JP3101427B2 - Sheet post-processing equipment - Google Patents

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, more specifically, for example, receiving one or more sheets of copying paper or the like discharged from an image forming apparatus such as a copying machine or a printing machine after image formation. The present invention relates to a sheet post-processing apparatus including a sorting device that classifies and stores the bins (hereinafter, referred to as a “bin tray”) and a stack device that stacks a sheet bundle.

[0002]

2. Description of the Related Art Conventionally, sorting apparatuses for distributing and storing sheets can be broadly classified into bin moving sorters and bin fixed sorters.

[0003] The bin moving sorter controls the movement of the entire bin tray stack for vertically stacking the bin trays with respect to the sheet discharge port of the image forming apparatus, and sequentially positions the sheet entrances of the individual bin trays. Is used to distribute sheets to individual bin trays.

In the fixed bin sorter, the bin tray stack is immobilized, and a sheet path is selectively switched from a sheet discharge port of the image forming apparatus to a sheet inlet of each bin tray of the bin tray assembly by a guide plate, a deflecting plate or the like. A mechanism is formed in which a sheet discharged from a sheet discharge port of an image forming apparatus is sequentially conveyed and distributed to individual bin trays via the sheet path mechanism.

[0005] Then, as shown in FIG.
A stacking device A attached to the sorting device for the purpose of classifying and storing sheets exceeding the number of a to Bj has been considered. The stacking apparatus A includes a stack tray Aa for stacking a sheet bundle at a time, and a conveying unit A for conveying the sheet bundle from the bin trays Ba to Bj to the stack tray Aa.
b. The position of the stack tray Aa and the conveying means Ab are controlled by means of raising and lowering each of them so that the stack of sheets placed on the individual bin trays can be transferred. That is, the stack tray Aa is moved from the lowest bin tray Bj of the bin tray stack to the highest bin tray B
a (solid line tray Bj)
And the floor surface) and the two-dot chain line position.

[0006]

However, when the sorter to which the stacking device is attached is a fixed bin sorter, there are the following problems.

(1) Since the lowest bin tray Bj and the floor of the bin tray assembly are positioned at a predetermined interval L shown in FIG. 15, the capacity of the sheet bundle stored in the stack tray Aa increases, and When the paper surface of the tray Aa is located between the bin tray Bh and the bin tray Bi as shown in FIG. 16, the bin tray Bi and the bin tray Bj
Cannot be transported to the stack tray.

(2) If the distance between the lowermost bin tray Bj and the floor surface described in (1) is increased, the entire apparatus becomes larger in the bin arrangement direction. In order to increase the interval between the lower bin tray Bj and the floor, the total number of bin trays to be arranged must be reduced, or the interval between the bin trays must be reduced. The reduction in the number of bin trays reduces the number of sortable copies. When the interval between the bin trays is small, the capacity of each bin tray to load sheets decreases.

In addition, the bin-movable sorter has a problem that the bin tray assembly must be moved up and down every time a sheet is discharged from the image forming apparatus, and vibration and noise are generated in association with the up-and-down movement. .

[0010]

Means (and action) for solving the problems The present invention provides:
It is an object of the present invention to solve the problems of the conventional apparatus, and it is possible to sort and store a sheet bundle exceeding the number of bin trays arranged in a fixed bin sorter. A post-processing device is provided.

According to the present invention, in order to achieve the above objects, (1) a plurality of bin trays fixedly arranged in upper and lower stages capable of storing sheets, sheet discharging means for discharging sheets to the bin trays, and each of the bin trays A transport unit that can be moved up and down to a position opposite to and transports the sheet on the bin tray;
A stack tray capable of moving up and down to a position corresponding to the transport unit, receiving the transported sheets, and stacking the transported sheets, wherein the transport unit includes a lower bin tray on which a sheet bundle is placed. By sequentially transferring the sheet bundle to the stack tray, all the sheets can be transferred even if the sheet capacity of the stack tray increases.

(2) Further, in the above-mentioned apparatus, a paper surface position detecting means for detecting the paper surface at the lowermost position of the stack tray accommodating the sheet bundle, and a means for recognizing the number of bin trays located above the paper surface are provided. With this arrangement, even if the stack tray paper surface rises, sheets can be continuously stored in the bin tray located above the stack tray.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a main cross section of a sheet post-processing apparatus embodying the apparatus of the present invention. The sorting apparatus 100 in which a plurality of bin trays B are vertically arranged is an image forming apparatus 300.
A stacking device 200 for storing a sheet bundle is provided in front of the sorting device 100.

Since the configuration and image forming process of the image forming apparatus 300 are well known, only the reference numerals of the main components will be described here. Reference numeral 301 denotes a platen glass (original platen glass), 302 denotes an original pressing plate, 303 denotes an original moving mechanism of an optical system including an original illumination lamp, a moving mirror, an imaging lens, a fixed mirror, and the like, 304 denotes a rotating photosensitive drum, 305 is a charger, 306 is a developing device, 307 is a transfer separation charger, 308 is a cleaning device, and 309 and 3
10 is the first and second transfer sheet storage cassettes, 31
Reference numeral 1 denotes a sheet conveying device, 312 denotes an image fixing device, and 313 denotes a sheet discharge roller pair.

The sorting apparatus 100 is disclosed in Japanese Patent Laid-Open No. 63-262.
This is the same as that disclosed in Japanese Patent No. 373, and will be briefly described here. B _{1 to} B ₁₀ are a plurality of bin trays fixedly arranged in upper and lower stages. 101 is the image forming apparatus 3
Reference numeral 105 denotes a first distributing device which can control up and down movement between the sheet discharge roller pair 313 side of the sheet tray 00 and the sheet insertion port side of the bin trays B _{1 to} B ₁₀ .
Is a second distributing device which is adjacent to the downstream of the device and which can also be controlled to move up and down. The first distributing device 101 has a pair of rollers and rollers 101a and 101b for pinching and conveying a sheet, a motor (not shown) for rotating the roller and a sensor 101c for detecting the presence of the sheet, and the like. The driving pulley 102 is mounted on and supported by a belt 104 suspended and stretched between the pulley 102 and the upper driven pulley 103, and is controlled to move up and down with the forward and reverse rotation of the belt 104 by the forward and reverse rotation control of the driving pulley 102. Similarly, the second distribution device 105 holds the sheet.
It has a pair of rollers and rollers 105a and 105b to be conveyed, a motor (not shown) for rotating the rollers 105a and 105b, a sensor 105c for detecting the presence of a sheet, etc., and a suspension between a lower driving pulley 106 and an upper driven pulley 107. Stretched belt 108
, And is controlled to move up and down with forward and reverse rotation of the belt 108 by forward and reverse rotation control of the driving pulley 106. Then, by integrating the bin tray B ₁ .about.B _10,
The bin unit 105 including the aligning means for aligning the sheets stored in the bin tray will be described. As shown in detail in FIG. 2, the bin unit 105 is provided with an alignment reference member 108 that contacts the sheet from the upper cover 106 to the lower cover 107. And the bin unit 10
5 includes a rotation center shaft 111 having an upper end fixed to the upper arm 109 and a lower end fixed to the lower arm 110, a rotation shaft 106a provided on the upper cover 106, and a lower cover 107.
And is rotatably supported by a rotating shaft (not shown) provided at the first position. The lower cover 107 has a sector gear 112.
The lower arm 110 is fixed to a sector gear 112 so as to be rotatable about a rotation shaft provided on the lower cover 107. Further, a pulse motor 113 is disposed below the lower cover 107, and the pulse motor 1
A pinion 113 a fixed to the output shaft 13 meshes with the sector gear 112. Each of the bin trays B is provided at the tip of the lower arm 110 and the tip of the upper arm 109.
An alignment bar 115 is provided to penetrate the notch 114 provided in the entire bin tray.
Is configured to swing by rotation of the sector gear 112. Further, a light-shielding plate 116 is provided on a part of the lower arm 110, and the light-shielding plate 116 rotates integrally with the lower arm 110 so that the lower cover 107
The home position sensor 118 fixed via the switch 7 is turned on and off.

The reference rod 1 is located on the front side of the alignment rod 115.
Reference numeral 08 is disposed through a notch 119 provided in all bin trays similarly to the alignment rod 115, and a lower end of the reference rod 108 is fixedly provided with a sector gear 120. The sector gear 120 is a rotating shaft 121 provided on the lower cover 107.
And the upper arm 122 fixed to the upper end of the reference rod 108 is supported by a rotating shaft 123 provided on the upper cover 106. A pulse motor 124 is disposed on the lower cover 107, and a pinion gear 124 a fixed to an output shaft of the pulse motor 124 meshes with the sector gear 120 to rotate the sector gear 120, whereby the reference rod 10 is rotated.
8 swings. Further, a light shielding plate 125 is provided at an end of the sector gear 120 so that the home position sensor 126 disposed on the back side of the lower cover 107 is turned on and off by the rotation of the sector gear 120. It is configured.

As shown in FIG. 3, which is a top view of FIG. 2, when the copying operation of the image forming apparatus 300 is started, the standby position 1
The reference rod 108 waiting at 08a (the position of the chain line) moves in the direction of the arrow by the rotation of the pulse motor 124,
It stops at the matching reference position 108b (the position indicated by the solid line). Thereafter, the sheet S on which an image is formed by the image forming apparatus 300
Is discharged from the discharge roller pair 313 to the bin tray via the sheet distributing device 101 of the sorting device 100, and the rear end stopper B 'is placed on the bin tray B, which is inclined downward, by the weight of the bin to the rear end stopper B'. Move toward.

Next, as shown in FIG. 4, the aligning rod 115 is moved by a predetermined amount in the direction of the arrow from the standby position 115a (the position of the chain line) by the pulse motor 113 which rotates based on a pulse signal corresponding to the sheet size. (The position indicated by the solid line), the reference rod 10 stopping the sheet at the alignment reference position 108b.
Press on 8.

The reference bar 108 continues to be stopped at the alignment reference position until all the sheets by the image forming apparatus 300 are stored in the bin trays B. However, after the alignment bar 115 has moved by a predetermined amount, the reference bar 108 is discharged. To return to the standby position 115a. By repeating the above operation, a sheet bundle composed of one or more sheets is placed on
8, the rear end is aligned with the rear end stopper B '. Note that the alignment bar 115 penetrates all bin trays, and the sheets S stored in other bin trays are similarly aligned.

Next, the configuration of the stack device 200 will be described.

FIG. 5 is a main sectional view of the stack device 200.
And a stacking device 2 as shown in FIG.
00 is an intermediate unit 210 that conveys a sheet bundle;
Stack tray 220 for loading the conveyed sheet bundle
And The intermediate unit 210 is fixed to a belt 203 suspended between a driving lower pulley 201 and a driven upper pulley 202 disposed on a vertical frame of the stacking device 200. Then, the intermediate unit 210 is controlled to move up and down by the forward / reverse rotation of the motor Ma that rotates the lower pulley 201. On the other hand, the stack tray 220 is fixed to a belt 206 stretched between a driving lower pulley 204 and a driven upper pulley 205 disposed on a frame extending in the vertical direction of the stacking device 200, Up / down movement is controlled by forward / reverse rotation of a motor Mb for rotating the pulley 204.

The intermediate unit 210 includes an intermediate tray 211 for temporarily storing a sheet bundle, a gripper unit 212 for transferring the sheet bundle on the bin tray B to the intermediate tray 211, and a sheet on the intermediate tray 211. A transfer unit 213 for transferring the stack to the stack tray 220;
Consists of The intermediate tray 211, and inclined parallel to the bin tray B ₁ .about.B _10, which is fixed to the frame of the intermediate unit 210 (not shown), the sheet stopper 211a is upright on the rear end. As shown in FIG. 7, the gripper unit 212 includes a belt 216 stretched between a driving front pulley 214 and a rear pulley 215 provided at both ends of a frame (not shown) extending in the front-rear direction of the intermediate unit 210. , And reciprocates in the direction of the arrow by forward and reverse rotation of the motor Md that rotates the front pulley 214. In the frame, a sensor S for detecting the third position (solid line position) of the gripper unit 212, a sensor S _A for detecting the first position (dotted line), and a second position (dotted line) are detected. a sensor S _B which is arranged. Furthermore, gripper unit 2
12 is a lower gripper arm 217 as shown in detail in FIG.
The upper gripper arm 218 is supported by a shaft 219, and the eccentric cams 217a and 218a that are in contact with each other are rotated by a motor Me, so that the solid line position (clamping position) and the two-dot chain line position (opening position) are set. Rocks. The spring members 217b and 218b attached to the respective gripper arms always bias the gripper arm to the eccentric cam, and at the same time provide a predetermined clamping force.

The transport unit 213 will be described with reference to FIG. Two lower conveying rollers 222 are provided in the axial direction on a lower roller shaft 222 a supported by front and rear side plates (not shown) of the intermediate unit 210.
An upper transport roller 221 is disposed on the upper roller shaft 221a on the upper side facing the upper roller 2. Both ends of the upper roller shaft 221a are held by a swing arm 221b fitted to a shaft 221d supported by the side plate. And the swing arm 2
Abuts against one end 221e of the swing arm 21b.
An eccentric cam 223 is provided on a shaft 223a which is rotated by a motor Mg so as to swing between a position indicated by a solid line (a holding position) and a position indicated by a two-dot broken line (an opening position). The upper transport roller 221 and the lower transport roller 222 have the same outer diameter and rotate at a constant speed in the direction of the arrow when driven by the motor Mf.

Then, as shown in FIG.
0, the bin tray B
A bin sensor group _SN including sensors S ₁ , S ₂ , S ₃ ... S ₈ , S ₉ , and S ₁₀ is opposed to each lowermost position of ₁ , B ₂ , B ₃ ... B ₈ , B ₉ , and B _10. It is fixed. Each of the sensors S ₁ .
S ₁₀ detects the sheet surface at the lowermost point 211b and the stack tray 220 of the intermediate tray 211. A sensor Se is disposed below the nip position of the roller pair 221 and 222 of the intermediate unit 210,
Is detected. The sensor _SD is fixed to the frame of the stacking device and detects the lower limit position of the stack tray 220. The sensor Sf is provided on the surface of the stack tray 220 near the intermediate unit 210, and detects the rear end of the conveyed sheet bundle. Then, the CPU receives the signal of each sensor, controls the motor output of each sensor, and
0 and a computer that communicates with the image forming apparatus 300.

The operation of the apparatus based on the above configuration will be described with reference to a flowchart (FIG. 10) and other drawings.

(Step 1) The operator operates the image forming apparatus 30
The original is set to 0, the number of sorts N is set, and the start key is pressed.

[0028] (Step2, Step3) as shown in FIG. 6, lowered to the intermediate unit 210 is moved to a position corresponding to the lowermost bin tray B _10, the stack tray 220 is detected by the lower limit sensor S _D is driven by the motor Mb I do.

(Step 4) The CPU recognizes the number n of bin trays (the number of bin trays located above the paper surface of the stack tray 220) that can be used by the bin sensor group _SN detecting the paper surface of the stack tray 220. For example, in the state of FIG. 6, the sensor for detecting the paper surface is S ₆
And the number n of usable bin trays is the bin trays S _{1 to} S ₆
6 steps.

(Steps 5 to 8) The CPU compares the number N of sort copies at the time of initial setting with the number n of usable bin trays (Step 5). If N ≦ n, the CPU sorts the N copies according to the set value (Step 6). , N> n, sorting of n copies is first started (Step 7).

The sorting operation is described in JP-A-63-262.
Since this is described in detail in Japanese Unexamined Patent Publication No. 373, it will be briefly described here. As shown in FIG. 5, a discharge sheet on which an image is formed by the image forming apparatus 300 is held between the roller-roller pairs 101a and 101b of the first distribution device 101 which is on standby at a position corresponding to the discharge roller pair 313. Then, the first distributing device 101 is moved to the position of the second distributing device 105 waiting at the sheet insertion port of the predetermined bin tray. Thereafter, the sheet is transferred to the second distribution device 105 by the rotation of the roller-roller pair 101a, 101b, and the roller-roller pair 105a, 105b of the second distribution device 105 is rotated.
Is discharged to a predetermined bin tray via the. In addition, the first
The distributing device 105 is configured such that the leading end of the sheet is
Is returned to the position of the discharge roller pair 313 of the image forming apparatus 300, and the next discharge sheet is clamped. Then, the second distribution device 105 stopped at the predetermined bin tray moves up or down by one stage, and waits for delivery of the next sheet conveyed by the first distribution device 101.

By repeating the above operation, sheets are sequentially distributed to each bin tray. The alignment of the sheets discharged to each bin tray is as described above. Then, all the image sheets are aligned and stacked on each bin tray (Step 8).

(Steps 9 and 10) The above (Step 8)
Sends a sort end signal to the stack device 200.
Whether the gripper unit 212 of the intermediate unit 210 is a first position sensor S _A detects (Fig. 7), if not the first position is moved until the sensor S _A is detected. Also, it is confirmed whether the lower gripper 217 and the upper gripper 218 are in the open state (FIG. 8), and when not in the open state, both grippers are swung to open. Further, the transport roller pairs 221 and 222 of the transport unit 213
Make sure that is in the open state.
The upper conveying roller 221 is swung to open.

(Step 11 ) In the aligned sheet bundle shown in FIG. 4, as shown in FIG. 11, after the reference rod 108 returns to the standby position 108a, the alignment rod 115 is swung in the arrow direction by a predetermined amount (115c). ), The side end of the sheet bundle is moved to the stacking device 200.

[0035] (Step12) above (Step3) intermediate unit 210 which has been on standby at a position corresponding to the lowermost bin tray B ₁₀ by rises in the driving of the motor Ma, lowermost in the bottle seat is Noseki Bin tray B _N
When the bin sensor S _N (S 6 in the example of FIG. ₆ ) corresponding to is detected, the operation is stopped. Furthermore stack tray 220 is raised, the sensor S _A of the intermediate unit 210 is stopped when it is detected the paper.

[0036] (Step13) as shown in FIG. 12, the gripper unit 212 is moved by the motor Md, sensor S _C is stopped when it reaches the third position to be detected.
At this time, the leading edge of the sheet bundle S is inserted between the upper and lower grippers 217 and 218 in the open state, and the leading and lower grippers 217 and 218 shift to the holding state, whereby the leading edge is securely held. You. Then the sheet bundle S by moving to the first position the gripper unit 212 is the position of the sensor S _A and below the conveying rollers of the open state 22
1 and 222 (FIG. 13). Subsequently, the gripper pairs 217 and 218 are opened and the sheet bundle is opened, and then the transport roller pairs 221 and 222 are shifted to the clamping state, and the sheet bundle is clamped by a predetermined pressure. Then, the conveying roller pairs 221 and 222 are rotated in the direction of the arrow by the driving of the motor Mf to transfer the sheet bundle to the stack tray 220 (FIG. 14).

[0037] (Step14) When sensor S _f shown in FIG. 13 detects the trailing edge of the sheet bundle S to be transported, the sheet bundle S is stacked on the stack tray 220 (loading completion detection).

[0038] (Step 15) When the (Step12) of the lowermost sheet is placed in the bin trays B _N was bin tray B ₁ represents, as (Step1
Move to 6), otherwise (Step 12)
(Step 15) are repeated, and the sheet bundle is sequentially conveyed and stored in the stack tray 220 from the lower bin tray.

(Step 16) N in the above (Step 5)
If ≤n, the operation is terminated. Also (Ste
If N> n in p5) and the remaining number of copies N ′ exists, the process returns to (Step2) and returns to (Step2) to (S2).
Repeat until step 16).

(Other Embodiments) The sheet bundle created by the apparatus of the above embodiment is an unbound bundle that has not been subjected to a binding process such as gluing or staple binding. A binding unit may be provided to perform a binding process on a sheet bundle.

Further, in (Step 13) of the above embodiment, the stop position of the gripper unit holding the sheet bundle is only the first position, but the stop position is set to the first position described with reference to FIG. The position may be changed to the second position. The sheet bundle stored in the stack tray 220 with the above operation is spatially divided for each bundle.

Further, an example in which the processing speed is improved when a plurality of sorts are performed by the sheet processing apparatus will be described.

The CPU sets the number of sorts N to at least two.
Divided into One (N ₁ and N _2), first, the number of copies N ₁ (St
EP6) subsequent operation is performed, the number of copies N ₂ upon reaching (Step6) subsequent operations are simultaneously proceeding in (Step9). As described above, while the sheet bundle initially loaded on the bin tray is being transferred to the stack tray 220, the sorting process for the remaining copies is performed and thereafter, so that the processing time can be reduced. The value divided into N ₁ and N ₂ is a value that is calculated as the value most suitable for the processing speed of the apparatus. At this time, the above-described alignment on the bin tray is not performed.

[0044] The spacing between each Binsensa S _N for detecting the sheet surface of the sensor S ₁ and the stack tray 220 corresponding to the uppermost bin in (Step3) is a value determined in the design, stowable seat that interval The number can be known experimentally. Accordingly, by inputting the number of storable sheets corresponding to each of the intervals in advance to the CPU, the total number of sheets calculated based on the number of originals and the number of sorts set in (Step 1) becomes the number of storable sheets. In the case of exceeding, the operation may be prohibited or the operator may be warned.

In the above embodiment, the transfer of the sheet bundle placed on each bin tray to the stack tray is performed in order from the lower sheet bundle. However, as described below, whether to transfer the sheet bundle from the top or to transfer the sheet bundle from the bottom may be appropriately selected according to the situation.

For example, as described above, the number of sheets that can be stored within the interval between the bin sensors _SN is input to the CPU in advance. Then, calculates the number of documents that have been set, the total number of sheets N ₃ the sort number of copies n to the original in (Step1). Here, in order to clarify the explanation, the stack device 20
When 0 is in the state shown in FIG. 6, also the set sorting copies n is "4", the sensor S ₄ and the stack tray 22 and the corresponding lowermost bin tray B ₄ to be used in sorting
Number of sheets N ₄ that can be housed between the sensor S ₆ for detecting the paper of 0 is recognized by the CPU, the N ₃ and N ₄
Are N ₃ <n ₄ , the bin trays B _{1 to} B ₄
Are sorted by the intermediate unit 210 into B
₁ , B ₂ , B ₃ , B ₄ , or B ₄ ,
It is selected whether or not to be taken out in the order of B ₃ , B ₂ , B ₁ . That is, the intermediate tray 210 starts to transfer the sheet from the side of the bin tray in which the last sheet of the sort is stored first. This selection is determined by the number of original documents at the time of setting, and the sheet bundle is sequentially taken out from the bin tray in which all the sheets are stored, so that the standby time of the apparatus is shortened and the processing time is shortened.

When the CPU determines that N ₃ > N ₄ , the selection is not performed and the sheet bundle is taken out from the lower bin tray sequentially as in the above-described embodiment.

In the above embodiment, the sheet is transferred from the bin tray to the stack tray via the intermediate tray. However, the present invention is not limited to the above configuration. For example, the intermediate unit 210 may be configured to include only the transport roller unit 213 (a gripper may be used) for transporting the sheets on the bin tray to the near side, and the stack tray 220 may be disposed downstream of the transport roller unit 213. The operation and the like of each member are all the same as those of the above-described embodiment. As shown in FIG. 18 which is a top view of FIG. 17, an intermediate unit which raises and lowers the sheets stored in each bin tray to a position facing each bin tray The stack tray 220 whose paper surface is controlled is transported by the transport roller unit 213 of FIG.
Is to be stored.

[0049]

The sheet post-processing apparatus according to the present invention has the above-described configuration, and the transport unit transfers the sheet bundle to the stack tray in order from the lower bin tray on which the sheets are placed. Even if the sheet storage capacity increases, all sheets can be transferred to the stack tray.

Further, by providing means for detecting the position of the sheet at the lowermost position of the stack tray of the above-mentioned apparatus and means for recognizing the number of bin trays located above the sheet, the sheet can be stored and the stack can be advanced. Even if the tray paper surface position rises, sheets can be stored in the bin tray above it.

[Brief description of the drawings]

FIG. 1 is a main sectional view of the device of the present invention.

FIG. 2 is a perspective view illustrating a bin unit.

FIG. 3 is a top view of FIG. 1;

FIG. 4 is a top view of FIG. 1;

FIG. 5 is a main sectional view of a sorting device and a stack device.

FIG. 6 is a main sectional view of a sorting device and a stacking device.

FIG. 7 is a top view illustrating a stack device.

FIG. 8 is a front view of a grip for explaining the stacking device.

FIG. 9 is a front view of a transport unit for explaining a stacking device.

FIG. 10 is a flowchart of the operation.

FIG. 11 is a top view illustrating the operation.

FIG. 12 is an enlarged view illustrating an operation.

FIG. 13 is a front view illustrating operation.

FIG. 14 is a front view illustrating operation.

FIG. 15 is a diagram of a conventional device.

FIG. 16 is a front view of a conventional device.

FIG. 17 is a front view of another embodiment.

FIG. 18 is a top view of another embodiment.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 sorting device 108 reference bar 115 alignment bar 200 stacking device 210 intermediate unit 211 intermediate tray 212 gripper device 213 transport roller 220 stack tray 300 image forming device B ₁ bin tray

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-45060 (JP, A) JP-A-59-26857 (JP, A) JP-A-4-164692 (JP, A) 66474 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 39/00-39/16 B65H 31/00-31/40

Claims (3)

(57) [Claims] 1. A plurality of sheet trays fixed vertically, which can store sheets, sheet discharging means for discharging sheets to the trays, and can be raised and lowered to a position facing each of the trays. A sheet post-processing apparatus comprising: a conveying unit that conveys the sheet; a sheet stacking tray that receives and conveys the conveyed sheet; and a lifting unit that moves a sheet surface of the sheet stacking plate up and down to a position corresponding to the conveying unit. When the sheet stacking tray is at the lowermost position, the sheet stacking tray includes a sheet surface position detecting unit that detects a sheet surface of the sheet stacking plate, and a recognition unit that recognizes the number of trays existing above the sheet surface. A sheet post-processing device for transporting sheets to a sheet stacking tray in order from a lower tray. 2. The sheet post-processing apparatus according to claim 1, wherein the sheet is stored by using a tray located above the paper surface position detected by the paper surface position detecting means. 3. A plurality of sheet trays, which are fixed vertically, capable of storing sheets, sheet discharging means for discharging sheets to the trays, and can be raised and lowered to a position facing each of the trays, and A transport unit for transporting the sheets, a sheet loading tray for receiving and loading the transported sheets, an elevating means for lifting and lowering the sheet surface of the sheet loading tray to a position corresponding to the transport unit, and a sheet loading tray at the lowest position. A sheet post-processing apparatus comprising: a sheet surface position detecting unit that detects a sheet surface position at a certain time; a recognition unit that recognizes the number of trays existing above the sheet surface; and a control unit that controls the units. When the space between the paper surface position detected by the paper surface position detection means and the lowermost tray for storing sheets above the paper surface position can accommodate all the sheets stored in each of the trays, The last sheet of the sheet is conveyed to the sheet stacking tray in order from the tray in which the last sheet is stored first, the paper surface position detected by the paper surface position detecting means, and the lower tray for storing the sheet above the paper surface position. A sheet post-processing apparatus wherein the conveying section conveys the sheets sequentially from the lower tray to the sheet stacking tray when the total interval of the sheets cannot be stored in the respective trays.