JP2011190052A - Paper sheet stacking device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate any wasteful waiting time by detecting the paper sheet stacking weight load in a tray, and changing the tray elevating/lowering speed based on the result of detection including a case in which a truck with paper sheets being once stacked is taken out of a paper sheet stacking device, and the truck is again set to the device while the paper sheets being stacked therein. <P>SOLUTION: A CPU is provided which detects the weight of a tray with paper sheets stacked therein, and controls an elevating/lowering means. The CPU divides the paper sheet stacking weight load in three-stage range (small, medium and large loads) (Sp4, Sp6) in advance based on the detected tray weight, and sets the number of rotation of the tray elevating/lowering motor corresponding to each load to, for example, three stages of high-speed, medium-speed and low-speed. The CPU variably controls the elevating/lowering speed corresponding to the detected paper sheet stacking weight load (Sp5, Sp7, Sp8), and eliminates any wasteful waiting time. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  As a paper stacking apparatus connected as a paper post-processing machine such as an image forming apparatus, for example, an apparatus described in Patent Document 1 or 2 is known. Among them, in Patent Document 1 (Japanese Patent Laid-Open No. 2005-170578), in a post-processing apparatus that performs post-processing on paper discharged from an image forming apparatus and then stacks it on a liftable discharge tray, the paper is discharged by a driving unit. In order to control the lifting speed of the paper tray, a tray lift position detection sensor that detects the paper discharge standby position of the paper discharge tray, and the operation speed switching of the paper discharge tray by detecting the upper surface position of the paper loaded on the paper discharge tray Based on the detection result of the tray speed determination sensor, the tray speed determination sensor for selecting the position, the drive means for driving the discharge tray up and down with variable speed, the post-processing control means for controlling the drive means with variable speed, A configuration is disclosed in which the raising / lowering speed of the paper discharge tray is controlled by the driving means.

  Further, in Patent Document 2 (Japanese Patent Laid-Open No. 2003-26366), in the finisher, the paper discharge tray is provided so as to be able to move through the discharge port in the vertical direction, and when the paper is extracted from the paper discharge tray, In order to calculate the estimated time when the paper discharge tray finishes rising from the top surface position, a change in the top surface of the paper is detected by a distance measuring sensor provided on the bottom surface side of the paper discharge tray, and this time is notified to the image forming apparatus, In the image forming apparatus, a configuration is disclosed in which a time obtained by subtracting the sheet conveyance time in the image forming apparatus from the predicted time is calculated and set as a delay time for delaying the sheet output.

  On the other hand, there is a paper stacking apparatus connected as a paper post-processing machine such as an image forming apparatus in addition to the above-described known technology. In this type of paper stacking device, a maximum of about 5000 sheets of copied and printed paper are stacked on a tray inside the paper stacking device, and about 50 kg in weight and about 50 cm in height can be loaded. it can. Normally, the tray is on a carriage that can be attached to and removed from the paper stacking device. When the cart is set at a predetermined position in the paper stacking device, the cart storage door (hereinafter referred to as the front door) of the paper stacking device is closed. Only the tray on the carriage rises to the paper receiving position. After that, the paper discharged from the image forming apparatus or the like is received, stacked on the tray, and stacked several times, and the stack is lowered while keeping the uppermost surface of the stacked paper at a certain height. Is done. When removing the loaded paper from the device after the job is finished, press the tray lowering switch provided on the paper loading device to lower the tray to the carriage removal position on the carriage, and remove the loaded paper together with the carriage from the apparatus. It has become.

  By the way, in the latter paper stacking apparatus, the tray on the carriage set in the paper stacking apparatus has various load conditions. The paper size loaded on the paper stacking device is A6 for small ones and SRA3 for large ones, and the number of loaded papers is from 0 to about 5000 sheets (weight is about 50kg, height is about 50cm) before the loaded paper is full. And various. In some cases, the carriage may be set in the apparatus without removing the stacked sheets, and therefore, it is necessary to be able to raise the tray in which about 5000 sheets are loaded before the sheet is full. Furthermore, since it is possible to stack 5000 sheets at a time, the number of corresponding service life required for the apparatus is tens of millions in terms of A4. There are many OFF times. Therefore, a motor that is a tray lifting drive source of the paper stacking device needs to have a high output and can withstand frequent ON / OFF.

  A motor serving as a drive source generally has a low output torque during high-speed rotation and a high output torque during low-speed rotation. Further, since it is necessary to raise and lower the tray on which 5000 sheets are stacked, the motor is normally controlled at a low speed and used at a low speed capable of withstanding a high load. Normally, in the case of a paper stacking device (stacker), it is necessary to lower the tray to the top of the carriage in order to take out the loaded paper after the job is finished, and then the loaded paper together with the carriage is taken out from the apparatus and transported to the next process. After removing the paper from the tray, it is necessary to set the carriage on the apparatus and to raise the tray to the upper part, which is the paper receiving position, in preparation for the next job. The term “job” here means a series of image forming processes of the same type executed by the image forming apparatus. For example, 50 pages of a 100-page booklet are printed. Then, 2500 jobs are obtained.

  In this job, while the paper stacking apparatus is discharging paper, the paper size and the number of discharged paper sheets can be managed, and the CPU of the paper stacking apparatus can recognize the paper stacking weight load. However, when the job is finished and the cart is once taken out of the paper stacking device, the information is cleared and the cart is set on the paper stacking device again with the paper loaded. In this case, the load weight of the paper is not known. Therefore, it is necessary to move the tray at a low speed on the assumption that the maximum number of sheets are always loaded, and if the maximum number of sheets has not been reached, a wasteful waiting time is generated for the user. That is, when no paper is loaded on the tray, the ascending distance of the tray is about 55 cm, and the time is about 20 seconds. During that time, the next job could not be started, and this time wasted. Similarly, when the number of sheets for one job is small and the paper is taken out, it is necessary to lower the tray. In this case, the same wasteful waiting time occurs.

  Note that the sheet stacking apparatus is controlled by a DC voltage for ease of control, and a DC motor is generally used as a tray lifting drive source. Examples of the DC motor include a stepping motor, a DC brush motor, and a DC brushless motor. The stepping motor is easy to control because it can be controlled by open loop. However, if the load is unexpectedly applied, the motor will step out and cannot rotate. It is not suitable for use in places where a large load is applied, such as lifting parts. The DC brush motor is not suitable for use in a tray lifting motor of a paper stacking device that has a short life due to frequent ON / OFF, has a short life, and stacks a large amount of paper. When a DC brushless motor is used, even if the load on the tray fluctuates, control is performed to keep the rotational speed constant, so that the tray can be raised and lowered at a constant speed even if the load on the tray fluctuates. Further, unlike the DC brush motor, since it does not have an electrical contact, the life is not shortened with respect to frequent ON / OFF, and it is suitable for use in the tray lifting motor of the paper stacking apparatus. Therefore, a DC brushless motor is often used for this type of device.

  By the way, in the invention described in Patent Document 1, a tray raising position detection sensor that detects a paper discharge standby position of the paper discharge tray, and an operation speed of the paper discharge tray by detecting the upper surface position of the paper stacked on the paper discharge tray. Although a tray speed judgment sensor for selecting the switching position is provided, the actual load loaded on the tray cannot be detected, and it is not a control for raising or lowering the tray relative to the magnitude of the load viewed from the tray, such as the number of stacked sheets. Therefore, when the load on the tray is large, the torque of the motor becomes insufficient, and the tray lifting speed cannot be increased. Therefore, useless waiting time cannot be eliminated.

  In the invention described in Patent Document 2, the position of the uppermost surface of the loaded paper on the tray is detected by the distance measuring sensor, but the paper size on the tray cannot be detected. Impossible. Therefore, the tray lifting speed cannot be changed due to the load on the tray, and it is impossible to eliminate the wasteful waiting time.

  Therefore, the problem to be solved by the present invention is to reduce the load of paper loaded on the tray including the case where the carriage on which the paper is loaded is taken out of the apparatus and set again in the apparatus with the paper loaded again. It is to detect and change the tray raising / lowering speed based on the detection result to eliminate useless waiting time.

  In order to solve the above-mentioned problem, the first means is placed when a tray for loading the loaded paper, a tray lifting / lowering means for lifting / lowering the tray, and a tray for lifting / lowering are positioned at the lowest position. A paper loading device for taking out a tray on which paper is loaded via the carriage, a tray load detecting means for detecting the weight of the tray on which the paper is loaded, the lifting means, Control means for controlling tray load detection means, and the control means variably controls the tray lifting speed based on the detection result of the tray load detection means.

  The second means is characterized in that, in the first means, the tray load detecting means comprises a plurality of detecting means for optically measuring the distance provided on the apparatus main body side.

  The third means is the second means, wherein the plurality of detecting means are tray loaded paper height detecting means for detecting the height of the loaded paper, and tray loaded paper length for detecting the paper length in the paper discharge direction. A tray loading sheet width detecting means for detecting the sheet width with respect to the sheet discharge direction, and detecting the tray load by obtaining the weight of the loaded sheet based on the detection result of the detecting means. Features.

  The fourth means is the second means, wherein the plurality of detecting means are tray loaded paper height detecting means for detecting the height of the loaded paper, and tray loaded paper length for detecting the paper length in the paper discharge direction. And detecting a tray load by obtaining the weight of the loaded paper based on the detection results of each of the detection means. It is characterized by.

  The fifth means is characterized in that, in the third or fourth means, the tray loaded paper height detecting means is arranged immediately above the minimum loaded paper size.

  A sixth means is the third or fourth means, wherein the tray stacked paper length detecting means is arranged on a vertical line with respect to a direction perpendicular to the paper discharge direction of the minimum stacked paper size. And

  A seventh means is characterized in that, in the third or fourth means, the tray stacked paper width detecting means is arranged on a vertical line with respect to the paper discharge direction of the minimum stacked paper size.

  The eighth means is the third or fourth means, wherein one of the tray-loaded paper length detecting means and the tray-loaded paper width detecting means is in the vicinity of the tray stacking surface when the tray is lowered to the carriage removal position. It is arranged at a position for detecting the side surface of the stacked paper.

  A ninth means is any one of the first to eighth means, wherein the tray load detecting means further comprises a paper information obtaining means and a paper discharge counting means, and the plurality of detecting means when the tray is lowered. The sheet load on the tray is detected in combination with the detection result.

  A tenth means is any one of the first to ninth means, wherein the control means increases the tray lowering speed when the tray is lowered compared to when the tray is raised.

  The eleventh means is any one of the first to tenth means, wherein the control means sets the tray lifting speed before driving the tray lifting means.

  A twelfth means is characterized in that the image forming apparatus includes a paper stacking apparatus according to any one of the first to eleventh means.

  In the embodiment described later, the tray is the shift tray 102, the tray lifting / lowering means is the tray lifting / lowering motor 107, the gear train 107a, the timing belt 104, the timing pulley 105, the carriage is the reference numeral 108, and the paper stacking device is the stacker 100. The tray load detecting means is the CPU 501, the tray loaded paper height detecting means C1, the tray loaded paper length detecting means C2, and the tray loaded paper width detecting means C3, the control means is the CPU 501, and the image forming apparatus is denoted by reference symbol A. Each corresponds.

  According to the present invention, since the tray lifting speed is variably controlled based on the detection result of the tray load detecting means, the carriage on which the paper is loaded is once taken out from the apparatus and set again in the apparatus with the paper loaded again. In this case, it is possible to detect the sheet load weight load on the tray, change the tray lifting speed based on the detection result, and eliminate unnecessary waiting time.

1 is a perspective view illustrating an overall configuration of an image forming system including a paper stacking device (stacker) and an image forming apparatus according to an embodiment of the present invention. It is a schematic sectional drawing which shows the internal structure of a stacker, and shows a state when a shift tray is raised to a paper discharge position. FIG. 6 is a perspective view illustrating a configuration of a paper leading edge 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 a main jogger mechanism. It is a perspective view of a main jogger. It is a perspective view which shows a sub jogger mechanism part. 1 is a block diagram illustrating an electrical configuration of a system including an image forming apparatus and a stacker. FIG. 5 is a front view showing an internal state when there is no sheet stacking on the shift tray of the stacker. It is the top view which looked at the shift tray in FIG. 9 from the top. FIG. 5 is a front view showing an internal state when sheets are stacked on the shift tray of the stacker. It is the top view which looked at the paper stacking part of FIG. 11 from the top. It is a flowchart which shows the operation | movement procedure of tray raising control in embodiment of this invention. It is a flowchart which shows the operation | movement procedure of tray lowering control in embodiment of this invention.

  The present invention, in a paper stacking apparatus for stacking paper that has been carried in, detects the paper load weight on the tray, sets the optimal lifting speed for the load on the tray, and eliminates unnecessary waiting time It is. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an overall configuration of an image forming system including a sheet stacking apparatus and an image forming apparatus according to an embodiment of the present invention.
In this figure, this system is composed of an image forming apparatus A and a paper stacking apparatus (hereinafter referred to as a stacker) 100, and the paper on which an image is formed by the image forming apparatus A is carried into the stacker 100. Stacking or discharging to an upper proof tray, or a downstream paper post-processing device (not shown) such as a paper folding device, a paper binding device, and a bookbinding device are connected as necessary. 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. It is not limited.

  On the front surface of the stacker 100, a door 902 that separates the shift paper discharge unit from the outside is provided, and a door opening / closing detection member (not shown) that detects opening / closing of the door 902 is further provided. An operation unit 900 is disposed at the upper front of the stacker 100, and a tray movement SW 901 that is pressed when taking out paper from the shift tray (paper stacking tray), a display unit, and the like.

  FIG. 2 is a schematic cross-sectional view showing the internal structure of the stacker, and shows a state when the shift tray in the stacker is raised to the paper discharge position. The sheet discharged from the image forming apparatus A is carried in from the arrow X direction. The stacker 100 according to the present embodiment can select a proof paper discharge mode, a straight paper discharge mode, and a shift paper discharge mode, and the paper transport direction is controlled according to each mode. The proof sheet discharge mode is an operation mode in which sheets are guided and stacked on the proof tray 101 from the sheet conveyance path L1. The straight sheet discharge mode is an operation mode for guiding the sheet from the sheet conveyance path L2 to the subsequent sheet post-processing apparatus. The shift paper discharge mode is an operation mode in which paper is discharged from the paper transport path L3 onto the shift tray 102 and stacked. In the shift discharge mode, a predetermined number of sheets are stacked at different shift positions on the shift tray 102. Details of the shift will be described later.

  The carriage 108 can be freely moved on the floor on which the stacker 100 is installed in FIG. 2 by a caster. In this embodiment, the carriage 108 is set at a predetermined position on the floor in the space at the lower center of the stacker 100. In the stacker 100, a cart set sensor (not shown) is turned on, and it is confirmed that the cart 108 is positioned at a predetermined position. Thereafter, the door 902 is closed, and the lift mechanism of the shift tray 102 is operated, and the shift tray 102 is operated. 102 rises to a predetermined position.

  The end of the shift tray 102 is placed on an elevator 103 that can be raised and lowered. The four corners of the elevator 103 are suspended by a total of four timing belts 104, and each timing belt 104 is wound around a corresponding four timing pulleys 105. These timing pulleys 105 are linked by a worm gear 106 and a gear train 107 a composed of a plurality of gears, and are synchronously rotated by the driving force of the tray lifting / lowering motor 107 to lift and lower the elevator 103 together with the shift tray 102. Let Since the power transmission system is via the worm gear 106, the shift tray 102 can be kept at a fixed position.

  When the elevator 103 is lowered to a predetermined paper stacking full position, the stacker 100 transmits a full signal to the image forming apparatus A main body, and then stops receiving paper. In other words, paper discharge from the image forming apparatus A main body stops. At this time, the elevator 103 has not yet reached the lowest position, and the shift tray 102 is not positioned on the carriage 108. Therefore, when the user presses down the tray movement SW 901 on the operation unit 900, the elevator 103 is lowered to the lowest position. When the elevator 103 is lowered to the lowest position, the shift tray 102 is placed on the carriage 108, so that the paper loaded on the shift tray 102 can be carried out by the carriage 108. Similarly, when the job is completed before the elevator 103 reaches the full position, the elevator 103 is lowered to the lowest position by depressing the tray movement SW 901, and the sheet on the shift tray 102 can be taken out.

  Reference numeral 110 denotes a paddle that rotates in conjunction with the paper discharge roller 111 in the paper transport path L3, and strikes and presses the rear end of the paper discharged onto the shift tray 102 downward. The paper stacked on the shift tray 102 gradually pushes up the filler 112, and the optical paper surface sensor S3 detects the stack height of the paper on the shift tray 102 based on the movement of the filler 112. To do. When the paper surface sensor S3 is ON, the shift tray 102 is lowered by the tray lifting motor 107, and the tray lifting motor 107 is stopped after the paper surface sensor S3 is turned OFF. Therefore, every time the paper surface sensor S3 is turned on by the paper S stacked on the shift tray 102, the shift tray 102 is lowered by a predetermined distance.

A paper transport path sensor (hereinafter referred to as an “entrance sensor”) S1 for detecting the passage of the paper is disposed at the paper transport entrance, and a paper transport path sensor (hereinafter referred to as a paper transport path sensor for detecting the passage of the paper in the paper transport path L3) S2) (referred to as “paper ejection sensor”) is arranged on the most downstream side of the paper transport L3. Further, a driven roller 113 biased by a spring is pressed against a paper discharge roller 111 that discharges the paper to the shift tray 102, and the paper is nipped between these rollers 111 and 113. Reference numeral 114 denotes an entrance roller that carries the paper discharged from the image forming apparatus when driven.
FIG. 3 is a perspective view showing the configuration of the paper leading edge alignment mechanism. In the figure, a leading edge aligning mechanism 70 is a mechanism for aligning the leading end of the paper discharged onto the shift tray 102, and includes a stopper 71 whose position can be adjusted in the directions of arrows H1 and H2. The stopper 71 is attached to a slider 72, and the slider 72 is slidably guided by a shaft 73 extending in the arrow H1 direction, as shown in FIG. The slider 72 is connected to a belt 76 that is stretched between pulleys 74 and 75. Then, by moving the belt 76 by the motor 77, the slider 72 moves in the arrow H1 direction together with the stopper 71, and the position of the stopper 71 is adjusted. The slider 72 is provided with a shielding plate 78, and when the stopper 71 moves to the home position, the shielding plate 78 is detected by the optical home position sensor S5. Therefore, the position of the stopper 71 is accurately adjusted as the position from the home position.

  4 to 6 are views showing the main jogger mechanism. FIG. 4 is a front view of the main jogger mechanism viewed from the sheet discharge direction. FIG. 5 is a perspective view of the main jogger mechanism. FIG. 6 is a perspective view of the main jogger. is there. 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, first and second sliders 207F and 207R connected to the driving shaft 206, and It comprises sensors S6F and S6R that detect the first and second sliders 207F and 207R, a filler 208 provided in the gear 204 that indicates the rotation state of the rotating shaft 205, and a sensor S7 that detects the filler 208. The first and second main joggers 210F and 210R are widened between the two. The 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 direction G.

  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. 16, the first and second main joggers 210 </ b> F and 210 </ b> R remove sheets discharged from the conveyance roller 111 shown in FIG. 2 within the interval between 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 to the sheet, 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. The first and second relief portions 212F and 212R are provided. The first and second main joggers 210F and 210R are configured such that the roots are sandwiched and pressed by the first and second sliders 207F and 207R, respectively, and depending on the positions of the first and second sliders 207F and 207R. 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 a sheet discharged from the conveying roller 111, the first and second main joggers 210F and 210R stand by in a state of facing each other at a receiving position with a predetermined interval. In this state, every time a sheet is discharged from the conveying roller 111 and stacked on the tray 102, the opposing interval is set from the receiving position, moved to a position where it abuts against the sheet end surface, and then moved so as to widen the opposing interval. Return to the receiving position. By repeating this series of aligning operations for each sheet discharged, the end faces of the sheets are aligned.

  The paper discharge roller 111 performs a 10 mm shift operation in the front direction after finishing discharging a predetermined number of sheets constituting the first paper bundle while repeating a 10 mm shift operation in the back direction orthogonal to the paper transport direction for each paper. Repeat to load paper. When the shift direction is switched, the main joggers 210F and 210R move to the retracted rotation position to enter the aligning member retracted state, and the main joggers 210F and 210R perform a shift operation under the retracted state.

  For example, when the paper discharge roller 111 is shifted to the main jogger 210F side, the main jogger 210R is disposed at a position where it abuts on the back side of the discharged paper stacked on the shift tray 102 and the front “part” paper bundle. It will be. The other main jogger 210F is positioned on the front side surface of the sheets stacked on the shift tray 102, and takes the home position as the vertical position. Each time the shift operation of the discharge roller 111 is reversed, the rotary shaft 205 is rotated in the direction in which the arms 209F and 209R attached to the rotary shaft 205 press the bases of the main joggers 210F and 210R downward. Move to. 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 main joggers 210F and 210R set the friction coefficient so that the paper does not shift, so that the paper can be stably aligned.

  The retraction amounts of the main joggers 210F and 210R are retraction amounts from the home position where the filler 206 is detected by the sensor S6, so that 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 for dealing with curling and folding of the discharged paper increases. However, it also takes a return time when the next sheet is received when the sheet gap is jammed.

  FIG. 7 is a perspective view showing the sub jogger mechanism. In the figure, a sub-jogger mechanism 300 is a mechanism for aligning the leading end side of the sheet discharged onto the shift tray 102, and the first and second sub-positions that can be adjusted in the width direction by the stepping motor 301. Joggers 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 in the width direction of the seat. It is slidably guided by two parallel shafts 302 and 303 arranged along. The first and second sliders 311F and 311R are connected to a belt 306 that is stretched between pulleys 304 and 305. When the belt 306 is moved 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 the optical home position sensor S8.

FIG. 8 is a block diagram showing an electrical configuration of a system including an image forming apparatus and a stacker.
In the figure, the stacker 100 includes a control plate D, and the control plate D controls the entire stacker 100. A CPU 501 of a microcomputer is mounted on the control board D, and a ROM 502 for storing a program is provided inside the CPU 501. The CPU 501 expands a program stored in the ROM 502 in a RAM (not shown), uses the RAM as a work area and a data buffer, and executes control in the stacker 100.

  The CPU 501 has an entrance sensor S1 that detects that a sheet has been carried into the stacker 100, a sheet discharge sensor S2 that is provided on the conveyance path for discharging the sheet to the shift tray 102, and a sheet receiving height of the shift tray 102 that is constant. In order to achieve this, a sheet surface detection sensor S3 that detects the stack height of the sheets on the shift tray 102, a tray movement SW 901 that lowers the shift tray 102 to the carriage removal position at the end of the job, and a sheet stacking height on the shift tray are detected. Tray loaded paper height detecting means C1, tray loaded paper length detecting means C2 for detecting the length of the paper loaded on the shift tray, and tray loaded paper width detecting for detecting the width of the paper loaded on the shift tray 102 Means C3 and many other sensors are connected, and information detected by each of these units is input. On the other hand, a tray lifting / lowering motor 107 that moves the shift tray 102 up and down, and many other motors are connected to the CPU 501. As a result, the CPU 501 can detect the volume of the stacked paper from the detection values of the detection means C1, C2, and C3. If the density of the paper is added to this volume, the weight of the stacked paper is obtained. It can be easily calculated.

  The CPU 501 is electrically connected with an I / F cable in order to perform control communication with the control unit 500 of the image forming apparatus A. Therefore, information on the size and thickness of the paper discharged from the image forming apparatus A and accepted by the stacker 100 can be obtained. Further, information such as tray fullness and other alert information can be provided from the stacker 100 to the image forming apparatus A side.

  FIG. 9 is a front view showing an internal state when there is no paper stack on the shift tray 102 of the stacker, and FIG. 10 is a plan view of the paper stacking portion, ie, the shift tray 102 in FIG. FIG. 11 is a front view showing an internal state when sheets are stacked on the shift tray 102 of the stacker 100, and FIG. 12 is a plan view of the sheet stacking section of FIG. In these figures, the positions of the tray loaded paper height detecting means C1, the tray loaded paper length detecting means C2, the tray loaded paper width detecting means C3, and the paper discharge sensor S2 as the paper discharge count means are shown. ing. Also, it can be seen from these drawings that the tray loaded paper height detecting means C1, the tray loaded paper length detecting means C2, and the tray loaded paper width detecting means C3 are respectively attached to the wall surface of the paper stacking section of the apparatus main body. That is, the tray loaded paper height detecting means C1 is on the uppermost wall surface of the portion constituting the paper stacking portion of the stacker 100, and the tray loaded paper length detecting means C2 is the paper stacking portion of the stacker 100. A wall surface on the downstream side in the paper transport direction of the portion below the portion constituting the space and slightly above the upper surface of the tray 102 when the tray 102 is placed on the carriage 108, and faces the tray 102. On the other hand, the tray loaded paper width detecting means C3 is below the portion constituting the space that is the paper stacking portion of the stacker 100, and from the upper surface of the tray 102 when the tray 102 is placed on the carriage 108. It is attached to a wall surface on the downstream side in the sheet conveying direction of a slightly upper portion, which faces the side surface of the tray 102.

  More specifically, the tray loaded paper height detection means C1 is arranged directly above the minimum loaded paper size loaded on the tray 102. The tray loaded paper length detection means C2 is arranged on a vertical line with respect to the direction perpendicular to the paper discharge direction of the minimum stacked paper size, and the tray stacked paper width detection means C3 discharges the paper of the minimum stacked paper size. It is arranged on a vertical line with respect to the direction. In addition, one of the tray loading sheet length detection means C2 and the tray loading sheet width detection means C3 is arranged at a position for detecting the loading sheet side surface in the vicinity of the tray loading surface when the tray 102 is lowered to the carriage removal position. .

  The distance Z0 shown in FIG. 9 is the distance from the tray loaded paper height detection means C1 to the shift tray 102 when the shift tray 102 is at the lowest level (cart removal position). Since this is a design factor, it is known in advance. A distance Z1 shown in FIG. 11 where the sheets are loaded is a distance from the tray loaded sheet height detecting means C1 to the loaded sheets on the shift tray 102. The tray loaded paper height detection means C1 transmits light in the direction of the shift tray 102 (vertically downward), and the light reflected by the upper surface of the loaded paper (P) is received by the tray loaded paper height detection means C1 and received. Thus, the distance Z1 can be measured by the amount of light. Thereby, it is understood that the distance (Z0-Z1) is the sheet stacking height.

  Further, if a hole or a concave portion is provided in the shift tray 102 portion, which is the opposite surface of the light transmitted from the tray loaded paper height detecting means C1, the detection result becomes longer than the distance Z0. Presence detection is possible. That is, when the detection result is greater than the distance Z0, it can be determined that there is no sheet stacking load on the shift tray 102, and therefore the tray can be raised at high speed.

  The distance X0 shown in FIG. 10 is the distance to the alignment reference (end fence position) in the length direction when sheets are stacked on the shift tray 102. Since this is a design factor, it is known in advance. A distance X1 in FIG. 12 where the sheets are loaded is a distance from the tray loaded sheet length detection means C2 to the side of the loaded sheets on the shift tray 102. The tray loaded paper length detection means C2 transmits light in the direction of the shift tray 102 (vertically to the right in FIG. 12), and the light reflected on the side of the loaded paper (P) is received by the tray loaded paper length detection means C2. The distance X1 can be measured by the amount of received light. Thereby, it can be seen that the distance (X0-X1) is the length of the sheet.

  In this case, as described above, the mounting position of the tray loading sheet length detection means C2 is set to the loading sheet side surface near the sheet loading surface of the shift tray 102 when the shift tray 102 is lowered to the carriage removal position, and a small amount of loading sheets is present. Even so, length detection is possible. Further, when the loading amount is such that the sheet loading cannot be detected, it can be determined that the sheet loading weight load is extremely small, and thus the influence on the tray lifting / lowering motor 107 can be ignored.

  A distance Y0 shown in FIG. 10 is a distance to the sheet discharge reference (the center of the conveyance path) in the width direction when sheets are stacked on the shift tray 102. Since this is a design factor, it is known in advance. A distance Y1 in FIG. 12 where the sheets are loaded is a distance from the tray loaded sheet width detecting means C3 to the side surface of the loaded sheets on the shift tray 102. The tray loaded paper width detecting means C3 transmits light in the direction of the shift tray 102 (vertically downward in FIG. 12), and the light reflected on the side surface of the loaded paper (P) is received by the tray loaded paper width detecting means C3 and received. Thus, the distance Y1 can be measured by the amount of light. As a result, it can be seen that the distance (Y0−Y1) * 2 is the width of the sheet.

  In this case, as described above, the mounting position of the tray loading sheet width detecting means C3 is set to the loading sheet side surface in the vicinity of the shift tray loading surface when the shift tray 102 is lowered to the carriage removal position, so that a small amount of loading sheets can be obtained. Even if there is, width detection is possible. Further, when the loading amount is such that the sheet loading cannot be detected, it can be determined that the sheet loading weight load is extremely small, and thus the influence on the tray lifting / lowering motor 107 can be ignored.

The calculation of the paper loading weight load is performed by calculating the stacked paper height (Z0-Z1) which is the detection result of the tray stacked paper height detection unit C1, and the stacked paper length (the detection result of the tray stacked paper length detection unit C2). X0-X1), the volume is obtained from the stacked paper width (Y0-Y1) * 2 which is the detection result of the tray stacked paper width detection means C3, and is multiplied by a predetermined weight coefficient R, that is,
Paper loading weight load = (Z0−Z1) × (X0−X1) × 2 (Y0−Y1) × R (1)
By doing so, it is possible to calculate the paper load weight load.

On the other hand, when there are two detection means such as the tray loaded paper height detecting means C1 and the tray loaded paper length detecting means C2, the width direction is calculated using the maximum paper width U supported by the apparatus. If this is the case, the maximum load of paper loading weight that can be considered is paper loading weight load = (Z0−Z1) × (X0−X1) × U × R
Can be calculated as

  When the detecting means is the tray loaded paper height detecting means C1 and the tray loaded paper width detecting means C3, the maximum load of paper loaded weight can be calculated by the same method as described above. When there are two detection means, another selection other than the tray loaded paper height detection means C1 can determine which can calculate a more accurate paper load weight load depending on the apparatus to be used. Depending on the apparatus, the stackable size may be shorter in the length direction than in the width direction.

  Further, the paper loading weight load for optimizing the tray lowering speed at the time of lowering when the job is finished is obtained by obtaining the paper size information from the image forming apparatus main body by the paper information obtaining unit and, in some cases, the paper thickness information. Then, by measuring the number of sheets discharged and stacked on the shift tray 102 by the sheet discharge counting means, it is possible to determine the sheet load weight load added by passing paper. Therefore, by adding the additional paper stacking weight load to the paper stacking weight load obtained from the detection results of the tray stacking paper height detection unit C1, the tray stacking paper length detection unit C2, the tray stacking paper width detection unit C3, and the like, The weight of the paper loaded on the tray 102 is accurately obtained. Originally, when there is no stacked paper in the tray 102, the paper load weight load is only an additional paper load weight load, and when there is a load paper, “paper load weight load + additional paper load weight load”.

FIG. 13 is a flowchart showing an operation procedure of tray raising control in this embodiment.
In this operation procedure, first, it is determined whether or not the carriage 108 is set in the apparatus (step Sp1), and it is confirmed whether or not the front door 902 is closed at the time of setting (step Sp2). If the front door 902 is closed in this confirmation process, the addition of the paper weight is detected, and if not closed, the process waits until it is closed, and the paper weight load is detected when the front door 902 is closed (step Sp3). In the paper weight load detection process at step Sp3, the paper load weight on the shift tray 102 is determined based on the detection results from the tray load paper height detection means C1, the tray load paper length detection means C2, and the tray paper width detection means C3. Find the load. The paper loading weight load is divided into three stages (low load, medium and large) in advance, and the number of rotations of the tray lifting motor 107 corresponding to those loads is three (high speed, medium speed, and low speed). ) Is set. Therefore, when the paper loading weight load is obtained, the load small, medium and large are obtained, and the speed setting of the tray lifting / lowering motor 107 is set before the motor is driven. Thus, the tray can be moved up and down more quickly than once the motor is driven to obtain the load condition.

  Therefore, in step Sp4, it is determined whether the paper load weight load on the shift tray 102 is small. If it is small, in step Sp5, the tray lifting / lowering motor 107 is rotated at a high speed to raise the shift tray 102, and the shift tray 102 It is determined whether or not the height has risen to a predetermined height (step Sp9). If it is determined that the height has risen to the predetermined height, the tray lifting / lowering motor 107 is stopped (step Sp10), and the process ends. If it has not risen to the predetermined height, the tray elevating motor 107 is stopped after waiting to rise to the predetermined height (step Sp10), and the process is completed.

  If the paper loading weight load is not small in step Sp4, it is further determined in step Sp6 whether the paper loading weight load on the shift tray 102 is medium. If the paper loading weight load is medium, in step Sp7, the tray lifting / lowering motor 107 is rotated at a medium speed to raise the shift tray 102. Then, when the tray is raised to a predetermined position in Step Sp9, the tray lifting / lowering motor 107 is stopped (Step Sp10), and the process is finished.

  If the paper loading weight load is not medium in step Sp6, the tray elevating motor 107 is rotated at a low speed in step Sp8 to raise the shift tray 102. Then, when the tray is raised to a predetermined position in Step Sp9, the tray lifting / lowering motor 107 is stopped (Step Sp10), and the process is finished.

  By controlling the operation in this way, the raising / lowering speed of the shift tray 102 can be changed in accordance with the paper load.

FIG. 14 is a flowchart showing an operation procedure of tray lowering control in the present embodiment.
In this operation procedure, first, when the job is started (step Sp20: Yes), the sheet information is obtained from the image forming apparatus A (step Sp21), and whether or not the sheet is discharged to the shift tray 102 is determined by the discharge sensor S2. It judges from a detection result (step Sp22). If it is confirmed from the detection result that the sheet has been discharged (step Sp22: Yes), the number of discharged sheets is counted up and the number of discharged sheets is measured (step Sp23).

  Next, it waits for the end of the job. Meanwhile, returning to step Sp22, the count of the number of sheets discharged to the shift tray is repeated (steps Sp22 and 23), and when the job is completed (step Sp24: Yes), the shift tray 102 is moved to the carriage 108 takeout position to take out the loaded paper. It is determined whether the tray movement SW 901 to be lowered is pressed (step Sp25). If it is pressed, the paper load weight load is calculated in step Sp26, and if not pressed, the paper load weight load is calculated after waiting for the press.

  In step Sp26, the sheet loading weight load obtained when the carriage 108 is set in the apparatus during the tray raising control and the additional sheet loading weight load of the sheet newly discharged onto the shift tray 102 are displayed as sheet information. Obtained from the result of the obtaining means and the result of the paper counting means, and adds them to calculate the paper loading weight load. That is, the paper load weight load on the shift tray 102 when the carriage 108 on which the paper is loaded is once taken out of the stacker and set on the stacker 100 with the paper loaded again is calculated.

  Here again, as in the case of the lift control, the paper loading weight load is divided into three ranges (small, medium, and large) in advance, and the number of rotations of the tray lifting motor 107 corresponding to those loads is set to three. Yes. Here, the number of rotations of the tray lifting / lowering motor 107 at the time of lowering is different from the case of raising the shift tray 102, because the shift tray 102 is subjected to gravity acceleration in the vertical downward direction due to the paper loading weight load. Even if the load detection (calculation) result is the same as when the load is raised, the rotation speed of the tray lifting / lowering motor 107 can be increased. Therefore, even if the number of rotations of the tray lifting / lowering motor 107 is the same three steps, it is set to high speed + α rotation, medium speed + α rotation, and low speed + α rotation.

  That is, in step Sp27, it is determined whether or not the accumulated paper weight load on the shift tray 102 is small. If it is small, in step Sp28, the tray lifting / lowering motor 107 is rotated at high speed + α rotation, and the shift tray 102 is lowered. Then, it is determined whether or not the shift tray 102 has been lowered to a predetermined height, which is the take-out position of the carriage 108 (step Sp32). If it is lowered, the tray lifting / lowering motor 107 is stopped (step Sp33), and the process ends. If it is not lowered, the shift tray 102 is continuously lowered at the set rotational speed, and after waiting for the shift tray 102 to be lowered to a predetermined position, the tray lifting / lowering motor 107 is stopped (step Sp33) and the processing is ended.

  If the paper loading weight load is not small in step Sp27, it is determined in step Sp29 whether the paper loading weight load on the shift tray 102 is medium. If so, in step Sp30, the tray lifting / lowering motor 107 is set to medium speed + α. The shift tray 102 is lowered by rotation. Then, it is determined whether or not the shift tray 102 has been lowered to a predetermined height, which is the take-out position of the carriage 108 (step Sp32). If it is lowered, the tray lifting / lowering motor 107 is stopped (step Sp33), and the process ends. If it is not lowered, the shift tray 102 is continuously lowered at the set rotational speed, and after waiting for the shift tray 102 to be lowered to a predetermined position, the tray lifting / lowering motor 107 is stopped (step Sp33) and the processing is ended.

  If the paper loading weight load is not medium in step Sp29, the load is increased and the tray lifting / lowering motor 107 is rotated at a low speed + α rotation in step Sp31 to lower the shift tray 102. Then, it is determined whether or not the shift tray 102 has been lowered to a predetermined height, which is the take-out position of the carriage 108 (step Sp32). If it is lowered, the tray lifting / lowering motor 107 is stopped (step Sp33), and the process ends. If it is not lowered, the shift tray 102 is continuously lowered at the set rotational speed, and after waiting for the shift tray 102 to be lowered to a predetermined position, the tray lifting / lowering motor 107 is stopped (step Sp33) and the processing is ended.

  In the operation procedure shown in FIGS. 13 and 14, the paper load weight load is divided into three stages in advance, and the number of rotations of the tray lifting motor 107 corresponding to those loads is set to three stages. The method of dividing the paper loading weight load is not limited to three stages, but may be two stages, and even if divided into more stages of four or more stages, the waiting time of the user can be shortened. Further, although the speed setting at the time of descent is uniformly + α rotation, it may be different for each speed.

As described above, according to the present embodiment,
1) Since the CPU 501 can grasp the weight load of the paper loaded on the tray 102 (load at the time of raising / lowering the tray), the tray raising / lowering speed can be variably controlled according to the load. That is, when the tray load is small, the tray lifting speed can be increased compared to when the tray load is large, and the setup time of the paper stacking apparatus can be shortened. As a result, it is possible to shorten the waiting time of the user, and it is possible to provide a user-friendly paper stacking apparatus.
2) In order to detect the tray load, the means is composed of a plurality of detection means (C1, C2, C3) that measure the distance optically provided on the apparatus main body side, whereby the paper size on the tray, The load amount (height) can be detected, the sheet load weight load on the tray can be known, and the tray lifting speed can be varied according to the load. When the tray load is small, the tray lifting speed can be increased compared to when the tray load is large, so the setup time of the paper stacker can be shortened and the waiting time of the user can be shortened. It becomes.
3) Since it is not necessary to provide an electrical connection to the trolley 108 part that can be attached to and detached from the stacker 100, or mechanically, it is not necessary to add a structural member. Is possible.
4) Since it has any one of the tray loaded paper height detecting means C1, the tray loaded paper length detecting means C2, and the tray loaded paper width detecting means C3, the approximate loaded paper size and paper on the tray are determined from these detection results. The load capacity can be determined. By minimizing the detection means, it is possible to reduce the number of parts and thereby reduce the cost.
5) It has a tray loaded paper height detecting means C1, a tray loaded paper length detecting means C2, and a tray loaded paper width detecting means C3. From these detection results, the paper size and the paper loaded amount can be determined. Therefore, it is possible to know the paper loading weight load and to accurately detect the tray load. As a result, an optimum tray lifting speed can be set, and the waiting time of the user can be shortened most.
6) Since the tray stacking height detection means C1 is disposed immediately above the minimum sheet size, the height of the sheet stacked on the tray can be detected even if the stacked sheet size changes.
7) Since the tray loaded paper length detection means C2 is arranged on the vertical line with respect to the direction (paper width) perpendicular to the paper discharge direction of the smallest loaded paper size, the paper is loaded on the tray even if the loaded paper size changes. The detected paper length can be detected.
8) Since the mounting position of the tray loaded paper width detecting means C3 is arranged on the vertical line with respect to the paper discharge direction (paper length) of the smallest loaded paper size, it is loaded on the tray even if the loaded paper size changes. The detected paper width can be detected.
9) When the tray 102 is lowered to the take-out position of the carriage 108 when the tray loading paper length detection means C2 or the tray loading paper length detection means C2 and the tray loading paper width detection means C3 are attached in the height direction. Since it is arranged at the position for detecting the side of the stacked paper near the tray stacking surface, the paper length or the paper size can be accurately detected even if the loaded paper on the carriage is small (height).
10) Since the CPU 501 further includes paper information acquisition means and paper discharge count means, it is possible to determine the weight load of newly discharged paper in addition to the paper load originally loaded on the tray. More accurate tray weight load can be recognized.
11) When the tray is lowered, gravitational acceleration acts on the tray due to the weight of the tray, so the tray lowering speed increases even if the weight load state of the tray is the same as when the tray is raised. Shortening is possible.
12) Since the speed setting of the tray lifting / lowering means can be set before driving the tray lifting / lowering motor, the tray lifting / lowering operation can be performed at an earlier timing than when the load condition is obtained after driving the motor.
There are effects such as.

  It should be noted that the present invention is not limited to this embodiment, and various modifications are possible, and all technical matters included in the technical idea of the invention described in the scope of claims are the subject of the present invention. .

DESCRIPTION OF SYMBOLS 100 Stacker 102 Shift tray 104 Timing belt 105 Timing pulley 107 Tray raising / lowering motor 107a Gear train 108 Carriage 501 CPU
A Image forming apparatus C1 Tray loaded paper height detecting means C2 Tray loaded paper length detecting means C3 Tray loaded paper width detecting means

JP 2005-170578 A JP 2003-026366 A

Claims (12)

A tray on which loaded paper is loaded;
Tray elevating means for elevating the tray;
A carriage that is placed when the raising and lowering tray is located at the lowest position;
A paper stacking device for taking out a tray on which paper is stacked via the carriage,
Tray load detection means for detecting the weight of the tray loaded with paper; and
Control means for controlling the elevating means and the tray load detecting means;
With
The sheet stacking apparatus according to claim 1, wherein the control unit variably controls a tray lifting speed based on a detection result of the tray load detection unit. The paper stacking apparatus according to claim 1,
The tray load detecting means comprises a plurality of detecting means for optically measuring the distance provided on the apparatus main body side. The paper stacking apparatus according to claim 2,
The plurality of detection means include
Tray loaded paper height detection means for detecting the height of the loaded paper;
Either a tray-stacked paper length detection means for detecting the paper length in the paper discharge direction or a tray-stacked paper width detection means for detecting a paper width in the paper discharge direction;
A paper stacking apparatus, wherein the weight of the stacked paper is obtained based on the detection result of the detection means, and the tray load is detected. The paper stacking apparatus according to claim 2,
The plurality of detection means include
Tray loaded paper height detection means for detecting the height of the loaded paper;
Tray loaded paper length detection means for detecting the paper length in the paper discharge direction;
Tray loaded paper width detection means for detecting the paper width relative to the paper discharge direction;
A paper stacking apparatus, wherein the weight of the stacked paper is obtained based on the detection results of each of these detection means, and the tray load is detected. The paper stacking apparatus according to claim 3 or 4,
The sheet stacking apparatus, wherein the tray stack sheet height detecting means is disposed immediately above the minimum stack sheet size. The paper stacking apparatus according to claim 3 or 4,
The sheet stacking device is characterized in that the tray stacking sheet length detecting means is arranged on a vertical line with respect to a direction orthogonal to a sheet discharging direction of a minimum stacking sheet size. The paper stacking apparatus according to claim 3 or 4,
The paper stacking apparatus according to claim 1, wherein the tray stack paper width detecting means is arranged on a vertical line with respect to a paper discharge direction of a minimum stack paper size. The paper stacking apparatus according to claim 3 or 4,
One of the tray-loaded paper length detecting means and the tray-loaded paper width detecting means is disposed at a position for detecting the side of the stacked paper in the vicinity of the tray stacking surface when the tray is lowered to the carriage take-out position. Characteristic paper stacking device. The paper stacking apparatus according to any one of claims 1 to 8,
The tray load detecting means further includes a paper information obtaining means and a paper discharge counting means, and detects the paper load on the tray when the tray is lowered, together with the detection results of the plurality of detecting means. Characteristic paper stacking device. The paper stacking apparatus according to any one of claims 1 to 9,
The sheet stacking apparatus is characterized in that the control means increases the tray lowering speed when the tray is lowered compared to when the tray is raised. The paper stacking device according to any one of claims 1 to 10,
The sheet stacking apparatus, wherein the control unit sets a tray lifting speed before driving the tray lifting unit.   An image forming apparatus comprising the paper stacking device according to claim 1.

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