JPH08119518A - Sheet after-treatment device - Google Patents

Abstract

PURPOSE: To eliminate wasteful movement of a movable tray and to increase durability of a movable tray vertical movement mechanism by furnishing a control means to move the movable tray at a stand-by position to a paper discharging position in the case when discharge of a sheet to the movable tray from an image formation device is designated. CONSTITUTION: Discharged paper trays 4, 5, 6 to load sheets discharged from an image formation device 1 are arranged in a plural number in the vertical direction, and at least the discharged paper tray 4 is made a movable tray free to vertically move. A control means to move the movable tray 4 at a stand-by position to a paper discharging position in the case when discharge of the sheets to the movable tray from the image formation device 1 is designated is furnished. Additionally, the stand-by position of the movable tray 4 is below the paper discharging position. Consequently, wasteful movement of the movable tray is eliminated, and it is possible to increase durability of a movable tray vertical movement mechanism while maintaining sheet discharge efficiency to the movable tray at a high level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet post-processing apparatus mounted on an image forming apparatus such as a copying machine, a facsimile machine or a printer, and more particularly to a sheet discharge tray for stacking sheets discharged from the image forming apparatus. While arranging a plurality in the vertical direction,
The present invention relates to a sheet post-processing device in which at least one sheet discharge tray is a movable tray that can be moved up and down.

[0002]

2. Description of the Related Art In a sheet post-processing apparatus provided with a movable tray, the movable tray is moved downward as the sheets are stacked so that the height between the upper surface of the sheet and the sheet discharge section is always kept at an appropriate level to ensure the sheet alignment. I am maintaining. Therefore, the movable tray is below the initial position when a predetermined number of sheets are discharged to the movable tray in a series of jobs. If the paper for the next job is ejected in this state, the falling angle of the leading edge of the sheet becomes large, and the leading edge of the sheet is bent, inverted in extreme cases, or even if it does not reach it, the sheet alignment becomes poor.

For this reason, generally, movement control is performed prior to the copy operation in order to bring the movable tray to an appropriate position. For example, Japanese Patent Application Laid-Open No. 61-295970 discloses a technique in which a tray is uniquely moved when a copy operation is started. Also, Japanese Patent Laid-Open No. 3-2729
Japanese Patent Laid-Open No. 64 has disclosed a technique in which a paper detection unit is provided on the tray, the removal of the paper is detected, and the tray is moved.

[0004]

However, the technique disclosed in Japanese Patent Laid-Open No. 61-295970 has an unnecessary operation of constantly moving the tray when the copying operation is started even when the tray is not used. Therefore, the durability of the tray vertical movement mechanism has been a problem. Further, the technique disclosed in Japanese Patent Laid-Open No. 3-272964 has a drawback that the number of parts is increased due to the provision of the paper detection means and the cost is increased.

A first object of the present invention is to eliminate the waste of movement of the movable tray, increase the durability of the movable tray vertical movement mechanism while maintaining a high level of paper discharge efficiency to the movable tray, and at a low price. A paper post-processing device is provided. A second object of the present invention is to provide a sheet post-processing apparatus which can improve the operability by improving the ability to take out discharged sheets from the lower tray.

[0006]

A first object of the present invention is to arrange a plurality of paper discharge trays for stacking paper discharged from an image forming apparatus in a vertical direction and to move at least one paper discharge tray up and down. In the sheet post-processing apparatus as a movable tray, when the image forming apparatus designates the sheet discharge to the movable tray, the first means is provided with a control means for moving the movable tray at the standby position to the sheet discharge position. Achieved by means.

The first object is, in the first means,
The standby position of the movable tray is achieved by the second means below the paper discharge position.

The second object is that in the first and second means, the control means is in the standby position when the paper discharge to the paper discharge tray one step below the movable tray is designated. This is achieved by the third means that controls the movement of the movable tray to the paper discharge position.

[0009]

According to the first and second means, the movable tray is moved only when the paper is discharged to the movable tray among the plurality of paper discharge trays, so that the movable tray is not wasted. .

According to the third means, even when the sheet is discharged to the discharge tray one step below the movable tray, the movable tray is discharged from the discharge section at the discharge position, that is, above the standby position. By moving the movable tray to a position for receiving the sheet, it is possible to widen the interval between the movable tray and the sheet discharge tray below the movable tray.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a sheet post-processing apparatus according to an embodiment. In FIG. 1, discharge rollers 2 and 3 are provided in a paper discharge unit provided on the discharge side of the image forming apparatus 1. A sheet post-processing device (sorter) 100 is provided adjacent to the side surface of the main body of the image forming apparatus 1. In the figure, 1- to 3-bin delivery trays 4, 5, and 6 are provided on the left side, and the right side is provided on the right side. Inlet guide plates 37 and 38, which correspond to the ends of the sheet conveyance path 71, are provided so as to project, and are connected (inserted) to the main body side. A drive side entrance roller 7 and a driven side entrance roller 8 are provided on the downstream side of the entrance guide plates 37 and 38 in the sheet carrying direction, and an entrance sensor 9 is provided at a position close to the downstream side in the carrying direction. There is.

A sheet conveying path 71 extending directly to the discharge trays 4, 5 and 6 is formed in a substantially "C" shape in the figure, and a curved conveying path for reversing extending to the reversing tray 16 side. (Hereinafter, also referred to as “reversing path”.) 72 and a switching claw 10 for switching the conveyance direction are installed, and a reversing roller 11 and a reversing claw 12 are provided below the switching claw 10. Below the reversing roller 11, a reversing guide plate 13 and a conveying roller 14 are provided.
Also, a beating roller 15 is provided. A reversing sensor 17 is installed on the upstream side in the conveying direction when the reversing claw 12 is reversed, and along the conveying path 71 above the reversing sensor 17, the lower three-bin paper ejection tray 6 is provided.
The 3-bin paper ejection sensor 18, the 3-bin paper ejection roller 19, the driven roller 20, and the 3-bin paper ejection claw 21 are provided at the locations corresponding to the 2-bin paper ejection sensor 2 at the location corresponding to the middle-stage ejection tray 5.
The 2-bin ejection roller 23, the driven roller 24, and the 2-bin ejection claw 25 are located at positions corresponding to the upper ejection tray 4 at the 1-bin ejection sensor 26, the 1-bin ejection roller 27, and the driven roller 28. And a waist support guide 29 are provided respectively.

The upper and lower guide rollers 30, the upper and lower guide rails 31, the front and rear guide rollers 32, the front and rear guide rails 33, the shift tray base 34, the tray upper surface detection sensor 35, and the end fence 36 are provided along the vertically extending conveying path 71. , Upper entrance guide plate 37, lower entrance guide plate 38, 1
Bin discharge guides 39 are provided respectively. In addition,
The reverse tray 16 is provided with a tray paper detection sensor 60.

The sorter 100 described above is used in the image forming apparatus 1.
The sheets ejected by the ejection rollers 2 and 3 of the image forming apparatus 1 are attached to the side portions of the sheet as described above and are distributed to the sheet ejection trays 4, 5 and 6 and stacked in that state (straight). There are two types of modes: a straight paper discharge mode and a reverse paper discharge mode in which the front and back are reversed and distributed and stacked.

Hereinafter, the sorter 10 configured as described above
The operation of 0 will be described. When the sorter 100 is started by the start information from the image forming apparatus 1, the entrance rollers 7 and 8 and the reversing roller 11 driven by the first driving unit.
Is rotated at a speed equal to or slightly higher than the transport speed of the main body discharge rollers 2 and 3, and the transport roller 14 driven by the second drive means and the respective discharge rollers 19, 23 and 27 are images. It rotates at a speed higher than the conveying speed of the forming apparatus 1. In this embodiment, the first conveying means is composed of the inlet rollers 7 and 8, the second conveying means is composed of the conveying rollers 14 and the paper discharging rollers 19, 23 and 27, and the third conveying means is It is composed of the reversing roller 11. Further, the first drive means drives the first and third transport means, and the second drive means drives the second transport means.
In such a configuration, at the same time that the leading ends of the paper are ejected from the ejection rollers 2 and 3 of the image forming apparatus 1, the mode information indicating whether the paper is ejected straight from the image forming apparatus 1 or ejected in reverse. Is sent to the sorter 100,
The sorter 100 conveys and ejects the sheet by different operations based on the respective information.

The respective parts will be described below in accordance with the flow of paper. (1) Straight paper discharge mode When the leading edge of the paper reaches the discharge rollers 2 and 3 of the image forming apparatus 1,
The image forming apparatus 1 sends to the sorter 100 information that the sheet is discharged in the straight sheet discharge mode. In this mode, the sheet is guided by the inlet guide plates 37 and 38 to the inlet rollers 7 and 8 driven by the first drive means. This time,
The peripheral speed of the entrance roller 7 is set to be equal to or slightly higher than the peripheral speed of the discharge rollers 2 and 3, and the paper can be smoothly carried into the sorter 100 without burdening the paper. At this time, the switching pawl solenoid (not shown) that operates the switching pawl 10 is turned on, and the switching pawl 10 is at the position indicated by the solid line.
The paper discharge rollers 19 and 2 for driving the paper by the second drive means.
Lead in the direction of 3,27. On the other hand, when the sorter 100 receives the mode information, the paper ejecting rollers 19, 23, 27 driven by the second driving means have the leading end of the paper ejected by the 3-bin ejecting roller 1.
Before reaching 9, the transport speed of the second transport means driven by the second drive means is reduced to the same speed as the first drive means, and the transport is performed from the entrance roller 7 driven by the first drive means. The 3-bin paper discharge roller 19 smoothly receives and conveys the received paper.

Next, when the trailing edge of the sheet passes through the ejection rollers 2 and 3, the trailing edge of the sheet is ejected from the image forming apparatus 1 and 2.
A signal that the signal has passed through is sent, and this signal is sent to the sorter 10
When 0 is received, the first,
When the entrance sensor 9 detects that the trailing edge of the paper has passed through the entrance rollers 7 and 8, the speed of the second driving means increases, and after a certain time, the first driving means operates before the next paper enters. Return to the original transport speed (peripheral speed). At this time, the paper has been delivered to the second conveying means, which is driven at high speed,
After passing through the 3-bin sensor 18, the sheet is conveyed upward so as to be discharged to each of the discharge trays 4, 5, and 6.

Then, for example, when the sheet is discharged to one bin according to the information from the image forming apparatus 1, the respective sheet discharge rollers 19, 23, 27 driven by the second driving means are kept at the speed which has been previously accelerated. It is rotating and the 2-bin and 3-bin solenoids (not shown) that operate the 2-bin paper ejecting claw 25 and the 3-bin paper ejecting claw 21 are off.
Since 1 is in the position of the solid line, the paper is 1 bin discharge roller 27
Will be guided in the direction of. Next, the paper is ejected onto the 1-bin ejection tray 4 along the 1-bin ejection guide 39. The sheet is wavy in the transport direction by the waisting guide 29 protruding from the one-bin sheet discharging guide 39, and is driven by the second driving means when the trailing edge leaves the paper discharging roller 27. Since the bin delivery roller 27 is decelerated, the
It is stocked in the bin discharge tray 4. The main deceleration timing is determined by the 1-bin paper ejection sensor 26 to determine whether the trailing edge of the sheet has passed. When the trailing edge of the sheet has passed, the deceleration is decelerated to a speed suitable for ejecting the sheet, and After the calculated fixed time, it is determined that the trailing edge of the sheet has left the 1-bin sheet discharge roller 27, the speed of the second driving unit is increased again, and preparation for receiving the next sheet is performed.

Next, for example, when the paper is discharged to the 2-bin according to the information from the image forming apparatus 1, the 2-bin paper discharge roller 23 driven by the second driving means and the 3-bin paper discharge roller 19 are discharged to the 1-bin paper. In the same manner as above, the three-bin solenoid that operates the three-bin paper ejection pawl 21 is turned off while the three-bin paper ejection pawl 21 is in the position (E position) indicated by the solid line. Yes, a 2-bin solenoid (not shown) for activating the 2-bin paper ejecting claw 25 is turned on, and the 2-bin paper ejecting claw 25 ejects the paper onto the 2-bin paper ejection tray 5 at a position indicated by a chain double-dashed line (D). Position). As a result, the sheet is discharged onto the 2-bin sheet discharge tray 5 along the 2-bin sheet discharge claw 25 and the 2-bin sheet discharge roller 23 that project onto the transport path 71. In addition, the paper has a wavy waist in the transport direction due to the overlap between the projection provided at the center of the 2-bin paper ejection claw 25 and the 2-bin paper ejection roller 23, and the rear end of the paper is ejected by the 2-bin paper ejection roller 23. Paper roller 2
2 which is driven by the second drive means when leaving 3
Since the bin discharge rollers 23 are decelerated, they are smoothly and accurately stocked in the 2-bin discharge tray 5.

The deceleration timing is determined by the 2-bin paper ejection sensor 22.
Is determined by detecting whether the trailing edge of the paper has passed, and when the trailing edge of the paper has passed, the speed is reduced to a speed suitable for ejecting the paper, and a fixed time period calculated by the speed and the transport distance has elapsed. After that, it is determined that the trailing edge of the sheet has left the 2-bin sheet discharge roller 23, the speed of the second conveying means is increased again by the second driving means, and preparation for receiving the next sheet is performed.

When the paper is discharged to the 3-bin, the 2-bin solenoid is off, the 2-bin paper ejecting claw 25 is at the position indicated by the solid line, and
The operation is the same as the operation for discharging to the 2-bin, except that the bin solenoid is turned on and the 3-bin delivery claw 21 is moved to the position indicated by the chain double-dashed line.

As a method of detecting that the trailing edge of the sheet has passed through the entrance roller 7, the discharging roller 2 is based on the information that the trailing edge of the sheet from the image forming apparatus 1 has passed through the discharging rollers 2 and 3. , 3 and the entrance rollers 7 and 8 of the sorter, there is a method of making a determination by the passage of time calculated from the carrying distance and the carrying speed. If this method is adopted, the detection means such as the entrance sensor 9 can be omitted.

(2) Reversed paper discharge mode In the reversed paper discharge mode, when the leading edge of the paper comes into the discharge rollers 2 and 3 of the image forming apparatus 1, the image forming apparatus 1 reports the information of the reverse paper discharge mode. Sent to.

The sheet is guided to the entrance rollers 7 and 8 by the entrance guide plates 37 and 38. At this time, the peripheral speed of the entrance roller 7 is set to be equal to or slightly higher than the peripheral speed of the discharge rollers 2 and 3, and the sheet is smoothly conveyed into the sorter 100 without burdening the sheet. . In the reverse sheet discharge mode, the sheet is directly conveyed from the inlet rollers 7 and 8 to the side of the reverse roller 11, so that the sheet should be conveyed across the drive system by the first driving means and the second driving means. There is no. Therefore,
The transport roller 14 driven by the second drive means and the respective paper discharge rollers 19, 23, 27 remain rotating at a speed higher than the peripheral speed of the discharge rollers 2, 3. At this time, the switching pawl solenoid for operating the switching pawl 10 is off, and the switching pawl 10 is set to 2
At the position indicated by the dotted chain line, the sheet enters the wedge-shaped portion composed of the reversing claw 12 and the reversing roller 11 to perform the reversing operation. The tip of the reversing claw 12 is set so as to overlap the reversing roller 11 and is pressed in the counterclockwise direction so that it can be rotated clockwise so as not to obstruct the entrance of the sheet. Is attached to. As a result, the sheet is conveyed along the reversing guide plate 13 by the conveying force generated by the reversing roller 11 and the reversing claw 12 to the reversing path 7.
2 is conveyed onto the reversing tray 16.

Next, when the trailing edge of the sheet passes through the ejection rollers 2 and 3, the trailing edge of the sheet of paper is ejected from the image forming apparatus 1.
A signal that the signal has passed through is sent, and this signal is sent to the sorter 10
When 0 is received, the first driving means speeds up the entrance roller 7 and the reversing roller 11 at a speed higher than the conveyance speed of the image forming apparatus 1 in order to make a space between the paper and the next paper, and the trailing edge of the paper enters the entrance. After a certain time has passed from the roller 7, the transport speed of the entrance roller 7 and the reversing roller 11 returns to the original peripheral speed before the next sheet enters.

Next, when the trailing edge of the sheet comes out of the portion contacting the reversing roller 11 and the reversing claw 12, the reversing claw 12 moves from the position indicated by the solid line to the position indicated by the chain double-dashed line by the rotational force. At this time, since the sheet has no carrying force, the sheet is stopped at a position slightly out of the tip of the reversing claw 12. When the trailing edge of the sheet comes out of the tip of the reversing claw 12, the reversing claw 12
Moves to the position indicated by the chain double-dashed line, the reversing solenoid that drives the hitting roller 15 is turned on, and the hitting roller 15 contacts the transport roller 14 that is being driven at high speed by the second driving means from the position indicated by the solid line. The sheet is moved to the position of (1), the conveyance direction is reversed in the front-rear direction (switchback), and is conveyed at a high speed along the reversing claw 12 to the upper side of the sheet (in the direction of 1, 2 and 3 bins). The sheet is discharged from each of the sheet discharge rollers 19, 23, 27 driven by. At this time, the space between the sheets is sufficiently widened so that the trailing edge of the sheet does not overlap with the leading edge of the next sheet at the position of the reversing sensor 17. It should be noted that each paper discharge roller 1 to each paper discharge tray 4, 5, 6
The discharge operation of 9, 23, and 27 is the same as that of the straight paper discharge mode.

FIG. 2 is a control block diagram of the sheet post-processing apparatus. In the figure, the CPU 41 on the side of the post-processing device takes in signals from each sensor 42 and
0 and the I / F 43 are used to exchange signals. 44 is a ROM, 45 is each driver, 46 is each motor, 47 is an entrance motor for driving the entrance roller 7 and the conveyance roller 11, 48 is the conveyance roller 14 and the paper ejection rollers 19, 23,
Discharge motor for driving 27, 49 for each solenoid, 45
Are drivers for these motors and solenoids.
In this embodiment, the above-mentioned first driving means is constituted by the inlet motor 47, the second driving means is constituted by the discharge motor 48, and the CPU 41 is constituted by the ROM 44.
The above-described various sheet post-processing operations are executed according to the program written in.

In the reverse sheet discharge mode, the sheet is reversed claw 1.
When the paper passes through 2 and is conveyed by the hit roller 15, a sheet may be caught by the reversing claw 12 and a jam may occur. At this time, the sheet post-processing apparatus transmits the data indicating the occurrence of the jam to the image forming apparatus 1 and stops. The jammed paper comes out on the reversing tray 16 and is stopped. At this time, the tray paper detection sensor 60 is on. When the operator removes the jammed paper, the tray paper detection sensor 60 turns off. Further, when all the sensors in the sorter are off, it is determined that the jam clearance is completed, and the jam reset data is transmitted to the image forming apparatus 1. This allows the next copy operation.

As a result, even if a jam occurs on the reversing path 72, it is confirmed that the jammed paper has been removed on the reversing tray 16 and a signal that the next process can be performed is sent to the main body. This eliminates the need for extra operations such as opening the cover, improving operability.

Next, the horizontal movement mechanism of the paper discharge tray will be described with reference to FIGS. FIG. 3 is a perspective view showing a horizontal movement mechanism of the paper discharge tray, and FIG. 4 is a front view of the relevant part. 1-bin paper ejection tray 4 attached to the shift tray base 34
The end fence 36 connected to the eccentric is eccentrically connected to the crankshaft 50 of the gear 82 via the lever 81,
Further, the gear trains 54 and 55 are connected to the shift motor 84. Further, the cutout portion 5 is coaxial with the gear 82.
A detection plate 85 having 1, 51 is provided, and the plate surface of the detection plate 85 and the cutout portion 51 are detected by the position detection sensor 86. Reference numeral 52 is a support shaft of the gear 82, 53 is a gear of the shift motor 84, and 56 is an opening provided in the end fence 36. In such a configuration, by driving the shift motor 84, the 1-bin sheet discharge tray 4 is horizontally moved in the left-right direction (front side and rear side when viewed from the operation surface), and on the 1-bin sheet discharge tray 4. It enables the sorting of paper (so-called doggytail function). Further, the output of the position detection sensor 86 controls the shift motor 84 to determine the stop position of the 1-bin sheet discharge tray 4.

Next, the vertical movement mechanism of the one-bin paper ejection tray, which is the main part of the present invention, will be described with reference to FIGS. 5, 6 and 7. 5 is an enlarged configuration diagram of a 1-bin sheet ejection tray (movable tray) portion, FIG. 6 is a configuration diagram of a 1-bin sheet ejection tray vertical movement mechanism, and FIG. 7 is a front view of an end fence section.

The front and rear guide rails 33, which hold the shift tray base 34 to which the one-bin discharge tray 4 is attached by the front and rear guide rollers 32, are provided on the outer sides of the front and rear side plates as viewed from the operation surface. Timing belt 8
It is fixed to 7 (see FIG. 7).

The first timing belt 87 is wound around a pulley 88 attached to a side plate, and has a large gear 89 coaxially attached to the pulley 88, a small gear 90 meshing with the large gear 89, and a small gear 90. The worm gear 91 intermittently connected by the torque limiter function part 57, the worm wheel 58 meshing with the worm gear 91, the pulley 59 coaxial with the worm wheel 58, and the second timing belt 92 hung on the pulley 59 are used to lift the lift. It is connected to the pulley 61 of the motor 93 (see FIG. 6). Reference numeral 62 is a coil spring of the torque limiter function part 57.

Further, the first timing belt 87 has
As shown in FIG. 7, the height detecting plate 94 is fixed, and the height detecting sensor 9 is arranged so as to face the height detecting plate 94.
5 is installed, and the position of the 1-bin paper discharge tray 4 is detected by detecting the height detection plate 94.

The height of the paper (the height of the tray) is detected by a tray upper surface detection sensor 35 attached to the end fence 36. The tray upper surface detection sensor 35 has the opening 5
Located at 6.

In such a structure, when the paper is discharged, it is stacked on the 1-bin paper discharge tray 4. When a certain amount of sheets are stacked, the tray upper surface detection sensor 35 is turned on (the position shown by the broken line in FIG. 5), so the lift motor 93 is driven and the tray upper surface detection sensor 35 is turned off (the solid line in FIG. 5). The 1-bin paper ejection tray 4 is lowered to the position (shown by).

In this way, the CPU 41 keeps the distance between the position of the one-bin paper discharge roller 27 and the paper stacking position constant.
It is controlled by.

As described above, the 1-bin sheet ejection tray 4 descends as the sheets are stacked, and the 1-bin sheet ejection roller 27 is always provided.
And the paper surface height is kept constant. Therefore, after the paper is removed, the 1-bin paper ejection tray 4 is located below the normal paper ejection position (this is called a standby position). In the present invention, the following movement control is performed on the 1-bin delivery tray 4 at the standby position.

The contents of the discharge tray movement control of the present invention will be described below with reference to the flow charts shown in FIGS. 8, 9 and 10. At the start of the next copying operation, the 1-bin delivery tray 4 is at the standby position below the delivery position as shown by the chain double-dashed line in FIG. 1 or the solid line position in FIG. 5 (the tray upper surface detection sensor 35 is off. In position). At this time, the start instruction of the sheet post-processing device is turned on from the main body (Y in S1),
The lift initial is not completed (N in S2), and the ejection destination bin is the 1-bin ejection tray 4 or the 2-bin ejection tray 5
If it is (Y in S3), the tray upper surface detection sensor 35
Is not turned on (N in S4), the lift motor 93
Is rotated normally to raise the 1-bin discharge tray 4 (S5), and the lift counter is set to 1 (S6). Lift counter is 1
In this case (Y in S7 of FIG. 9), the 1-bin discharge tray 4 continues to move up, but in the process, the 1-bin discharge tray 4 comes to a position where the tray upper surface detection sensor 35 is turned on (S8). And Y). At this time, the rotation direction of the lift motor 93 is switched. That is, the lift motor 93 is reversely rotated (S
9). As a result, the 1-bin paper ejection tray 4 is now lowered along the upper and lower guide rails 31. At this time, the lift counter is set to 2 (S10). When the lift counter is 2 (Y in S11 of FIG. 10), the 1-bin discharge tray 4 continues to descend, but as it descends, the tray upper surface detection sensor 35 turns from on to off (S1).
2 for Y). Then, within several hundreds of milliseconds (Y in S13), the lift motor 93 is stopped (S14). This position is the paper discharge position. At this time, the lift counter is set to 0 (S1
5). When the tray upper surface detection sensor 35 continues to be turned on in S12 (N in S12), the lift timer is set to 0.
Is set (S16), and the process ends. If there is a sheet left by the operator on the 1-bin delivery tray 4 and the tray upper surface detection sensor 35 is on (S4
Then, the lift motor 93 is rotated in the reverse direction to lower the 1-bin discharge tray 4 (S9 '), and the lift counter is set to 2 (S10'). Then, the lift initial is completed (S17).

Here, if the instruction is to discharge the paper to the 3-bin discharge tray 6, the 1-bin discharge tray 4 is not moved. When sorting, the first sheet is 3 bins and the second sheet is 2 bins.
In the case of the paper discharge operation in which the third bin is the first bin, the first bin eject tray 4 is moved by the second bin ejection instruction for the second bin.

In this embodiment, the paper discharge tray is shown as three bins, but the operation does not change even if the number of bins is other than this. Further, although the movable tray is shown as the uppermost tray in the present embodiment, there is no inconvenience even if the movable tray is provided in other places.

As described above, in the above embodiment, a plurality of paper discharge trays for stacking the paper discharged from the image forming apparatus are arranged in the vertical direction, and at least one paper discharge tray is movable up and down. In the sheet post-processing apparatus described above, when the image forming apparatus designates sheet ejection to the movable tray, the sheet post-processing apparatus includes control means for moving the movable tray at the standby position to the sheet ejection position. Since the standby position of the tray is below the paper discharge position, there is no waste of movement of the movable tray, and it is possible to increase the durability of the movable tray vertical movement mechanism while maintaining a high level of paper discharge efficiency to the movable tray. it can. Further, in the above-described embodiment, the control means moves the movable tray at the standby position to the sheet discharge position when the sheet discharge to the sheet discharge tray one step below the movable tray is designated. In order to perform the control to perform the control so that the movable tray is ejected to the ejection tray one step below the movable tray, the movable tray is at the ejection position, that is, a position above the standby position to receive the sheet ejected from the ejection unit. By moving the sheet tray to the movable tray, the distance between the movable tray and the sheet discharge tray below it can be widened, so that the operability in taking out the discharged sheet from the lower tray can be improved.

[0043]

According to the inventions of claims 1 and 2,
Of the multiple paper ejection trays, the movable tray is moved only when the paper is ejected to the movable tray, eliminating the waste of moving the movable tray and maintaining a high level of paper ejection efficiency to the movable tray. However, the durability of the movable tray vertical movement mechanism can be increased.

According to the third aspect of the present invention, even when the sheet is discharged to the sheet discharge tray one step below the movable tray, the movable tray is discharged from the sheet discharge section at the sheet discharge position, that is, above the standby position. By moving to the position for receiving the paper to be printed, the distance between the movable tray and the paper discharge tray below it can be widened, and therefore the operability in taking out the discharged paper from the lower tray can be improved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a sheet post-processing apparatus according to an embodiment of the present invention.

FIG. 2 is a control block diagram of a sheet post-processing device.

FIG. 3 is a perspective view showing a horizontal movement mechanism of a paper discharge tray.

FIG. 4 is a main part front view showing a horizontal movement mechanism of a paper discharge tray.

FIG. 5 is an enlarged configuration diagram of a 1-bin delivery tray portion.

FIG. 6 is a configuration diagram of a 1-bin paper ejection tray vertical movement mechanism.

FIG. 7 is a front view of an end fence section.

FIG. 8 is a flow chart showing the contents of the discharge tray movement control of the present invention.

FIG. 9 is a flowchart showing the contents of the paper discharge tray movement control of the present invention.

FIG. 10 is a flowchart showing the contents of the paper discharge tray movement control of the present invention.

[Explanation of symbols]

4 1-bin paper ejection tray (movable tray) 5 2-bin paper ejection tray (paper ejection tray one step below the movable tray 4) 41 CPU (control means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Gogata 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Shinji Asami 1-3-3 Nakamagome, Ota-ku, Tokyo Shares Company Ricoh

Claims (3)

[Claims] 1. A paper post-processing apparatus in which a plurality of paper discharge trays for stacking paper discharged from an image forming apparatus are arranged in a vertical direction and at least one paper discharge tray is a movable tray that can be moved vertically. A sheet post-processing apparatus comprising: a control unit that moves the movable tray at the standby position to a sheet discharging position when the forming apparatus specifies sheet discharging to the movable tray. 2. The sheet post-processing device according to claim 1, wherein the standby position of the movable tray is below the sheet discharge position. 3. The apparatus according to claim 1 or 2, wherein the control means discharges the movable tray at the standby position when the discharge of the sheet to the discharge tray one step below the movable tray is designated. A sheet post-processing device characterized by performing control to move to a position.