore, the sheet P is inserted under the sheet surface detection filler 115, and the stopper 71 pushes the sheet P toward the end fence 99, so that the sheet can be aligned in the transport direction. This is because the thickness of the paper P is smaller than the vertical movement movable distance of the paper surface detection filler.

  However, when the paper P is ultra-thick paper and the paper surface detection filler vertical movement movable distance is zero, the paper P is pressed against the shift tray 102 side by the paddle 118, and the rotation of the paddle 118 tries to pull the paper P toward the end fence 99 side. However, since the thickness of the paper P is larger than the vertical movement movable distance of the paper surface filler, the paper P cannot be submerged under the paper surface detection filler 115 by the rotation operation of the paddle 118 and the movement of the stopper 71. As a result, it is not possible to align the paper in the transport direction.

Therefore, the number N of stacked sheets P is counted during a section J from the start of stacking of sheets P until the output of the sheet surface detection sensor S3 is reversed so that the sheet cannot be aligned in the transport direction. From the known vertical movement movable operating distance ΔG = (H1−H2) of the paper surface detection filler 115 of the paper P, the thickness Th of the paper P is set to Th = ΔG / N.
Calculate from

  Next, when the calculated thickness Th of the paper P is large, that is, ultra-thick paper, the section I in FIG. 5 is shortened and the shift tray lowering timing is advanced.

3. Control Configuration FIG. 6 is a block diagram showing an electrical configuration of a system including the image forming apparatus A and the sheet post-processing apparatus B1 (stacker 100). In the figure, a control plate PB is provided in the stacker 100, and a CPU 501 is mounted on the control plate PB. The CPU 501 includes a ROM 502, and a control program for the stacker 100 is written in the ROM 502 in advance. The CPU 501 controls various operations of each unit of the stacker 100 while using a RAM (not shown) as a work area and a data buffer.

  The CPU 501 is connected to a group of sensors for detecting an operation position in various controls such as a tray lowering SW P100, a jam release SW P101, an inlet sensor S1, a shift paper discharge sensor S2, and a paper surface detection sensor S3. A detection signal is input to the CPU 501. An operation request to the stacker 100 and operation information of the image forming apparatus A are also input from the control unit 500 of the image forming apparatus A, and information corresponding to this or information requested by the image forming apparatus A is received from the stacker 100. Are output to the control unit 500 of the image forming apparatus A. The CPU 501 is connected to a tray lifting motor 107, a lower branch claw motor M120, an upper branch claw motor M121, and other motor groups used for paper conveyance, stack control, etc., and outputs an operation signal to these connected motor groups. Control according to the operating situation.

  Further, a tray lowering LED P102, a jam release LED P103, an output LED P104, a full LED P105, and an error LED P106 on the operation unit C are also connected. Depending on the operation status of the stacker 100, each display unit of the operation unit C It also controls the operation of turning on, blinking, and turning off the LED.

  Further, the image forming apparatus A can be connected to a device such as a personal computer and a FAX (not shown) that can be remotely connected to the image forming apparatus A through a network connection, and information such as a PC can be connected to the image forming apparatus A. It is also possible to print.

  The output of the entrance sensor S1 is “L” when there is no paper, and the output becomes “H” when the paper P passes through the entrance sensor S1. Therefore, the CPU 501 monitors the output of the entrance sensor S1, and counts the number of times “L” → “H” during the inversion of the output of the paper surface detection sensor S3 from the start of paper P stacking. The count value becomes the number of sheets P stacked, and the thickness of the stacked sheets P can be calculated from the operating distance of the paper surface detection filler 15. The sheet thickness information is transmitted to the image forming apparatus A. Therefore, the CPU 501 functions as a counting unit and a calculating unit.

  By configuring and controlling in this way, on the image forming apparatus A side, it becomes possible to adjust the fixing temperature in accordance with the sheet thickness or to adjust the nip pressure of the roller during sheet conveyance. There is no need to provide a sheet thickness detecting means on the A side.

4). Shift Transport Mechanism FIG. 7 is a perspective view showing the shift transport mechanism. In the figure, the shift conveyance mechanism unit 50 moves the paper discharge roller 111 and the driven roller 113 in the directions indicated by arrows G1 and G2 in FIG. 3 (the arrow G1 is the front side of the stacker 100 and the arrow G2 is the back side of the stacker 100). By moving the sheet, the sheet discharge position on the shift tray 102 is shifted to the near side or the far side. That is, the paper discharge roller 111 and the driven roller 113 are connected to holders 51 and 52 that move in the direction of the arrow and shafts 53 and 54 that connect them. The paper discharge roller 111 is driven and rotated by the motor 55 regardless of the movement position in the directions of the arrows G1 and G2. In other words, the driven gear 56 attached to the paper discharge roller 111 is located at the movement position in the arrow direction of the paper discharge roller 111 with respect to the drive gear 60 driven by the stepping motor 55 via the gears 57 and 58 and the belt 59. Regardless of meshing.

  The holder 51 is provided with a rack 61, and the rack 61 is connected to a shift motor 63 via a pinion 62. The paper discharge roller 111 and the driven roller 113 are slid by a predetermined amount (10 mm) in the directions of arrows G1 and G2 with the position in FIG. 8 as the center position. The home positions of the paper discharge roller 111 and the driven roller 113 are set at the center position and are detected by the optical home position sensor S12. By rotating the stepping motor 63 by a predetermined amount based on the home position, the paper discharge roller 111 and the driven roller 113 are moved to the shift position. Reference numeral 99 denotes an end fence that regulates the rear end of the sheet in the shift tray 102.

5. Tip Alignment Mechanism FIG. 8 is a perspective view showing the tip alignment mechanism. In the drawing, a leading edge aligning mechanism 70 is a mechanism for aligning the leading end of the sheet discharged onto the shift tray 102, and a leading end stopper 71 that can be adjusted in the direction of arrow H, which is a direction parallel to the sheet conveying direction. It has. The tip stopper 71 is attached to a slider 72, and the slider 72 is slidably guided by a pair of shafts 73 having an axial center extending in the arrow H direction as shown in FIG. The slider 72 is connected to a belt 76 that is stretched between pulleys 74 and 75. Then, by driving the belt 76 by the stepping motor 77, the slider 72 moves in the arrow H direction together with the tip stopper 71, and the position of the tip stopper 71 is adjusted.
The slider 72 is provided with a shielding plate 78, and when the leading end stopper 71 moves to the home position, the shielding plate 78 is detected by an optical home position sensor S13.

6). 9 to 11 are views showing the main jogger mechanism. FIG. 9 is a front view of the main jogger mechanism as viewed from the sheet discharge direction. FIG. 10 is a perspective view of the main jogger mechanism as viewed from the back of the apparatus. FIG. 11 is a perspective view of the main jogger. In these drawings, a main jogger mechanism 200 includes stepping motors 201 and 202 that control movement in the width direction (a direction that is perpendicular to the paper discharge direction and horizontal), a stepping motor 203 that controls movement in the vertical direction, and a stepping motor. A gear 204 meshing with the gear 203, a rotating shaft 205 to which the gear 204 is attached, a driving shaft 206 parallel to the rotating shaft 205, first and second sliders 207F and 207R connected to the driving shaft 206, The sensors S6F and S6R that detect the first and second sliders 207F and 207R, the filler 208 provided in the gear 204 that indicates the rotation state of the rotating shaft 205, and the sensor S7 that detects the filler 208 are configured. The first and second main joggers 210F and 210R are wide and narrow. Sea urchin, also move to up and down them. The position where the sensor 208 detects the filler 208 is the home position, and the first and second main joggers 210F and 210R are in a lowered state. In the present embodiment, each part located on the front side of the apparatus is distinguished by attaching an F suffix, and each part located on the far side is assigned an R suffix.

  The first and second main joggers 210F and 210R are formed of plate-like bodies, and the first and second alignment portions 211F and 211R provided respectively are located at the lowermost portions of the main joggers 210F and 210R, and The opposing surface is a flat surface orthogonal to the shift directions G1 and G2. As described above, the first and second aligning portions 211F and 211R are configured by flat surfaces whose opposing surfaces are orthogonal to the shift directions G1 and G2, thereby shifting the first and second main joggers 210F and 210R. By moving in the directions G1 and G2, the first and second aligning portions 211F and 211R can be reliably brought into and out of contact with the end surfaces of the sheets stacked on the tray 102, and the sheet bundle can be aligned.

  As shown in FIG. 11, the first and second main joggers 210 </ b> F and 210 </ b> R are configured so that the sheets discharged from the paper discharge roller 111 shown in FIG. 1 are opposed to the first and second main joggers 210 </ b> F and 210 </ b> R. In order to avoid interference with the paper discharged when being guided in, the upper portions of the first and second aligning portions 211F and 211R are formed at intervals wider than the facing interval between the aligning portions 211F and 211R. Stepped first and second relief portions 212F and 212R are provided. The first and second main joggers 210F and 210R are configured so that the roots are sandwiched and pressed by the first and second sliders 207F and 207R, respectively. The positions of the first and second sliders 207F and 207R Thus, the first and second main joggers 210F and 210R do not hang down below a predetermined state, but can move freely in the upward direction.

  When the first and second main joggers 210F and 210R receive the paper P discharged from the paper discharge roller 111, the first and second main joggers 210F and 210R are waiting at a receiving position in an opposed state with a predetermined acceptable interval. In this state, each time the paper P is discharged from the paper discharge roller 111 and stacked on the shift tray 102, the opposing distance is set from the receiving position and moved to a position where it contacts the end surface of the paper P, and then the opposing distance is increased. And return to the receiving position. By repeating this series of alignment operations for each sheet discharged, the end surfaces of the paper P (surface parallel to the transport direction: horizontal direction) are aligned.

  The discharge roller 111 repeats a predetermined number of sheets constituting the first sheet bundle while repeating the 10 mm shift operation in the arrow G1 direction for each sheet, and then repeats the 10 mm shift operation in the arrow G2 direction to load the next sheet bundle. I will do it. When the shift direction is switched, the first and second main joggers 210F and 210R are moved to the retracted rotation position to enter the aligning member retracted state, and the paper discharge roller 111 performs a shift operation in the retracted state.

  For example, when the paper discharge roller 111 is shifted to the first main jogger 210F side, the second main jogger 210R is applied to the back side of the discharged paper stacked on the shift tray 102 and onto the front “part” paper bundle. It will be arranged at the position of contact. The first main jogger 210F is located on the front side surface of the paper loaded on the shift tray 102, and takes the home position as the vertical position. Each time the shift operation of the paper discharge roller 111 is reversed, the rotary shaft 205 is replaced by the first and second arms 209F and 209R (FIG. 10) attached to the rotary shaft 205, and the first and second main joggers 210F. , 210R is moved to the retracted position by rotating it in the direction of pressing down. Each time a shift operation occurs, the opposite side aligning member is brought into contact with (placed on) the preceding “part” sheet bundle to align the discharged sheet bundle. At this time, the first and second main joggers 210F and 210R set the friction coefficient so that the sheets do not shift so that the sheets can be stably aligned.

  The retraction amounts of the first and second main joggers 210F and 210R are retraction amounts from the home position where the fillers 208 are detected by the sensors S6F and S6R, and therefore the increase amount is always a constant amount. If the uppermost surface + α of the discharge bundle is not moved (raised) from the home position, it interferes (contacts) with the stacked sheet bundle that is shifted, and the aligned bundle is broken. + Α is a certain position between the uppermost position, but if the α value is large, the margin to cope with curling and folding of the discharged paper increases, but the return when receiving the next paper when the paper gap is jammed It will take time.

7). Sub-Jogger Mechanism FIG. 12 is a perspective view showing the sub-jogger mechanism. A sub-jogger mechanism 300 shown in FIG. 12 is a mechanism for aligning the leading ends of the sheets discharged onto the shift tray 102, and the first and second sub-joggers whose position can be adjusted in the width direction by the stepping motor 301. 310F and 310R are provided. The first and second sub joggers 310F and 310R are attached to the first and second sliders 311F and 311R, respectively, and the first and second sliders 311F and 311R have their axes along the width direction of the sheet. Are slidably guided by two parallel shafts 302 and 303 arranged in parallel. The first and second sliders 311F and 311R are connected to a belt 306 that is stretched between the first and second pulleys 304 and 305.

  With this configuration, when the belt 306 is driven by the stepping motor 301, the first and second sliders 311F and 311R move in the width direction together with the first and second sub joggers 310F and 310R. When the second slider 311R moves to the home position, it is detected by an optical home position sensor (not shown).

8). Shift tray lifting / lowering control 8.1 Example of changing the lowering timing according to the paper thickness calculation result (part 1)
FIG. 13 is a flowchart showing a processing procedure executed by the CPU 501 of the present embodiment.

Stacker In this embodiment, the sheet stacking job start information from the image forming apparatus A is output to the stacker 100, the sheet P is more stacker 100 are sent to the next stage of the stacker 100 (Step S 101), and accept the paper P 100 counts the number of sheets stacked on the shift tray 102 (step S102). In this process, as shown in FIG. 5, it is determined whether or not the output of the paper surface detection sensor S3 is inverted (step S103). If it is not reversed by this determination (No), the process returns to Step S102, and the processing after Step S102 is repeated. If it is reversed (Yes), the process proceeds to Step S104.

  In step S104, the paper surface detection filler operating distance is divided by the number of sheets counted in step S102, the paper thickness is calculated, and is changed to the time tc after the paper surface detection sensor S3 is turned off according to the paper thickness. It is determined whether or not it has been turned off for time tc or more (step S105). If it is off for the time tc or longer, the shift tray 102 is immediately lowered until the paper surface detection sensor S3 is turned on (steps S106, S107). If it is not off, it waits until it is turned off. (Step S105: Yes) The shift tray 102 is lowered until the paper surface detection sensor S3 is turned on (steps S106, S107), and when it is turned on, the lowering of the shift tray 102 is stopped (step S108). The processing from step S102 to step S108 is repeated until the end of the paper stacking job (step S109), and the processing is completed when the paper stacking job ends.

  In this processing procedure, if the job is not completed in step S109, the processing is repeated from step S102. Therefore, when the shift tray 102 is lowered, the paper thickness is calculated in step S104 every time. Thereby, it is possible to detect the sheet thickness with high accuracy.

  Note that the thickness information of the paper P calculated in step S104 is transferred from the CPU 501 to the main body control unit 500 of the image forming apparatus A. As a result, the control unit 500 of the image forming apparatus A can change the fixing temperature according to the paper thickness at the time of copying or printing, and saves the user from having to input the paper thickness information conventionally. It is possible to provide the image forming apparatus A including the convenient stacker 100. In this case, since the sheet thickness information cannot be transferred to the image forming apparatus A until the sheet thickness information is acquired in step S104, the fixing temperature is set to a preset initial value until the sheet thickness information is acquired. Is executed.

  The paper stacking job here is a unit of paper processing that is instructed to the stacker 100 from the image forming apparatus A side and executed by the stacker 100. The same document is input on the image forming apparatus A side by copying or printing. For example, when the number of copies is created, or when another document is added and stacked, the normal setting is performed from the image forming apparatus A side.

  The paper surface detection sensor S3 is initialized by lowering the shift tray once and then raising it when the power is turned on. The initialization is also executed when the paper P is removed from the shift tray 102 and raised for discharging the next job. Under this assumption, the processing from step S101 is started.

  If the shift tray lowering timing is changed according to the calculated sheet thickness, the sheet P can be reliably moved to the lower side of the detection end 115b of the sheet surface detection filler 115, and the conveyance direction can be changed. In addition to eliminating paper misalignment, high productivity can be secured.

8.2 Example of changing the lowering timing according to the paper thickness calculation result (part 2)
It is a flowchart which shows the modification of the process sequence of FIG. 13 of FIG. In the flowchart shown in FIG. 13, if the job has not ended in the job end determination step in step S <b> 109, the process returns to step S <b> 102 and the subsequent processing is repeated. The paper thickness is calculated in step S104. If processed in this way, the sheet thickness detection accuracy is surely increased, but there are many control steps and it is not efficient.

  In addition, when the paper loaded on the shift tray 102 has curl, the curl amount increases as the number of stacked sheets increases. Therefore, in this example, as shown in the flowchart of FIG. 14, the processing is executed from step S101 to step S108 in the processing procedure shown in the flowchart of FIG. 13, and the sheet stacking job is not completed in step S109a. Returns to the determination process of step S105, and repeats the process from step S105 to step S109a. As a result, the paper thickness can be calculated only once in step S104 when the shift tray 102 is lowered for the first time.

  If the sheet thickness calculation is executed only once in this way, and thereafter the tray lowering stop operation from step S105 to step S108 is repeated without calculating the sheet thickness, the control of the stacker 100 is simplified. In addition, since the effect of curling of the paper P is the least during the first shift tray lowering operation, it is possible to accurately calculate the paper thickness.

  The processing of other steps is as described in the above section 8.1.

8.3 Example of changing the lowering timing according to the paper thickness calculation result (part 3)
In this example, the sheet lowering timing is changed to be inversely proportional to the calculated thickness of the sheet P. That is, as shown in FIG. 4, the thickness Th per sheet P is calculated from the sheet filler operating distance ΔG = H1−H2 and the number N of sheets P stacked while the output of the sheet filler S3 is reversed. However, if the thickness of the paper P is large, the gap between the front end of the paper surface detection filler 115 and the stacked paper P shown in FIG. For this reason, the lowering timing of the shift tray 102 is delayed with respect to the sheet stacking. Therefore, the timing is changed so that the lowering timing is inversely proportional to the thickness of the paper P.

  FIG. 15 is a diagram showing a change state of the gap (corresponding to the operation distance ΔG of the paper surface filler in FIG. 4) between the paper surface detection sensor and the paper surface in the case of thick paper and thin paper. The gap between the paper surface detection sensor and the paper surface is taken. Productivity (for example, Paper per Minute) is common to both thick paper and thin paper, and the red line in FIG. 15 is the tray lowering threshold. Below this, the shift tray 102 is lowered. A solid line indicates thick paper, and a broken line indicates thin paper.

  In the case of thin paper, when the gap (ΔG) falls below the tray lowering threshold value and the next paper P is stacked, the paper P is pushed into the shift tray 102 side by the paddle 118 and the paper P is pushed toward the shift tray 102 side. Therefore, the paper P can be drawn into the end fence 99 side. However, in the case of thick paper, when the gap (ΔG) falls below the tray lowering threshold and the next paper P is loaded, the paper P is pushed toward the shift tray 102 by the paddle 118, but the paper P is sufficiently moved toward the shift tray 102. The paper cannot be pressed and a paper stacking failure occurs. Therefore, in order to prevent stacking failure, the time corresponding to the section I shown in FIG. 5 is shortened according to the thickness of the stacked paper P, and the shift tray lowering timing is changed in inverse proportion to the calculated thickness of the paper P. To do. Here, the shift tray lowering timing that is inversely proportional to the calculated thickness of the paper P is not specifically illustrated. However, for example, a plurality of data are acquired in the laboratory for the paper P having different thicknesses, and the paper is based on the data. A shift tray lowering timing that is inversely proportional to the thickness of P is tabulated, and based on the thickness of the paper P detected from the image forming apparatus A based on the detected paper thickness information input from the operation unit C by the user. Thus, the lowering timing of the shift tray 102 is changed or set.

  As a result, an optimum shift tray lowering operation according to the sheet thickness is performed, and a highly accurate sheet alignment accuracy can be ensured.

8.4 Example of increasing tray lowering distance according to paper thickness calculation result In the above example, the lowering timing is changed according to the paper thickness calculation result, but instead of or in addition to changing the lowering timing. You can also change the descent distance.

  FIG. 16 is a flowchart showing a control procedure for changing the descending distance. In the flowchart of FIG. 16, the processing from step S101 to step S107 and the processing of step S108 and step S109 are the same as those in the flowchart shown in FIG. The overlapping description will be omitted as appropriate.

  In FIG. 16, when a paper stacking job is started (step S101), the processing from step S102 to step S107 described above is executed. When the output of the paper surface detection sensor S3 is turned on in step S107, the paper thickness is specified. It is compared with the thickness, and it is determined whether or not the specific thickness or less (step S107-1). The specific thickness here is a thickness for determining whether or not the paper is thin, and a thickness for dividing the thin paper and the thick paper is set in advance as a threshold value. Then, when it is determined that the thickness is equal to or less than a specific thickness, that is, thin paper, a predetermined time is waited (step S107-2). This predetermined time may be a fixed time or a variable time that can be changed by the operator. In the case of variable time, for example, a standby time setting mode screen is called from the operation unit C and set.

  When a predetermined time elapses in step S107-2, the shift tray 102 stops the lowering operation (step S108), determines whether the paper stacking job is finished (step S109), and if the job is not finished. Returning to step S102, the subsequent processing is repeated, and if the job is finished, the processing is finished as it is.

  If the sheet thickness is thicker than the specific thickness in step S107-1, that is, if the sheet is thick, the time waiting process in step S107-2 is skipped, and the lowering operation of the shift tray 102 is immediately stopped. The process proceeds to the determination process in step S109.

  As described above, when the paper P is thick, the shift tray lowering distance is adjusted so that the lowering amount of the shift tray 102 is increased when the paper P is thick, so that the paper P is surely placed below the paper surface detection sensor S3. It can be moved and high-precision paper alignment can be secured.

9. Discharge roller pressurization control In step S104, the sheet thickness is calculated, and the time tc after the paper surface detection sensor S3 is turned off is changed in accordance with the sheet thickness. Based on the thickness information, the nip pressure between the discharge roller 111 and the driven roller 113 that changes the sheet thickness to the shift tray 102 based on a specific thickness is changed. This change is performed by adjusting the pressing force of the driven roller 113 to the paper discharge roller 111. Although not shown, this embodiment includes a pressure change mechanism that changes the pressure applied to the paper discharge roller 111 by the driven roller 113. The pressurizing force changing mechanism is performed, for example, by changing the inter-axis distance of the driven roller 113 to the paper discharge roller 111 using a stepping motor and a cam.

  The stepping motor is rotationally driven based on an instruction from the CPU 501, and changes the inter-axis distance of the driven roller 113 to the paper discharge roller 111. At that time, the thin paper having the specific thickness or less increases the pressurizing force, For cardboard thicker than the specific thickness, the pressure is reduced. As a result, a necessary conveying force can be applied without damaging the paper P.

  In this way, by changing the applied pressure between the paper discharge path roller 111 and the driven roller 113 based on the paper thickness information, the applied pressure is increased for thin paper to provide sufficient support during paper output, and the applied pressure is reduced for thick paper. Thus, by not increasing the load applied to the paper P more than necessary, it becomes difficult for the roller marks to be applied to the paper P. As a result, it is possible to perform sheet alignment with higher accuracy without damaging the sheet.

10. FIG. 17 is a diagram showing the relationship between the number of times the shift tray is lowered and the sheet detection thickness. As can be understood from the processing procedure of steps S106 → S107 → S108 → S109 → S102 → S103 → S104, the sheet thickness is calculated each time the output of the sheet surface detection sensor S3 is turned on in the shift tray lowering operation. At that time, when the output of the paper surface detection sensor S3 increases in proportion to the number of times the shift tray is lowered as shown in FIG. 17, the paper loaded on the shift tray 102 is curled, and the paper surface is detected by the curl. The detection end 115b of the filler 115 is pushed upward, and the gap ΔG between the detection end 115b and the actual paper surface is narrowed, indicating that the detected paper thickness is increased.

  When the stacked paper P is curled, the curling edge pushes the detection end 115b of the paper surface detection filler 115 upward, and the gap between the detection end 115b and the actual paper surface becomes narrow. When the normal alignment operation is executed in such a state, the end of the paper P cannot be surely pushed because the paper P is curled, and a so-called idling state occurs, resulting in a poor alignment. 17 is detected, the CPU 501 drives the stepping motors 201, 202, 301, and 77 to determine the movement amounts of the main joggers 210F and 210R, the sub joggers 310F and 310R, and the stopper 71 used for paper alignment. It is increased more than usual, and the paper P is reliably contacted and pushed in the aligning direction to align the paper P. As a result, sheet alignment can be performed reliably and high sheet alignment accuracy can be ensured.

  As described above, in the stacker 100 according to this embodiment that stacks a large amount on the shift tray 102, after discharging the paper to the shift tray 102, the paper P discharged by the leading end stopper 71 is pushed into the end fence 99 side, and the end fence 99 side Then, the paddle 118 is rotated to press the paper P toward the shift tray 102 side, and further, the paddle 118 is rotated to draw the paper P below the detection end 115b of the paper surface filler 115 on the end fence 99 side. Yes. In such a configuration, when stacking the uppermost paper surface of the paper P so as to have a certain height, the gap between the papers increases because the number of papers is large if the paper is thin. Therefore, when the paper is aligned, if the paddle 118 is rotated and the end surface of the paper is pressed against the shift tray 102, there are many gaps between the papers. Therefore, the rotation of the paddle 118 causes the end surface of the paper to be violated and the upper surface of the paper is detected. The position of the paper surface detection filler 115 is varied. As a result, the output of the paper surface detection sensor S3 varies.

  However, if the paper P is a thick paper, the number of paper sheets is small, so that the gap between the papers is reduced. Even when the paper end surface is pressed against the shift tray 102 by the rotation of the paddle 118, the paper surface detection sensor The output variation is small. That is, in the case of thick paper stacking, since the output variation of the paper surface detection sensor S3 is small, the integration time for monitoring the output of the paper surface detection sensor S3 can be shortened, and as a result, the lowering timing of the shift tray 102 can be advanced. Become. If the sheet thickness of the stacked sheets is known, the lowering control of the shift tray 102 can be optimized.

  As a result, highly accurate sheet alignment and high productivity can be ensured regardless of the sheet thickness of the sheet being conveyed.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention, and all technical matters included in the technical idea described in the claims are included. The subject of the present invention. The above embodiment shows a preferred embodiment, but those skilled in the art can realize various alternatives, modifications, variations, and improvements from the contents disclosed in this specification. These are included within the scope defined by the appended claims.

100 Stacker (paper stacking device, paper post-processing device)
102 Shift tray 103 Elevator 104, 107b Timing belt 106 Worm gear 107 Tray lifting motor 107a Pulley 108 Carriage 109, 112 Gear 115 Paper surface detection filler 501 CPU
A Image forming device S3 Paper surface detection sensor

Japanese Patent No. 4328855

Claims (12)

A loading means on which the conveyed paper is loaded;
Elevating means for elevating and lowering the loading means;
It includes a detection end for detecting the position of the uppermost paper surface of the stacking means or the paper loaded on the placement means , and a closed end that moves according to the detected position, and is turned on according to the position of the shield end. Or a paper surface detecting means to be turned off ,
Control means for controlling the elevating means and lowering the stacking means until the paper surface detecting means is turned off to on ;
Counting means for counting the number of sheets received in the stacking means ;
Calculating means for calculating the paper thickness of the paper ,
The counting means counts the number of sheets received by the stacking means in a state where the sheet surface detecting means is turned on and the stacking means is stopped at the lowered position until the sheet surface detecting means is turned off,
The calculation means calculates the paper thickness from the counted number of sheets and the operating distance that the detection end of the paper surface detection means has moved until the paper surface detection means is turned on from off.
The sheet stacking apparatus according to claim 1, wherein the control unit controls a lowering operation of the stacking unit in accordance with the calculated sheet thickness .
The paper stacking apparatus according to claim 1,
The paper stacking apparatus, wherein the calculating means calculates the paper thickness when the stacking means is first lowered. The paper stacking apparatus according to claim 1 or 2,
A sheet stacking apparatus comprising: a sheet thickness information transfer unit configured to transfer the calculated sheet thickness information to another apparatus. The paper stacking apparatus according to any one of claims 1 to 3,
The sheet stacking apparatus, wherein the control unit changes a lowering timing of the stacking unit in accordance with a calculation result of the sheet thickness by the calculating unit. The paper stacking apparatus according to claim 4,
The paper stacking apparatus according to claim 1, wherein when the paper thickness is thick, the control means makes the lowering timing earlier than when the paper thickness is thin. A paper stacking apparatus according to any one of claims 1 to 5,
The paper stacking apparatus according to claim 1, wherein the control unit changes a descending distance of the stacking unit according to a calculation result of the paper thickness by the calculation unit. The paper stacking apparatus according to claim 6,
The paper stacking apparatus according to claim 1, wherein the control unit increases the descending distance when the paper thickness is thicker than when the paper thickness is thin. A paper stacking apparatus according to any one of claims 1 to 7,
An adjusting means for adjusting the holding force of the paper of the carry-out means for carrying out the paper to the stacking means;
The paper stacking apparatus according to claim 1, wherein the adjusting unit changes the clamping force according to a calculation result of the paper thickness by the calculation unit. The paper stacking apparatus according to claim 8, wherein
The paper stacking apparatus according to claim 1, wherein the adjusting means reduces the clamping force when the paper thickness is large compared to when the paper thickness is thin. The paper stacking apparatus according to any one of claims 1 to 9,
An alignment means for performing a sheet alignment process in a direction perpendicular to the sheet conveyance direction and the sheet conveyance direction;
An alignment control means for gradually increasing the amount of movement of the alignment means when the sheet thickness calculated by the calculation means for each lowering action is increased for each lowering action;
A paper stacking device characterized by comprising: The paper stacking device according to any one of claims 1 to 10,
A paper stacking apparatus comprising a carriage for supporting the stacking means when the stacking means is positioned at the lowest position and for carrying it out of the apparatus.   An image forming apparatus comprising the paper stacking device according to claim 1.

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