JPH115662A - Sheet post-processing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a discharge failure due to a lowering of a discharge tray due to friction between a rear end portion of a sheet stacked on a discharge tray means and a rear end stopper surface portion, and to reduce a size of the apparatus. Attainment. SOLUTION: Discharge tray means 20 includes a movable discharge tray 21 for stacking sheets discharged by the discharge means, a fixed discharge tray 22 supporting the movable discharge tray 21, and a fixed discharge tray 22.
A spring member 24 interposed between the movable paper discharge tray 21 and the movable paper discharge tray 21 to urge the end of the movable paper discharge tray 21 close to the discharge means upward;
The movable discharge tray 21 has a sheet loading surface 21A on which sheets can be loaded, and a stopper surface portion 21B for bringing the end surface of the sheet into contact with an end portion close to the discharge means. A sheet post-processing apparatus supported so as to be swingable about a support shaft 23 provided at a leading end of the sheet, and capable of moving up and down at an end near the discharge means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine, a printer or a printing machine, which receives a sheet on which an image has been formed and performs post-processing such as stapling by a stapler and shift processing. The present invention relates to a sheet post-processing apparatus that discharges a sheet to a sheet discharge tray by a discharge unit after performing the operation.

[0002]

2. Description of the Related Art A sheet post-processing apparatus called a finisher is used as an apparatus for collating and binding a plurality of image-recorded sheets discharged from an image forming apparatus for each copy by a stapler.

The finisher has a function connected to an image forming apparatus main body such as a copying machine or a printer, and is driven in accordance with a sequence operation of a copy or print process.

Therefore, for an image forming apparatus capable of performing a large amount of image forming processes at a high speed, a finisher capable of performing a function at a high speed following the processing speed is required. .

A finisher capable of such high-speed processing has been disclosed in Japanese Patent Application Laid-Open Nos. 60-142359 and 60-142359.
Japanese Patent Publication Nos. 0-158463 and 62-239169, and Japanese Patent Application Laid-Open Nos. 62-288002, 63-267667, Japanese Patent Application Laid-Open No. 2-276691, and Japanese Patent Publication No. 5-41991 are disclosed.

[0006] Sheets with images recorded thereon, which are carried out of the image forming apparatus main body, are sequentially stacked while being aligned in the intermediate stacker, and after storing one set of sheet bundles, sheet post-processing such as a stapler is performed, and binding is performed. The sheet bundle placed is conveyed on a discharge belt provided at the bottom of the intermediate stacker, further nipped by a pair of upper and lower discharge rollers, and discharged onto a discharge tray.

The recording paper post-processing apparatus described in Japanese Patent Application Laid-Open No. 8-42728 is provided with one stapler and one corresponding paper discharge tray. Also, Japanese Patent Application Laid-Open
The sheet post-processing apparatus described in Japanese Patent Application No. 76190/1990 includes two staplers and two corresponding paper discharge trays.

[0008]

In a conventional sheet post-processing apparatus, an image-formed sheet carried out of the image forming apparatus is processed by sheet post-processing means (staplers, shift means, bookbinding means, punching means, etc.). After the sheet is post-processed, the sheet is discharged onto the sheet discharge tray by the discharge means, descends along the inclined sheet discharge tray surface, and the sheet rear end comes into contact with the stopper and stops. Sheets that do not require post-processing are directly discharged to the fixed paper discharge tray, descend along the inclined paper discharge tray surface, and stop at the rear end of the sheet contacting the stopper surface.

The problems in the conventional sheet post-processing apparatus will be listed below.

(1) Since the height of the stacked sheets increases as the number of sheets discharged and stacked on the sheet discharge tray means for stacking the sheets post-processed by the sheet post-processing apparatus increases, A sheet height detecting means is provided so as not to block the discharge path, and the discharge tray means is controlled to descend so that the height of the sheet stacking surface is constant. Therefore, the control and the mechanism become complicated.

(2) When the post-processed sheet is discharged by the discharge means and stacked on the sheet mounting surface of the discharge tray means having an inclined surface with a raised front end, the leading end of the large-size sheet is The portion may protrude from the leading end of the paper discharge tray means and hang down, may be slid and pushed by a subsequent discharge sheet, and may fall from the sheet mounting surface of the paper discharge tray means. To prevent this sheet from falling,
If the sheet mounting surface is made sufficiently large, there is a problem that the sheet post-processing device becomes large and the installation space increases.

(3) When sheets not subjected to post-processing are stacked on the sheet mounting surface of the discharge tray means (non-sort tray) of the sheet post-processing apparatus, the sheets fall due to the drooping of the leading end of the sheets. And the problem that the tip of the hanging sheet comes into contact with the elevating sheet discharge tray at the bottom.

An object of the present invention is to solve the above-mentioned problems,
The rear end of the sheets stacked on the movable tray of the sheet discharge tray means is smoothly lowered by its own weight to prevent sheet discharge failure and simplify the control mechanism. Provided is a small-sized sheet discharge tray means without sagging of a leading end portion of a large-sized sheet to be stacked,
It is an object of the present invention to provide a sheet post-processing apparatus capable of stacking large-size sheets not subjected to post-processing on a miniaturized non-sort tray.

[0014]

A sheet post-processing apparatus according to the present invention, which achieves the above object, post-processes an image-formed sheet conveyed from an image forming apparatus and then discharges the sheet to a discharge tray means by a discharge means. In the sheet post-processing apparatus, the discharge tray means includes a movable discharge tray member on which sheets discharged by the discharge means are stacked, a fixed discharge member supporting the movable discharge tray member, and the fixed discharge member. A spring member interposed between the paper member and the movable discharge tray member to bias an end of the movable discharge tray member close to the discharge means upward, and the movable discharge tray member is A sheet stacking surface on which the sheet can be stacked, and a stopper surface for bringing an end surface of the sheet into contact with an end portion close to the discharge unit, and a support shaft provided at a front end portion of the fixed discharge member. Centered and swingably supported , It is characterized in that it allows lowering the end proximate to the discharge means. (Claim 1) The sheet post-processing apparatus according to the present invention is a sheet post-processing apparatus for discharging an image-formed sheet conveyed from an image forming apparatus to a discharge tray by discharge means. Has a protruding portion protruding above the sheet stacking surface near the leading end side in the sheet discharging direction near both ends in the width direction orthogonal to the sheet discharging direction of the sheet discharged by the discharging means. It is. (Claim 6)

[0015]

Next, an embodiment of a sheet post-processing apparatus according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a sectional view showing the structure of the sheet post-processing apparatus (finisher).

The sheet post-processing apparatus is installed with its position and height adjusted so that the receiving portion of the sheet P coincides with the discharge port of the main body of the image forming apparatus (copier, printer, etc.). It is connected to a control system to be driven in response to the operation.

The P introduced into the receiving portion is switched between an upper conveying path a and a lower conveying path b by swinging switching of a switching gate (branch plate) 1.

Sheet P discharged from the image forming apparatus main body
The sheet passes through the upper conveying path a by switching the switching gate 1 of the receiving section, is nipped by the discharge roller pair 2, and is discharged to the discharge tray 10 fixedly arranged at the uppermost stage of the sheet post-processing apparatus. You.

On the other hand, the switching gate 1 of the receiving section
The sheet P that has passed through the lower conveying path b by switching (indicated by the dashed line) is nipped and conveyed by an intermediate conveying roller pair 3 including a driving roller and a pinch roller, and passes through a conveying path c including a fixed guide plate. And the sheet reversing conveyance drum 4
And is conveyed onto the peripheral surface of the sheet reversal conveyance drum 4 by being nipped by the conveyance roller pair 5 above the sheet. Sheet reversal transport drum 4
Is driven and rotated by a driving source (not shown) in the direction indicated by the arrow. A sheet pressing member (gripper) 6 is swingably supported near the peripheral surface of the sheet reversing / conveying drum 4. The sheet pressing member 6 is biased by a spring and is swung by a cam mechanism (not shown).

The leading end of the sheet P sent from the nip position of the pair of carrying rollers 5 to the peripheral surface of the sheet reversing / conveying drum 4 is connected to the leading end of the sheet pressing member 6 opened by the cam mechanism and the sheet reversing / conveying. The sheet enters the V-shaped gap between the drum 4 and the peripheral surface of the rotating sheet reversing / conveying drum 4, and is pressed and sandwiched between the peripheral surface of the rotating sheet reversing / conveying drum 4 and the tip of the spring-biased sheet pressing member 6. It is transported on the peripheral surface of the reverse transport drum 4. At the time of this sheet conveyance, the peripheral speeds of the conveyance roller pair 5 and the sheet reversal conveyance drum 4 are equal.

FIGS. 2 to 4 are partial sectional views showing a sheet conveying process of the sheet post-processing apparatus.

In FIG. 2A, the leading end of the sheet P is pressed against the leading end of the spring-biased sheet pressing member 6 on the peripheral surface of the rotating sheet reversing / conveying drum 4 and conveyed. During the process, when the speed of the conveying roller pair 5 is increased, the leading end of the sheet P is nipped by the sheet pressing member 6, but the vicinity of the rear end of the sheet P is accelerated by the conveying roller pair 5 to increase the speed of the sheet. P is sent out in excess, and the intermediate portion of the sheet P is separated from the peripheral surface of the sheet reversing and conveying drum 4 and bulges outward.

In FIG. 2B, as the sheet reversing and conveying drum 4 continues to rotate, the moment the rear end of the sheet P separates from the nip position of the pair of conveying rollers 5, the pair of conveying rollers 5 Inverted by the conveying force and the rigidity of the sheet P,
The sheet is separated from the peripheral surface of the sheet reversal conveyance drum 4. Sheet P
When the leading end reaches the stopper 7 and stops, the sheet pressing member 6 separates from the sheet P.

As the sheet reversing / conveying drum 4 continues to rotate further, as shown in FIG. 3A, two sheet aligning members rotatably supported at two positions in the sheet reversing / conveying drum 4. 8A and 8B successively rub the vicinity of the leading end of the sheet P, stop the leading end of the sheet P by contacting the stopper 7, and align the sheets in the conveying direction of the sheet P. The leading end of the aligned sheets P is placed on the intermediate discharge tray 9A, and the rear end is placed on the movable discharge tray 21 and the fixed discharge tray 22 of the discharge tray means 20.

In the process shown in FIG. 3B in which the leading end of the sheet P contacts the stopper 7, the shift aligning means 9B
Performs the paper alignment (width alignment) in the width direction of the sheet P (the direction orthogonal to the sheet conveyance direction). Alternatively, when the shift mode is set, the alignment plate is alternately shifted to a plurality of predetermined positions to perform the width alignment. After the sheet reversing / conveying drum 4 completes one rotation and the positioning of the first sheet P is completed, the second sheet P is fed to the sheet reversing / conveying drum 4, and the same conveyance as described above is performed, and the positioning is performed. And stop. When the number of sheets P positioned and brought into contact with the stopper 7 reaches the predetermined number, the stapler ST drives the staples into predetermined positions of the sheets P and binds them. Alternatively, when the shift mode is set, the shift operation by the matching plate is performed.

FIG. 4A shows a sheet P, which has been subjected to a sheet post-processing such as a stapling process or a shifting process, and a movable sheet discharging member (hereinafter referred to as a movable sheet discharging plate) 21 and a fixed sheet discharging member (hereinafter, referred to as a movable sheet discharging plate). , Which is referred to as a fixed discharge tray).

The driving motor M1 of the discharging means 11 has a gear G
1, G2, G3, G4
Is driven to rotate. The other end of the crank 13, one end of which is supported at an eccentric position of the disk 12, is rotatably supported by a part of a discharge arm 14 that can swing about a fulcrum shaft 15. The disk 12 driven and rotated by the drive source causes the crank 13 to eccentrically move and further causes the discharge arm 14 to swing. Due to the swinging movement of the discharge arm 14, the front end portion 14A of the discharge arm 14 presses the front end portion of the sheet P that has completed the sheet post-processing, and the movable discharge of the discharge tray means 20 from the position where it comes into contact with the stopper 7. Paper plate 21 and fixed paper discharge plate 2
Extrude towards 2. The sheet P pushed out by the discharge arm 14 slides on the upper surfaces of the movable discharge tray 21 and the fixed discharge tray 22, and then the leading end of the sheet P descends by its own weight, and the sheet P moves to the stopper surface 21 </ b> B of the movable discharge tray 21. Stop by contact. Since the leading end 14A of the discharge arm 14 advances to a position near vertically above the stopper surface 21B of the movable discharge tray 21, the sheet bundle remains in the post-processing section without leaving the sheet bundle.
The sheet is reliably transferred to the zero sheet stacking surface 21A.

FIG. 5 is a perspective view of the paper discharge tray means, and FIG. 6 is a sectional view of the paper discharge tray means. Since the upper discharge tray 20 and the lower discharge tray 30 have the same shape, the upper discharge tray 20 will be described below as a representative.

The paper discharge tray means 20 includes a fixed paper discharge tray 22
A movable discharge tray 21, a support shaft 23 for pivotally supporting one end of the movable discharge tray 21 on the fixed discharge tray 22, and a spring member for urging the other end of the movable discharge tray 21 upward. 24.

The sheet stacking surface 22A of the fixed discharge tray 22 is
The leading end portion of the stacked sheets is formed with a high slope, and the rear end portion is formed with a low slope. A curved auxiliary stopper surface portion 22B is integrally formed on the lower side of the inclined surface.

In the vicinity of both ends of the tip end of the fixed paper discharge tray 22, that is,
Protrusions 22C that are higher than near the center in the width direction are formed near both ends in the width direction orthogonal to the sheet discharge direction of the mounting surface on which the vicinity of the leading end of the sheet is mounted.

The fixed discharge tray 22 is provided with a protruding locking portion 22D.
The sheet post-processing device main body is locked and fixed to the lifting / lowering means of the sheet post-processing apparatus main body by the concave groove-shaped locking portion 22E, and is driven to move up and down.

The sheet stacking surface 21A of the movable discharge tray 21 is
A plurality of protrusions (ribs) 21C which are located between the sheet stacking surfaces 22A on both sides of the fixed sheet discharge tray 22 and are in sliding contact with the sheet surface.
And a recess 21D for taking out the sheet.

On the end face side of the movable discharge tray 21 connected to the sheet stacking face 21A, that is, on the side where the rear end of the stacked sheets is located, the base of the stopper face 21B is connected to the end of the sheet stacking face 21A. Connected and united. The stopper surface 21B is formed on a cylindrical surface having a radius R with the center line of the support shaft 23 as a center axis. 21E is a movable discharge tray 21
Upper stopper provided below the stopper surface 21B of the fixed paper discharge tray 22, abuts on a locking surface 22F formed near the auxiliary stopper surface 22B of the fixed paper discharge tray 22, and stops the movable paper discharge tray 21 at the upper limit position. Let it.

After the sheet discharged by the discharge means 11 is discharged onto the sheet stacking surface 21A, the sheet slides down on the sheet stacking surface 21A by its own weight, and the rear end of the sheet is moved to the stopper surface 21B. Proceed toward.

The upper end of the spring member 24 is positioned at the bottom of the movable paper discharge tray 21 and is fixed by a locking member 25. The lower end of the spring member 24 is loosely fitted and positioned in the concave portion 22 </ b> G provided on the bottom of the fixed sheet discharge tray 22.

FIG. 7 is a side view of the paper discharge tray means. The sheet stacking surface 21A of the movable discharge tray 21 and the fixed discharge tray 22
Both ends of the large-size sheet P placed on the sheet stacking surface 22A in the direction orthogonal to the sheet discharge direction are curved upward by protrusions 22C protruding to both sides of the fixed sheet discharge tray 22. The sheet P whose vicinity of the leading end is curved in a direction orthogonal to the discharge direction is moved to the movable discharge tray 2.
Even if it protrudes further forward than the front end of the first and fixed sheet discharge trays 22, the front end of the sheet P does not hang down. Therefore, each sheet stacking surface of the movable sheet discharge tray 21 and the fixed sheet discharge tray 22 can be shorter than the length of the large-size sheet P in the discharge direction, and the discharged sheet that projects from the main body of the sheet post-processing apparatus and moves up and down. The miniaturization of the tray means is achieved.

FIG. 8 is a partial plan view of the discharge tray means. The stopper surface portion 21B of the movable paper discharge tray 21 protrudes from the auxiliary stopper surface portion 22B of the fixed paper discharge plate 22. The protruding step h is about 1 mm. The auxiliary stopper surface portion 22B has a radius (R
+ H) on the cylindrical surface.

The movable discharge tray 2 which is discharged to the discharge tray means
1 and the sheet P sliding down on the fixed sheet discharge tray 22, the leading end thereof abuts against the stopper surface 21 </ b> B of the movable sheet discharge tray 21, stops, and is aligned.

FIG. 9 shows the movable discharge tray 2 of the discharge tray means 20.
It is sectional drawing which shows the state which 1 fell. When a large number of sheets P are stacked on the sheet discharge tray means 20 and exceed a predetermined weight, the movable sheet tray 21 descends due to the weight of the sheet P against the urging force of the spring member 24. Movable paper output tray 2
First, as shown in FIG. 6, the stopper top 21H is
At the position substantially coincident with or slightly above the auxiliary stopper top 22H of the fixed sheet discharge tray 22, the rear end of the stacked sheets P comes into contact with the stopper surface 21B of the movable sheet discharge tray 21 and stops. Even when the sheets P are stacked on the movable sheet discharge tray 21 and descend, the leading ends of the sheets P come into contact with the stopper surface portions 21B, stop and are aligned. In the above-described sheet stacking process, the leading end of the sheet P is brought into contact with the stopper surface 21B of the movable discharge tray 21 that can be moved up and down, and the leading end is aligned. Therefore, no frictional resistance is added to the leading end of the sheet P. The movable discharge tray 21 descends smoothly.

When the sheet P is further stacked on the sheet stacking surface 21A and passes over the stopper top 21H, the leading end of the sheet P comes into contact with the auxiliary stopper surface 22B of the fixed sheet discharge tray 22 and stops.

When the sensor detects that the post-processed sheets P stacked on the movable discharge tray 21 of the upper discharge tray means 20 are full (upper limit of the stacking amount) and a signal is generated. Then, a control unit (not shown) drives the drive motor M2 for raising and lowering the tray of the raising and lowering driving means 40 to raise the upper discharge tray means 20. That is, the gear train including the gears G5, G6, G7, G8, G9, and G10 drives and rotates the drive pulley 41 by driving the drive motor M2. A drive wire 43 is wound between the drive pulley 41 and an upper driven pulley 42. By the driving rotation of the driving pulley 41, the driving wire 43 reciprocates in the vertical direction.

The base of the frame of the upper discharge tray means 20 is fixed to a part of the drive wire 43 by a discharge tray hanging member. The frame 26 of the upper discharge tray 20 and the frame 36 of the lower discharge tray 30 are connected by a connecting rod 45. That is, a long groove portion 451 is formed in the connecting rod 45, and a pin 46 fixed to the frame 26 of the upper discharge tray means 20 comes into sliding contact with the connecting rod 45 (FIG. 1).
reference). Further, the vicinity of the lower end of the connecting stick 45 is fixed to the frame 36 of the lower sheet ejection tray means 30.

When the upper discharge tray means 20 is moved upward by the driving wire 43, the pins 46 (see FIG. 1) fixed to the frame 36 of the upper discharge tray means 20 are connected to the connecting rod 45. Only the upper discharge tray means 20 is moved upward in sliding contact with the long groove portion 451. When the pin 46 abuts on the uppermost end of the long groove 451 of the connecting rod 45, the moved upper discharge tray means 20 and the stopped lower discharge tray means 30 have a maximum separation distance.

The upper discharge tray means 20 is provided with the driving wire 4
3, the pin 46 of the upper discharge tray 20 moves the connecting stick 45 upward in a state of contact with the long groove 451, and is fixed to the lower end of the connecting stick 45. The lower discharge tray means 30 is lifted and moved. Therefore, the upper discharge tray means 20 and the lower discharge tray means 30 move upward integrally while maintaining the maximum separation interval.

FIG. 10 is a sectional view of the uppermost discharge tray 10, FIG. 11A is a plan view of the discharge tray 10, and FIG.
FIG. 2B is a cross-sectional view of the discharge tray 10 taken along line AA.

The uppermost sheet discharge tray 10 also serves as a top plate of the sheet post-processing device, and directly stores sheets that are not subjected to post-processing such as stapling.

The discharge tray 10 has an inclined sheet stacking surface 10A, a substantially vertical stopper surface 10B, and a plurality of projections (ribs) 10C formed on the sheet stacking surface 10A.
Having. At the leading end of the sheet stacking surface 10A in the sheet discharging direction, a protrusion 10D is provided in a direction orthogonal to the sheet discharging direction.
Protrudes higher than the protrusion 10C.

As shown in FIG. 11B, the leading end of the sheet P discharged from the sheet discharge tray 10 curves upward and is stacked on the sheet stacking surface 10A. In this way, the sheet P whose vicinity of the leading end is curved in a direction orthogonal to the discharge direction is
Even if the overhang is caused by projecting further forward than the sheet stacking surface 10A of the sheet discharge tray 10, the leading end of the sheet P does not hang down. Therefore, the sheet stacking surface 10A of the sheet discharge tray 10 can be made shorter than the length of the large-sized sheet P in the discharge direction, and as shown in FIG. When the sheet P rises, the uppermost sheet discharge tray 10 and the upper sheet discharge tray 20 have little vertical overlap, so that the post-processed sheet P can be easily removed from the upper sheet discharge tray 20. Can do things.

In the embodiment of the present invention, the sheet post-processing apparatus connected to the copying machine has been described. However, the sheet post-processing apparatus used by connecting to an image forming apparatus such as a printer or a facsimile or a light printing machine. Is also applicable.

[0052]

According to the sheet post-processing apparatus of the present invention, the following excellent effects can be obtained.

(1) When the sheets are stacked, the trailing edge of the sheet and the stopper surface of the movable sheet tray do not come into sliding contact with each other, so that the movable sheet tray descends smoothly, and the succeeding sheet due to the advancing of the trailing edge of the sheet. Collision with the tip portion is avoided, and poor discharge is prevented. (Claim 1).

(2) By providing protrusions at both ends of the fixed sheet discharge tray and curving the sheet leading end, a large sheet can be stacked on a small sheet discharge tray having a small sheet mounting surface. become. (Claim 4).

(3) When sheets not subjected to post-processing are to be stacked on the sheet mounting surface of the discharge tray means (non-sort tray) of the sheet post-processing apparatus, similarly, projecting portions are provided at both ends of the discharge tray. Is provided, and the leading end of the sheet is curved, so that a large-size sheet can be stacked on a small discharge tray having a small sheet placement surface. Further, the leading end of the large-sized sheet does not hang down and does not interfere with the movable sheet discharge tray below (claim 6).

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a sheet post-processing apparatus of the present invention.

FIG. 2 is a partial cross-sectional view illustrating a sheet conveying process of the sheet post-processing apparatus.

FIG. 3 is a partial cross-sectional view illustrating a sheet conveying process of the sheet post-processing apparatus.

FIG. 4 is a partial cross-sectional view illustrating a sheet conveying process of the sheet post-processing apparatus.

FIG. 5 is a perspective view of a discharge tray unit.

FIG. 6 is a cross-sectional view of a paper discharge tray unit.

FIG. 7 is a side view of the paper discharge tray means.

FIG. 8 is a partial plan view of the paper discharge tray means.

FIG. 9 is a cross-sectional view showing a state where a movable paper discharge tray of the paper discharge tray means is lowered.

FIG. 10 is a cross-sectional view of the uppermost discharge tray.

11A and 11B are a plan view and a cross-sectional view taken along line AA of the uppermost sheet discharge tray.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Top discharge tray 10A, 21A, 22A Sheet loading surface 10B, 21B Stopper surface 10D, 22C Projection 11 Discharge means 14 Discharge arm (discharge member) 20 Upper discharge tray means 21 Movable discharge tray member (movable Discharge tray) 21H Stopper top 22 Fixed discharge member (fixed discharge tray) 22B Auxiliary stopper surface 22H Auxiliary stopper top 23 Support shaft 24 Spring member 30 Lower discharge tray means 40 Elevating drive means M1, M2 Drive motor

Claims (6)

[Claims] 1. A sheet post-processing apparatus for post-processing an image-formed sheet carried out of an image forming apparatus and discharging the sheet to a discharge tray means by a discharge means, wherein the discharge tray means is provided by the discharge means. A movable discharge tray member for stacking the discharged sheets; a fixed discharge member supporting the movable discharge tray member; and the movable discharge tray interposed between the fixed discharge member and the movable discharge tray member. A spring member for urging an end of the plate member close to the discharge unit upward, the movable discharge plate member being a sheet stacking surface on which the sheets can be stacked, and being close to the discharge unit. An end portion having a stopper surface portion for bringing the end surface of the sheet into contact with an end portion, the end portion being swingably supported about a support shaft provided at a leading end portion of the fixed sheet discharging member, and being close to the discharging means. Characterized by being able to move up and down Sheet post-processing equipment. 2. A sheet stacking surface of the movable discharge tray member,
The sheet post-processing apparatus according to claim 1, wherein the stopper surface forms an inclined surface lower than a leading end. 3. The sheet discharge tray means includes a fixed sheet discharge member having a sheet stacking surface near an end in a width direction orthogonal to the sheet discharge direction, and a center in a width direction orthogonal to the sheet discharge direction. The sheet post-processing apparatus according to claim 1, further comprising: a movable sheet discharging tray member having a sheet stacking surface in the vicinity. 4. The fixed discharge member has a protrusion protruding higher than a sheet stacking surface of the movable discharge tray member near a front end near both sides in a width direction orthogonal to a sheet conveying direction. The sheet post-processing apparatus according to any one of claims 1 to 3, wherein: 5. The sheet post-processing apparatus according to claim 1, wherein the sheet discharge tray is supported by a driving unit of the sheet post-processing apparatus so as to be able to move up and down. . 6. A sheet post-processing apparatus for discharging an image-formed sheet carried out from an image forming apparatus to a paper discharge tray means by a discharge means, wherein the paper discharge tray means is provided for the sheet discharged by the discharge means. A sheet post-processing apparatus, comprising: a protrusion protruding higher than a sheet stacking surface near both ends in a width direction orthogonal to a discharge direction and near a leading end side in the discharge direction of the sheet.