JPH0678149B2 - Loading device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a stacking device for stacking output materials such as a copying machine or a laser beam printer.

2. Description of the Related Art As a device for loading a large amount of output paper, a method has been widely used in which an elevator mechanism is widely used to gradually lower the loading table according to the loading amount of paper to keep the loading surface constant. In this case, as an example of the method of detecting the stacking surface, there is a method of arranging a photo sensor at the edge of the paper and controlling the elevator motor in response to whether or not the beam is blocked. In the case of this method, when the paper stacking surface changes for some reason,
For example, when paper with large curl is loaded, the sensor shutoff time becomes longer than usual, so the elevator descent amount also increases, and when the paper is loaded, it may drop more than the required distance to keep the loading stable. . In this case, the stacking becomes more unstable, the stacked papers are disturbed, and in extreme cases, the papers may be reversed on the stacking surface or the page order may be out of order.

Aim The present invention has been made in view of the above points, and an object thereof is to provide a stacking device capable of stably stacking conveyed sheets.

Embodiment One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram schematically showing a paper transport path according to an embodiment of the present invention. Hereinafter, description will be given based on this figure.
The paper loaded in the printer 1 and fed from the cassette 2 has an image developed with toner transferred from the photosensitive drum 3, and undergoes a known fixing process, and then the paper is discharged from the paper discharge roller 4 with the image surface facing upward. Is discharged.

The discharged paper is fed to the stacking device 5. Paper is pinched into the input part of the stacker 5 by the pulley 20 and the pressing roller 19, and is horizontally conveyed by the conveyor belt 6 in the arrow direction. At the end of the belt, there is a horizontal deflector 7. By activating this horizontal deflector, it is determined whether the horizontal deflector 7 or the vertical deflector 7 is energized, and whether or not the solenoid 29 connected to the horizontal deflector 7 is excited. Controlled by. In FIG. 1, the paper is shown fed vertically downward. The paper is conveyed by the conveyance guide 8 and the feed rollers, and is guided to two storages by a movable vertical deflector 10a and a fixed vertical deflector 10b. First
In the figure, the solenoid 30 connected to the vertical deflector is in a non-excited state, the paper is not branched at this deflector portion and is sent downward, is branched to the left by the vertical deflector 10b, and is discharged by the paper discharge roller 11b. It The conveyor belt 6, the drive roller 9, and the paper discharge rollers 11a and 11b are increased by 10% to 20% from the conveyance speed of the paper discharge roller 4 of the printer 1 by a drive motor 27 via a drive transmission means (not shown). Being driven.

In FIG. 1, the output storage section (hereinafter, abbreviated as a "decks section") is vertically arranged at two points A and B. The two drawer rails 18a and 18b (hereinafter, suffices a and b are omitted) of the deck portions A and B are connected by a loading plate 17, and there is a positioning member shown on the plate 17, and the positioning member has a sheet container. 12 is detachably engaged. A pallet 13 for loading paper is slidable in the paper container 12, and when the pallet 13 comes into contact with the bottom of the container, a gap of about 20 mm is opened, and the pallet 13 is placed in this gap. Elevator equipment 14 for raising and lowering
It is configured so that the fork tip of can be retracted.

The pallet 13 on the fork rises to a specified height and stops when no paper is loaded. The paper output from the paper discharge roller 11 with the printing surface facing down is lowered onto the pallet 13 with the front end portion in the transport direction being restricted by the alignment guide 16. The alignment guide portion has a light emitting element 23 and a light receiving element for paper surface detection.
A photo sensor composed of 24 is provided, and when the paper 15 stacked on the pallet 13 reaches a certain height or higher, the sensor output is cut off, and the elevator motor 28 is driven by the signal change to lower the paper surface by a certain amount. In this way, when the load increases and the elevator repeatedly descends and reaches the specified position on the stroke, it is detected that the deck part is full, and subsequent access to paper is prohibited.

Remove the paper from the full container and reload it,
Empty sensor of container, that is, light emitting element 25, light receiving element 26
If the photo sensor consisting of 1 detects that the paper has run out, the paper is again permitted to access the same deck unit and the paper is stacked. Details of the control of the deck unit will be described later.

FIG. 2 is a perspective view showing the structure of the deck, and the positional relationship among the elevator container pallet, the alignment plate, and the discharge roller will be apparent from this figure. FIG. 3 shows a cross section of the deck portion from the side. Front plate of stacker 5
31 and a rear side plate 32 are erected vertically, and both side plates are connected and positioned by an upper plate 33 and a lower plate 34. Light emitting elements (LEDs) 23 and 25 are mounted on the upper plate 33. An aligning plate 16 is pivotally attached to the upper plate 33 so as to be adjustable according to the paper transport position. A light receiving element (phototransistor) 26 is provided on the lower plate 34.
Is installed. A drawer rail 18 is fixed between the both side plates by a metal fitting (not shown), and a loading plate 17 is pivotally mounted on the rail 18. On the loading plate 17, a container positioning hole is opened, and on the other hand, a positioning boss projects from the bottom surface of the container 12, and by this boss,
Fit and lock with the hole. Further, the stacking plate 17, the container 12 and the pallet 13 are perforated on the same line to detect the absence of paper, so that the emission beam of the LED 25 can pass through. A cache 37 is attached to the rear side plate 32.After the container 12 is set on the loading plate 17, it is pushed all the way into the drawer rail 18 to engage with the window holes at the end of the tray 37 and the loading plate 17. Stop sticking.

At the same time, in order to check the presence or absence of the container 12, a micro switch 36 is attached to the rear side plate 32 via a mounting member 35. Micro switch 36 is activated and container 12
When the photo sensors 25 and 26 detect that there is no paper inside, the elevator fork rises while pushing up the pallet 13.
It stops when it reaches the upper limit position.

The elevator section is fixed to the rear side plate 32 by a bracket 38. The bracket 38 vertically supports and fixes the guide 39, and the elevator fork can be vertically moved by a driving means (not shown). A cam 40 is fixed to one end of the elevator fork. An upper limit detection micro switch 41, a full load detection micro switch 42, and a lower limit detection micro switch 43 are attached to the bracket 38, and the cam 40 operates these detection micro switches according to the stroke position. An operation panel 44 is mounted on the front side plate 31.

FIG. 4 is a rear view of the elevator section showing a state in which the elevator section is viewed from the rear. A motor bracket 51 is mounted on the bracket 38, and the motor with encoder 28 is adjustably fixed to the motor bracket 51. A drive sprocket 53 is pivotally attached to the output shaft of the motor 28, and a chain 54 is wound around the sprocket 53 via an idler sprocket 52, and a part of the chain is screwed onto a fork of the elevator device 14. Is locked in. That is, the rotational movement of the motor 53 is converted into vertical movement by the chain 54. An encoder (not shown) is incorporated in the rear portion of the motor 28 and outputs a pulse according to the rotation of the drive shaft of the motor 28.

FIG. 5 shows a front view of the operation panel 44. A push button switch 45 is mounted on the operation panel 44, and by pushing the push button switch 45, the elevator can be lowered. In addition, as a status display, BUSY lamp
46 and a READY lamp 47 are attached. Details of these functions will be described later.

The control of each elevator will be described below, following the outline of the paper conveyance of the above embodiment and the description of the function of the elevator unit.

FIG. 6 shows a block diagram of the control unit of the paper stacking apparatus of this embodiment. In the figure, a block 10 is an arithmetic processing block of the stacker 5, a block 200 is an arithmetic processing block of the printer 1, and various information is exchanged between the blocks 200 and 100 via a bus 250. The block 100 has a central processing unit (CPU) 101, which is the center of control, and a peripheral interface adapter (PI) for controlling input / output signals.
A) 104 and 105, a random access memory (RAM) 102, and a read only memory (ROM) 103 are connected. The same applies to the control block 200 on the printer side, which has a configuration in which the PIA 204, RAM 202, and ROM 203 are connected to the CPU 201.

As an example, CPU11,201 is a Motorola M6800, PIA104,
Motorola M6820 is used for 105 and 204.

Each I / O in the stacker is connected to the stacker side PIA104, which is roughly divided into three blocks, the stacker main body I / O block 106, A deck I / O block 107, and B deck I / O block 108, respectively. And

The main body I / O block 106 consists of one input and three output circuits. Entrance sensor 151 composed of light emitting element 21 and light receiving element 22
The analog signal from is binarized by the comparator 152 and input to the PIA 104.

The output command from the PIA104 is converted into an ON / OFF signal of 24V DC in the drive circuits 153 and 155, and an ON / OFF signal of 100V AC in the drive circuit 157, and the solenoid # 1 (154), solenoid # 2 (156), and main motor 158, respectively. To drive.

The A-disk I / O block 107 consists of a 7-input / 3-output circuit.
A paper surface sensor including a light emitting element 23a and a light receiving element 24a
An analog signal from the paperless sensor 162 including 161, the light emitting element 25a and the light receiving element 26a is binarized by the comparators 168 and 169 and input to the PIA 104.

Lower limit detection micro switch (hereinafter referred to as MS
163 (corresponding to the micro switch 43 in FIG. 3), full load detection MS164 (corresponding to the micro switch 42 in FIG. 3), upper limit detection MS165 (corresponding to the micro switch 41 in FIG. 3), set Detection MS166 (corresponding to micro switch 36 in FIG. 3), DOWN SW167 (corresponding to switch 45 in FIG. 5) and encoder 174 incorporated in elevator motor 171 (corresponding to elevator motor 28 in FIG. 1). The signal from is directly input to PIA104.

An output command from the PIA 104 is converted into an ON / OFF signal of AC100V in the drive circuit 170 to control and drive the elevator motor 171. In addition, READY LANP172 (ready lamp 47 in Fig. 5)
, BUSY LAMP173 (busy lamp 46 in Fig. 5)
(Corresponding to) is directly driven by the output signal of PIA104.

The B-disk I / O block 108 has the same structure as the A-disk I / O block 107.

Next, the actual operation of the stacker 5 will be described according to the flow of processing controlled by the CPU 101 based on each I / O information connected to the PIA 104.

FIG. 7 is a control flow chart of the entire stacker 5.
First, 0 is stored in the program switch (P, SW) as an initial setting, and the lamps of BUSY46 and READY47 on the display panel are turned off (step 352). Then, elevator raising control is performed (step 301). Here, if it is A tech gadget (step 353-Y), the READY lamp 47 is turned on (step 354), and if not, it is turned off (step 355). Similarly, for B-decchi, depending on its state, REA
Turn the DY lamp on / off (steps 356-358). Next, check the job mode to select whether to randomly access the A and B decks from the printer (hereinafter referred to as random mode) or continuously access until one deck is fully loaded (hereinafter referred to as stack mode). (Step 359). In the random mode, turn the BUSY lamp on for both A and B to notify the operator that the job mode is random (step
374,375). Only when both A and B are ready, proceed to step 372. On the other hand, when at least one side is not ready (step 380-N), the stacker main motor (corresponding to drive motor 27 in FIG. 1). ) Is turned off (step 376) and the process returns to step 353, and an infinite loop is formed until the deck becomes ready. During this time, the operator needs to perform an operation for readying, for example, taking out a full of paper or resetting the container 12.

If the job mode is stack mode in step 359, P
Examine the SW. (Step 360). Initially PSW is 0, so
It is checked whether the B-disk is ready, and if it is ready (step 361-Y), the CPU determines that the access target is the B-disk.
Notify 101 (step 362). And A DECK's BUSY
The lamp is turned off (step 363), and the BUSY lamp of B-deck is turned on (step 364). If B deck is not ready at step 361, it is checked whether A deck is ready or not. If A deck is ready (step 365-Y), the CPU 101 is notified that the access target is A deck (step 362). Then, the BUSY lamp of A deck is turned on (step 367), the BUSY lamp of B deck is turned off (step 368), and PSW is set to 1 (step 369).

Here, if both A and B decks are ready at the beginning,
Although PSW is set to give priority to B deck, if the priority is given to B deck out of A and B decks, A deck will be accessed while A deck is being accessed. As a result, the B deck is accessed before the stack is full, and the operator does not know in what order the stack was stored in the stacker. In order to avoid such a situation, PSW is set to 1 so that once the A-disk is selected, the A-disk is continuously selected. At step 365, if A-deki is not ready, PSW is set to 0 (step 370) and priority is given to B-deki, and it is checked whether B-deki is ready (step 371). If it is ready, the process returns to step 353. If not ready, go to step 376 and turn off the stacker main motor 27.

Here, when A deck is continuously accessed and A deck becomes full, for example, and when it is not ready, it is judged whether or not B deck can be accessed this time.

In this way, the busy lamp is A or B in the stack mode.
Lights up, thereby notifying the operator that the job mode is the stack mode. In the random mode, the printer 1 notifies and determines the paper access destination, but in the stack mode, the stacker can determine the access destination.

When the A and B decks advance to step 372 on a ready basis, the stacker main motor 27 is turned on and the transport system is driven to prepare for the transport of the paper from the printer 1. If the job is not completed (step 373-N), the solenoid is controlled in accordance with the access index (step 331), and the process goes to the accumulated cumulative number of sheets corresponding to the paper destination. First, in step 381, the destination of the paper is determined, and when the paper is conveyed to the next stacker, it is irrelevant to the elevator control, and therefore the process returns to step 353. When the destination of the paper is A deck, the content of the A deck cumulative number counter KA is incremented by 1 (step 382), and the values of the number counters KA 'and KA indicating the number of sheets when the elevator descends last time are respectively registered in the registers K ,. It is stored in K '(step 383) and the elevator descending process (step 311) is performed. Then, the value of the register K'is returned to KA 'again (step 384) and the process returns to step 353.

Also, when the destination of the paper is B-decks (step 381-B-decks), the accumulated B-deposit number counter KB is incremented by 1 (step 385) as in the case of the deck A, and the B-decks number counters KB 'and KB are added. Value is stored in registers K and K '(step 386), elevator descent processing (step 311) is performed, and then the value in register K'is stored in KB' (step
387) Return to step 353.

When the job is completed (step 373-Y), the stacker main motor 27 is turned off (step 377), then the elevator is lowered (step 331), and the READY lamp and BUSY lamp of both decks are turned off (step). 378, 379), and control ends.

Now, if the elevator is lowered at step 311, the paper will not be ready unless the paper is removed from the paper when the next job is attempted. That is, by doing so, it is possible to prevent the output papers of the previous job and the next job from being mixed.

The details of the elevator raising control procedure of step 301 are shown in FIG.

The operator removes the stacked paper on the container 12
When 12 is set to a fixed position and the SET switch 36 is turned on (step 302), it is checked whether or not the container 12 is empty by the container empty detection sensors 25 and 26 (step 303). If the operator does not remove the paper or does not set the container 12 and pushes the slide rail into the stacker, the empty sensor of the container does not detect the empty of the container 12. When the operator has emptied the container 12 and set it to a fixed position in the stacker, wait for a fixed time (step 304), rotate the motor 28 forward until the upper limit detection MS41 is activated, and raise the elevator ( Steps 305, 306).
When the upper limit position is reached (step 306-Y), the motor 28 is stopped (step 307) and the CPU 101 is notified that the deck has become READY (step 308). Then, the cumulative number counter KA, KB and the number counter KA ', K
B'is cleared (step 309) and the elevator raising control is ended.

Next, the details of the elevator descent control of step 311 in FIG. 7 will be described with reference to the flow chart shown in FIG. The elevator descent control is performed when the DOWN switch 45 on the operation panel 44 is pressed (step 312-Y)
There are three cases: when the descent request is output from 101 (step 313-Y) and when the output of the paper surface sensor 161 is detected for a certain time or more (step 314-Y).

First, at step 312, when the DOWN switch 45 of the operation panel 44 is pressed (step 312-Y), and when the job is completed and the descent request is output from the CPU 101 (step 313-
Y) both notify CPU 101 of Not Ready (step
327), the elevator motor 28 is rotated in the reverse direction to lower the elevator (step 328). Here, the lower limit detection MS43
Lower until is on (step 329-Y). When the lower limit detection MS43 is turned on, the descent of the elevator is completed, so the elevator motor 28 is stopped (step 330) and the process is completed.

Also, when the output of the paper surface sensor 161 is on (step 314-
Y) checks the output of the paper surface sensor 161 and if the output of the paper surface sensor 161 is on for a certain time or more (step 315-
Y) The value of the pulse counter set in the RAM 102 is cleared (step 316), the elevator motor 28 is rotated in the reverse direction (step 319), and the elevator is lowered until the output of the paper surface sensor 161 is turned off. During this descent, step 31
Elevator motor 2 by the pulse counter cleared in 6
The encoder pulses generated by the rotation of 8 are counted (step 331). When the output of the paper surface sensor 161 is turned off (step 319-Y), the elevator motor 28 is stopped (step 320). However, full load detection during elevator descent M
If S42 is turned on, more paper cannot be stacked, so the process proceeds to step 327 and the elevator is lowered until the lower limit detection MS43 is turned on (step 318).

FIG. 10 shows a timing chart of the relationship between the output of the paper surface sensor 161 and the motor reverse rotation command. As paper is loaded on the pallet 13, the paper surface gradually rises and the paper surface sensor 161
It sometimes comes to shut off the optical path. (Define the output as ON when the light path is blocked). At this time, if a command is immediately given to the motor in response to the instantaneous ON output of the paper surface sensor 161, the stage will be lowered too much and the paper stacking will be deteriorated. In order to prevent this, the motor 28 is controlled to be driven only when the ON output time of the paper surface sensor 161 exceeds the set time Ts. Conversely, if Ts is not reached, nothing is done. The energization time T _M of the motor 28 may be appropriately set according to the elevator ascending / descending speed.

When the elevator motor 28 is stopped (step 320),
Read the value n of the pulse counter (step 321), n
If is zero, the elevator descent control is terminated (step 32
2-Y), if not zero (step 322-N) register K
Then, the value of the register K'is subtracted (K is the cumulative number of decks and K'is the number of decks loaded at the time of the previous elevator descent), and the difference .DELTA.K is obtained (step 323). This ΔK is the number of sheets loaded from the time of the previous elevator descent to this time of the elevator descent. Then, .DELTA.K is divided by the encoder pulse count number n to obtain .DELTA.K / n and the average number of sheets I to be loaded per encoder pulse is obtained (step 324). Then, the value of the cumulative load number register K up to now is stored in K '(step 325), and in preparation for the next process, the current average load number I is compared with the set value I _0, and if I> I ₀ (Step 326-Y) Since an abnormal descent has occurred, the program proceeds to Step 327 and the elevator is lowered to the lower limit position. In other words, it is possible to significantly improve the accuracy of the judgment because the abnormal judgment is made not by judging the abnormal drop based on the magnitude of the descent amount but by determining the average descent amount.

In the flow chart of FIG. 7, the automatic switching of A and B decks in the stack mode has been described. However, in this embodiment, when the abnormal drop of the decks is detected, it is not ready, so the access to the papers of the decks is prohibited. The paper can be automatically directed to another ready-made deck.

The detailed flow chart of the solenoid control of step 331 is shown in FIG. 11 and its timing chart is shown in FIG.

Solenoid control will be described below with reference to the drawings.

When the printer 1 receives a destination address for the stacker 5 to convey the paper to the stacker 5 (step 33).
2) The CPU 101 is notified of the time t when the paper intercepts the entrance sensor 151 and turns on the output of the entrance sensor (step 33).
3). The transport length L ₁ from the entrance sensor 151 to the tip of the horizontal deflector 7 which is the first branch along the transport path, and the transport length L ₂ to the tip of the vertical deflector 10 which is the next branch are values determined by design. The transport speed V is also a numerical value determined by design. From these values, the delay time tn and ta from the time when the entrance sensor 151 is cut off by the paper until the deflectors are activated (the output when the cut-off is turned on) are tn = L ₁ / V ta = L ₂ / V If V = constant, tn and ta are constants.
Also, the time required for one sheet of paper to pass through the deflector tp
Is given by tp = Lp / V because the length Lp of the paper used in the transport direction is known. That is, if the paper blocking the entrance sensor 151 is branched to the next stacker at the time t, the solenoid # 1 may be turned on at the time t + tn and turned off at the time t + tn + tp.
Similarly, at time T, if the paper blocking the entrance sensor 151 is branched into A-decks, solenoid # 2 may be turned on at time t + ta and turned off at time t + ta + tp.

Therefore, at step 334, each step is branched according to the destination address, and in the case of A-decks, the solenoid # 2 is turned on at time t + ta (step 335), and the solenoid # 2 is turned off at time t + ta + tp (step 336). In the case of the next stacker, solenoid # 1 is turned on at time t + tn (step
337) At time t + tn + tp, solenoid # 1 is turned off (step 338).

In the case of B deviation, it is not necessary to drive the solenoid, and the control is ended as it is.

Now, as shown in FIG.
When a total of 5 sheets from the page to n + 4 pages are fed and the branch destinations of the respective sheets are different, from the time t when the entrance sensor 151 is shut off, after each time elapses (tn time or
Drive the corresponding solenoid for ta time) tp time. B
In the case of decking, it is clear that if no deflector is driven, it will automatically go to the B deck.

In the above description, the elevator descent amount, the average number of loaded sheets, I, and the constant I ₀ are compared to determine the elevator descent abnormality, but the following may be performed. That is, it is a method of changing the value of the constant I ₀ in accordance with the stroke position of the elevator. It is empirically known that when the number of stacked sheets increases, the uppermost surface is affected by paper curl and the stacked state is likely to be disturbed. Since the disturbance of the stacking state affects the paper surface sensor, it is better to set a margin for an abnormal drop in advance. On the other hand, when the number of sheets to be loaded is small, if a margin is left over, a problem will occur unless it is useful for the check of abnormal descent. Since the same thing can be said depending on the difference in paper quality and the like, it is effective to determine the value of I ₀ in consideration of the paper quality and the stroke position of the elevator.

FIG. 13 shows an example of the value of I ₀ . In the figure, the stroke position of the elevator is divided into 6 equal parts from S ₁ to S ₆ , and the paper quality is divided into 3 types. The stroke position of the elevator may be obtained by counting the output pulses from the encoder. The paper quality may be input to a stacker or a printer by a paper quality switching switch, a ten-key pad, a keyboard, or other input means. As an example, paper quality 1 is thin paper, 2
Is plain cardboard, 3 is cardboard, or special paper. I ₁₁ to I
Values up to ₃₆ can be set experimentally.

The case where an encoder is used to detect an abnormal drop has been described above, but time may be used without using the encoder. That is, the elevator sensor is
After the 161 is turned on, the power is turned on for a fixed period of time to make the amount of descent for each time almost constant, and then to check how many times it has dropped during the loading of a certain number of sheets to detect the presence or absence of an abnormality. Is.

This control flow chart is shown in FIG. In FIG. 14, steps 312 to 315 and 327 to 330 are the same as the processes with the same numbers in FIG. However, step 314
Then, when the paper surface sensor output is turned on, the elevator descent control is not ended, and the process proceeds to step 334.

Now, when the paper surface sensor 161 is turned on for a certain period of time (step 315-Y), the elevator motor 28 is rotated in the reverse direction (step 317), and the elevator is lowered until a certain period of time elapses (step 331-N). When a certain period of time has passed (step 331-Y), the elevator motor 28 is stopped (step 332). However, if the full load detection MS (42) is turned on while the elevator is descending, the process proceeds to step 327 as in FIG. 9 to lower the elevator to the lower limit position (step 31
8). When the elevator is stopped at step 332, the value of the counter J which was reset when the elevator was raised to the ready state is incremented by 1 and the number of times the elevator is descended is counted up (step 333). Then, the counter L indicating the number of sheets stacked on the deck is incremented by 1 (step 334). Even when the paper surface sensor output is off, steps 334 and below are executed.

If the number of stacked sheets [L] is less than or equal to the set number of sheets [L ₀ ], the elevator descent control is terminated (step 335-Y),
When [L] is equal to or greater than [L ₀ ], the stacking number counter L is cleared (step 336) and the elevator descent number counter J
And the set value J ₀ are compared (step 337),
If [J] <[J ₀ ], the number of loaded sheets (L ₀ / J) for one descent of the elevator is equal to or more than the specified value, so the counter J is cleared (step 338) and the processing is ended. If [J] ≧ [J ₀ ] here (step 337-N), the number of loaded sheets for the descending of the elevator is small, and it is determined that there is an abnormality and the process goes to step 327 to lower the elevator to the lower limit position to make it not ready. As yet another modification, the number of drops L is checked every fixed number of drops J ₀ , as opposed to checking the size of the number of drops per fixed number of copies L _0, and an error occurs if the number of stacked sheets L is less than the set value L _0. You may make it determine that it is a descent.

In addition, all the abnormal descent checks that have been described so far are intended to check when the number of loaded sheets is too low, but on the contrary, it is possible to check when the number of loaded sheets is too large. It is possible. For example, if an abnormality occurs in the drive system, or if an abnormality occurs in the drive control system, the specified amount will not drop even if a descent command is issued, or it will remain stopped at all. It will be obvious that it will be abnormal, but it will be clear that even in such a case, it is possible to judge by checking one check.

Further, in such a case, if not only READY but also the status display is also used, it is possible to self-diagnose whether the elevator is lowered too much or is not moving properly.

Also, as the descent control, the number of times of descent was counted when the time was made constant, but the pulse from the encoder used in FIG. 9 was used to descent by a constant stroke, and this number of descent was compared with the number of loaded sheets. It is also possible to detect abnormalities.

Further, although paper has been described as the conveying material in this embodiment, it is needless to say that the same effect can be obtained even if the plastic film or the like is used as long as it is a paper sheet.

As described above, in the present embodiment, when there is an abnormality in the loading in the deck due to checking while converting the amount of descent of the elevator per number of loaded sheets, or when there is an abnormality in the drive system or control system of the elevator mechanism. In addition to being able to make reliable judgments, it also has the effect of preventing jams.
In addition, even if an abnormal effect occurs, in the case of a stacker having multiple decks, the downtime can be reduced by shifting the control to another deck.
Allows efficient operation of the job without dropping the printer's sloop.

Effect As described above, according to the present invention, it is possible to reliably detect and notify a defective stacking of conveyed sheets.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a stacker, FIG. 2 is a perspective view of a deck unit, FIG. 3 is a transverse sectional view of a deck unit, FIG. 4 is a rear view of an elevator unit, and FIG. Front view, FIG. 6 is a stacker control circuit block diagram, FIG. 7 is an overall control flow chart, FIG. 8 is an elevator raising control flow chart, FIG. 9 is a step processing control flow chart, and FIG. 11 is an elevator motor control timing chart, FIG. 11 is a solenoid control flow chart, FIG. 12 (A) is a diagram schematically showing a conveying path, FIG. 12 (B) is a timing chart relating to a solenoid and an inlet sensor, and FIG. The figure shows an example of a table of I ₀ values, and FIG. 14 shows another elevator descent control flow chart. In the figure, 1 ... Printer, 5 ... Stacker, 6 ...
Conveyor belt, 7 ... Horizontal deflector, 9 ... Conveyor roller, 10 ... Vertical deflector, 11 ... Discharge roller, 12 ...
Container, 13 ... pallet, 14 ... elevator, 16 ...
Alignment guide, 17 …… Loading plate, 18 …… Drawer rail, 21,22 …… Inlet sensor, 23,24 …… Paper surface sensor, 25,2
6 ... paperless sensor, 27 ... main motor, 28 ... elevator motor with encoder, 29, 30 ... solenoid, 44 ... operation panel, 50 ... frame.

Continued Front Page (72) Inventor Tadashi Yagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toshio Zenmoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References Japanese Unexamined Patent Publication No. Sho 53-105470 (JP, A) Actual publication No. Sho 57-18353 (JP, Y2)

Claims (1)

[Claims] 1. A stacking unit for stacking and storing conveyed sheets, an elevating unit for elevating and lowering the stacking unit, and an upper end provided at a predetermined height for detecting an upper end of the sheets stacked on the stacking unit. Detection means, control means for performing control for lowering the stacking means by a predetermined amount by the elevating means in response to detection of the upper edge of the sheet by the upper end detection means, and the upper end detecting means from the time when the stacking means descends by a predetermined amount. If the number of sheets detected by the number detecting means detects the number of sheets stacked on the stacking means before the upper end is detected, or if the number of sheets detected by the number detecting means is larger than a predetermined number, or If the number of sheets is smaller than the predetermined number, the stacking device further comprises a notification unit for notifying that the sheets are not normally stacked.